Text file src/cmd/compile/internal/ssa/_gen/generic.rules

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Simplifications that apply to all backend architectures. As an example, this
     6  // Go source code
     7  //
     8  // y := 0 * x
     9  //
    10  // can be translated into y := 0 without losing any information, which saves a
    11  // pointless multiplication instruction. Other .rules files in this directory
    12  // (for example AMD64.rules) contain rules specific to the architecture in the
    13  // filename. The rules here apply to every architecture.
    14  //
    15  // The code for parsing this file lives in rulegen.go; this file generates
    16  // ssa/rewritegeneric.go.
    17  
    18  // values are specified using the following format:
    19  // (op <type> [auxint] {aux} arg0 arg1 ...)
    20  // the type, aux, and auxint fields are optional
    21  // on the matching side
    22  //  - the type, aux, and auxint fields must match if they are specified.
    23  //  - the first occurrence of a variable defines that variable.  Subsequent
    24  //    uses must match (be == to) the first use.
    25  //  - v is defined to be the value matched.
    26  //  - an additional conditional can be provided after the match pattern with "&&".
    27  // on the generated side
    28  //  - the type of the top-level expression is the same as the one on the left-hand side.
    29  //  - the type of any subexpressions must be specified explicitly (or
    30  //    be specified in the op's type field).
    31  //  - auxint will be 0 if not specified.
    32  //  - aux will be nil if not specified.
    33  
    34  // blocks are specified using the following format:
    35  // (kind controlvalue succ0 succ1 ...)
    36  // controlvalue must be "nil" or a value expression
    37  // succ* fields must be variables
    38  // For now, the generated successors must be a permutation of the matched successors.
    39  
    40  // constant folding
    41  (Trunc16to8  (Const16  [c])) => (Const8   [int8(c)])
    42  (Trunc32to8  (Const32  [c])) => (Const8   [int8(c)])
    43  (Trunc32to16 (Const32  [c])) => (Const16  [int16(c)])
    44  (Trunc64to8  (Const64  [c])) => (Const8   [int8(c)])
    45  (Trunc64to16 (Const64  [c])) => (Const16  [int16(c)])
    46  (Trunc64to32 (Const64  [c])) => (Const32  [int32(c)])
    47  (Cvt64Fto32F (Const64F [c])) => (Const32F [float32(c)])
    48  (Cvt32Fto64F (Const32F [c])) => (Const64F [float64(c)])
    49  (Cvt32to32F  (Const32  [c])) => (Const32F [float32(c)])
    50  (Cvt32to64F  (Const32  [c])) => (Const64F [float64(c)])
    51  (Cvt64to32F  (Const64  [c])) => (Const32F [float32(c)])
    52  (Cvt64to64F  (Const64  [c])) => (Const64F [float64(c)])
    53  (Cvt32Fto32  (Const32F [c])) => (Const32  [int32(c)])
    54  (Cvt32Fto64  (Const32F [c])) => (Const64  [int64(c)])
    55  (Cvt64Fto32  (Const64F [c])) => (Const32  [int32(c)])
    56  (Cvt64Fto64  (Const64F [c])) => (Const64  [int64(c)])
    57  (Round32F x:(Const32F)) => x
    58  (Round64F x:(Const64F)) => x
    59  (CvtBoolToUint8 (ConstBool [false])) => (Const8 [0])
    60  (CvtBoolToUint8 (ConstBool [true])) => (Const8 [1])
    61  (BitLen64 (Const64 [c])) && config.PtrSize == 8 => (Const64 [int64(bits.Len64(uint64(c)))])
    62  (BitLen32 (Const32 [c])) && config.PtrSize == 8 => (Const64 [int64(bits.Len32(uint32(c)))])
    63  (BitLen16 (Const16 [c])) && config.PtrSize == 8 => (Const64 [int64(bits.Len16(uint16(c)))])
    64  (BitLen8  (Const8  [c])) && config.PtrSize == 8 => (Const64 [int64(bits.Len8(uint8(c)))])
    65  (BitLen64 (Const64 [c])) && config.PtrSize == 4 => (Const32 [int32(bits.Len64(uint64(c)))])
    66  (BitLen32 (Const32 [c])) && config.PtrSize == 4 => (Const32 [int32(bits.Len32(uint32(c)))])
    67  (BitLen16 (Const16 [c])) && config.PtrSize == 4 => (Const32 [int32(bits.Len16(uint16(c)))])
    68  (BitLen8  (Const8  [c])) && config.PtrSize == 4 => (Const32 [int32(bits.Len8(uint8(c)))])
    69  (PopCount64 (Const64 [c])) && config.PtrSize == 8 => (Const64 [int64(bits.OnesCount64(uint64(c)))])
    70  (PopCount32 (Const32 [c])) && config.PtrSize == 8 => (Const64 [int64(bits.OnesCount32(uint32(c)))])
    71  (PopCount16 (Const16 [c])) && config.PtrSize == 8 => (Const64 [int64(bits.OnesCount16(uint16(c)))])
    72  (PopCount8  (Const8  [c])) && config.PtrSize == 8 => (Const64 [int64(bits.OnesCount8(uint8(c)))])
    73  (PopCount64 (Const64 [c])) && config.PtrSize == 4 => (Const32 [int32(bits.OnesCount64(uint64(c)))])
    74  (PopCount32 (Const32 [c])) && config.PtrSize == 4 => (Const32 [int32(bits.OnesCount32(uint32(c)))])
    75  (PopCount16 (Const16 [c])) && config.PtrSize == 4 => (Const32 [int32(bits.OnesCount16(uint16(c)))])
    76  (PopCount8  (Const8  [c])) && config.PtrSize == 4 => (Const32 [int32(bits.OnesCount8(uint8(c)))])
    77  (Add64carry (Const64 <t> [x]) (Const64 [y]) (Const64 [c])) && c >= 0 && c <= 1 => (MakeTuple (Const64 <t> [bitsAdd64(x, y, c).sum]) (Const64 <t> [bitsAdd64(x, y, c).carry]))
    78  
    79  (Trunc16to8  (ZeroExt8to16  x)) => x
    80  (Trunc32to8  (ZeroExt8to32  x)) => x
    81  (Trunc32to16 (ZeroExt8to32  x)) => (ZeroExt8to16  x)
    82  (Trunc32to16 (ZeroExt16to32 x)) => x
    83  (Trunc64to8  (ZeroExt8to64  x)) => x
    84  (Trunc64to16 (ZeroExt8to64  x)) => (ZeroExt8to16  x)
    85  (Trunc64to16 (ZeroExt16to64 x)) => x
    86  (Trunc64to32 (ZeroExt8to64  x)) => (ZeroExt8to32  x)
    87  (Trunc64to32 (ZeroExt16to64 x)) => (ZeroExt16to32 x)
    88  (Trunc64to32 (ZeroExt32to64 x)) => x
    89  (Trunc16to8  (SignExt8to16  x)) => x
    90  (Trunc32to8  (SignExt8to32  x)) => x
    91  (Trunc32to16 (SignExt8to32  x)) => (SignExt8to16  x)
    92  (Trunc32to16 (SignExt16to32 x)) => x
    93  (Trunc64to8  (SignExt8to64  x)) => x
    94  (Trunc64to16 (SignExt8to64  x)) => (SignExt8to16  x)
    95  (Trunc64to16 (SignExt16to64 x)) => x
    96  (Trunc64to32 (SignExt8to64  x)) => (SignExt8to32  x)
    97  (Trunc64to32 (SignExt16to64 x)) => (SignExt16to32 x)
    98  (Trunc64to32 (SignExt32to64 x)) => x
    99  
   100  (ZeroExt8to16  (Const8  [c])) => (Const16 [int16( uint8(c))])
   101  (ZeroExt8to32  (Const8  [c])) => (Const32 [int32( uint8(c))])
   102  (ZeroExt8to64  (Const8  [c])) => (Const64 [int64( uint8(c))])
   103  (ZeroExt16to32 (Const16 [c])) => (Const32 [int32(uint16(c))])
   104  (ZeroExt16to64 (Const16 [c])) => (Const64 [int64(uint16(c))])
   105  (ZeroExt32to64 (Const32 [c])) => (Const64 [int64(uint32(c))])
   106  (SignExt8to16  (Const8  [c])) => (Const16 [int16(c)])
   107  (SignExt8to32  (Const8  [c])) => (Const32 [int32(c)])
   108  (SignExt8to64  (Const8  [c])) => (Const64 [int64(c)])
   109  (SignExt16to32 (Const16 [c])) => (Const32 [int32(c)])
   110  (SignExt16to64 (Const16 [c])) => (Const64 [int64(c)])
   111  (SignExt32to64 (Const32 [c])) => (Const64 [int64(c)])
   112  
   113  (Neg8   (Const8   [c])) => (Const8   [-c])
   114  (Neg16  (Const16  [c])) => (Const16  [-c])
   115  (Neg32  (Const32  [c])) => (Const32  [-c])
   116  (Neg64  (Const64  [c])) => (Const64  [-c])
   117  (Neg32F (Const32F [c])) && c != 0 => (Const32F [-c])
   118  (Neg64F (Const64F [c])) && c != 0 => (Const64F [-c])
   119  
   120  (Add8   (Const8 [c])   (Const8 [d]))   => (Const8  [c+d])
   121  (Add16  (Const16 [c])  (Const16 [d]))  => (Const16 [c+d])
   122  (Add32  (Const32 [c])  (Const32 [d]))  => (Const32 [c+d])
   123  (Add64  (Const64 [c])  (Const64 [d]))  => (Const64 [c+d])
   124  (Add32F (Const32F [c]) (Const32F [d])) && c+d == c+d => (Const32F [c+d])
   125  (Add64F (Const64F [c]) (Const64F [d])) && c+d == c+d => (Const64F [c+d])
   126  (AddPtr <t> x (Const64 [c])) => (OffPtr <t> x [c])
   127  (AddPtr <t> x (Const32 [c])) => (OffPtr <t> x [int64(c)])
   128  
   129  (Sub8   (Const8 [c]) (Const8 [d]))     => (Const8 [c-d])
   130  (Sub16  (Const16 [c]) (Const16 [d]))   => (Const16 [c-d])
   131  (Sub32  (Const32 [c]) (Const32 [d]))   => (Const32 [c-d])
   132  (Sub64  (Const64 [c]) (Const64 [d]))   => (Const64 [c-d])
   133  (Sub32F (Const32F [c]) (Const32F [d])) && c-d == c-d => (Const32F [c-d])
   134  (Sub64F (Const64F [c]) (Const64F [d])) && c-d == c-d => (Const64F [c-d])
   135  
   136  (Mul8   (Const8 [c])   (Const8 [d]))   => (Const8  [c*d])
   137  (Mul16  (Const16 [c])  (Const16 [d]))  => (Const16 [c*d])
   138  (Mul32  (Const32 [c])  (Const32 [d]))  => (Const32 [c*d])
   139  (Mul64  (Const64 [c])  (Const64 [d]))  => (Const64 [c*d])
   140  (Mul32F (Const32F [c]) (Const32F [d])) && c*d == c*d => (Const32F [c*d])
   141  (Mul64F (Const64F [c]) (Const64F [d])) && c*d == c*d => (Const64F [c*d])
   142  (Mul32uhilo (Const32 [c]) (Const32 [d])) => (MakeTuple (Const32 <typ.UInt32> [bitsMulU32(c, d).hi]) (Const32 <typ.UInt32> [bitsMulU32(c,d).lo]))
   143  (Mul64uhilo (Const64 [c]) (Const64 [d])) => (MakeTuple (Const64 <typ.UInt64> [bitsMulU64(c, d).hi]) (Const64 <typ.UInt64> [bitsMulU64(c,d).lo]))
   144  (Mul32uover (Const32 [c]) (Const32 [d])) => (MakeTuple (Const32 <typ.UInt32> [bitsMulU32(c, d).lo]) (ConstBool <typ.Bool> [bitsMulU32(c,d).hi != 0]))
   145  (Mul64uover (Const64 [c]) (Const64 [d])) => (MakeTuple (Const64 <typ.UInt64> [bitsMulU64(c, d).lo]) (ConstBool <typ.Bool> [bitsMulU64(c,d).hi != 0]))
   146  
   147  (And8   (Const8 [c])   (Const8 [d]))   => (Const8  [c&d])
   148  (And16  (Const16 [c])  (Const16 [d]))  => (Const16 [c&d])
   149  (And32  (Const32 [c])  (Const32 [d]))  => (Const32 [c&d])
   150  (And64  (Const64 [c])  (Const64 [d]))  => (Const64 [c&d])
   151  
   152  (Or8   (Const8 [c])   (Const8 [d]))   => (Const8  [c|d])
   153  (Or16  (Const16 [c])  (Const16 [d]))  => (Const16 [c|d])
   154  (Or32  (Const32 [c])  (Const32 [d]))  => (Const32 [c|d])
   155  (Or64  (Const64 [c])  (Const64 [d]))  => (Const64 [c|d])
   156  
   157  (Xor8   (Const8 [c])   (Const8 [d]))   => (Const8  [c^d])
   158  (Xor16  (Const16 [c])  (Const16 [d]))  => (Const16 [c^d])
   159  (Xor32  (Const32 [c])  (Const32 [d]))  => (Const32 [c^d])
   160  (Xor64  (Const64 [c])  (Const64 [d]))  => (Const64 [c^d])
   161  
   162  (Ctz64 (Const64 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz64(c))])
   163  (Ctz32 (Const32 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz32(c))])
   164  (Ctz16 (Const16 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz16(c))])
   165  (Ctz8  (Const8  [c])) && config.PtrSize == 4 => (Const32 [int32(ntz8(c))])
   166  
   167  (Ctz64 (Const64 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz64(c))])
   168  (Ctz32 (Const32 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz32(c))])
   169  (Ctz16 (Const16 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz16(c))])
   170  (Ctz8  (Const8  [c])) && config.PtrSize == 8 => (Const64 [int64(ntz8(c))])
   171  
   172  (Div8   (Const8  [c])  (Const8  [d])) && d != 0 => (Const8  [c/d])
   173  (Div16  (Const16 [c])  (Const16 [d])) && d != 0 => (Const16 [c/d])
   174  (Div32  (Const32 [c])  (Const32 [d])) && d != 0 => (Const32 [c/d])
   175  (Div64  (Const64 [c])  (Const64 [d])) && d != 0 => (Const64 [c/d])
   176  (Div8u  (Const8  [c])  (Const8  [d])) && d != 0 => (Const8  [int8(uint8(c)/uint8(d))])
   177  (Div16u (Const16 [c])  (Const16 [d])) && d != 0 => (Const16 [int16(uint16(c)/uint16(d))])
   178  (Div32u (Const32 [c])  (Const32 [d])) && d != 0 => (Const32 [int32(uint32(c)/uint32(d))])
   179  (Div64u (Const64 [c])  (Const64 [d])) && d != 0 => (Const64 [int64(uint64(c)/uint64(d))])
   180  (Div32F (Const32F [c]) (Const32F [d])) && c/d == c/d => (Const32F [c/d])
   181  (Div64F (Const64F [c]) (Const64F [d])) && c/d == c/d => (Const64F [c/d])
   182  (Div128u <t> (Const64 [0]) lo y) => (MakeTuple (Div64u <t.FieldType(0)> lo y) (Mod64u <t.FieldType(1)> lo y))
   183  
   184  (Not (ConstBool [c])) => (ConstBool [!c])
   185  
   186  (Floor       (Const64F [c])) => (Const64F [math.Floor(c)])
   187  (Ceil        (Const64F [c])) => (Const64F [math.Ceil(c)])
   188  (Trunc       (Const64F [c])) => (Const64F [math.Trunc(c)])
   189  (RoundToEven (Const64F [c])) => (Const64F [math.RoundToEven(c)])
   190  
   191  // Convert x * 1 to x.
   192  (Mul(8|16|32|64)  (Const(8|16|32|64)  [1]) x) => x
   193  (Mul(32|64)uover <t> (Const(32|64) [1]) x) => (MakeTuple x (ConstBool <t.FieldType(1)> [false]))
   194  
   195  // Convert x * -1 to -x.
   196  (Mul(8|16|32|64)  (Const(8|16|32|64)  [-1]) x) => (Neg(8|16|32|64)  x)
   197  
   198  // DeMorgan's Laws
   199  (And(8|16|32|64) <t> (Com(8|16|32|64) x) (Com(8|16|32|64) y)) => (Com(8|16|32|64) (Or(8|16|32|64) <t> x y))
   200  (Or(8|16|32|64) <t> (Com(8|16|32|64) x) (Com(8|16|32|64) y)) => (Com(8|16|32|64) (And(8|16|32|64) <t> x y))
   201  
   202  // Convert multiplication by a power of two to a shift.
   203  (Mul8  <t> n (Const8  [c])) && isPowerOfTwo(c) => (Lsh8x64  <t> n (Const64 <typ.UInt64> [log8(c)]))
   204  (Mul16 <t> n (Const16 [c])) && isPowerOfTwo(c) => (Lsh16x64 <t> n (Const64 <typ.UInt64> [log16(c)]))
   205  (Mul32 <t> n (Const32 [c])) && isPowerOfTwo(c) => (Lsh32x64 <t> n (Const64 <typ.UInt64> [log32(c)]))
   206  (Mul64 <t> n (Const64 [c])) && isPowerOfTwo(c) => (Lsh64x64 <t> n (Const64 <typ.UInt64> [log64(c)]))
   207  (Mul8  <t> n (Const8  [c])) && t.IsSigned() && isPowerOfTwo(-c) => (Neg8  (Lsh8x64  <t> n (Const64 <typ.UInt64> [log8(-c)])))
   208  (Mul16 <t> n (Const16 [c])) && t.IsSigned() && isPowerOfTwo(-c) => (Neg16 (Lsh16x64 <t> n (Const64 <typ.UInt64> [log16(-c)])))
   209  (Mul32 <t> n (Const32 [c])) && t.IsSigned() && isPowerOfTwo(-c) => (Neg32 (Lsh32x64 <t> n (Const64 <typ.UInt64> [log32(-c)])))
   210  (Mul64 <t> n (Const64 [c])) && t.IsSigned() && isPowerOfTwo(-c) => (Neg64 (Lsh64x64 <t> n (Const64 <typ.UInt64> [log64(-c)])))
   211  
   212  (Mod8  (Const8  [c]) (Const8  [d])) && d != 0 => (Const8  [c % d])
   213  (Mod16 (Const16 [c]) (Const16 [d])) && d != 0 => (Const16 [c % d])
   214  (Mod32 (Const32 [c]) (Const32 [d])) && d != 0 => (Const32 [c % d])
   215  (Mod64 (Const64 [c]) (Const64 [d])) && d != 0 => (Const64 [c % d])
   216  
   217  (Mod8u  (Const8 [c])  (Const8  [d])) && d != 0 => (Const8  [int8(uint8(c) % uint8(d))])
   218  (Mod16u (Const16 [c]) (Const16 [d])) && d != 0 => (Const16 [int16(uint16(c) % uint16(d))])
   219  (Mod32u (Const32 [c]) (Const32 [d])) && d != 0 => (Const32 [int32(uint32(c) % uint32(d))])
   220  (Mod64u (Const64 [c]) (Const64 [d])) && d != 0 => (Const64 [int64(uint64(c) % uint64(d))])
   221  
   222  (Lsh64x64  (Const64 [c]) (Const64 [d])) => (Const64 [c << uint64(d)])
   223  (Rsh64x64  (Const64 [c]) (Const64 [d])) => (Const64 [c >> uint64(d)])
   224  (Rsh64Ux64 (Const64 [c]) (Const64 [d])) => (Const64 [int64(uint64(c) >> uint64(d))])
   225  (Lsh32x64  (Const32 [c]) (Const64 [d])) => (Const32 [c << uint64(d)])
   226  (Rsh32x64  (Const32 [c]) (Const64 [d])) => (Const32 [c >> uint64(d)])
   227  (Rsh32Ux64 (Const32 [c]) (Const64 [d])) => (Const32 [int32(uint32(c) >> uint64(d))])
   228  (Lsh16x64  (Const16 [c]) (Const64 [d])) => (Const16 [c << uint64(d)])
   229  (Rsh16x64  (Const16 [c]) (Const64 [d])) => (Const16 [c >> uint64(d)])
   230  (Rsh16Ux64 (Const16 [c]) (Const64 [d])) => (Const16 [int16(uint16(c) >> uint64(d))])
   231  (Lsh8x64   (Const8  [c]) (Const64 [d])) => (Const8  [c << uint64(d)])
   232  (Rsh8x64   (Const8  [c]) (Const64 [d])) => (Const8  [c >> uint64(d)])
   233  (Rsh8Ux64  (Const8  [c]) (Const64 [d])) => (Const8  [int8(uint8(c) >> uint64(d))])
   234  
   235  // Fold IsInBounds when the range of the index cannot exceed the limit.
   236  (IsInBounds (ZeroExt8to32  _) (Const32 [c])) && (1 << 8)  <= c => (ConstBool [true])
   237  (IsInBounds (ZeroExt8to64  _) (Const64 [c])) && (1 << 8)  <= c => (ConstBool [true])
   238  (IsInBounds (ZeroExt16to32 _) (Const32 [c])) && (1 << 16) <= c => (ConstBool [true])
   239  (IsInBounds (ZeroExt16to64 _) (Const64 [c])) && (1 << 16) <= c => (ConstBool [true])
   240  (IsInBounds x x) => (ConstBool [false])
   241  (IsInBounds                (And8  (Const8  [c]) _)  (Const8  [d])) && 0 <= c && c < d => (ConstBool [true])
   242  (IsInBounds (ZeroExt8to16  (And8  (Const8  [c]) _)) (Const16 [d])) && 0 <= c && int16(c) < d => (ConstBool [true])
   243  (IsInBounds (ZeroExt8to32  (And8  (Const8  [c]) _)) (Const32 [d])) && 0 <= c && int32(c) < d => (ConstBool [true])
   244  (IsInBounds (ZeroExt8to64  (And8  (Const8  [c]) _)) (Const64 [d])) && 0 <= c && int64(c) < d => (ConstBool [true])
   245  (IsInBounds                (And16 (Const16 [c]) _)  (Const16 [d])) && 0 <= c && c < d => (ConstBool [true])
   246  (IsInBounds (ZeroExt16to32 (And16 (Const16 [c]) _)) (Const32 [d])) && 0 <= c && int32(c) < d => (ConstBool [true])
   247  (IsInBounds (ZeroExt16to64 (And16 (Const16 [c]) _)) (Const64 [d])) && 0 <= c && int64(c) < d => (ConstBool [true])
   248  (IsInBounds                (And32 (Const32 [c]) _)  (Const32 [d])) && 0 <= c && c < d => (ConstBool [true])
   249  (IsInBounds (ZeroExt32to64 (And32 (Const32 [c]) _)) (Const64 [d])) && 0 <= c && int64(c) < d => (ConstBool [true])
   250  (IsInBounds                (And64 (Const64 [c]) _)  (Const64 [d])) && 0 <= c && c < d => (ConstBool [true])
   251  (IsInBounds (Const32 [c]) (Const32 [d])) => (ConstBool [0 <= c && c < d])
   252  (IsInBounds (Const64 [c]) (Const64 [d])) => (ConstBool [0 <= c && c < d])
   253  // (Mod64u x y) is always between 0 (inclusive) and y (exclusive).
   254  (IsInBounds (Mod32u _ y) y) => (ConstBool [true])
   255  (IsInBounds (Mod64u _ y) y) => (ConstBool [true])
   256  // Right shifting an unsigned number limits its value.
   257  (IsInBounds (ZeroExt8to64  (Rsh8Ux64  _ (Const64 [c]))) (Const64 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d => (ConstBool [true])
   258  (IsInBounds (ZeroExt8to32  (Rsh8Ux64  _ (Const64 [c]))) (Const32 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d => (ConstBool [true])
   259  (IsInBounds (ZeroExt8to16  (Rsh8Ux64  _ (Const64 [c]))) (Const16 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d => (ConstBool [true])
   260  (IsInBounds                (Rsh8Ux64  _ (Const64 [c]))  (Const64 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d => (ConstBool [true])
   261  (IsInBounds (ZeroExt16to64 (Rsh16Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d => (ConstBool [true])
   262  (IsInBounds (ZeroExt16to32 (Rsh16Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d => (ConstBool [true])
   263  (IsInBounds                (Rsh16Ux64 _ (Const64 [c]))  (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d => (ConstBool [true])
   264  (IsInBounds (ZeroExt32to64 (Rsh32Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 32 && 1<<uint(32-c)-1 < d => (ConstBool [true])
   265  (IsInBounds                (Rsh32Ux64 _ (Const64 [c]))  (Const64 [d])) && 0 < c && c < 32 && 1<<uint(32-c)-1 < d => (ConstBool [true])
   266  (IsInBounds                (Rsh64Ux64 _ (Const64 [c]))  (Const64 [d])) && 0 < c && c < 64 && 1<<uint(64-c)-1 < d => (ConstBool [true])
   267  
   268  (IsSliceInBounds x x) => (ConstBool [true])
   269  (IsSliceInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c <= d => (ConstBool [true])
   270  (IsSliceInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c <= d => (ConstBool [true])
   271  (IsSliceInBounds (Const32 [0]) _) => (ConstBool [true])
   272  (IsSliceInBounds (Const64 [0]) _) => (ConstBool [true])
   273  (IsSliceInBounds (Const32 [c]) (Const32 [d])) => (ConstBool [0 <= c && c <= d])
   274  (IsSliceInBounds (Const64 [c]) (Const64 [d])) => (ConstBool [0 <= c && c <= d])
   275  (IsSliceInBounds (SliceLen x) (SliceCap x)) => (ConstBool [true])
   276  
   277  (Eq(64|32|16|8) x x) => (ConstBool [true])
   278  (EqB (ConstBool [c]) (ConstBool [d])) => (ConstBool [c == d])
   279  (EqB (ConstBool [false]) x) => (Not x)
   280  (EqB (ConstBool [true]) x) => x
   281  
   282  (Neq(64|32|16|8) x x) => (ConstBool [false])
   283  (NeqB (ConstBool [c]) (ConstBool [d])) => (ConstBool [c != d])
   284  (NeqB (ConstBool [false]) x) => x
   285  (NeqB (ConstBool [true]) x) => (Not x)
   286  (NeqB (Not x) (Not y)) => (NeqB x y)
   287  
   288  (Eq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Eq64 (Const64 <t> [c-d]) x)
   289  (Eq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Eq32 (Const32 <t> [c-d]) x)
   290  (Eq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Eq16 (Const16 <t> [c-d]) x)
   291  (Eq8  (Const8  <t> [c]) (Add8  (Const8  <t> [d]) x)) => (Eq8  (Const8  <t> [c-d]) x)
   292  
   293  (Neq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Neq64 (Const64 <t> [c-d]) x)
   294  (Neq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Neq32 (Const32 <t> [c-d]) x)
   295  (Neq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Neq16 (Const16 <t> [c-d]) x)
   296  (Neq8  (Const8  <t> [c]) (Add8  (Const8  <t> [d]) x)) => (Neq8  (Const8  <t> [c-d]) x)
   297  
   298  (CondSelect x _ (ConstBool [true ])) => x
   299  (CondSelect _ y (ConstBool [false])) => y
   300  (CondSelect x x _) => x
   301  
   302  // signed integer range: ( c <= x && x (<|<=) d ) -> ( unsigned(x-c) (<|<=) unsigned(d-c) )
   303  (AndB (Leq64 (Const64 [c]) x) ((Less|Leq)64 x (Const64 [d]))) && d >= c => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c])) (Const64 <x.Type> [d-c]))
   304  (AndB (Leq32 (Const32 [c]) x) ((Less|Leq)32 x (Const32 [d]))) && d >= c => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c])) (Const32 <x.Type> [d-c]))
   305  (AndB (Leq16 (Const16 [c]) x) ((Less|Leq)16 x (Const16 [d]))) && d >= c => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c])) (Const16 <x.Type> [d-c]))
   306  (AndB (Leq8  (Const8  [c]) x) ((Less|Leq)8  x (Const8  [d]))) && d >= c => ((Less|Leq)8U  (Sub8  <x.Type> x (Const8  <x.Type> [c])) (Const8  <x.Type> [d-c]))
   307  
   308  // signed integer range: ( c < x && x (<|<=) d ) -> ( unsigned(x-(c+1)) (<|<=) unsigned(d-(c+1)) )
   309  (AndB (Less64 (Const64 [c]) x) ((Less|Leq)64 x (Const64 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c+1])) (Const64 <x.Type> [d-c-1]))
   310  (AndB (Less32 (Const32 [c]) x) ((Less|Leq)32 x (Const32 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c+1])) (Const32 <x.Type> [d-c-1]))
   311  (AndB (Less16 (Const16 [c]) x) ((Less|Leq)16 x (Const16 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c+1])) (Const16 <x.Type> [d-c-1]))
   312  (AndB (Less8  (Const8  [c]) x) ((Less|Leq)8  x (Const8  [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)8U  (Sub8  <x.Type> x (Const8  <x.Type> [c+1])) (Const8  <x.Type> [d-c-1]))
   313  
   314  // unsigned integer range: ( c <= x && x (<|<=) d ) -> ( x-c (<|<=) d-c )
   315  (AndB (Leq64U (Const64 [c]) x) ((Less|Leq)64U x (Const64 [d]))) && uint64(d) >= uint64(c) => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c])) (Const64 <x.Type> [d-c]))
   316  (AndB (Leq32U (Const32 [c]) x) ((Less|Leq)32U x (Const32 [d]))) && uint32(d) >= uint32(c) => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c])) (Const32 <x.Type> [d-c]))
   317  (AndB (Leq16U (Const16 [c]) x) ((Less|Leq)16U x (Const16 [d]))) && uint16(d) >= uint16(c) => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c])) (Const16 <x.Type> [d-c]))
   318  (AndB (Leq8U  (Const8  [c]) x) ((Less|Leq)8U  x (Const8  [d]))) && uint8(d)  >= uint8(c)  => ((Less|Leq)8U  (Sub8  <x.Type> x (Const8  <x.Type> [c])) (Const8  <x.Type> [d-c]))
   319  
   320  // unsigned integer range: ( c < x && x (<|<=) d ) -> ( x-(c+1) (<|<=) d-(c+1) )
   321  (AndB (Less64U (Const64 [c]) x) ((Less|Leq)64U x (Const64 [d]))) && uint64(d) >= uint64(c+1) && uint64(c+1) > uint64(c) => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c+1])) (Const64 <x.Type> [d-c-1]))
   322  (AndB (Less32U (Const32 [c]) x) ((Less|Leq)32U x (Const32 [d]))) && uint32(d) >= uint32(c+1) && uint32(c+1) > uint32(c) => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c+1])) (Const32 <x.Type> [d-c-1]))
   323  (AndB (Less16U (Const16 [c]) x) ((Less|Leq)16U x (Const16 [d]))) && uint16(d) >= uint16(c+1) && uint16(c+1) > uint16(c) => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c+1])) (Const16 <x.Type> [d-c-1]))
   324  (AndB (Less8U  (Const8  [c]) x) ((Less|Leq)8U  x (Const8  [d]))) && uint8(d)  >= uint8(c+1)  && uint8(c+1)  > uint8(c)  => ((Less|Leq)8U  (Sub8  <x.Type> x (Const8  <x.Type> [c+1]))  (Const8  <x.Type> [d-c-1]))
   325  
   326  // signed integer range: ( c (<|<=) x || x < d ) -> ( unsigned(c-d) (<|<=) unsigned(x-d) )
   327  (OrB ((Less|Leq)64 (Const64 [c]) x) (Less64 x (Const64 [d]))) && c >= d => ((Less|Leq)64U (Const64 <x.Type> [c-d]) (Sub64 <x.Type> x (Const64 <x.Type> [d])))
   328  (OrB ((Less|Leq)32 (Const32 [c]) x) (Less32 x (Const32 [d]))) && c >= d => ((Less|Leq)32U (Const32 <x.Type> [c-d]) (Sub32 <x.Type> x (Const32 <x.Type> [d])))
   329  (OrB ((Less|Leq)16 (Const16 [c]) x) (Less16 x (Const16 [d]))) && c >= d => ((Less|Leq)16U (Const16 <x.Type> [c-d]) (Sub16 <x.Type> x (Const16 <x.Type> [d])))
   330  (OrB ((Less|Leq)8  (Const8  [c]) x) (Less8  x (Const8  [d]))) && c >= d => ((Less|Leq)8U  (Const8  <x.Type> [c-d]) (Sub8  <x.Type> x (Const8  <x.Type> [d])))
   331  
   332  // signed integer range: ( c (<|<=) x || x <= d ) -> ( unsigned(c-(d+1)) (<|<=) unsigned(x-(d+1)) )
   333  (OrB ((Less|Leq)64 (Const64 [c]) x) (Leq64 x (Const64 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)64U (Const64 <x.Type> [c-d-1]) (Sub64 <x.Type> x (Const64 <x.Type> [d+1])))
   334  (OrB ((Less|Leq)32 (Const32 [c]) x) (Leq32 x (Const32 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)32U (Const32 <x.Type> [c-d-1]) (Sub32 <x.Type> x (Const32 <x.Type> [d+1])))
   335  (OrB ((Less|Leq)16 (Const16 [c]) x) (Leq16 x (Const16 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)16U (Const16 <x.Type> [c-d-1]) (Sub16 <x.Type> x (Const16 <x.Type> [d+1])))
   336  (OrB ((Less|Leq)8  (Const8  [c]) x) (Leq8  x (Const8  [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)8U  (Const8  <x.Type> [c-d-1]) (Sub8  <x.Type> x (Const8  <x.Type> [d+1])))
   337  
   338  // unsigned integer range: ( c (<|<=) x || x < d ) -> ( c-d (<|<=) x-d )
   339  (OrB ((Less|Leq)64U (Const64 [c]) x) (Less64U x (Const64 [d]))) && uint64(c) >= uint64(d) => ((Less|Leq)64U (Const64 <x.Type> [c-d]) (Sub64 <x.Type> x (Const64 <x.Type> [d])))
   340  (OrB ((Less|Leq)32U (Const32 [c]) x) (Less32U x (Const32 [d]))) && uint32(c) >= uint32(d) => ((Less|Leq)32U (Const32 <x.Type> [c-d]) (Sub32 <x.Type> x (Const32 <x.Type> [d])))
   341  (OrB ((Less|Leq)16U (Const16 [c]) x) (Less16U x (Const16 [d]))) && uint16(c) >= uint16(d) => ((Less|Leq)16U (Const16 <x.Type> [c-d]) (Sub16 <x.Type> x (Const16 <x.Type> [d])))
   342  (OrB ((Less|Leq)8U  (Const8  [c]) x) (Less8U  x (Const8  [d]))) && uint8(c)  >= uint8(d)  => ((Less|Leq)8U  (Const8  <x.Type> [c-d]) (Sub8  <x.Type> x (Const8  <x.Type> [d])))
   343  
   344  // unsigned integer range: ( c (<|<=) x || x <= d ) -> ( c-(d+1) (<|<=) x-(d+1) )
   345  (OrB ((Less|Leq)64U (Const64 [c]) x) (Leq64U x (Const64 [d]))) && uint64(c) >= uint64(d+1) && uint64(d+1) > uint64(d) => ((Less|Leq)64U (Const64 <x.Type> [c-d-1]) (Sub64 <x.Type> x (Const64 <x.Type> [d+1])))
   346  (OrB ((Less|Leq)32U (Const32 [c]) x) (Leq32U x (Const32 [d]))) && uint32(c) >= uint32(d+1) && uint32(d+1) > uint32(d) => ((Less|Leq)32U (Const32 <x.Type> [c-d-1]) (Sub32 <x.Type> x (Const32 <x.Type> [d+1])))
   347  (OrB ((Less|Leq)16U (Const16 [c]) x) (Leq16U x (Const16 [d]))) && uint16(c) >= uint16(d+1) && uint16(d+1) > uint16(d) => ((Less|Leq)16U (Const16 <x.Type> [c-d-1]) (Sub16 <x.Type> x (Const16 <x.Type> [d+1])))
   348  (OrB ((Less|Leq)8U  (Const8  [c]) x) (Leq8U  x (Const8  [d]))) && uint8(c)  >= uint8(d+1)  && uint8(d+1)  > uint8(d)  => ((Less|Leq)8U  (Const8  <x.Type> [c-d-1]) (Sub8  <x.Type> x (Const8  <x.Type> [d+1])))
   349  
   350  // Canonicalize x-const to x+(-const)
   351  (Sub64 x (Const64 <t> [c])) && x.Op != OpConst64 => (Add64 (Const64 <t> [-c]) x)
   352  (Sub32 x (Const32 <t> [c])) && x.Op != OpConst32 => (Add32 (Const32 <t> [-c]) x)
   353  (Sub16 x (Const16 <t> [c])) && x.Op != OpConst16 => (Add16 (Const16 <t> [-c]) x)
   354  (Sub8  x (Const8  <t> [c])) && x.Op != OpConst8  => (Add8  (Const8  <t> [-c]) x)
   355  
   356  // fold negation into comparison operators
   357  (Not (Eq(64|32|16|8|B|Ptr|64F|32F) x y)) => (Neq(64|32|16|8|B|Ptr|64F|32F) x y)
   358  (Not (Neq(64|32|16|8|B|Ptr|64F|32F) x y)) => (Eq(64|32|16|8|B|Ptr|64F|32F) x y)
   359  
   360  (Not (Less(64|32|16|8) x y)) => (Leq(64|32|16|8) y x)
   361  (Not (Less(64|32|16|8)U x y)) => (Leq(64|32|16|8)U y x)
   362  (Not (Leq(64|32|16|8) x y)) => (Less(64|32|16|8) y x)
   363  (Not (Leq(64|32|16|8)U x y)) => (Less(64|32|16|8)U y x)
   364  
   365  // Distribute multiplication c * (d+x) -> c*d + c*x. Useful for:
   366  // a[i].b = ...; a[i+1].b = ...
   367  (Mul64 (Const64 <t> [c]) (Add64 <t> (Const64 <t> [d]) x)) =>
   368    (Add64 (Const64 <t> [c*d]) (Mul64 <t> (Const64 <t> [c]) x))
   369  (Mul32 (Const32 <t> [c]) (Add32 <t> (Const32 <t> [d]) x)) =>
   370    (Add32 (Const32 <t> [c*d]) (Mul32 <t> (Const32 <t> [c]) x))
   371  (Mul16 (Const16 <t> [c]) (Add16 <t> (Const16 <t> [d]) x)) =>
   372    (Add16 (Const16 <t> [c*d]) (Mul16 <t> (Const16 <t> [c]) x))
   373  (Mul8 (Const8 <t> [c]) (Add8 <t> (Const8 <t> [d]) x)) =>
   374    (Add8 (Const8 <t> [c*d]) (Mul8 <t> (Const8 <t> [c]) x))
   375  
   376  // Rewrite x*y ± x*z  to  x*(y±z)
   377  (Add(64|32|16|8) <t> (Mul(64|32|16|8) x y) (Mul(64|32|16|8) x z))
   378  	=> (Mul(64|32|16|8) x (Add(64|32|16|8) <t> y z))
   379  (Sub(64|32|16|8) <t> (Mul(64|32|16|8) x y) (Mul(64|32|16|8) x z))
   380  	=> (Mul(64|32|16|8) x (Sub(64|32|16|8) <t> y z))
   381  
   382  // rewrite shifts of 8/16/32 bit consts into 64 bit consts to reduce
   383  // the number of the other rewrite rules for const shifts
   384  (Lsh64x32  <t> x (Const32 [c])) => (Lsh64x64  x (Const64 <t> [int64(uint32(c))]))
   385  (Lsh64x16  <t> x (Const16 [c])) => (Lsh64x64  x (Const64 <t> [int64(uint16(c))]))
   386  (Lsh64x8   <t> x (Const8  [c])) => (Lsh64x64  x (Const64 <t> [int64(uint8(c))]))
   387  (Rsh64x32  <t> x (Const32 [c])) => (Rsh64x64  x (Const64 <t> [int64(uint32(c))]))
   388  (Rsh64x16  <t> x (Const16 [c])) => (Rsh64x64  x (Const64 <t> [int64(uint16(c))]))
   389  (Rsh64x8   <t> x (Const8  [c])) => (Rsh64x64  x (Const64 <t> [int64(uint8(c))]))
   390  (Rsh64Ux32 <t> x (Const32 [c])) => (Rsh64Ux64 x (Const64 <t> [int64(uint32(c))]))
   391  (Rsh64Ux16 <t> x (Const16 [c])) => (Rsh64Ux64 x (Const64 <t> [int64(uint16(c))]))
   392  (Rsh64Ux8  <t> x (Const8  [c])) => (Rsh64Ux64 x (Const64 <t> [int64(uint8(c))]))
   393  
   394  (Lsh32x32  <t> x (Const32 [c])) => (Lsh32x64  x (Const64 <t> [int64(uint32(c))]))
   395  (Lsh32x16  <t> x (Const16 [c])) => (Lsh32x64  x (Const64 <t> [int64(uint16(c))]))
   396  (Lsh32x8   <t> x (Const8  [c])) => (Lsh32x64  x (Const64 <t> [int64(uint8(c))]))
   397  (Rsh32x32  <t> x (Const32 [c])) => (Rsh32x64  x (Const64 <t> [int64(uint32(c))]))
   398  (Rsh32x16  <t> x (Const16 [c])) => (Rsh32x64  x (Const64 <t> [int64(uint16(c))]))
   399  (Rsh32x8   <t> x (Const8  [c])) => (Rsh32x64  x (Const64 <t> [int64(uint8(c))]))
   400  (Rsh32Ux32 <t> x (Const32 [c])) => (Rsh32Ux64 x (Const64 <t> [int64(uint32(c))]))
   401  (Rsh32Ux16 <t> x (Const16 [c])) => (Rsh32Ux64 x (Const64 <t> [int64(uint16(c))]))
   402  (Rsh32Ux8  <t> x (Const8  [c])) => (Rsh32Ux64 x (Const64 <t> [int64(uint8(c))]))
   403  
   404  (Lsh16x32  <t> x (Const32 [c])) => (Lsh16x64  x (Const64 <t> [int64(uint32(c))]))
   405  (Lsh16x16  <t> x (Const16 [c])) => (Lsh16x64  x (Const64 <t> [int64(uint16(c))]))
   406  (Lsh16x8   <t> x (Const8  [c])) => (Lsh16x64  x (Const64 <t> [int64(uint8(c))]))
   407  (Rsh16x32  <t> x (Const32 [c])) => (Rsh16x64  x (Const64 <t> [int64(uint32(c))]))
   408  (Rsh16x16  <t> x (Const16 [c])) => (Rsh16x64  x (Const64 <t> [int64(uint16(c))]))
   409  (Rsh16x8   <t> x (Const8  [c])) => (Rsh16x64  x (Const64 <t> [int64(uint8(c))]))
   410  (Rsh16Ux32 <t> x (Const32 [c])) => (Rsh16Ux64 x (Const64 <t> [int64(uint32(c))]))
   411  (Rsh16Ux16 <t> x (Const16 [c])) => (Rsh16Ux64 x (Const64 <t> [int64(uint16(c))]))
   412  (Rsh16Ux8  <t> x (Const8  [c])) => (Rsh16Ux64 x (Const64 <t> [int64(uint8(c))]))
   413  
   414  (Lsh8x32  <t> x (Const32 [c])) => (Lsh8x64  x (Const64 <t> [int64(uint32(c))]))
   415  (Lsh8x16  <t> x (Const16 [c])) => (Lsh8x64  x (Const64 <t> [int64(uint16(c))]))
   416  (Lsh8x8   <t> x (Const8  [c])) => (Lsh8x64  x (Const64 <t> [int64(uint8(c))]))
   417  (Rsh8x32  <t> x (Const32 [c])) => (Rsh8x64  x (Const64 <t> [int64(uint32(c))]))
   418  (Rsh8x16  <t> x (Const16 [c])) => (Rsh8x64  x (Const64 <t> [int64(uint16(c))]))
   419  (Rsh8x8   <t> x (Const8  [c])) => (Rsh8x64  x (Const64 <t> [int64(uint8(c))]))
   420  (Rsh8Ux32 <t> x (Const32 [c])) => (Rsh8Ux64 x (Const64 <t> [int64(uint32(c))]))
   421  (Rsh8Ux16 <t> x (Const16 [c])) => (Rsh8Ux64 x (Const64 <t> [int64(uint16(c))]))
   422  (Rsh8Ux8  <t> x (Const8  [c])) => (Rsh8Ux64 x (Const64 <t> [int64(uint8(c))]))
   423  
   424  // shifts by zero
   425  (Lsh(64|32|16|8)x64  x (Const64 [0])) => x
   426  (Rsh(64|32|16|8)x64  x (Const64 [0])) => x
   427  (Rsh(64|32|16|8)Ux64 x (Const64 [0])) => x
   428  
   429  // rotates by multiples of register width
   430  (RotateLeft64 x (Const64 [c])) && c%64 == 0 => x
   431  (RotateLeft32 x (Const32 [c])) && c%32 == 0 => x
   432  (RotateLeft16 x (Const16 [c])) && c%16 == 0 => x
   433  (RotateLeft8  x (Const8 [c]))  && c%8  == 0 => x
   434  
   435  // zero shifted
   436  (Lsh64x(64|32|16|8)  (Const64 [0]) _) => (Const64 [0])
   437  (Rsh64x(64|32|16|8)  (Const64 [0]) _) => (Const64 [0])
   438  (Rsh64Ux(64|32|16|8) (Const64 [0]) _) => (Const64 [0])
   439  (Lsh32x(64|32|16|8)  (Const32 [0]) _) => (Const32 [0])
   440  (Rsh32x(64|32|16|8)  (Const32 [0]) _) => (Const32 [0])
   441  (Rsh32Ux(64|32|16|8) (Const32 [0]) _) => (Const32 [0])
   442  (Lsh16x(64|32|16|8)  (Const16 [0]) _) => (Const16 [0])
   443  (Rsh16x(64|32|16|8)  (Const16 [0]) _) => (Const16 [0])
   444  (Rsh16Ux(64|32|16|8) (Const16 [0]) _) => (Const16 [0])
   445  (Lsh8x(64|32|16|8)   (Const8  [0]) _) => (Const8  [0])
   446  (Rsh8x(64|32|16|8)   (Const8  [0]) _) => (Const8  [0])
   447  (Rsh8Ux(64|32|16|8)  (Const8  [0]) _) => (Const8  [0])
   448  
   449  // large left shifts of all values, and right shifts of unsigned values
   450  ((Lsh64|Rsh64U)x64  _ (Const64 [c])) && uint64(c) >= 64 => (Const64 [0])
   451  ((Lsh32|Rsh32U)x64  _ (Const64 [c])) && uint64(c) >= 32 => (Const32 [0])
   452  ((Lsh16|Rsh16U)x64  _ (Const64 [c])) && uint64(c) >= 16 => (Const16 [0])
   453  ((Lsh8|Rsh8U)x64    _ (Const64 [c])) && uint64(c) >= 8  => (Const8  [0])
   454  
   455  // combine const shifts
   456  (Lsh64x64 <t> (Lsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh64x64 x (Const64 <t> [c+d]))
   457  (Lsh32x64 <t> (Lsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh32x64 x (Const64 <t> [c+d]))
   458  (Lsh16x64 <t> (Lsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh16x64 x (Const64 <t> [c+d]))
   459  (Lsh8x64  <t> (Lsh8x64  x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh8x64  x (Const64 <t> [c+d]))
   460  
   461  (Rsh64x64 <t> (Rsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh64x64 x (Const64 <t> [c+d]))
   462  (Rsh32x64 <t> (Rsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh32x64 x (Const64 <t> [c+d]))
   463  (Rsh16x64 <t> (Rsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh16x64 x (Const64 <t> [c+d]))
   464  (Rsh8x64  <t> (Rsh8x64  x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh8x64  x (Const64 <t> [c+d]))
   465  
   466  (Rsh64Ux64 <t> (Rsh64Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh64Ux64 x (Const64 <t> [c+d]))
   467  (Rsh32Ux64 <t> (Rsh32Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh32Ux64 x (Const64 <t> [c+d]))
   468  (Rsh16Ux64 <t> (Rsh16Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh16Ux64 x (Const64 <t> [c+d]))
   469  (Rsh8Ux64  <t> (Rsh8Ux64  x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh8Ux64  x (Const64 <t> [c+d]))
   470  
   471  // Remove signed right shift before an unsigned right shift that extracts the sign bit.
   472  (Rsh8Ux64  (Rsh8x64  x _) (Const64 <t> [7] )) => (Rsh8Ux64  x (Const64 <t> [7] ))
   473  (Rsh16Ux64 (Rsh16x64 x _) (Const64 <t> [15])) => (Rsh16Ux64 x (Const64 <t> [15]))
   474  (Rsh32Ux64 (Rsh32x64 x _) (Const64 <t> [31])) => (Rsh32Ux64 x (Const64 <t> [31]))
   475  (Rsh64Ux64 (Rsh64x64 x _) (Const64 <t> [63])) => (Rsh64Ux64 x (Const64 <t> [63]))
   476  
   477  // Convert x>>c<<c to x&^(1<<c-1)
   478  (Lsh64x64 i:(Rsh(64|64U)x64  x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 64 && i.Uses == 1 => (And64 x (Const64 <v.Type> [int64(-1) << c]))
   479  (Lsh32x64 i:(Rsh(32|32U)x64  x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 32 && i.Uses == 1 => (And32 x (Const32 <v.Type> [int32(-1) << c]))
   480  (Lsh16x64 i:(Rsh(16|16U)x64  x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 16 && i.Uses == 1 => (And16 x (Const16 <v.Type> [int16(-1) << c]))
   481  (Lsh8x64  i:(Rsh(8|8U)x64    x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 8  && i.Uses == 1 => (And8  x (Const8  <v.Type> [int8(-1)  << c]))
   482  // similarly for x<<c>>c
   483  (Rsh64Ux64 i:(Lsh64x64 x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 64 && i.Uses == 1 => (And64 x (Const64 <v.Type> [int64(^uint64(0)>>c)]))
   484  (Rsh32Ux64 i:(Lsh32x64 x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 32 && i.Uses == 1 => (And32 x (Const32 <v.Type> [int32(^uint32(0)>>c)]))
   485  (Rsh16Ux64 i:(Lsh16x64 x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 16 && i.Uses == 1 => (And16 x (Const16 <v.Type> [int16(^uint16(0)>>c)]))
   486  (Rsh8Ux64  i:(Lsh8x64  x (Const64 [c])) (Const64 [c])) && c >= 0 && c < 8  && i.Uses == 1 => (And8  x (Const8  <v.Type> [int8 (^uint8 (0)>>c)]))
   487  
   488  // ((x >> c1) << c2) >> c3
   489  (Rsh(64|32|16|8)Ux64 (Lsh(64|32|16|8)x64 (Rsh(64|32|16|8)Ux64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3]))
   490    && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3)
   491    => (Rsh(64|32|16|8)Ux64 x (Const64 <typ.UInt64> [c1-c2+c3]))
   492  
   493  // ((x << c1) >> c2) << c3
   494  (Lsh(64|32|16|8)x64 (Rsh(64|32|16|8)Ux64 (Lsh(64|32|16|8)x64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3]))
   495    && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3)
   496    => (Lsh(64|32|16|8)x64 x (Const64 <typ.UInt64> [c1-c2+c3]))
   497  
   498  // (x >> c) & uppermask = 0
   499  (And64 (Const64 [m]) (Rsh64Ux64 _ (Const64 [c]))) && c >= int64(64-ntz64(m)) => (Const64 [0])
   500  (And32 (Const32 [m]) (Rsh32Ux64 _ (Const64 [c]))) && c >= int64(32-ntz32(m)) => (Const32 [0])
   501  (And16 (Const16 [m]) (Rsh16Ux64 _ (Const64 [c]))) && c >= int64(16-ntz16(m)) => (Const16 [0])
   502  (And8  (Const8  [m]) (Rsh8Ux64  _ (Const64 [c]))) && c >= int64(8-ntz8(m))  => (Const8  [0])
   503  
   504  // (x << c) & lowermask = 0
   505  (And64 (Const64 [m]) (Lsh64x64  _ (Const64 [c]))) && c >= int64(64-nlz64(m)) => (Const64 [0])
   506  (And32 (Const32 [m]) (Lsh32x64  _ (Const64 [c]))) && c >= int64(32-nlz32(m)) => (Const32 [0])
   507  (And16 (Const16 [m]) (Lsh16x64  _ (Const64 [c]))) && c >= int64(16-nlz16(m)) => (Const16 [0])
   508  (And8  (Const8  [m]) (Lsh8x64   _ (Const64 [c]))) && c >= int64(8-nlz8(m))  => (Const8  [0])
   509  
   510  // replace shifts with zero extensions
   511  (Rsh16Ux64 (Lsh16x64 x (Const64  [8])) (Const64  [8])) => (ZeroExt8to16  (Trunc16to8  <typ.UInt8>  x))
   512  (Rsh32Ux64 (Lsh32x64 x (Const64 [24])) (Const64 [24])) => (ZeroExt8to32  (Trunc32to8  <typ.UInt8>  x))
   513  (Rsh64Ux64 (Lsh64x64 x (Const64 [56])) (Const64 [56])) => (ZeroExt8to64  (Trunc64to8  <typ.UInt8>  x))
   514  (Rsh32Ux64 (Lsh32x64 x (Const64 [16])) (Const64 [16])) => (ZeroExt16to32 (Trunc32to16 <typ.UInt16> x))
   515  (Rsh64Ux64 (Lsh64x64 x (Const64 [48])) (Const64 [48])) => (ZeroExt16to64 (Trunc64to16 <typ.UInt16> x))
   516  (Rsh64Ux64 (Lsh64x64 x (Const64 [32])) (Const64 [32])) => (ZeroExt32to64 (Trunc64to32 <typ.UInt32> x))
   517  
   518  // replace shifts with sign extensions
   519  (Rsh16x64 (Lsh16x64 x (Const64  [8])) (Const64  [8])) => (SignExt8to16  (Trunc16to8  <typ.Int8>  x))
   520  (Rsh32x64 (Lsh32x64 x (Const64 [24])) (Const64 [24])) => (SignExt8to32  (Trunc32to8  <typ.Int8>  x))
   521  (Rsh64x64 (Lsh64x64 x (Const64 [56])) (Const64 [56])) => (SignExt8to64  (Trunc64to8  <typ.Int8>  x))
   522  (Rsh32x64 (Lsh32x64 x (Const64 [16])) (Const64 [16])) => (SignExt16to32 (Trunc32to16 <typ.Int16> x))
   523  (Rsh64x64 (Lsh64x64 x (Const64 [48])) (Const64 [48])) => (SignExt16to64 (Trunc64to16 <typ.Int16> x))
   524  (Rsh64x64 (Lsh64x64 x (Const64 [32])) (Const64 [32])) => (SignExt32to64 (Trunc64to32 <typ.Int32> x))
   525  
   526  // ((x >> c) & d) << e
   527  (Lsh64x64 (And64 (Rsh(64|64U)x64 <t> x (Const64 <t2> [c])) (Const64 [d])) (Const64 [e])) && c >= e => (And64 (Rsh(64|64U)x64 <t> x (Const64 <t2> [c-e])) (Const64 <t> [d<<e]))
   528  (Lsh32x64 (And32 (Rsh(32|32U)x64 <t> x (Const64 <t2> [c])) (Const32 [d])) (Const64 [e])) && c >= e => (And32 (Rsh(32|32U)x64 <t> x (Const64 <t2> [c-e])) (Const32 <t> [d<<e]))
   529  (Lsh16x64 (And16 (Rsh(16|16U)x64 <t> x (Const64 <t2> [c])) (Const16 [d])) (Const64 [e])) && c >= e => (And16 (Rsh(16|16U)x64 <t> x (Const64 <t2> [c-e])) (Const16 <t> [d<<e]))
   530  (Lsh8x64  (And8  (Rsh(8|8U)x64   <t> x (Const64 <t2> [c])) (Const8  [d])) (Const64 [e])) && c >= e => (And8  (Rsh(8|8U)x64   <t> x (Const64 <t2> [c-e])) (Const8  <t> [d<<e]))
   531  (Lsh64x64 (And64 (Rsh(64|64U)x64 <t> x (Const64 <t2> [c])) (Const64 [d])) (Const64 [e])) && c < e =>  (And64 (Lsh64x64 <t> x (Const64 <t2> [e-c])) (Const64 <t> [d<<e]))
   532  (Lsh32x64 (And32 (Rsh(32|32U)x64 <t> x (Const64 <t2> [c])) (Const32 [d])) (Const64 [e])) && c < e =>  (And32 (Lsh32x64 <t> x (Const64 <t2> [e-c])) (Const32 <t> [d<<e]))
   533  (Lsh16x64 (And16 (Rsh(16|16U)x64 <t> x (Const64 <t2> [c])) (Const16 [d])) (Const64 [e])) && c < e =>  (And16 (Lsh16x64 <t> x (Const64 <t2> [e-c])) (Const16 <t> [d<<e]))
   534  (Lsh8x64  (And8  (Rsh(8|8U)x64   <t> x (Const64 <t2> [c])) (Const8  [d])) (Const64 [e])) && c < e =>  (And8  (Lsh8x64  <t> x (Const64 <t2> [e-c])) (Const8  <t> [d<<e]))
   535  
   536  // constant comparisons
   537  (Eq(64|32|16|8)   (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c == d])
   538  (Neq(64|32|16|8)  (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c != d])
   539  (Less(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c < d])
   540  (Leq(64|32|16|8)  (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c <= d])
   541  
   542  (Less64U (Const64 [c]) (Const64 [d])) => (ConstBool [uint64(c) < uint64(d)])
   543  (Less32U (Const32 [c]) (Const32 [d])) => (ConstBool [uint32(c) < uint32(d)])
   544  (Less16U (Const16 [c]) (Const16 [d])) => (ConstBool [uint16(c) < uint16(d)])
   545  (Less8U  (Const8  [c]) (Const8  [d])) => (ConstBool [ uint8(c) <  uint8(d)])
   546  
   547  (Leq64U (Const64 [c]) (Const64 [d])) => (ConstBool [uint64(c) <= uint64(d)])
   548  (Leq32U (Const32 [c]) (Const32 [d])) => (ConstBool [uint32(c) <= uint32(d)])
   549  (Leq16U (Const16 [c]) (Const16 [d])) => (ConstBool [uint16(c) <= uint16(d)])
   550  (Leq8U  (Const8  [c]) (Const8  [d])) => (ConstBool [ uint8(c) <=  uint8(d)])
   551  
   552  (Leq8  (Const8  [0]) (And8  _ (Const8  [c]))) && c >= 0 => (ConstBool [true])
   553  (Leq16 (Const16 [0]) (And16 _ (Const16 [c]))) && c >= 0 => (ConstBool [true])
   554  (Leq32 (Const32 [0]) (And32 _ (Const32 [c]))) && c >= 0 => (ConstBool [true])
   555  (Leq64 (Const64 [0]) (And64 _ (Const64 [c]))) && c >= 0 => (ConstBool [true])
   556  
   557  (Leq8  (Const8  [0]) (Rsh8Ux64  _ (Const64 [c]))) && c > 0 => (ConstBool [true])
   558  (Leq16 (Const16 [0]) (Rsh16Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true])
   559  (Leq32 (Const32 [0]) (Rsh32Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true])
   560  (Leq64 (Const64 [0]) (Rsh64Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true])
   561  
   562  // prefer equalities with zero
   563  (Less(64|32|16|8) (Const(64|32|16|8) <t> [0]) x) && isNonNegative(x) => (Neq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x)
   564  (Less(64|32|16|8) x (Const(64|32|16|8) <t> [1])) && isNonNegative(x) => (Eq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x)
   565  (Less(64|32|16|8)U x (Const(64|32|16|8) <t> [1])) => (Eq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x)
   566  (Leq(64|32|16|8)U (Const(64|32|16|8) <t> [1]) x) => (Neq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x)
   567  
   568  // prefer comparisons with zero
   569  (Less(64|32|16|8) x (Const(64|32|16|8) <t> [1])) => (Leq(64|32|16|8) x (Const(64|32|16|8) <t> [0]))
   570  (Leq(64|32|16|8) x (Const(64|32|16|8) <t> [-1])) => (Less(64|32|16|8) x (Const(64|32|16|8) <t> [0]))
   571  (Leq(64|32|16|8) (Const(64|32|16|8) <t> [1]) x) => (Less(64|32|16|8) (Const(64|32|16|8) <t> [0]) x)
   572  (Less(64|32|16|8) (Const(64|32|16|8) <t> [-1]) x) => (Leq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x)
   573  
   574  // constant floating point comparisons
   575  (Eq32F   (Const32F [c]) (Const32F [d])) => (ConstBool [c == d])
   576  (Eq64F   (Const64F [c]) (Const64F [d])) => (ConstBool [c == d])
   577  (Neq32F  (Const32F [c]) (Const32F [d])) => (ConstBool [c != d])
   578  (Neq64F  (Const64F [c]) (Const64F [d])) => (ConstBool [c != d])
   579  (Less32F (Const32F [c]) (Const32F [d])) => (ConstBool [c < d])
   580  (Less64F (Const64F [c]) (Const64F [d])) => (ConstBool [c < d])
   581  (Leq32F  (Const32F [c]) (Const32F [d])) => (ConstBool [c <= d])
   582  (Leq64F  (Const64F [c]) (Const64F [d])) => (ConstBool [c <= d])
   583  
   584  // simplifications
   585  (Or(64|32|16|8) x x) => x
   586  (Or(64|32|16|8) (Const(64|32|16|8)  [0]) x) => x
   587  (Or(64|32|16|8) (Const(64|32|16|8) [-1]) _) => (Const(64|32|16|8) [-1])
   588  (Or(64|32|16|8) (Com(64|32|16|8)     x)  x) => (Const(64|32|16|8) [-1])
   589  
   590  (And(64|32|16|8) x x) => x
   591  (And(64|32|16|8) (Const(64|32|16|8) [-1]) x) => x
   592  (And(64|32|16|8) (Const(64|32|16|8)  [0]) _) => (Const(64|32|16|8) [0])
   593  (And(64|32|16|8) (Com(64|32|16|8)     x)  x) => (Const(64|32|16|8) [0])
   594  
   595  (Xor(64|32|16|8) x x) => (Const(64|32|16|8) [0])
   596  (Xor(64|32|16|8) (Const(64|32|16|8) [0]) x) => x
   597  (Xor(64|32|16|8) (Com(64|32|16|8)    x)  x) => (Const(64|32|16|8) [-1])
   598  
   599  (Add(64|32|16|8) (Const(64|32|16|8) [0]) x) => x
   600  (Sub(64|32|16|8) x x) => (Const(64|32|16|8) [0])
   601  (Mul(64|32|16|8) (Const(64|32|16|8) [0]) _) => (Const(64|32|16|8) [0])
   602  (Mul(64|32)uover <t> (Const(64|32) [0]) x) => (MakeTuple (Const(64|32) <t.FieldType(0)> [0]) (ConstBool <t.FieldType(1)> [false]))
   603  
   604  (Com(64|32|16|8) (Com(64|32|16|8)  x)) => x
   605  (Com(64|32|16|8) (Const(64|32|16|8) [c])) => (Const(64|32|16|8) [^c])
   606  
   607  (Neg(64|32|16|8) (Sub(64|32|16|8) x y)) => (Sub(64|32|16|8) y x)
   608  (Add(64|32|16|8) x (Neg(64|32|16|8) y)) => (Sub(64|32|16|8) x y)
   609  
   610  (Xor(64|32|16|8) (Const(64|32|16|8) [-1]) x) => (Com(64|32|16|8) x)
   611  
   612  (Sub(64|32|16|8) (Neg(64|32|16|8) x) (Com(64|32|16|8) x)) => (Const(64|32|16|8) [1])
   613  (Sub(64|32|16|8) (Com(64|32|16|8) x) (Neg(64|32|16|8) x)) => (Const(64|32|16|8) [-1])
   614  (Add(64|32|16|8) (Com(64|32|16|8) x)                  x)  => (Const(64|32|16|8) [-1])
   615  
   616  // Simplification when involving common integer
   617  // (t + x) - (t + y) == x - y
   618  // (t + x) - (y + t) == x - y
   619  // (x + t) - (y + t) == x - y
   620  // (x + t) - (t + y) == x - y
   621  // (x - t) + (t + y) == x + y
   622  // (x - t) + (y + t) == x + y
   623  (Sub(64|32|16|8) (Add(64|32|16|8) t x) (Add(64|32|16|8) t y)) => (Sub(64|32|16|8) x y)
   624  (Add(64|32|16|8) (Sub(64|32|16|8) x t) (Add(64|32|16|8) t y)) => (Add(64|32|16|8) x y)
   625  
   626  // ^(x-1) == ^x+1 == -x
   627  (Add(64|32|16|8) (Const(64|32|16|8) [1]) (Com(64|32|16|8) x)) => (Neg(64|32|16|8) x)
   628  (Com(64|32|16|8) (Add(64|32|16|8) (Const(64|32|16|8) [-1]) x)) => (Neg(64|32|16|8) x)
   629  
   630  // -(-x) == x
   631  (Neg(64|32|16|8) (Neg(64|32|16|8) x)) => x
   632  
   633  // -^x == x+1
   634  (Neg(64|32|16|8) <t> (Com(64|32|16|8) x)) => (Add(64|32|16|8) (Const(64|32|16|8) <t> [1]) x)
   635  
   636  (And(64|32|16|8) x (And(64|32|16|8) x y)) => (And(64|32|16|8) x y)
   637  (Or(64|32|16|8) x (Or(64|32|16|8) x y)) => (Or(64|32|16|8) x y)
   638  (Xor(64|32|16|8) x (Xor(64|32|16|8) x y)) => y
   639  
   640  // Fold comparisons with numeric bounds
   641  (Less(64|32|16|8)U _ (Const(64|32|16|8) [0]))  => (ConstBool [false])
   642  (Leq(64|32|16|8)U (Const(64|32|16|8) [0]) _)   => (ConstBool [true])
   643  (Less(64|32|16|8)U (Const(64|32|16|8) [-1]) _) => (ConstBool [false])
   644  (Leq(64|32|16|8)U _ (Const(64|32|16|8) [-1]))  => (ConstBool [true])
   645  (Less64 _ (Const64 [math.MinInt64])) => (ConstBool [false])
   646  (Less32 _ (Const32 [math.MinInt32])) => (ConstBool [false])
   647  (Less16 _ (Const16 [math.MinInt16])) => (ConstBool [false])
   648  (Less8  _ (Const8  [math.MinInt8 ])) => (ConstBool [false])
   649  (Leq64 (Const64 [math.MinInt64]) _)  => (ConstBool [true])
   650  (Leq32 (Const32 [math.MinInt32]) _)  => (ConstBool [true])
   651  (Leq16 (Const16 [math.MinInt16]) _)  => (ConstBool [true])
   652  (Leq8  (Const8  [math.MinInt8 ]) _)  => (ConstBool [true])
   653  (Less64 (Const64 [math.MaxInt64]) _) => (ConstBool [false])
   654  (Less32 (Const32 [math.MaxInt32]) _) => (ConstBool [false])
   655  (Less16 (Const16 [math.MaxInt16]) _) => (ConstBool [false])
   656  (Less8  (Const8  [math.MaxInt8 ]) _) => (ConstBool [false])
   657  (Leq64 _ (Const64 [math.MaxInt64]))  => (ConstBool [true])
   658  (Leq32 _ (Const32 [math.MaxInt32]))  => (ConstBool [true])
   659  (Leq16 _ (Const16 [math.MaxInt16]))  => (ConstBool [true])
   660  (Leq8  _ (Const8  [math.MaxInt8 ]))  => (ConstBool [true])
   661  
   662  // Canonicalize <= on numeric bounds and < near numeric bounds to ==
   663  (Leq(64|32|16|8)U x c:(Const(64|32|16|8) [0]))     => (Eq(64|32|16|8) x c)
   664  (Leq(64|32|16|8)U c:(Const(64|32|16|8) [-1]) x)    => (Eq(64|32|16|8) x c)
   665  (Less(64|32|16|8)U x (Const(64|32|16|8) <t> [1]))  => (Eq(64|32|16|8) x (Const(64|32|16|8) <t> [0]))
   666  (Less(64|32|16|8)U (Const(64|32|16|8) <t> [-2]) x) => (Eq(64|32|16|8) x (Const(64|32|16|8) <t> [-1]))
   667  (Leq64 x c:(Const64 [math.MinInt64])) => (Eq64 x c)
   668  (Leq32 x c:(Const32 [math.MinInt32])) => (Eq32 x c)
   669  (Leq16 x c:(Const16 [math.MinInt16])) => (Eq16 x c)
   670  (Leq8  x c:(Const8  [math.MinInt8 ])) => (Eq8  x c)
   671  (Leq64 c:(Const64 [math.MaxInt64]) x) => (Eq64 x c)
   672  (Leq32 c:(Const32 [math.MaxInt32]) x) => (Eq32 x c)
   673  (Leq16 c:(Const16 [math.MaxInt16]) x) => (Eq16 x c)
   674  (Leq8  c:(Const8  [math.MaxInt8 ]) x) => (Eq8  x c)
   675  (Less64 x (Const64 <t> [math.MinInt64+1])) => (Eq64 x (Const64 <t> [math.MinInt64]))
   676  (Less32 x (Const32 <t> [math.MinInt32+1])) => (Eq32 x (Const32 <t> [math.MinInt32]))
   677  (Less16 x (Const16 <t> [math.MinInt16+1])) => (Eq16 x (Const16 <t> [math.MinInt16]))
   678  (Less8  x (Const8  <t> [math.MinInt8 +1])) => (Eq8  x (Const8  <t> [math.MinInt8 ]))
   679  (Less64 (Const64 <t> [math.MaxInt64-1]) x) => (Eq64 x (Const64 <t> [math.MaxInt64]))
   680  (Less32 (Const32 <t> [math.MaxInt32-1]) x) => (Eq32 x (Const32 <t> [math.MaxInt32]))
   681  (Less16 (Const16 <t> [math.MaxInt16-1]) x) => (Eq16 x (Const16 <t> [math.MaxInt16]))
   682  (Less8  (Const8  <t> [math.MaxInt8 -1]) x) => (Eq8  x (Const8  <t> [math.MaxInt8 ]))
   683  
   684  // Ands clear bits. Ors set bits.
   685  // If a subsequent Or will set all the bits
   686  // that an And cleared, we can skip the And.
   687  // This happens in bitmasking code like:
   688  //   x &^= 3 << shift // clear two old bits
   689  //   x  |= v << shift // set two new bits
   690  // when shift is a small constant and v ends up a constant 3.
   691  (Or8  (And8  x (Const8  [c2])) (Const8  <t> [c1])) && ^(c1 | c2) == 0 => (Or8  (Const8  <t> [c1]) x)
   692  (Or16 (And16 x (Const16 [c2])) (Const16 <t> [c1])) && ^(c1 | c2) == 0 => (Or16 (Const16 <t> [c1]) x)
   693  (Or32 (And32 x (Const32 [c2])) (Const32 <t> [c1])) && ^(c1 | c2) == 0 => (Or32 (Const32 <t> [c1]) x)
   694  (Or64 (And64 x (Const64 [c2])) (Const64 <t> [c1])) && ^(c1 | c2) == 0 => (Or64 (Const64 <t> [c1]) x)
   695  
   696  (Trunc64to8  (And64 (Const64 [y]) x)) && y&0xFF == 0xFF => (Trunc64to8 x)
   697  (Trunc64to16 (And64 (Const64 [y]) x)) && y&0xFFFF == 0xFFFF => (Trunc64to16 x)
   698  (Trunc64to32 (And64 (Const64 [y]) x)) && y&0xFFFFFFFF == 0xFFFFFFFF => (Trunc64to32 x)
   699  (Trunc32to8  (And32 (Const32 [y]) x)) && y&0xFF == 0xFF => (Trunc32to8 x)
   700  (Trunc32to16 (And32 (Const32 [y]) x)) && y&0xFFFF == 0xFFFF => (Trunc32to16 x)
   701  (Trunc16to8  (And16 (Const16 [y]) x)) && y&0xFF == 0xFF => (Trunc16to8 x)
   702  
   703  (ZeroExt8to64  (Trunc64to8  x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 56 => x
   704  (ZeroExt16to64 (Trunc64to16 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 48 => x
   705  (ZeroExt32to64 (Trunc64to32 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 32 => x
   706  (ZeroExt8to32  (Trunc32to8  x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 24 => x
   707  (ZeroExt16to32 (Trunc32to16 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 16 => x
   708  (ZeroExt8to16  (Trunc16to8  x:(Rsh16Ux64 _ (Const64 [s])))) && s >= 8 => x
   709  
   710  (SignExt8to64  (Trunc64to8  x:(Rsh64x64 _ (Const64 [s])))) && s >= 56 => x
   711  (SignExt16to64 (Trunc64to16 x:(Rsh64x64 _ (Const64 [s])))) && s >= 48 => x
   712  (SignExt32to64 (Trunc64to32 x:(Rsh64x64 _ (Const64 [s])))) && s >= 32 => x
   713  (SignExt8to32  (Trunc32to8  x:(Rsh32x64 _ (Const64 [s])))) && s >= 24 => x
   714  (SignExt16to32 (Trunc32to16 x:(Rsh32x64 _ (Const64 [s])))) && s >= 16 => x
   715  (SignExt8to16  (Trunc16to8  x:(Rsh16x64 _ (Const64 [s])))) && s >= 8 => x
   716  
   717  (Slicemask (Const32 [x])) && x > 0 => (Const32 [-1])
   718  (Slicemask (Const32 [0]))          => (Const32 [0])
   719  (Slicemask (Const64 [x])) && x > 0 => (Const64 [-1])
   720  (Slicemask (Const64 [0]))          => (Const64 [0])
   721  
   722  // simplifications often used for lengths.  e.g. len(s[i:i+5])==5
   723  (Sub(64|32|16|8) (Add(64|32|16|8) x y) x) => y
   724  (Sub(64|32|16|8) (Add(64|32|16|8) x y) y) => x
   725  (Sub(64|32|16|8) (Sub(64|32|16|8) x y) x) => (Neg(64|32|16|8) y)
   726  (Sub(64|32|16|8) x (Add(64|32|16|8) x y)) => (Neg(64|32|16|8) y)
   727  (Add(64|32|16|8) x (Sub(64|32|16|8) y x)) => y
   728  (Add(64|32|16|8) x (Add(64|32|16|8) y (Sub(64|32|16|8) z x))) => (Add(64|32|16|8) y z)
   729  
   730  // basic phi simplifications
   731  (Phi (Const8  [c]) (Const8  [c])) => (Const8  [c])
   732  (Phi (Const16 [c]) (Const16 [c])) => (Const16 [c])
   733  (Phi (Const32 [c]) (Const32 [c])) => (Const32 [c])
   734  (Phi (Const64 [c]) (Const64 [c])) => (Const64 [c])
   735  
   736  // slice and interface comparisons
   737  // The frontend ensures that we can only compare against nil,
   738  // so we need only compare the first word (interface type or slice ptr).
   739  (EqInter x y)  => (EqPtr  (ITab x) (ITab y))
   740  (NeqInter x y) => (NeqPtr (ITab x) (ITab y))
   741  (EqSlice x y)  => (EqPtr  (SlicePtr x) (SlicePtr y))
   742  (NeqSlice x y) => (NeqPtr (SlicePtr x) (SlicePtr y))
   743  
   744  // Load of store of same address, with compatibly typed value and same size
   745  (Load <t1> p1 (Store {t2} p2 x _))
   746  	&& isSamePtr(p1, p2)
   747  	&& copyCompatibleType(t1, x.Type)
   748  	&& t1.Size() == t2.Size()
   749  	=> x
   750  (Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 x _)))
   751  	&& isSamePtr(p1, p3)
   752  	&& copyCompatibleType(t1, x.Type)
   753  	&& t1.Size() == t3.Size()
   754  	&& disjoint(p3, t3.Size(), p2, t2.Size())
   755  	=> x
   756  (Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 x _))))
   757  	&& isSamePtr(p1, p4)
   758  	&& copyCompatibleType(t1, x.Type)
   759  	&& t1.Size() == t4.Size()
   760  	&& disjoint(p4, t4.Size(), p2, t2.Size())
   761  	&& disjoint(p4, t4.Size(), p3, t3.Size())
   762  	=> x
   763  (Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 _ (Store {t5} p5 x _)))))
   764  	&& isSamePtr(p1, p5)
   765  	&& copyCompatibleType(t1, x.Type)
   766  	&& t1.Size() == t5.Size()
   767  	&& disjoint(p5, t5.Size(), p2, t2.Size())
   768  	&& disjoint(p5, t5.Size(), p3, t3.Size())
   769  	&& disjoint(p5, t5.Size(), p4, t4.Size())
   770  	=> x
   771  
   772  // Pass constants through math.Float{32,64}bits and math.Float{32,64}frombits
   773  (Load <t1> p1 (Store {t2} p2 (Const64  [x]) _)) && isSamePtr(p1,p2) && t2.Size() == 8 && is64BitFloat(t1) && !math.IsNaN(math.Float64frombits(uint64(x))) => (Const64F [math.Float64frombits(uint64(x))])
   774  (Load <t1> p1 (Store {t2} p2 (Const32  [x]) _)) && isSamePtr(p1,p2) && t2.Size() == 4 && is32BitFloat(t1) && !math.IsNaN(float64(math.Float32frombits(uint32(x)))) => (Const32F [math.Float32frombits(uint32(x))])
   775  (Load <t1> p1 (Store {t2} p2 (Const64F [x]) _)) && isSamePtr(p1,p2) && t2.Size() == 8 && is64BitInt(t1)   => (Const64  [int64(math.Float64bits(x))])
   776  (Load <t1> p1 (Store {t2} p2 (Const32F [x]) _)) && isSamePtr(p1,p2) && t2.Size() == 4 && is32BitInt(t1)   => (Const32  [int32(math.Float32bits(x))])
   777  
   778  // Float Loads up to Zeros so they can be constant folded.
   779  (Load <t1> op:(OffPtr [o1] p1)
   780  	(Store {t2} p2 _
   781  		mem:(Zero [n] p3 _)))
   782  	&& o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p3)
   783  	&& CanSSA(t1)
   784  	&& disjoint(op, t1.Size(), p2, t2.Size())
   785  	=> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p3) mem)
   786  (Load <t1> op:(OffPtr [o1] p1)
   787  	(Store {t2} p2 _
   788  		(Store {t3} p3 _
   789  			mem:(Zero [n] p4 _))))
   790  	&& o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p4)
   791  	&& CanSSA(t1)
   792  	&& disjoint(op, t1.Size(), p2, t2.Size())
   793  	&& disjoint(op, t1.Size(), p3, t3.Size())
   794  	=> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p4) mem)
   795  (Load <t1> op:(OffPtr [o1] p1)
   796  	(Store {t2} p2 _
   797  		(Store {t3} p3 _
   798  			(Store {t4} p4 _
   799  				mem:(Zero [n] p5 _)))))
   800  	&& o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p5)
   801  	&& CanSSA(t1)
   802  	&& disjoint(op, t1.Size(), p2, t2.Size())
   803  	&& disjoint(op, t1.Size(), p3, t3.Size())
   804  	&& disjoint(op, t1.Size(), p4, t4.Size())
   805  	=> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p5) mem)
   806  (Load <t1> op:(OffPtr [o1] p1)
   807  	(Store {t2} p2 _
   808  		(Store {t3} p3 _
   809  			(Store {t4} p4 _
   810  				(Store {t5} p5 _
   811  					mem:(Zero [n] p6 _))))))
   812  	&& o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p6)
   813  	&& CanSSA(t1)
   814  	&& disjoint(op, t1.Size(), p2, t2.Size())
   815  	&& disjoint(op, t1.Size(), p3, t3.Size())
   816  	&& disjoint(op, t1.Size(), p4, t4.Size())
   817  	&& disjoint(op, t1.Size(), p5, t5.Size())
   818  	=> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p6) mem)
   819  
   820  // Zero to Load forwarding.
   821  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   822  	&& t1.IsBoolean()
   823  	&& isSamePtr(p1, p2)
   824  	&& n >= o + 1
   825  	=> (ConstBool [false])
   826  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   827  	&& is8BitInt(t1)
   828  	&& isSamePtr(p1, p2)
   829  	&& n >= o + 1
   830  	=> (Const8 [0])
   831  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   832  	&& is16BitInt(t1)
   833  	&& isSamePtr(p1, p2)
   834  	&& n >= o + 2
   835  	=> (Const16 [0])
   836  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   837  	&& is32BitInt(t1)
   838  	&& isSamePtr(p1, p2)
   839  	&& n >= o + 4
   840  	=> (Const32 [0])
   841  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   842  	&& is64BitInt(t1)
   843  	&& isSamePtr(p1, p2)
   844  	&& n >= o + 8
   845  	=> (Const64 [0])
   846  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   847  	&& is32BitFloat(t1)
   848  	&& isSamePtr(p1, p2)
   849  	&& n >= o + 4
   850  	=> (Const32F [0])
   851  (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _))
   852  	&& is64BitFloat(t1)
   853  	&& isSamePtr(p1, p2)
   854  	&& n >= o + 8
   855  	=> (Const64F [0])
   856  
   857  // Eliminate stores of values that have just been loaded from the same location.
   858  // We also handle the common case where there are some intermediate stores.
   859  (Store {t1} p1 (Load <t2> p2 mem) mem)
   860  	&& isSamePtr(p1, p2)
   861  	&& t2.Size() == t1.Size()
   862  	=> mem
   863  (Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ oldmem))
   864  	&& isSamePtr(p1, p2)
   865  	&& t2.Size() == t1.Size()
   866  	&& disjoint(p1, t1.Size(), p3, t3.Size())
   867  	=> mem
   868  (Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ (Store {t4} p4 _ oldmem)))
   869  	&& isSamePtr(p1, p2)
   870  	&& t2.Size() == t1.Size()
   871  	&& disjoint(p1, t1.Size(), p3, t3.Size())
   872  	&& disjoint(p1, t1.Size(), p4, t4.Size())
   873  	=> mem
   874  (Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ (Store {t4} p4 _ (Store {t5} p5 _ oldmem))))
   875  	&& isSamePtr(p1, p2)
   876  	&& t2.Size() == t1.Size()
   877  	&& disjoint(p1, t1.Size(), p3, t3.Size())
   878  	&& disjoint(p1, t1.Size(), p4, t4.Size())
   879  	&& disjoint(p1, t1.Size(), p5, t5.Size())
   880  	=> mem
   881  
   882  // Don't Store zeros to cleared variables.
   883  (Store {t} (OffPtr [o] p1) x mem:(Zero [n] p2 _))
   884  	&& isConstZero(x)
   885  	&& o >= 0 && t.Size() + o <= n && isSamePtr(p1, p2)
   886  	=> mem
   887  (Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Zero [n] p3 _)))
   888  	&& isConstZero(x)
   889  	&& o1 >= 0 && t1.Size() + o1 <= n && isSamePtr(p1, p3)
   890  	&& disjoint(op, t1.Size(), p2, t2.Size())
   891  	=> mem
   892  (Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Store {t3} p3 _ (Zero [n] p4 _))))
   893  	&& isConstZero(x)
   894  	&& o1 >= 0 && t1.Size() + o1 <= n && isSamePtr(p1, p4)
   895  	&& disjoint(op, t1.Size(), p2, t2.Size())
   896  	&& disjoint(op, t1.Size(), p3, t3.Size())
   897  	=> mem
   898  (Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 _ (Zero [n] p5 _)))))
   899  	&& isConstZero(x)
   900  	&& o1 >= 0 && t1.Size() + o1 <= n && isSamePtr(p1, p5)
   901  	&& disjoint(op, t1.Size(), p2, t2.Size())
   902  	&& disjoint(op, t1.Size(), p3, t3.Size())
   903  	&& disjoint(op, t1.Size(), p4, t4.Size())
   904  	=> mem
   905  
   906  // Collapse OffPtr
   907  (OffPtr (OffPtr p [y]) [x]) => (OffPtr p [x+y])
   908  (OffPtr p [0]) && v.Type.Compare(p.Type) == types.CMPeq => p
   909  
   910  // indexing operations
   911  // Note: bounds check has already been done
   912  (PtrIndex <t> ptr idx) && config.PtrSize == 4 && is32Bit(t.Elem().Size()) => (AddPtr ptr (Mul32 <typ.Int> idx (Const32 <typ.Int> [int32(t.Elem().Size())])))
   913  (PtrIndex <t> ptr idx) && config.PtrSize == 8 => (AddPtr ptr (Mul64 <typ.Int> idx (Const64 <typ.Int> [t.Elem().Size()])))
   914  
   915  // struct operations
   916  (StructSelect [i] x:(StructMake ___)) => x.Args[i]
   917  (Load <t> _ _) && t.IsStruct() && CanSSA(t) => rewriteStructLoad(v)
   918  (Store _ (StructMake ___) _) => rewriteStructStore(v)
   919  
   920  (StructSelect [i] x:(Load <t> ptr mem)) && !CanSSA(t) =>
   921    @x.Block (Load <v.Type> (OffPtr <v.Type.PtrTo()> [t.FieldOff(int(i))] ptr) mem)
   922  
   923  // Putting struct{*byte} and similar into direct interfaces.
   924  (IMake _typ (StructMake ___)) => imakeOfStructMake(v)
   925  (StructSelect [_] (IData x)) => (IData x)
   926  
   927  // un-SSAable values use mem->mem copies
   928  (Store {t} dst (Load src mem) mem) && !CanSSA(t) =>
   929  	(Move {t} [t.Size()] dst src mem)
   930  (Store {t} dst (Load src mem) (VarDef {x} mem)) && !CanSSA(t) =>
   931  	(Move {t} [t.Size()] dst src (VarDef {x} mem))
   932  
   933  // array ops
   934  (ArraySelect (ArrayMake1 x)) => x
   935  
   936  (Load <t> _ _) && t.IsArray() && t.NumElem() == 0 =>
   937    (ArrayMake0)
   938  
   939  (Load <t> ptr mem) && t.IsArray() && t.NumElem() == 1 && CanSSA(t) =>
   940    (ArrayMake1 (Load <t.Elem()> ptr mem))
   941  
   942  (Store _ (ArrayMake0) mem) => mem
   943  (Store dst (ArrayMake1 e) mem) => (Store {e.Type} dst e mem)
   944  
   945  // Putting [1]*byte and similar into direct interfaces.
   946  (IMake _typ (ArrayMake1 val)) => (IMake _typ val)
   947  (ArraySelect [0] (IData x)) => (IData x)
   948  
   949  // string ops
   950  // Decomposing StringMake and lowering of StringPtr and StringLen
   951  // happens in a later pass, dec, so that these operations are available
   952  // to other passes for optimizations.
   953  (StringPtr (StringMake (Addr <t> {s} base) _)) => (Addr <t> {s} base)
   954  (StringLen (StringMake _ (Const64 <t> [c]))) => (Const64 <t> [c])
   955  (ConstString {str}) && config.PtrSize == 4 && str == "" =>
   956    (StringMake (ConstNil) (Const32 <typ.Int> [0]))
   957  (ConstString {str}) && config.PtrSize == 8 && str == "" =>
   958    (StringMake (ConstNil) (Const64 <typ.Int> [0]))
   959  (ConstString {str}) && config.PtrSize == 4 && str != "" =>
   960    (StringMake
   961      (Addr <typ.BytePtr> {fe.StringData(str)}
   962        (SB))
   963      (Const32 <typ.Int> [int32(len(str))]))
   964  (ConstString {str}) && config.PtrSize == 8 && str != "" =>
   965    (StringMake
   966      (Addr <typ.BytePtr> {fe.StringData(str)}
   967        (SB))
   968      (Const64 <typ.Int> [int64(len(str))]))
   969  
   970  // slice ops
   971  // Only a few slice rules are provided here.  See dec.rules for
   972  // a more comprehensive set.
   973  (SliceLen (SliceMake _ (Const64 <t> [c]) _)) => (Const64 <t> [c])
   974  (SliceCap (SliceMake _ _ (Const64 <t> [c]))) => (Const64 <t> [c])
   975  (SliceLen (SliceMake _ (Const32 <t> [c]) _)) => (Const32 <t> [c])
   976  (SliceCap (SliceMake _ _ (Const32 <t> [c]))) => (Const32 <t> [c])
   977  (SlicePtr (SliceMake (SlicePtr x) _ _)) => (SlicePtr x)
   978  (SliceLen (SliceMake _ (SliceLen x) _)) => (SliceLen x)
   979  (SliceCap (SliceMake _ _ (SliceCap x))) => (SliceCap x)
   980  (SliceCap (SliceMake _ _ (SliceLen x))) => (SliceLen x)
   981  (ConstSlice) && config.PtrSize == 4 =>
   982    (SliceMake
   983      (ConstNil <v.Type.Elem().PtrTo()>)
   984      (Const32 <typ.Int> [0])
   985      (Const32 <typ.Int> [0]))
   986  (ConstSlice) && config.PtrSize == 8 =>
   987    (SliceMake
   988      (ConstNil <v.Type.Elem().PtrTo()>)
   989      (Const64 <typ.Int> [0])
   990      (Const64 <typ.Int> [0]))
   991  
   992  // interface ops
   993  (ConstInterface) =>
   994    (IMake
   995      (ConstNil <typ.Uintptr>)
   996      (ConstNil <typ.BytePtr>))
   997  
   998  (NilCheck ptr:(GetG mem) mem) => ptr
   999  
  1000  (If (Not cond) yes no) => (If cond no yes)
  1001  (If (ConstBool [c]) yes no) && c => (First yes no)
  1002  (If (ConstBool [c]) yes no) && !c => (First no yes)
  1003  
  1004  (Phi <t> nx:(Not x) ny:(Not y)) && nx.Uses == 1 && ny.Uses == 1 => (Not (Phi <t> x y))
  1005  
  1006  // Get rid of Convert ops for pointer arithmetic on unsafe.Pointer.
  1007  (Convert (Add(64|32) (Convert ptr mem) off) mem) => (AddPtr ptr off)
  1008  (Convert (Convert ptr mem) mem) => ptr
  1009  // Note: it is important that the target rewrite is ptr+(off1+off2), not (ptr+off1)+off2.
  1010  // We must ensure that no intermediate computations are invalid pointers.
  1011  (Convert a:(Add(64|32) (Add(64|32) (Convert ptr mem) off1) off2) mem) => (AddPtr ptr (Add(64|32) <a.Type> off1 off2))
  1012  
  1013  // strength reduction of divide by a constant.
  1014  // See ../magic.go for a detailed description of these algorithms.
  1015  
  1016  // Unsigned divide by power of 2.  Strength reduce to a shift.
  1017  (Div8u  n (Const8  [c])) && isUnsignedPowerOfTwo(uint8(c)) => (Rsh8Ux64  n (Const64 <typ.UInt64> [log8u(uint8(c))]))
  1018  (Div16u n (Const16 [c])) && isUnsignedPowerOfTwo(uint16(c)) => (Rsh16Ux64 n (Const64 <typ.UInt64> [log16u(uint16(c))]))
  1019  (Div32u n (Const32 [c])) && isUnsignedPowerOfTwo(uint32(c)) => (Rsh32Ux64 n (Const64 <typ.UInt64> [log32u(uint32(c))]))
  1020  (Div64u n (Const64 [c])) && isUnsignedPowerOfTwo(uint64(c)) => (Rsh64Ux64 n (Const64 <typ.UInt64> [log64u(uint64(c))]))
  1021  
  1022  // Signed non-negative divide by power of 2.
  1023  (Div8  n (Const8  [c])) && isNonNegative(n) && isPowerOfTwo(c) => (Rsh8Ux64  n (Const64 <typ.UInt64> [log8(c)]))
  1024  (Div16 n (Const16 [c])) && isNonNegative(n) && isPowerOfTwo(c) => (Rsh16Ux64 n (Const64 <typ.UInt64> [log16(c)]))
  1025  (Div32 n (Const32 [c])) && isNonNegative(n) && isPowerOfTwo(c) => (Rsh32Ux64 n (Const64 <typ.UInt64> [log32(c)]))
  1026  (Div64 n (Const64 [c])) && isNonNegative(n) && isPowerOfTwo(c) => (Rsh64Ux64 n (Const64 <typ.UInt64> [log64(c)]))
  1027  (Div64 n (Const64 [-1<<63])) && isNonNegative(n)                 => (Const64 [0])
  1028  
  1029  // Unsigned divide, not a power of 2.  Strength reduce to a multiply.
  1030  // For 8-bit divides, we just do a direct 9-bit by 8-bit multiply.
  1031  (Div8u x (Const8 [c])) && umagicOK8(c) =>
  1032    (Trunc32to8
  1033      (Rsh32Ux64 <typ.UInt32>
  1034        (Mul32 <typ.UInt32>
  1035          (Const32 <typ.UInt32> [int32(1<<8+umagic8(c).m)])
  1036          (ZeroExt8to32 x))
  1037        (Const64 <typ.UInt64> [8+umagic8(c).s])))
  1038  
  1039  // For 16-bit divides on 64-bit machines, we do a direct 17-bit by 16-bit multiply.
  1040  (Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 8 =>
  1041    (Trunc64to16
  1042      (Rsh64Ux64 <typ.UInt64>
  1043        (Mul64 <typ.UInt64>
  1044          (Const64 <typ.UInt64> [int64(1<<16+umagic16(c).m)])
  1045          (ZeroExt16to64 x))
  1046        (Const64 <typ.UInt64> [16+umagic16(c).s])))
  1047  
  1048  // For 16-bit divides on 32-bit machines
  1049  (Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 4 && umagic16(c).m&1 == 0 =>
  1050    (Trunc32to16
  1051      (Rsh32Ux64 <typ.UInt32>
  1052        (Mul32 <typ.UInt32>
  1053          (Const32 <typ.UInt32> [int32(1<<15+umagic16(c).m/2)])
  1054          (ZeroExt16to32 x))
  1055        (Const64 <typ.UInt64> [16+umagic16(c).s-1])))
  1056  (Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 4 && c&1 == 0 =>
  1057    (Trunc32to16
  1058      (Rsh32Ux64 <typ.UInt32>
  1059        (Mul32 <typ.UInt32>
  1060          (Const32 <typ.UInt32> [int32(1<<15+(umagic16(c).m+1)/2)])
  1061          (Rsh32Ux64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [1])))
  1062        (Const64 <typ.UInt64> [16+umagic16(c).s-2])))
  1063  (Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 4 && config.useAvg =>
  1064    (Trunc32to16
  1065      (Rsh32Ux64 <typ.UInt32>
  1066        (Avg32u
  1067          (Lsh32x64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [16]))
  1068          (Mul32 <typ.UInt32>
  1069            (Const32 <typ.UInt32> [int32(umagic16(c).m)])
  1070            (ZeroExt16to32 x)))
  1071        (Const64 <typ.UInt64> [16+umagic16(c).s-1])))
  1072  
  1073  // For 32-bit divides on 32-bit machines
  1074  (Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 4 && umagic32(c).m&1 == 0 && config.useHmul =>
  1075    (Rsh32Ux64 <typ.UInt32>
  1076      (Hmul32u <typ.UInt32>
  1077        (Const32 <typ.UInt32> [int32(1<<31+umagic32(c).m/2)])
  1078        x)
  1079      (Const64 <typ.UInt64> [umagic32(c).s-1]))
  1080  (Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 4 && c&1 == 0 && config.useHmul =>
  1081    (Rsh32Ux64 <typ.UInt32>
  1082      (Hmul32u <typ.UInt32>
  1083        (Const32 <typ.UInt32> [int32(1<<31+(umagic32(c).m+1)/2)])
  1084        (Rsh32Ux64 <typ.UInt32> x (Const64 <typ.UInt64> [1])))
  1085      (Const64 <typ.UInt64> [umagic32(c).s-2]))
  1086  (Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 4 && config.useAvg && config.useHmul =>
  1087    (Rsh32Ux64 <typ.UInt32>
  1088      (Avg32u
  1089        x
  1090        (Hmul32u <typ.UInt32>
  1091          (Const32 <typ.UInt32> [int32(umagic32(c).m)])
  1092          x))
  1093      (Const64 <typ.UInt64> [umagic32(c).s-1]))
  1094  
  1095  // For 32-bit divides on 64-bit machines
  1096  // We'll use a regular (non-hi) multiply for this case.
  1097  (Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 8 && umagic32(c).m&1 == 0 =>
  1098    (Trunc64to32
  1099      (Rsh64Ux64 <typ.UInt64>
  1100        (Mul64 <typ.UInt64>
  1101          (Const64 <typ.UInt64> [int64(1<<31+umagic32(c).m/2)])
  1102          (ZeroExt32to64 x))
  1103        (Const64 <typ.UInt64> [32+umagic32(c).s-1])))
  1104  (Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 8 && c&1 == 0 =>
  1105    (Trunc64to32
  1106      (Rsh64Ux64 <typ.UInt64>
  1107        (Mul64 <typ.UInt64>
  1108          (Const64 <typ.UInt64> [int64(1<<31+(umagic32(c).m+1)/2)])
  1109          (Rsh64Ux64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [1])))
  1110        (Const64 <typ.UInt64> [32+umagic32(c).s-2])))
  1111  (Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 8 && config.useAvg =>
  1112    (Trunc64to32
  1113      (Rsh64Ux64 <typ.UInt64>
  1114        (Avg64u
  1115          (Lsh64x64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [32]))
  1116          (Mul64 <typ.UInt64>
  1117            (Const64 <typ.UInt32> [int64(umagic32(c).m)])
  1118            (ZeroExt32to64 x)))
  1119        (Const64 <typ.UInt64> [32+umagic32(c).s-1])))
  1120  
  1121  // For unsigned 64-bit divides on 32-bit machines,
  1122  // if the constant fits in 16 bits (so that the last term
  1123  // fits in 32 bits), convert to three 32-bit divides by a constant.
  1124  //
  1125  // If 1<<32 = Q * c + R
  1126  // and    x = hi << 32 + lo
  1127  //
  1128  // Then x = (hi/c*c + hi%c) << 32 + lo
  1129  //        = hi/c*c<<32 + hi%c<<32 + lo
  1130  //        = hi/c*c<<32 + (hi%c)*(Q*c+R) + lo/c*c + lo%c
  1131  //        = hi/c*c<<32 + (hi%c)*Q*c + lo/c*c + (hi%c*R+lo%c)
  1132  // and x / c = (hi/c)<<32 + (hi%c)*Q + lo/c + (hi%c*R+lo%c)/c
  1133  (Div64u x (Const64 [c])) && c > 0 && c <= 0xFFFF && umagicOK32(int32(c)) && config.RegSize == 4 && config.useHmul =>
  1134    (Add64
  1135      (Add64 <typ.UInt64>
  1136        (Add64 <typ.UInt64>
  1137          (Lsh64x64 <typ.UInt64>
  1138            (ZeroExt32to64
  1139              (Div32u <typ.UInt32>
  1140                (Trunc64to32 <typ.UInt32> (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [32])))
  1141                (Const32 <typ.UInt32> [int32(c)])))
  1142            (Const64 <typ.UInt64> [32]))
  1143          (ZeroExt32to64 (Div32u <typ.UInt32> (Trunc64to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(c)]))))
  1144        (Mul64 <typ.UInt64>
  1145          (ZeroExt32to64 <typ.UInt64>
  1146            (Mod32u <typ.UInt32>
  1147              (Trunc64to32 <typ.UInt32> (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [32])))
  1148              (Const32 <typ.UInt32> [int32(c)])))
  1149          (Const64 <typ.UInt64> [int64((1<<32)/c)])))
  1150        (ZeroExt32to64
  1151          (Div32u <typ.UInt32>
  1152            (Add32 <typ.UInt32>
  1153              (Mod32u <typ.UInt32> (Trunc64to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(c)]))
  1154              (Mul32 <typ.UInt32>
  1155                (Mod32u <typ.UInt32>
  1156                  (Trunc64to32 <typ.UInt32> (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [32])))
  1157                  (Const32 <typ.UInt32> [int32(c)]))
  1158                (Const32 <typ.UInt32> [int32((1<<32)%c)])))
  1159            (Const32 <typ.UInt32> [int32(c)]))))
  1160  
  1161  // For 64-bit divides on 64-bit machines
  1162  // (64-bit divides on 32-bit machines are lowered to a runtime call by the walk pass.)
  1163  (Div64u x (Const64 [c])) && umagicOK64(c) && config.RegSize == 8 && umagic64(c).m&1 == 0 && config.useHmul =>
  1164    (Rsh64Ux64 <typ.UInt64>
  1165      (Hmul64u <typ.UInt64>
  1166        (Const64 <typ.UInt64> [int64(1<<63+umagic64(c).m/2)])
  1167        x)
  1168      (Const64 <typ.UInt64> [umagic64(c).s-1]))
  1169  (Div64u x (Const64 [c])) && umagicOK64(c) && config.RegSize == 8 && c&1 == 0 && config.useHmul =>
  1170    (Rsh64Ux64 <typ.UInt64>
  1171      (Hmul64u <typ.UInt64>
  1172        (Const64 <typ.UInt64> [int64(1<<63+(umagic64(c).m+1)/2)])
  1173        (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [1])))
  1174      (Const64 <typ.UInt64> [umagic64(c).s-2]))
  1175  (Div64u x (Const64 [c])) && umagicOK64(c) && config.RegSize == 8 && config.useAvg && config.useHmul =>
  1176    (Rsh64Ux64 <typ.UInt64>
  1177      (Avg64u
  1178        x
  1179        (Hmul64u <typ.UInt64>
  1180          (Const64 <typ.UInt64> [int64(umagic64(c).m)])
  1181          x))
  1182      (Const64 <typ.UInt64> [umagic64(c).s-1]))
  1183  
  1184  // Signed divide by a negative constant.  Rewrite to divide by a positive constant.
  1185  (Div8  <t> n (Const8  [c])) && c < 0 && c != -1<<7  => (Neg8  (Div8  <t> n (Const8  <t> [-c])))
  1186  (Div16 <t> n (Const16 [c])) && c < 0 && c != -1<<15 => (Neg16 (Div16 <t> n (Const16 <t> [-c])))
  1187  (Div32 <t> n (Const32 [c])) && c < 0 && c != -1<<31 => (Neg32 (Div32 <t> n (Const32 <t> [-c])))
  1188  (Div64 <t> n (Const64 [c])) && c < 0 && c != -1<<63 => (Neg64 (Div64 <t> n (Const64 <t> [-c])))
  1189  
  1190  // Dividing by the most-negative number.  Result is always 0 except
  1191  // if the input is also the most-negative number.
  1192  // We can detect that using the sign bit of x & -x.
  1193  (Div8  <t> x (Const8  [-1<<7 ])) => (Rsh8Ux64  (And8  <t> x (Neg8  <t> x)) (Const64 <typ.UInt64> [7 ]))
  1194  (Div16 <t> x (Const16 [-1<<15])) => (Rsh16Ux64 (And16 <t> x (Neg16 <t> x)) (Const64 <typ.UInt64> [15]))
  1195  (Div32 <t> x (Const32 [-1<<31])) => (Rsh32Ux64 (And32 <t> x (Neg32 <t> x)) (Const64 <typ.UInt64> [31]))
  1196  (Div64 <t> x (Const64 [-1<<63])) => (Rsh64Ux64 (And64 <t> x (Neg64 <t> x)) (Const64 <typ.UInt64> [63]))
  1197  
  1198  // Signed divide by power of 2.
  1199  // n / c =       n >> log(c) if n >= 0
  1200  //       = (n+c-1) >> log(c) if n < 0
  1201  // We conditionally add c-1 by adding n>>63>>(64-log(c)) (first shift signed, second shift unsigned).
  1202  (Div8  <t> n (Const8  [c])) && isPowerOfTwo(c) =>
  1203    (Rsh8x64
  1204      (Add8  <t> n (Rsh8Ux64  <t> (Rsh8x64  <t> n (Const64 <typ.UInt64> [ 7])) (Const64 <typ.UInt64> [int64( 8-log8(c))])))
  1205      (Const64 <typ.UInt64> [int64(log8(c))]))
  1206  (Div16 <t> n (Const16 [c])) && isPowerOfTwo(c) =>
  1207    (Rsh16x64
  1208      (Add16 <t> n (Rsh16Ux64 <t> (Rsh16x64 <t> n (Const64 <typ.UInt64> [15])) (Const64 <typ.UInt64> [int64(16-log16(c))])))
  1209      (Const64 <typ.UInt64> [int64(log16(c))]))
  1210  (Div32 <t> n (Const32 [c])) && isPowerOfTwo(c) =>
  1211    (Rsh32x64
  1212      (Add32 <t> n (Rsh32Ux64 <t> (Rsh32x64 <t> n (Const64 <typ.UInt64> [31])) (Const64 <typ.UInt64> [int64(32-log32(c))])))
  1213      (Const64 <typ.UInt64> [int64(log32(c))]))
  1214  (Div64 <t> n (Const64 [c])) && isPowerOfTwo(c) =>
  1215    (Rsh64x64
  1216      (Add64 <t> n (Rsh64Ux64 <t> (Rsh64x64 <t> n (Const64 <typ.UInt64> [63])) (Const64 <typ.UInt64> [int64(64-log64(c))])))
  1217      (Const64 <typ.UInt64> [int64(log64(c))]))
  1218  
  1219  // Signed divide, not a power of 2.  Strength reduce to a multiply.
  1220  (Div8 <t> x (Const8 [c])) && smagicOK8(c) =>
  1221    (Sub8 <t>
  1222      (Rsh32x64 <t>
  1223        (Mul32 <typ.UInt32>
  1224          (Const32 <typ.UInt32> [int32(smagic8(c).m)])
  1225          (SignExt8to32 x))
  1226        (Const64 <typ.UInt64> [8+smagic8(c).s]))
  1227      (Rsh32x64 <t>
  1228        (SignExt8to32 x)
  1229        (Const64 <typ.UInt64> [31])))
  1230  (Div16 <t> x (Const16 [c])) && smagicOK16(c) =>
  1231    (Sub16 <t>
  1232      (Rsh32x64 <t>
  1233        (Mul32 <typ.UInt32>
  1234          (Const32 <typ.UInt32> [int32(smagic16(c).m)])
  1235          (SignExt16to32 x))
  1236        (Const64 <typ.UInt64> [16+smagic16(c).s]))
  1237      (Rsh32x64 <t>
  1238        (SignExt16to32 x)
  1239        (Const64 <typ.UInt64> [31])))
  1240  (Div32 <t> x (Const32 [c])) && smagicOK32(c) && config.RegSize == 8 =>
  1241    (Sub32 <t>
  1242      (Rsh64x64 <t>
  1243        (Mul64 <typ.UInt64>
  1244          (Const64 <typ.UInt64> [int64(smagic32(c).m)])
  1245          (SignExt32to64 x))
  1246        (Const64 <typ.UInt64> [32+smagic32(c).s]))
  1247      (Rsh64x64 <t>
  1248        (SignExt32to64 x)
  1249        (Const64 <typ.UInt64> [63])))
  1250  (Div32 <t> x (Const32 [c])) && smagicOK32(c) && config.RegSize == 4 && smagic32(c).m&1 == 0 && config.useHmul =>
  1251    (Sub32 <t>
  1252      (Rsh32x64 <t>
  1253        (Hmul32 <t>
  1254          (Const32 <typ.UInt32> [int32(smagic32(c).m/2)])
  1255          x)
  1256        (Const64 <typ.UInt64> [smagic32(c).s-1]))
  1257      (Rsh32x64 <t>
  1258        x
  1259        (Const64 <typ.UInt64> [31])))
  1260  (Div32 <t> x (Const32 [c])) && smagicOK32(c) && config.RegSize == 4 && smagic32(c).m&1 != 0 && config.useHmul =>
  1261    (Sub32 <t>
  1262      (Rsh32x64 <t>
  1263        (Add32 <t>
  1264          (Hmul32 <t>
  1265            (Const32 <typ.UInt32> [int32(smagic32(c).m)])
  1266            x)
  1267          x)
  1268        (Const64 <typ.UInt64> [smagic32(c).s]))
  1269      (Rsh32x64 <t>
  1270        x
  1271        (Const64 <typ.UInt64> [31])))
  1272  (Div64 <t> x (Const64 [c])) && smagicOK64(c) && smagic64(c).m&1 == 0 && config.useHmul =>
  1273    (Sub64 <t>
  1274      (Rsh64x64 <t>
  1275        (Hmul64 <t>
  1276          (Const64 <typ.UInt64> [int64(smagic64(c).m/2)])
  1277          x)
  1278        (Const64 <typ.UInt64> [smagic64(c).s-1]))
  1279      (Rsh64x64 <t>
  1280        x
  1281        (Const64 <typ.UInt64> [63])))
  1282  (Div64 <t> x (Const64 [c])) && smagicOK64(c) && smagic64(c).m&1 != 0 && config.useHmul =>
  1283    (Sub64 <t>
  1284      (Rsh64x64 <t>
  1285        (Add64 <t>
  1286          (Hmul64 <t>
  1287            (Const64 <typ.UInt64> [int64(smagic64(c).m)])
  1288            x)
  1289          x)
  1290        (Const64 <typ.UInt64> [smagic64(c).s]))
  1291      (Rsh64x64 <t>
  1292        x
  1293        (Const64 <typ.UInt64> [63])))
  1294  
  1295  // Unsigned mod by power of 2 constant.
  1296  (Mod8u  <t> n (Const8  [c])) && isUnsignedPowerOfTwo(uint8(c)) => (And8  n (Const8  <t> [c-1]))
  1297  (Mod16u <t> n (Const16 [c])) && isUnsignedPowerOfTwo(uint16(c)) => (And16 n (Const16 <t> [c-1]))
  1298  (Mod32u <t> n (Const32 [c])) && isUnsignedPowerOfTwo(uint32(c)) => (And32 n (Const32 <t> [c-1]))
  1299  (Mod64u <t> n (Const64 [c])) && isUnsignedPowerOfTwo(uint64(c)) => (And64 n (Const64 <t> [c-1]))
  1300  
  1301  // Signed non-negative mod by power of 2 constant.
  1302  (Mod8  <t> n (Const8  [c])) && isNonNegative(n) && isPowerOfTwo(c) => (And8  n (Const8  <t> [c-1]))
  1303  (Mod16 <t> n (Const16 [c])) && isNonNegative(n) && isPowerOfTwo(c) => (And16 n (Const16 <t> [c-1]))
  1304  (Mod32 <t> n (Const32 [c])) && isNonNegative(n) && isPowerOfTwo(c) => (And32 n (Const32 <t> [c-1]))
  1305  (Mod64 <t> n (Const64 [c])) && isNonNegative(n) && isPowerOfTwo(c) => (And64 n (Const64 <t> [c-1]))
  1306  (Mod64 n (Const64 [-1<<63])) && isNonNegative(n)                   => n
  1307  
  1308  // Signed mod by negative constant.
  1309  (Mod8  <t> n (Const8  [c])) && c < 0 && c != -1<<7  => (Mod8  <t> n (Const8  <t> [-c]))
  1310  (Mod16 <t> n (Const16 [c])) && c < 0 && c != -1<<15 => (Mod16 <t> n (Const16 <t> [-c]))
  1311  (Mod32 <t> n (Const32 [c])) && c < 0 && c != -1<<31 => (Mod32 <t> n (Const32 <t> [-c]))
  1312  (Mod64 <t> n (Const64 [c])) && c < 0 && c != -1<<63 => (Mod64 <t> n (Const64 <t> [-c]))
  1313  
  1314  // All other mods by constants, do A%B = A-(A/B*B).
  1315  // This implements % with two * and a bunch of ancillary ops.
  1316  // One of the * is free if the user's code also computes A/B.
  1317  (Mod8   <t> x (Const8  [c])) && x.Op != OpConst8  && (c > 0 || c == -1<<7)
  1318    => (Sub8  x (Mul8  <t> (Div8   <t> x (Const8  <t> [c])) (Const8  <t> [c])))
  1319  (Mod16  <t> x (Const16 [c])) && x.Op != OpConst16 && (c > 0 || c == -1<<15)
  1320    => (Sub16 x (Mul16 <t> (Div16  <t> x (Const16 <t> [c])) (Const16 <t> [c])))
  1321  (Mod32  <t> x (Const32 [c])) && x.Op != OpConst32 && (c > 0 || c == -1<<31)
  1322    => (Sub32 x (Mul32 <t> (Div32  <t> x (Const32 <t> [c])) (Const32 <t> [c])))
  1323  (Mod64  <t> x (Const64 [c])) && x.Op != OpConst64 && (c > 0 || c == -1<<63)
  1324    => (Sub64 x (Mul64 <t> (Div64  <t> x (Const64 <t> [c])) (Const64 <t> [c])))
  1325  (Mod8u  <t> x (Const8  [c])) && x.Op != OpConst8  && c > 0 && umagicOK8( c)
  1326    => (Sub8  x (Mul8  <t> (Div8u  <t> x (Const8  <t> [c])) (Const8  <t> [c])))
  1327  (Mod16u <t> x (Const16 [c])) && x.Op != OpConst16 && c > 0 && umagicOK16(c)
  1328    => (Sub16 x (Mul16 <t> (Div16u <t> x (Const16 <t> [c])) (Const16 <t> [c])))
  1329  (Mod32u <t> x (Const32 [c])) && x.Op != OpConst32 && c > 0 && umagicOK32(c)
  1330    => (Sub32 x (Mul32 <t> (Div32u <t> x (Const32 <t> [c])) (Const32 <t> [c])))
  1331  (Mod64u <t> x (Const64 [c])) && x.Op != OpConst64 && c > 0 && umagicOK64(c)
  1332    => (Sub64 x (Mul64 <t> (Div64u <t> x (Const64 <t> [c])) (Const64 <t> [c])))
  1333  
  1334  // For architectures without rotates on less than 32-bits, promote these checks to 32-bit.
  1335  (Eq8 (Mod8u x (Const8  [c])) (Const8 [0])) && x.Op != OpConst8 && udivisibleOK8(c) && !hasSmallRotate(config) =>
  1336  	(Eq32 (Mod32u <typ.UInt32> (ZeroExt8to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(uint8(c))])) (Const32 <typ.UInt32> [0]))
  1337  (Eq16 (Mod16u x (Const16  [c])) (Const16 [0])) && x.Op != OpConst16 && udivisibleOK16(c) && !hasSmallRotate(config) =>
  1338  	(Eq32 (Mod32u <typ.UInt32> (ZeroExt16to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(uint16(c))])) (Const32 <typ.UInt32> [0]))
  1339  (Eq8 (Mod8 x (Const8  [c])) (Const8 [0])) && x.Op != OpConst8 && sdivisibleOK8(c) && !hasSmallRotate(config) =>
  1340  	(Eq32 (Mod32 <typ.Int32> (SignExt8to32 <typ.Int32> x) (Const32 <typ.Int32> [int32(c)])) (Const32 <typ.Int32> [0]))
  1341  (Eq16 (Mod16 x (Const16  [c])) (Const16 [0])) && x.Op != OpConst16 && sdivisibleOK16(c) && !hasSmallRotate(config) =>
  1342  	(Eq32 (Mod32 <typ.Int32> (SignExt16to32 <typ.Int32> x) (Const32 <typ.Int32> [int32(c)])) (Const32 <typ.Int32> [0]))
  1343  
  1344  // Divisibility checks x%c == 0 convert to multiply and rotate.
  1345  // Note, x%c == 0 is rewritten as x == c*(x/c) during the opt pass
  1346  // where (x/c) is performed using multiplication with magic constants.
  1347  // To rewrite x%c == 0 requires pattern matching the rewritten expression
  1348  // and checking that the division by the same constant wasn't already calculated.
  1349  // This check is made by counting uses of the magic constant multiplication.
  1350  // Note that if there were an intermediate opt pass, this rule could be applied
  1351  // directly on the Div op and magic division rewrites could be delayed to late opt.
  1352  
  1353  // Unsigned divisibility checks convert to multiply and rotate.
  1354  (Eq8 x (Mul8 (Const8 [c])
  1355    (Trunc32to8
  1356      (Rsh32Ux64
  1357        mul:(Mul32
  1358          (Const32 [m])
  1359          (ZeroExt8to32 x))
  1360        (Const64 [s])))
  1361  	)
  1362  )
  1363    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1364    && m == int32(1<<8+umagic8(c).m) && s == 8+umagic8(c).s
  1365    && x.Op != OpConst8 && udivisibleOK8(c)
  1366   => (Leq8U
  1367  			(RotateLeft8 <typ.UInt8>
  1368  				(Mul8 <typ.UInt8>
  1369  					(Const8 <typ.UInt8> [int8(udivisible8(c).m)])
  1370  					x)
  1371  				(Const8 <typ.UInt8> [int8(8-udivisible8(c).k)])
  1372  				)
  1373  			(Const8 <typ.UInt8> [int8(udivisible8(c).max)])
  1374  		)
  1375  
  1376  (Eq16 x (Mul16 (Const16 [c])
  1377    (Trunc64to16
  1378      (Rsh64Ux64
  1379        mul:(Mul64
  1380          (Const64 [m])
  1381          (ZeroExt16to64 x))
  1382        (Const64 [s])))
  1383  	)
  1384  )
  1385    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1386    && m == int64(1<<16+umagic16(c).m) && s == 16+umagic16(c).s
  1387    && x.Op != OpConst16 && udivisibleOK16(c)
  1388   => (Leq16U
  1389  			(RotateLeft16 <typ.UInt16>
  1390  				(Mul16 <typ.UInt16>
  1391  					(Const16 <typ.UInt16> [int16(udivisible16(c).m)])
  1392  					x)
  1393  				(Const16 <typ.UInt16> [int16(16-udivisible16(c).k)])
  1394  				)
  1395  			(Const16 <typ.UInt16> [int16(udivisible16(c).max)])
  1396  		)
  1397  
  1398  (Eq16 x (Mul16 (Const16 [c])
  1399    (Trunc32to16
  1400      (Rsh32Ux64
  1401        mul:(Mul32
  1402          (Const32 [m])
  1403          (ZeroExt16to32 x))
  1404        (Const64 [s])))
  1405  	)
  1406  )
  1407    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1408    && m == int32(1<<15+umagic16(c).m/2) && s == 16+umagic16(c).s-1
  1409    && x.Op != OpConst16 && udivisibleOK16(c)
  1410   => (Leq16U
  1411  			(RotateLeft16 <typ.UInt16>
  1412  				(Mul16 <typ.UInt16>
  1413  					(Const16 <typ.UInt16> [int16(udivisible16(c).m)])
  1414  					x)
  1415  				(Const16 <typ.UInt16> [int16(16-udivisible16(c).k)])
  1416  				)
  1417  			(Const16 <typ.UInt16> [int16(udivisible16(c).max)])
  1418  		)
  1419  
  1420  (Eq16 x (Mul16 (Const16 [c])
  1421    (Trunc32to16
  1422      (Rsh32Ux64
  1423        mul:(Mul32
  1424          (Const32 [m])
  1425          (Rsh32Ux64 (ZeroExt16to32 x) (Const64 [1])))
  1426        (Const64 [s])))
  1427  	)
  1428  )
  1429    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1430    && m == int32(1<<15+(umagic16(c).m+1)/2) && s == 16+umagic16(c).s-2
  1431    && x.Op != OpConst16 && udivisibleOK16(c)
  1432   => (Leq16U
  1433  			(RotateLeft16 <typ.UInt16>
  1434  				(Mul16 <typ.UInt16>
  1435  					(Const16 <typ.UInt16> [int16(udivisible16(c).m)])
  1436  					x)
  1437  				(Const16 <typ.UInt16> [int16(16-udivisible16(c).k)])
  1438  				)
  1439  			(Const16 <typ.UInt16> [int16(udivisible16(c).max)])
  1440  		)
  1441  
  1442  (Eq16 x (Mul16 (Const16 [c])
  1443    (Trunc32to16
  1444      (Rsh32Ux64
  1445        (Avg32u
  1446          (Lsh32x64 (ZeroExt16to32 x) (Const64 [16]))
  1447          mul:(Mul32
  1448            (Const32 [m])
  1449            (ZeroExt16to32 x)))
  1450        (Const64 [s])))
  1451  	)
  1452  )
  1453    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1454    && m == int32(umagic16(c).m) && s == 16+umagic16(c).s-1
  1455    && x.Op != OpConst16 && udivisibleOK16(c)
  1456   => (Leq16U
  1457  			(RotateLeft16 <typ.UInt16>
  1458  				(Mul16 <typ.UInt16>
  1459  					(Const16 <typ.UInt16> [int16(udivisible16(c).m)])
  1460  					x)
  1461  				(Const16 <typ.UInt16> [int16(16-udivisible16(c).k)])
  1462  				)
  1463  			(Const16 <typ.UInt16> [int16(udivisible16(c).max)])
  1464  		)
  1465  
  1466  (Eq32 x (Mul32 (Const32 [c])
  1467  	(Rsh32Ux64
  1468  		mul:(Hmul32u
  1469  			(Const32 [m])
  1470  			x)
  1471  		(Const64 [s]))
  1472  	)
  1473  )
  1474    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1475    && m == int32(1<<31+umagic32(c).m/2) && s == umagic32(c).s-1
  1476  	&& x.Op != OpConst32 && udivisibleOK32(c)
  1477   => (Leq32U
  1478  			(RotateLeft32 <typ.UInt32>
  1479  				(Mul32 <typ.UInt32>
  1480  					(Const32 <typ.UInt32> [int32(udivisible32(c).m)])
  1481  					x)
  1482  				(Const32 <typ.UInt32> [int32(32-udivisible32(c).k)])
  1483  				)
  1484  			(Const32 <typ.UInt32> [int32(udivisible32(c).max)])
  1485  		)
  1486  
  1487  (Eq32 x (Mul32 (Const32 [c])
  1488    (Rsh32Ux64
  1489      mul:(Hmul32u
  1490        (Const32 <typ.UInt32> [m])
  1491        (Rsh32Ux64 x (Const64 [1])))
  1492      (Const64 [s]))
  1493  	)
  1494  )
  1495    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1496    && m == int32(1<<31+(umagic32(c).m+1)/2) && s == umagic32(c).s-2
  1497  	&& x.Op != OpConst32 && udivisibleOK32(c)
  1498   => (Leq32U
  1499  			(RotateLeft32 <typ.UInt32>
  1500  				(Mul32 <typ.UInt32>
  1501  					(Const32 <typ.UInt32> [int32(udivisible32(c).m)])
  1502  					x)
  1503  				(Const32 <typ.UInt32> [int32(32-udivisible32(c).k)])
  1504  				)
  1505  			(Const32 <typ.UInt32> [int32(udivisible32(c).max)])
  1506  		)
  1507  
  1508  (Eq32 x (Mul32 (Const32 [c])
  1509    (Rsh32Ux64
  1510      (Avg32u
  1511        x
  1512        mul:(Hmul32u
  1513          (Const32 [m])
  1514          x))
  1515      (Const64 [s]))
  1516  	)
  1517  )
  1518    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1519    && m == int32(umagic32(c).m) && s == umagic32(c).s-1
  1520  	&& x.Op != OpConst32 && udivisibleOK32(c)
  1521   => (Leq32U
  1522  			(RotateLeft32 <typ.UInt32>
  1523  				(Mul32 <typ.UInt32>
  1524  					(Const32 <typ.UInt32> [int32(udivisible32(c).m)])
  1525  					x)
  1526  				(Const32 <typ.UInt32> [int32(32-udivisible32(c).k)])
  1527  				)
  1528  			(Const32 <typ.UInt32> [int32(udivisible32(c).max)])
  1529  		)
  1530  
  1531  (Eq32 x (Mul32 (Const32 [c])
  1532    (Trunc64to32
  1533      (Rsh64Ux64
  1534        mul:(Mul64
  1535          (Const64 [m])
  1536          (ZeroExt32to64 x))
  1537        (Const64 [s])))
  1538  	)
  1539  )
  1540    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1541    && m == int64(1<<31+umagic32(c).m/2) && s == 32+umagic32(c).s-1
  1542  	&& x.Op != OpConst32 && udivisibleOK32(c)
  1543   => (Leq32U
  1544  			(RotateLeft32 <typ.UInt32>
  1545  				(Mul32 <typ.UInt32>
  1546  					(Const32 <typ.UInt32> [int32(udivisible32(c).m)])
  1547  					x)
  1548  				(Const32 <typ.UInt32> [int32(32-udivisible32(c).k)])
  1549  				)
  1550  			(Const32 <typ.UInt32> [int32(udivisible32(c).max)])
  1551  		)
  1552  
  1553  (Eq32 x (Mul32 (Const32 [c])
  1554    (Trunc64to32
  1555      (Rsh64Ux64
  1556        mul:(Mul64
  1557          (Const64 [m])
  1558          (Rsh64Ux64 (ZeroExt32to64 x) (Const64 [1])))
  1559        (Const64 [s])))
  1560  	)
  1561  )
  1562    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1563    && m == int64(1<<31+(umagic32(c).m+1)/2) && s == 32+umagic32(c).s-2
  1564  	&& x.Op != OpConst32 && udivisibleOK32(c)
  1565   => (Leq32U
  1566  			(RotateLeft32 <typ.UInt32>
  1567  				(Mul32 <typ.UInt32>
  1568  					(Const32 <typ.UInt32> [int32(udivisible32(c).m)])
  1569  					x)
  1570  				(Const32 <typ.UInt32> [int32(32-udivisible32(c).k)])
  1571  				)
  1572  			(Const32 <typ.UInt32> [int32(udivisible32(c).max)])
  1573  		)
  1574  
  1575  (Eq32 x (Mul32 (Const32 [c])
  1576    (Trunc64to32
  1577      (Rsh64Ux64
  1578        (Avg64u
  1579          (Lsh64x64 (ZeroExt32to64 x) (Const64 [32]))
  1580          mul:(Mul64
  1581            (Const64 [m])
  1582            (ZeroExt32to64 x)))
  1583        (Const64 [s])))
  1584  	)
  1585  )
  1586    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1587    && m == int64(umagic32(c).m) && s == 32+umagic32(c).s-1
  1588  	&& x.Op != OpConst32 && udivisibleOK32(c)
  1589   => (Leq32U
  1590  			(RotateLeft32 <typ.UInt32>
  1591  				(Mul32 <typ.UInt32>
  1592  					(Const32 <typ.UInt32> [int32(udivisible32(c).m)])
  1593  					x)
  1594  				(Const32 <typ.UInt32> [int32(32-udivisible32(c).k)])
  1595  				)
  1596  			(Const32 <typ.UInt32> [int32(udivisible32(c).max)])
  1597  		)
  1598  
  1599  (Eq64 x (Mul64 (Const64 [c])
  1600  	(Rsh64Ux64
  1601  		mul:(Hmul64u
  1602  			(Const64 [m])
  1603  			x)
  1604  		(Const64 [s]))
  1605  	)
  1606  ) && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1607    && m == int64(1<<63+umagic64(c).m/2) && s == umagic64(c).s-1
  1608    && x.Op != OpConst64 && udivisibleOK64(c)
  1609   => (Leq64U
  1610  			(RotateLeft64 <typ.UInt64>
  1611  				(Mul64 <typ.UInt64>
  1612  					(Const64 <typ.UInt64> [int64(udivisible64(c).m)])
  1613  					x)
  1614  				(Const64 <typ.UInt64> [64-udivisible64(c).k])
  1615  				)
  1616  			(Const64 <typ.UInt64> [int64(udivisible64(c).max)])
  1617  		)
  1618  (Eq64 x (Mul64 (Const64 [c])
  1619  	(Rsh64Ux64
  1620  		mul:(Hmul64u
  1621  			(Const64 [m])
  1622  			(Rsh64Ux64 x (Const64 [1])))
  1623  		(Const64 [s]))
  1624  	)
  1625  ) && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1626    && m == int64(1<<63+(umagic64(c).m+1)/2) && s == umagic64(c).s-2
  1627    && x.Op != OpConst64 && udivisibleOK64(c)
  1628   => (Leq64U
  1629  			(RotateLeft64 <typ.UInt64>
  1630  				(Mul64 <typ.UInt64>
  1631  					(Const64 <typ.UInt64> [int64(udivisible64(c).m)])
  1632  					x)
  1633  				(Const64 <typ.UInt64> [64-udivisible64(c).k])
  1634  				)
  1635  			(Const64 <typ.UInt64> [int64(udivisible64(c).max)])
  1636  		)
  1637  (Eq64 x (Mul64 (Const64 [c])
  1638  	(Rsh64Ux64
  1639  		(Avg64u
  1640  			x
  1641  			mul:(Hmul64u
  1642  				(Const64 [m])
  1643  				x))
  1644  		(Const64 [s]))
  1645  	)
  1646  ) && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1647    && m == int64(umagic64(c).m) && s == umagic64(c).s-1
  1648    && x.Op != OpConst64 && udivisibleOK64(c)
  1649   => (Leq64U
  1650  			(RotateLeft64 <typ.UInt64>
  1651  				(Mul64 <typ.UInt64>
  1652  					(Const64 <typ.UInt64> [int64(udivisible64(c).m)])
  1653  					x)
  1654  				(Const64 <typ.UInt64> [64-udivisible64(c).k])
  1655  				)
  1656  			(Const64 <typ.UInt64> [int64(udivisible64(c).max)])
  1657  		)
  1658  
  1659  // Signed divisibility checks convert to multiply, add and rotate.
  1660  (Eq8 x (Mul8 (Const8 [c])
  1661    (Sub8
  1662      (Rsh32x64
  1663        mul:(Mul32
  1664          (Const32 [m])
  1665          (SignExt8to32 x))
  1666        (Const64 [s]))
  1667      (Rsh32x64
  1668        (SignExt8to32 x)
  1669        (Const64 [31])))
  1670  	)
  1671  )
  1672    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1673    && m == int32(smagic8(c).m) && s == 8+smagic8(c).s
  1674  	&& x.Op != OpConst8 && sdivisibleOK8(c)
  1675   => (Leq8U
  1676  			(RotateLeft8 <typ.UInt8>
  1677  				(Add8 <typ.UInt8>
  1678  					(Mul8 <typ.UInt8>
  1679  						(Const8 <typ.UInt8> [int8(sdivisible8(c).m)])
  1680  						x)
  1681  					(Const8 <typ.UInt8> [int8(sdivisible8(c).a)])
  1682  				)
  1683  				(Const8 <typ.UInt8> [int8(8-sdivisible8(c).k)])
  1684  			)
  1685  			(Const8 <typ.UInt8> [int8(sdivisible8(c).max)])
  1686  		)
  1687  
  1688  (Eq16 x (Mul16 (Const16 [c])
  1689    (Sub16
  1690      (Rsh32x64
  1691        mul:(Mul32
  1692          (Const32 [m])
  1693          (SignExt16to32 x))
  1694        (Const64 [s]))
  1695      (Rsh32x64
  1696        (SignExt16to32 x)
  1697        (Const64 [31])))
  1698  	)
  1699  )
  1700    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1701    && m == int32(smagic16(c).m) && s == 16+smagic16(c).s
  1702  	&& x.Op != OpConst16 && sdivisibleOK16(c)
  1703   => (Leq16U
  1704  			(RotateLeft16 <typ.UInt16>
  1705  				(Add16 <typ.UInt16>
  1706  					(Mul16 <typ.UInt16>
  1707  						(Const16 <typ.UInt16> [int16(sdivisible16(c).m)])
  1708  						x)
  1709  					(Const16 <typ.UInt16> [int16(sdivisible16(c).a)])
  1710  				)
  1711  				(Const16 <typ.UInt16> [int16(16-sdivisible16(c).k)])
  1712  			)
  1713  			(Const16 <typ.UInt16> [int16(sdivisible16(c).max)])
  1714  		)
  1715  
  1716  (Eq32 x (Mul32 (Const32 [c])
  1717    (Sub32
  1718      (Rsh64x64
  1719        mul:(Mul64
  1720          (Const64 [m])
  1721          (SignExt32to64 x))
  1722        (Const64 [s]))
  1723      (Rsh64x64
  1724        (SignExt32to64 x)
  1725        (Const64 [63])))
  1726  	)
  1727  )
  1728    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1729    && m == int64(smagic32(c).m) && s == 32+smagic32(c).s
  1730  	&& x.Op != OpConst32 && sdivisibleOK32(c)
  1731   => (Leq32U
  1732  			(RotateLeft32 <typ.UInt32>
  1733  				(Add32 <typ.UInt32>
  1734  					(Mul32 <typ.UInt32>
  1735  						(Const32 <typ.UInt32> [int32(sdivisible32(c).m)])
  1736  						x)
  1737  					(Const32 <typ.UInt32> [int32(sdivisible32(c).a)])
  1738  				)
  1739  				(Const32 <typ.UInt32> [int32(32-sdivisible32(c).k)])
  1740  			)
  1741  			(Const32 <typ.UInt32> [int32(sdivisible32(c).max)])
  1742  		)
  1743  
  1744  (Eq32 x (Mul32 (Const32 [c])
  1745    (Sub32
  1746      (Rsh32x64
  1747        mul:(Hmul32
  1748          (Const32 [m])
  1749          x)
  1750        (Const64 [s]))
  1751      (Rsh32x64
  1752        x
  1753        (Const64 [31])))
  1754  	)
  1755  )
  1756    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1757    && m == int32(smagic32(c).m/2) && s == smagic32(c).s-1
  1758  	&& x.Op != OpConst32 && sdivisibleOK32(c)
  1759   => (Leq32U
  1760  			(RotateLeft32 <typ.UInt32>
  1761  				(Add32 <typ.UInt32>
  1762  					(Mul32 <typ.UInt32>
  1763  						(Const32 <typ.UInt32> [int32(sdivisible32(c).m)])
  1764  						x)
  1765  					(Const32 <typ.UInt32> [int32(sdivisible32(c).a)])
  1766  				)
  1767  				(Const32 <typ.UInt32> [int32(32-sdivisible32(c).k)])
  1768  			)
  1769  			(Const32 <typ.UInt32> [int32(sdivisible32(c).max)])
  1770  		)
  1771  
  1772  (Eq32 x (Mul32 (Const32 [c])
  1773    (Sub32
  1774      (Rsh32x64
  1775        (Add32
  1776          mul:(Hmul32
  1777            (Const32 [m])
  1778            x)
  1779          x)
  1780        (Const64 [s]))
  1781      (Rsh32x64
  1782        x
  1783        (Const64 [31])))
  1784  	)
  1785  )
  1786    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1787    && m == int32(smagic32(c).m) && s == smagic32(c).s
  1788  	&& x.Op != OpConst32 && sdivisibleOK32(c)
  1789   => (Leq32U
  1790  			(RotateLeft32 <typ.UInt32>
  1791  				(Add32 <typ.UInt32>
  1792  					(Mul32 <typ.UInt32>
  1793  						(Const32 <typ.UInt32> [int32(sdivisible32(c).m)])
  1794  						x)
  1795  					(Const32 <typ.UInt32> [int32(sdivisible32(c).a)])
  1796  				)
  1797  				(Const32 <typ.UInt32> [int32(32-sdivisible32(c).k)])
  1798  			)
  1799  			(Const32 <typ.UInt32> [int32(sdivisible32(c).max)])
  1800  		)
  1801  
  1802  (Eq64 x (Mul64 (Const64 [c])
  1803    (Sub64
  1804      (Rsh64x64
  1805        mul:(Hmul64
  1806          (Const64 [m])
  1807          x)
  1808        (Const64 [s]))
  1809      (Rsh64x64
  1810        x
  1811        (Const64 [63])))
  1812  	)
  1813  )
  1814    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1815    && m == int64(smagic64(c).m/2) && s == smagic64(c).s-1
  1816  	&& x.Op != OpConst64 && sdivisibleOK64(c)
  1817   => (Leq64U
  1818  			(RotateLeft64 <typ.UInt64>
  1819  				(Add64 <typ.UInt64>
  1820  					(Mul64 <typ.UInt64>
  1821  						(Const64 <typ.UInt64> [int64(sdivisible64(c).m)])
  1822  						x)
  1823  					(Const64 <typ.UInt64> [int64(sdivisible64(c).a)])
  1824  				)
  1825  				(Const64 <typ.UInt64> [64-sdivisible64(c).k])
  1826  			)
  1827  			(Const64 <typ.UInt64> [int64(sdivisible64(c).max)])
  1828  		)
  1829  
  1830  (Eq64 x (Mul64 (Const64 [c])
  1831    (Sub64
  1832      (Rsh64x64
  1833        (Add64
  1834          mul:(Hmul64
  1835            (Const64 [m])
  1836            x)
  1837          x)
  1838        (Const64 [s]))
  1839      (Rsh64x64
  1840        x
  1841        (Const64 [63])))
  1842  	)
  1843  )
  1844    && v.Block.Func.pass.name != "opt" && mul.Uses == 1
  1845    && m == int64(smagic64(c).m) && s == smagic64(c).s
  1846  	&& x.Op != OpConst64 && sdivisibleOK64(c)
  1847   => (Leq64U
  1848  			(RotateLeft64 <typ.UInt64>
  1849  				(Add64 <typ.UInt64>
  1850  					(Mul64 <typ.UInt64>
  1851  						(Const64 <typ.UInt64> [int64(sdivisible64(c).m)])
  1852  						x)
  1853  					(Const64 <typ.UInt64> [int64(sdivisible64(c).a)])
  1854  				)
  1855  				(Const64 <typ.UInt64> [64-sdivisible64(c).k])
  1856  			)
  1857  			(Const64 <typ.UInt64> [int64(sdivisible64(c).max)])
  1858  		)
  1859  
  1860  // Divisibility check for signed integers for power of two constant are simple mask.
  1861  // However, we must match against the rewritten n%c == 0 -> n - c*(n/c) == 0 -> n == c*(n/c)
  1862  // where n/c contains fixup code to handle signed n.
  1863  ((Eq8|Neq8) n (Lsh8x64
  1864    (Rsh8x64
  1865      (Add8  <t> n (Rsh8Ux64  <t> (Rsh8x64  <t> n (Const64 <typ.UInt64> [ 7])) (Const64 <typ.UInt64> [kbar])))
  1866      (Const64 <typ.UInt64> [k]))
  1867  	(Const64 <typ.UInt64> [k]))
  1868  ) && k > 0 && k < 7 && kbar == 8 - k
  1869    => ((Eq8|Neq8) (And8 <t> n (Const8 <t> [1<<uint(k)-1])) (Const8 <t> [0]))
  1870  
  1871  ((Eq16|Neq16) n (Lsh16x64
  1872    (Rsh16x64
  1873      (Add16 <t> n (Rsh16Ux64 <t> (Rsh16x64 <t> n (Const64 <typ.UInt64> [15])) (Const64 <typ.UInt64> [kbar])))
  1874      (Const64 <typ.UInt64> [k]))
  1875  	(Const64 <typ.UInt64> [k]))
  1876  ) && k > 0 && k < 15 && kbar == 16 - k
  1877    => ((Eq16|Neq16) (And16 <t> n (Const16 <t> [1<<uint(k)-1])) (Const16 <t> [0]))
  1878  
  1879  ((Eq32|Neq32) n (Lsh32x64
  1880    (Rsh32x64
  1881      (Add32 <t> n (Rsh32Ux64 <t> (Rsh32x64 <t> n (Const64 <typ.UInt64> [31])) (Const64 <typ.UInt64> [kbar])))
  1882      (Const64 <typ.UInt64> [k]))
  1883  	(Const64 <typ.UInt64> [k]))
  1884  ) && k > 0 && k < 31 && kbar == 32 - k
  1885    => ((Eq32|Neq32) (And32 <t> n (Const32 <t> [1<<uint(k)-1])) (Const32 <t> [0]))
  1886  
  1887  ((Eq64|Neq64) n (Lsh64x64
  1888    (Rsh64x64
  1889      (Add64 <t> n (Rsh64Ux64 <t> (Rsh64x64 <t> n (Const64 <typ.UInt64> [63])) (Const64 <typ.UInt64> [kbar])))
  1890      (Const64 <typ.UInt64> [k]))
  1891  	(Const64 <typ.UInt64> [k]))
  1892  ) && k > 0 && k < 63 && kbar == 64 - k
  1893    => ((Eq64|Neq64) (And64 <t> n (Const64 <t> [1<<uint(k)-1])) (Const64 <t> [0]))
  1894  
  1895  (Eq(8|16|32|64)  s:(Sub(8|16|32|64) x y) (Const(8|16|32|64) [0])) && s.Uses == 1 => (Eq(8|16|32|64)  x y)
  1896  (Neq(8|16|32|64) s:(Sub(8|16|32|64) x y) (Const(8|16|32|64) [0])) && s.Uses == 1 => (Neq(8|16|32|64) x y)
  1897  
  1898  // Optimize bitsets
  1899  (Eq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [y])) && oneBit8(y)
  1900    => (Neq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [0]))
  1901  (Eq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [y])) && oneBit16(y)
  1902    => (Neq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [0]))
  1903  (Eq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [y])) && oneBit32(y)
  1904    => (Neq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [0]))
  1905  (Eq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [y])) && oneBit64(y)
  1906    => (Neq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [0]))
  1907  (Neq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [y])) && oneBit8(y)
  1908    => (Eq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [0]))
  1909  (Neq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [y])) && oneBit16(y)
  1910    => (Eq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [0]))
  1911  (Neq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [y])) && oneBit32(y)
  1912    => (Eq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [0]))
  1913  (Neq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [y])) && oneBit64(y)
  1914    => (Eq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [0]))
  1915  
  1916  // Reassociate expressions involving
  1917  // constants such that constants come first,
  1918  // exposing obvious constant-folding opportunities.
  1919  // Reassociate (op (op y C) x) to (op C (op x y)) or similar, where C
  1920  // is constant, which pushes constants to the outside
  1921  // of the expression. At that point, any constant-folding
  1922  // opportunities should be obvious.
  1923  // Note: don't include AddPtr here! In order to maintain the
  1924  // invariant that pointers must stay within the pointed-to object,
  1925  // we can't pull part of a pointer computation above the AddPtr.
  1926  // See issue 37881.
  1927  // Note: we don't need to handle any (x-C) cases because we already rewrite
  1928  // (x-C) to (x+(-C)).
  1929  
  1930  // x + (C + z) -> C + (x + z)
  1931  (Add64 (Add64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Add64 i (Add64 <t> z x))
  1932  (Add32 (Add32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Add32 i (Add32 <t> z x))
  1933  (Add16 (Add16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Add16 i (Add16 <t> z x))
  1934  (Add8  (Add8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Add8  i (Add8  <t> z x))
  1935  
  1936  // x + (C - z) -> C + (x - z)
  1937  (Add64 (Sub64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Add64 i (Sub64 <t> x z))
  1938  (Add32 (Sub32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Add32 i (Sub32 <t> x z))
  1939  (Add16 (Sub16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Add16 i (Sub16 <t> x z))
  1940  (Add8  (Sub8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Add8  i (Sub8  <t> x z))
  1941  
  1942  // x - (C - z) -> x + (z - C) -> (x + z) - C
  1943  (Sub64 x (Sub64 i:(Const64 <t>) z)) && (z.Op != OpConst64 && x.Op != OpConst64) => (Sub64 (Add64 <t> x z) i)
  1944  (Sub32 x (Sub32 i:(Const32 <t>) z)) && (z.Op != OpConst32 && x.Op != OpConst32) => (Sub32 (Add32 <t> x z) i)
  1945  (Sub16 x (Sub16 i:(Const16 <t>) z)) && (z.Op != OpConst16 && x.Op != OpConst16) => (Sub16 (Add16 <t> x z) i)
  1946  (Sub8  x (Sub8  i:(Const8  <t>) z)) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Sub8  (Add8  <t> x z) i)
  1947  
  1948  // x - (z + C) -> x + (-z - C) -> (x - z) - C
  1949  (Sub64 x (Add64 z i:(Const64 <t>))) && (z.Op != OpConst64 && x.Op != OpConst64) => (Sub64 (Sub64 <t> x z) i)
  1950  (Sub32 x (Add32 z i:(Const32 <t>))) && (z.Op != OpConst32 && x.Op != OpConst32) => (Sub32 (Sub32 <t> x z) i)
  1951  (Sub16 x (Add16 z i:(Const16 <t>))) && (z.Op != OpConst16 && x.Op != OpConst16) => (Sub16 (Sub16 <t> x z) i)
  1952  (Sub8  x (Add8  z i:(Const8  <t>))) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Sub8 (Sub8  <t> x z) i)
  1953  
  1954  // (C - z) - x -> C - (z + x)
  1955  (Sub64 (Sub64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Sub64 i (Add64 <t> z x))
  1956  (Sub32 (Sub32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Sub32 i (Add32 <t> z x))
  1957  (Sub16 (Sub16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Sub16 i (Add16 <t> z x))
  1958  (Sub8  (Sub8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Sub8  i (Add8  <t> z x))
  1959  
  1960  // (z + C) -x -> C + (z - x)
  1961  (Sub64 (Add64 z i:(Const64 <t>)) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Add64 i (Sub64 <t> z x))
  1962  (Sub32 (Add32 z i:(Const32 <t>)) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Add32 i (Sub32 <t> z x))
  1963  (Sub16 (Add16 z i:(Const16 <t>)) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Add16 i (Sub16 <t> z x))
  1964  (Sub8  (Add8  z i:(Const8  <t>)) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Add8  i (Sub8  <t> z x))
  1965  
  1966  // x & (C & z) -> C & (x & z)
  1967  (And64 (And64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (And64 i (And64 <t> z x))
  1968  (And32 (And32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (And32 i (And32 <t> z x))
  1969  (And16 (And16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (And16 i (And16 <t> z x))
  1970  (And8  (And8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (And8  i (And8  <t> z x))
  1971  
  1972  // x | (C | z) -> C | (x | z)
  1973  (Or64 (Or64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Or64 i (Or64 <t> z x))
  1974  (Or32 (Or32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Or32 i (Or32 <t> z x))
  1975  (Or16 (Or16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Or16 i (Or16 <t> z x))
  1976  (Or8  (Or8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Or8  i (Or8  <t> z x))
  1977  
  1978  // x ^ (C ^ z) -> C ^ (x ^ z)
  1979  (Xor64 (Xor64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Xor64 i (Xor64 <t> z x))
  1980  (Xor32 (Xor32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Xor32 i (Xor32 <t> z x))
  1981  (Xor16 (Xor16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Xor16 i (Xor16 <t> z x))
  1982  (Xor8  (Xor8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Xor8  i (Xor8  <t> z x))
  1983  
  1984  // x * (D * z) = D * (x * z)
  1985  (Mul64 (Mul64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Mul64 i (Mul64 <t> x z))
  1986  (Mul32 (Mul32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Mul32 i (Mul32 <t> x z))
  1987  (Mul16 (Mul16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Mul16 i (Mul16 <t> x z))
  1988  (Mul8  (Mul8  i:(Const8  <t>) z) x) && (z.Op != OpConst8  && x.Op != OpConst8)  => (Mul8  i (Mul8  <t> x z))
  1989  
  1990  // C + (D + x) -> (C + D) + x
  1991  (Add64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Add64 (Const64 <t> [c+d]) x)
  1992  (Add32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Add32 (Const32 <t> [c+d]) x)
  1993  (Add16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Add16 (Const16 <t> [c+d]) x)
  1994  (Add8  (Const8  <t> [c]) (Add8  (Const8  <t> [d]) x)) => (Add8  (Const8  <t> [c+d]) x)
  1995  
  1996  // C + (D - x) -> (C + D) - x
  1997  (Add64 (Const64 <t> [c]) (Sub64 (Const64 <t> [d]) x)) => (Sub64 (Const64 <t> [c+d]) x)
  1998  (Add32 (Const32 <t> [c]) (Sub32 (Const32 <t> [d]) x)) => (Sub32 (Const32 <t> [c+d]) x)
  1999  (Add16 (Const16 <t> [c]) (Sub16 (Const16 <t> [d]) x)) => (Sub16 (Const16 <t> [c+d]) x)
  2000  (Add8  (Const8  <t> [c]) (Sub8  (Const8  <t> [d]) x)) => (Sub8  (Const8  <t> [c+d]) x)
  2001  
  2002  // C - (D - x) -> (C - D) + x
  2003  (Sub64 (Const64 <t> [c]) (Sub64 (Const64 <t> [d]) x)) => (Add64 (Const64 <t> [c-d]) x)
  2004  (Sub32 (Const32 <t> [c]) (Sub32 (Const32 <t> [d]) x)) => (Add32 (Const32 <t> [c-d]) x)
  2005  (Sub16 (Const16 <t> [c]) (Sub16 (Const16 <t> [d]) x)) => (Add16 (Const16 <t> [c-d]) x)
  2006  (Sub8  (Const8  <t> [c]) (Sub8  (Const8  <t> [d]) x)) => (Add8  (Const8  <t> [c-d]) x)
  2007  
  2008  // C - (D + x) -> (C - D) - x
  2009  (Sub64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Sub64 (Const64 <t> [c-d]) x)
  2010  (Sub32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Sub32 (Const32 <t> [c-d]) x)
  2011  (Sub16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Sub16 (Const16 <t> [c-d]) x)
  2012  (Sub8  (Const8  <t> [c]) (Add8  (Const8  <t> [d]) x)) => (Sub8  (Const8  <t> [c-d]) x)
  2013  
  2014  // C & (D & x) -> (C & D) & x
  2015  (And64 (Const64 <t> [c]) (And64 (Const64 <t> [d]) x)) => (And64 (Const64 <t> [c&d]) x)
  2016  (And32 (Const32 <t> [c]) (And32 (Const32 <t> [d]) x)) => (And32 (Const32 <t> [c&d]) x)
  2017  (And16 (Const16 <t> [c]) (And16 (Const16 <t> [d]) x)) => (And16 (Const16 <t> [c&d]) x)
  2018  (And8  (Const8  <t> [c]) (And8  (Const8  <t> [d]) x)) => (And8  (Const8  <t> [c&d]) x)
  2019  
  2020  // C | (D | x) -> (C | D) | x
  2021  (Or64 (Const64 <t> [c]) (Or64 (Const64 <t> [d]) x)) => (Or64 (Const64 <t> [c|d]) x)
  2022  (Or32 (Const32 <t> [c]) (Or32 (Const32 <t> [d]) x)) => (Or32 (Const32 <t> [c|d]) x)
  2023  (Or16 (Const16 <t> [c]) (Or16 (Const16 <t> [d]) x)) => (Or16 (Const16 <t> [c|d]) x)
  2024  (Or8  (Const8  <t> [c]) (Or8  (Const8  <t> [d]) x)) => (Or8  (Const8  <t> [c|d]) x)
  2025  
  2026  // C ^ (D ^ x) -> (C ^ D) ^ x
  2027  (Xor64 (Const64 <t> [c]) (Xor64 (Const64 <t> [d]) x)) => (Xor64 (Const64 <t> [c^d]) x)
  2028  (Xor32 (Const32 <t> [c]) (Xor32 (Const32 <t> [d]) x)) => (Xor32 (Const32 <t> [c^d]) x)
  2029  (Xor16 (Const16 <t> [c]) (Xor16 (Const16 <t> [d]) x)) => (Xor16 (Const16 <t> [c^d]) x)
  2030  (Xor8  (Const8  <t> [c]) (Xor8  (Const8  <t> [d]) x)) => (Xor8  (Const8  <t> [c^d]) x)
  2031  
  2032  // C * (D * x) = (C * D) * x
  2033  (Mul64 (Const64 <t> [c]) (Mul64 (Const64 <t> [d]) x)) => (Mul64 (Const64 <t> [c*d]) x)
  2034  (Mul32 (Const32 <t> [c]) (Mul32 (Const32 <t> [d]) x)) => (Mul32 (Const32 <t> [c*d]) x)
  2035  (Mul16 (Const16 <t> [c]) (Mul16 (Const16 <t> [d]) x)) => (Mul16 (Const16 <t> [c*d]) x)
  2036  (Mul8  (Const8  <t> [c]) (Mul8  (Const8  <t> [d]) x)) => (Mul8  (Const8  <t> [c*d]) x)
  2037  
  2038  // floating point optimizations
  2039  (Mul(32|64)F x (Const(32|64)F [1])) => x
  2040  (Mul32F x (Const32F [-1])) => (Neg32F x)
  2041  (Mul64F x (Const64F [-1])) => (Neg64F x)
  2042  (Mul32F x (Const32F [2])) => (Add32F x x)
  2043  (Mul64F x (Const64F [2])) => (Add64F x x)
  2044  
  2045  (Div32F x (Const32F <t> [c])) && reciprocalExact32(c) => (Mul32F x (Const32F <t> [1/c]))
  2046  (Div64F x (Const64F <t> [c])) && reciprocalExact64(c) => (Mul64F x (Const64F <t> [1/c]))
  2047  
  2048  // rewrite single-precision sqrt expression "float32(math.Sqrt(float64(x)))"
  2049  (Cvt64Fto32F sqrt0:(Sqrt (Cvt32Fto64F x))) && sqrt0.Uses==1 => (Sqrt32 x)
  2050  
  2051  (Sqrt (Const64F [c])) && !math.IsNaN(math.Sqrt(c)) => (Const64F [math.Sqrt(c)])
  2052  
  2053  // for rewriting constant folded math/bits ops
  2054  (Select0 (MakeTuple x y)) => x
  2055  (Select1 (MakeTuple x y)) => y
  2056  
  2057  // for rewriting results of some late-expanded rewrites (below)
  2058  (SelectN [n] m:(MakeResult ___)) => m.Args[n]
  2059  
  2060  // for late-expanded calls, recognize newobject and remove zeroing and nilchecks
  2061  (Zero (SelectN [0] call:(StaticLECall _ _)) mem:(SelectN [1] call))
  2062  	&& isSameCall(call.Aux, "runtime.newobject")
  2063  	=> mem
  2064  
  2065  (Store (SelectN [0] call:(StaticLECall _ _)) x mem:(SelectN [1] call))
  2066  	&& isConstZero(x)
  2067  	&& isSameCall(call.Aux, "runtime.newobject")
  2068  	=> mem
  2069  
  2070  (Store (OffPtr (SelectN [0] call:(StaticLECall _ _))) x mem:(SelectN [1] call))
  2071  	&& isConstZero(x)
  2072  	&& isSameCall(call.Aux, "runtime.newobject")
  2073  	=> mem
  2074  
  2075  (NilCheck ptr:(SelectN [0] call:(StaticLECall _ _)) _)
  2076  	&& isSameCall(call.Aux, "runtime.newobject")
  2077  	&& warnRule(fe.Debug_checknil(), v, "removed nil check")
  2078  	=> ptr
  2079  
  2080  (NilCheck ptr:(OffPtr (SelectN [0] call:(StaticLECall _ _))) _)
  2081  	&& isSameCall(call.Aux, "runtime.newobject")
  2082  	&& warnRule(fe.Debug_checknil(), v, "removed nil check")
  2083  	=> ptr
  2084  
  2085  // Addresses of globals are always non-nil.
  2086  (NilCheck          ptr:(Addr {_} (SB))    _) => ptr
  2087  (NilCheck ptr:(Convert (Addr {_} (SB)) _) _) => ptr
  2088  
  2089  // Addresses of locals are always non-nil.
  2090  (NilCheck ptr:(LocalAddr _ _) _)
  2091  	&& warnRule(fe.Debug_checknil(), v, "removed nil check")
  2092  	=> ptr
  2093  
  2094  // Nil checks of nil checks are redundant.
  2095  // See comment at the end of https://go-review.googlesource.com/c/go/+/537775.
  2096  (NilCheck ptr:(NilCheck _ _) _ ) => ptr
  2097  
  2098  // for late-expanded calls, recognize memequal applied to a single constant byte
  2099  // Support is limited by 1, 2, 4, 8 byte sizes
  2100  (StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [1]) mem)
  2101    && isSameCall(callAux, "runtime.memequal")
  2102    && symIsRO(scon)
  2103    => (MakeResult (Eq8 (Load <typ.Int8> sptr mem) (Const8 <typ.Int8> [int8(read8(scon,0))])) mem)
  2104  
  2105  (StaticLECall {callAux} (Addr {scon} (SB)) sptr (Const64 [1]) mem)
  2106    && isSameCall(callAux, "runtime.memequal")
  2107    && symIsRO(scon)
  2108    => (MakeResult (Eq8 (Load <typ.Int8> sptr mem) (Const8 <typ.Int8> [int8(read8(scon,0))])) mem)
  2109  
  2110  (StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [2]) mem)
  2111    && isSameCall(callAux, "runtime.memequal")
  2112    && symIsRO(scon)
  2113    && canLoadUnaligned(config)
  2114    => (MakeResult (Eq16 (Load <typ.Int16> sptr mem) (Const16 <typ.Int16> [int16(read16(scon,0,config.ctxt.Arch.ByteOrder))])) mem)
  2115  
  2116  (StaticLECall {callAux} (Addr {scon} (SB)) sptr (Const64 [2]) mem)
  2117    && isSameCall(callAux, "runtime.memequal")
  2118    && symIsRO(scon)
  2119    && canLoadUnaligned(config)
  2120    => (MakeResult (Eq16 (Load <typ.Int16> sptr mem) (Const16 <typ.Int16> [int16(read16(scon,0,config.ctxt.Arch.ByteOrder))])) mem)
  2121  
  2122  (StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [4]) mem)
  2123    && isSameCall(callAux, "runtime.memequal")
  2124    && symIsRO(scon)
  2125    && canLoadUnaligned(config)
  2126    => (MakeResult (Eq32 (Load <typ.Int32> sptr mem) (Const32 <typ.Int32> [int32(read32(scon,0,config.ctxt.Arch.ByteOrder))])) mem)
  2127  
  2128  (StaticLECall {callAux} (Addr {scon} (SB)) sptr (Const64 [4]) mem)
  2129    && isSameCall(callAux, "runtime.memequal")
  2130    && symIsRO(scon)
  2131    && canLoadUnaligned(config)
  2132    => (MakeResult (Eq32 (Load <typ.Int32> sptr mem) (Const32 <typ.Int32> [int32(read32(scon,0,config.ctxt.Arch.ByteOrder))])) mem)
  2133  
  2134  (StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [8]) mem)
  2135    && isSameCall(callAux, "runtime.memequal")
  2136    && symIsRO(scon)
  2137    && canLoadUnaligned(config) && config.PtrSize == 8
  2138    => (MakeResult (Eq64 (Load <typ.Int64> sptr mem) (Const64 <typ.Int64> [int64(read64(scon,0,config.ctxt.Arch.ByteOrder))])) mem)
  2139  
  2140  (StaticLECall {callAux} (Addr {scon} (SB)) sptr (Const64 [8]) mem)
  2141    && isSameCall(callAux, "runtime.memequal")
  2142    && symIsRO(scon)
  2143    && canLoadUnaligned(config) && config.PtrSize == 8
  2144    => (MakeResult (Eq64 (Load <typ.Int64> sptr mem) (Const64 <typ.Int64> [int64(read64(scon,0,config.ctxt.Arch.ByteOrder))])) mem)
  2145  
  2146  (StaticLECall {callAux} _ _ (Const64 [0]) mem)
  2147    && isSameCall(callAux, "runtime.memequal")
  2148    => (MakeResult (ConstBool <typ.Bool> [true]) mem)
  2149  
  2150  (Static(Call|LECall) {callAux} p q _ mem)
  2151    && isSameCall(callAux, "runtime.memequal")
  2152    && isSamePtr(p, q)
  2153    => (MakeResult (ConstBool <typ.Bool> [true]) mem)
  2154  
  2155  // Turn known-size calls to memclrNoHeapPointers into a Zero.
  2156  // Note that we are using types.Types[types.TUINT8] instead of sptr.Type.Elem() - see issue 55122 and CL 431496 for more details.
  2157  (SelectN [0] call:(StaticCall {sym} sptr (Const(64|32) [c]) mem))
  2158    && isInlinableMemclr(config, int64(c))
  2159    && isSameCall(sym, "runtime.memclrNoHeapPointers")
  2160    && call.Uses == 1
  2161    && clobber(call)
  2162    => (Zero {types.Types[types.TUINT8]} [int64(c)] sptr mem)
  2163  
  2164  // Recognise make([]T, 0) and replace it with a pointer to the zerobase
  2165  (StaticLECall {callAux} _ (Const(64|32) [0]) (Const(64|32) [0]) mem)
  2166  	&& isSameCall(callAux, "runtime.makeslice")
  2167  	=> (MakeResult (Addr <v.Type.FieldType(0)> {ir.Syms.Zerobase} (SB)) mem)
  2168  
  2169  // Evaluate constant address comparisons.
  2170  (EqPtr  x x) => (ConstBool [true])
  2171  (NeqPtr x x) => (ConstBool [false])
  2172  (EqPtr  (Addr {x} _) (Addr {y} _)) => (ConstBool [x == y])
  2173  (EqPtr  (Addr {x} _) (OffPtr [o] (Addr {y} _))) => (ConstBool [x == y && o == 0])
  2174  (EqPtr  (OffPtr [o1] (Addr {x} _)) (OffPtr [o2] (Addr {y} _))) => (ConstBool [x == y && o1 == o2])
  2175  (NeqPtr (Addr {x} _) (Addr {y} _)) => (ConstBool [x != y])
  2176  (NeqPtr (Addr {x} _) (OffPtr [o] (Addr {y} _))) => (ConstBool [x != y || o != 0])
  2177  (NeqPtr (OffPtr [o1] (Addr {x} _)) (OffPtr [o2] (Addr {y} _))) => (ConstBool [x != y || o1 != o2])
  2178  (EqPtr  (LocalAddr {x} _ _) (LocalAddr {y} _ _)) => (ConstBool [x == y])
  2179  (EqPtr  (LocalAddr {x} _ _) (OffPtr [o] (LocalAddr {y} _ _))) => (ConstBool [x == y && o == 0])
  2180  (EqPtr  (OffPtr [o1] (LocalAddr {x} _ _)) (OffPtr [o2] (LocalAddr {y} _ _))) => (ConstBool [x == y && o1 == o2])
  2181  (NeqPtr (LocalAddr {x} _ _) (LocalAddr {y} _ _)) => (ConstBool [x != y])
  2182  (NeqPtr (LocalAddr {x} _ _) (OffPtr [o] (LocalAddr {y} _ _))) => (ConstBool [x != y || o != 0])
  2183  (NeqPtr (OffPtr [o1] (LocalAddr {x} _ _)) (OffPtr [o2] (LocalAddr {y} _ _))) => (ConstBool [x != y || o1 != o2])
  2184  (EqPtr  (OffPtr [o1] p1) p2) && isSamePtr(p1, p2) => (ConstBool [o1 == 0])
  2185  (NeqPtr (OffPtr [o1] p1) p2) && isSamePtr(p1, p2) => (ConstBool [o1 != 0])
  2186  (EqPtr  (OffPtr [o1] p1) (OffPtr [o2] p2)) && isSamePtr(p1, p2) => (ConstBool [o1 == o2])
  2187  (NeqPtr (OffPtr [o1] p1) (OffPtr [o2] p2)) && isSamePtr(p1, p2) => (ConstBool [o1 != o2])
  2188  (EqPtr  (Const(32|64) [c]) (Const(32|64) [d])) => (ConstBool [c == d])
  2189  (NeqPtr (Const(32|64) [c]) (Const(32|64) [d])) => (ConstBool [c != d])
  2190  (EqPtr  (Convert (Addr {x} _) _) (Addr {y} _)) => (ConstBool [x==y])
  2191  (NeqPtr (Convert (Addr {x} _) _) (Addr {y} _)) => (ConstBool [x!=y])
  2192  
  2193  (EqPtr  (LocalAddr _ _) (Addr _)) => (ConstBool [false])
  2194  (EqPtr  (OffPtr (LocalAddr _ _)) (Addr _)) => (ConstBool [false])
  2195  (EqPtr  (LocalAddr _ _) (OffPtr (Addr _))) => (ConstBool [false])
  2196  (EqPtr  (OffPtr (LocalAddr _ _)) (OffPtr (Addr _))) => (ConstBool [false])
  2197  (NeqPtr (LocalAddr _ _) (Addr _)) => (ConstBool [true])
  2198  (NeqPtr (OffPtr (LocalAddr _ _)) (Addr _)) => (ConstBool [true])
  2199  (NeqPtr (LocalAddr _ _) (OffPtr (Addr _))) => (ConstBool [true])
  2200  (NeqPtr (OffPtr (LocalAddr _ _)) (OffPtr (Addr _))) => (ConstBool [true])
  2201  
  2202  // Simplify address comparisons.
  2203  (EqPtr  (AddPtr p1 o1) p2) && isSamePtr(p1, p2) => (Not (IsNonNil o1))
  2204  (NeqPtr (AddPtr p1 o1) p2) && isSamePtr(p1, p2) => (IsNonNil o1)
  2205  (EqPtr  (Const(32|64) [0]) p) => (Not (IsNonNil p))
  2206  (NeqPtr (Const(32|64) [0]) p) => (IsNonNil p)
  2207  (EqPtr  (ConstNil) p) => (Not (IsNonNil p))
  2208  (NeqPtr (ConstNil) p) => (IsNonNil p)
  2209  
  2210  // Evaluate constant user nil checks.
  2211  (IsNonNil (ConstNil)) => (ConstBool [false])
  2212  (IsNonNil (Const(32|64) [c])) => (ConstBool [c != 0])
  2213  (IsNonNil          (Addr _)   ) => (ConstBool [true])
  2214  (IsNonNil (Convert (Addr _) _)) => (ConstBool [true])
  2215  (IsNonNil (LocalAddr _ _)) => (ConstBool [true])
  2216  
  2217  // Inline small or disjoint runtime.memmove calls with constant length.
  2218  // See the comment in op Move in genericOps.go for discussion of the type.
  2219  //
  2220  // Note that we've lost any knowledge of the type and alignment requirements
  2221  // of the source and destination. We only know the size, and that the type
  2222  // contains no pointers.
  2223  // The type of the move is not necessarily v.Args[0].Type().Elem()!
  2224  // See issue 55122 for details.
  2225  //
  2226  // Because expand calls runs after prove, constants useful to this pattern may not appear.
  2227  // Both versions need to exist; the memory and register variants.
  2228  //
  2229  // Match post-expansion calls, memory version.
  2230  (SelectN [0] call:(StaticCall {sym} s1:(Store _ (Const(64|32) [sz]) s2:(Store  _ src s3:(Store {t} _ dst mem)))))
  2231  	&& sz >= 0
  2232  	&& isSameCall(sym, "runtime.memmove")
  2233  	&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
  2234  	&& isInlinableMemmove(dst, src, int64(sz), config)
  2235  	&& clobber(s1, s2, s3, call)
  2236  	=> (Move {types.Types[types.TUINT8]} [int64(sz)] dst src mem)
  2237  
  2238  // Match post-expansion calls, register version.
  2239  (SelectN [0] call:(StaticCall {sym} dst src (Const(64|32) [sz]) mem))
  2240  	&& sz >= 0
  2241  	&& call.Uses == 1 // this will exclude all calls with results
  2242  	&& isSameCall(sym, "runtime.memmove")
  2243  	&& isInlinableMemmove(dst, src, int64(sz), config)
  2244  	&& clobber(call)
  2245  	=> (Move {types.Types[types.TUINT8]} [int64(sz)] dst src mem)
  2246  
  2247  // Match pre-expansion calls.
  2248  (SelectN [0] call:(StaticLECall {sym} dst src (Const(64|32) [sz]) mem))
  2249  	&& sz >= 0
  2250  	&& call.Uses == 1 // this will exclude all calls with results
  2251  	&& isSameCall(sym, "runtime.memmove")
  2252  	&& isInlinableMemmove(dst, src, int64(sz), config)
  2253  	&& clobber(call)
  2254  	=> (Move {types.Types[types.TUINT8]} [int64(sz)] dst src mem)
  2255  
  2256  // De-virtualize late-expanded interface calls into late-expanded static calls.
  2257  (InterLECall [argsize] {auxCall} (Addr {fn} (SB)) ___) => devirtLECall(v, fn.(*obj.LSym))
  2258  
  2259  // Move and Zero optimizations.
  2260  // Move source and destination may overlap.
  2261  
  2262  // Convert Moves into Zeros when the source is known to be zeros.
  2263  (Move {t} [n] dst1 src mem:(Zero {t} [n] dst2 _)) && isSamePtr(src, dst2)
  2264  	=> (Zero {t} [n] dst1 mem)
  2265  (Move {t} [n] dst1 src mem:(VarDef (Zero {t} [n] dst0 _))) && isSamePtr(src, dst0)
  2266  	=> (Zero {t} [n] dst1 mem)
  2267  (Move {t} [n] dst (Addr {sym} (SB)) mem) && symIsROZero(sym) => (Zero {t} [n] dst mem)
  2268  
  2269  // Don't Store to variables that are about to be overwritten by Move/Zero.
  2270  (Zero {t1} [n] p1 store:(Store {t2} (OffPtr [o2] p2) _ mem))
  2271  	&& isSamePtr(p1, p2) && store.Uses == 1
  2272  	&& n >= o2 + t2.Size()
  2273  	&& clobber(store)
  2274  	=> (Zero {t1} [n] p1 mem)
  2275  (Move {t1} [n] dst1 src1 store:(Store {t2} op:(OffPtr [o2] dst2) _ mem))
  2276  	&& isSamePtr(dst1, dst2) && store.Uses == 1
  2277  	&& n >= o2 + t2.Size()
  2278  	&& disjoint(src1, n, op, t2.Size())
  2279  	&& clobber(store)
  2280  	=> (Move {t1} [n] dst1 src1 mem)
  2281  
  2282  // Don't Move to variables that are immediately completely overwritten.
  2283  (Zero {t} [n] dst1 move:(Move {t} [n] dst2 _ mem))
  2284  	&& move.Uses == 1
  2285  	&& isSamePtr(dst1, dst2)
  2286  	&& clobber(move)
  2287  	=> (Zero {t} [n] dst1 mem)
  2288  (Move {t} [n] dst1 src1 move:(Move {t} [n] dst2 _ mem))
  2289  	&& move.Uses == 1
  2290  	&& isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n)
  2291  	&& clobber(move)
  2292  	=> (Move {t} [n] dst1 src1 mem)
  2293  (Zero {t} [n] dst1 vardef:(VarDef {x} move:(Move {t} [n] dst2 _ mem)))
  2294  	&& move.Uses == 1 && vardef.Uses == 1
  2295  	&& isSamePtr(dst1, dst2)
  2296  	&& clobber(move, vardef)
  2297  	=> (Zero {t} [n] dst1 (VarDef {x} mem))
  2298  (Move {t} [n] dst1 src1 vardef:(VarDef {x} move:(Move {t} [n] dst2 _ mem)))
  2299  	&& move.Uses == 1 && vardef.Uses == 1
  2300  	&& isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n)
  2301  	&& clobber(move, vardef)
  2302  	=> (Move {t} [n] dst1 src1 (VarDef {x} mem))
  2303  (Store {t1} op1:(OffPtr [o1] p1) d1
  2304  	m2:(Store {t2} op2:(OffPtr [0] p2) d2
  2305  		m3:(Move [n] p3 _ mem)))
  2306  	&& m2.Uses == 1 && m3.Uses == 1
  2307  	&& o1 == t2.Size()
  2308  	&& n == t2.Size() + t1.Size()
  2309  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3)
  2310  	&& clobber(m2, m3)
  2311  	=> (Store {t1} op1 d1 (Store {t2} op2 d2 mem))
  2312  (Store {t1} op1:(OffPtr [o1] p1) d1
  2313  	m2:(Store {t2} op2:(OffPtr [o2] p2) d2
  2314  		m3:(Store {t3} op3:(OffPtr [0] p3) d3
  2315  			m4:(Move [n] p4 _ mem))))
  2316  	&& m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1
  2317  	&& o2 == t3.Size()
  2318  	&& o1-o2 == t2.Size()
  2319  	&& n == t3.Size() + t2.Size() + t1.Size()
  2320  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4)
  2321  	&& clobber(m2, m3, m4)
  2322  	=> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 mem)))
  2323  (Store {t1} op1:(OffPtr [o1] p1) d1
  2324  	m2:(Store {t2} op2:(OffPtr [o2] p2) d2
  2325  		m3:(Store {t3} op3:(OffPtr [o3] p3) d3
  2326  			m4:(Store {t4} op4:(OffPtr [0] p4) d4
  2327  				m5:(Move [n] p5 _ mem)))))
  2328  	&& m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 && m5.Uses == 1
  2329  	&& o3 == t4.Size()
  2330  	&& o2-o3 == t3.Size()
  2331  	&& o1-o2 == t2.Size()
  2332  	&& n == t4.Size() + t3.Size() + t2.Size() + t1.Size()
  2333  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5)
  2334  	&& clobber(m2, m3, m4, m5)
  2335  	=> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 (Store {t4} op4 d4 mem))))
  2336  
  2337  // Don't Zero variables that are immediately completely overwritten
  2338  // before being accessed.
  2339  (Move {t} [n] dst1 src1 zero:(Zero {t} [n] dst2 mem))
  2340  	&& zero.Uses == 1
  2341  	&& isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n)
  2342  	&& clobber(zero)
  2343  	=> (Move {t} [n] dst1 src1 mem)
  2344  (Move {t} [n] dst1 src1 vardef:(VarDef {x} zero:(Zero {t} [n] dst2 mem)))
  2345  	&& zero.Uses == 1 && vardef.Uses == 1
  2346  	&& isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n)
  2347  	&& clobber(zero, vardef)
  2348  	=> (Move {t} [n] dst1 src1 (VarDef {x} mem))
  2349  (Store {t1} op1:(OffPtr [o1] p1) d1
  2350  	m2:(Store {t2} op2:(OffPtr [0] p2) d2
  2351  		m3:(Zero [n] p3 mem)))
  2352  	&& m2.Uses == 1 && m3.Uses == 1
  2353  	&& o1 == t2.Size()
  2354  	&& n == t2.Size() + t1.Size()
  2355  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3)
  2356  	&& clobber(m2, m3)
  2357  	=> (Store {t1} op1 d1 (Store {t2} op2 d2 mem))
  2358  (Store {t1} op1:(OffPtr [o1] p1) d1
  2359  	m2:(Store {t2} op2:(OffPtr [o2] p2) d2
  2360  		m3:(Store {t3} op3:(OffPtr [0] p3) d3
  2361  			m4:(Zero [n] p4 mem))))
  2362  	&& m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1
  2363  	&& o2 == t3.Size()
  2364  	&& o1-o2 == t2.Size()
  2365  	&& n == t3.Size() + t2.Size() + t1.Size()
  2366  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4)
  2367  	&& clobber(m2, m3, m4)
  2368  	=> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 mem)))
  2369  (Store {t1} op1:(OffPtr [o1] p1) d1
  2370  	m2:(Store {t2} op2:(OffPtr [o2] p2) d2
  2371  		m3:(Store {t3} op3:(OffPtr [o3] p3) d3
  2372  			m4:(Store {t4} op4:(OffPtr [0] p4) d4
  2373  				m5:(Zero [n] p5 mem)))))
  2374  	&& m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 && m5.Uses == 1
  2375  	&& o3 == t4.Size()
  2376  	&& o2-o3 == t3.Size()
  2377  	&& o1-o2 == t2.Size()
  2378  	&& n == t4.Size() + t3.Size() + t2.Size() + t1.Size()
  2379  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5)
  2380  	&& clobber(m2, m3, m4, m5)
  2381  	=> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 (Store {t4} op4 d4 mem))))
  2382  
  2383  // Don't Move from memory if the values are likely to already be
  2384  // in registers.
  2385  (Move {t1} [n] dst p1
  2386  	mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2387  		(Store {t3} op3:(OffPtr <tt3> [0] p3) d2 _)))
  2388  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3)
  2389  	&& t2.Alignment() <= t1.Alignment()
  2390  	&& t3.Alignment() <= t1.Alignment()
  2391  	&& registerizable(b, t2)
  2392  	&& registerizable(b, t3)
  2393  	&& o2 == t3.Size()
  2394  	&& n == t2.Size() + t3.Size()
  2395  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2396  		(Store {t3} (OffPtr <tt3> [0] dst) d2 mem))
  2397  (Move {t1} [n] dst p1
  2398  	mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2399  		(Store {t3} op3:(OffPtr <tt3> [o3] p3) d2
  2400  			(Store {t4} op4:(OffPtr <tt4> [0] p4) d3 _))))
  2401  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4)
  2402  	&& t2.Alignment() <= t1.Alignment()
  2403  	&& t3.Alignment() <= t1.Alignment()
  2404  	&& t4.Alignment() <= t1.Alignment()
  2405  	&& registerizable(b, t2)
  2406  	&& registerizable(b, t3)
  2407  	&& registerizable(b, t4)
  2408  	&& o3 == t4.Size()
  2409  	&& o2-o3 == t3.Size()
  2410  	&& n == t2.Size() + t3.Size() + t4.Size()
  2411  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2412  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2413  			(Store {t4} (OffPtr <tt4> [0] dst) d3 mem)))
  2414  (Move {t1} [n] dst p1
  2415  	mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2416  		(Store {t3} op3:(OffPtr <tt3> [o3] p3) d2
  2417  			(Store {t4} op4:(OffPtr <tt4> [o4] p4) d3
  2418  				(Store {t5} op5:(OffPtr <tt5> [0] p5) d4 _)))))
  2419  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5)
  2420  	&& t2.Alignment() <= t1.Alignment()
  2421  	&& t3.Alignment() <= t1.Alignment()
  2422  	&& t4.Alignment() <= t1.Alignment()
  2423  	&& t5.Alignment() <= t1.Alignment()
  2424  	&& registerizable(b, t2)
  2425  	&& registerizable(b, t3)
  2426  	&& registerizable(b, t4)
  2427  	&& registerizable(b, t5)
  2428  	&& o4 == t5.Size()
  2429  	&& o3-o4 == t4.Size()
  2430  	&& o2-o3 == t3.Size()
  2431  	&& n == t2.Size() + t3.Size() + t4.Size() + t5.Size()
  2432  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2433  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2434  			(Store {t4} (OffPtr <tt4> [o4] dst) d3
  2435  				(Store {t5} (OffPtr <tt5> [0] dst) d4 mem))))
  2436  
  2437  // Same thing but with VarDef in the middle.
  2438  (Move {t1} [n] dst p1
  2439  	mem:(VarDef
  2440  		(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2441  			(Store {t3} op3:(OffPtr <tt3> [0] p3) d2 _))))
  2442  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3)
  2443  	&& t2.Alignment() <= t1.Alignment()
  2444  	&& t3.Alignment() <= t1.Alignment()
  2445  	&& registerizable(b, t2)
  2446  	&& registerizable(b, t3)
  2447  	&& o2 == t3.Size()
  2448  	&& n == t2.Size() + t3.Size()
  2449  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2450  		(Store {t3} (OffPtr <tt3> [0] dst) d2 mem))
  2451  (Move {t1} [n] dst p1
  2452  	mem:(VarDef
  2453  		(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2454  			(Store {t3} op3:(OffPtr <tt3> [o3] p3) d2
  2455  				(Store {t4} op4:(OffPtr <tt4> [0] p4) d3 _)))))
  2456  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4)
  2457  	&& t2.Alignment() <= t1.Alignment()
  2458  	&& t3.Alignment() <= t1.Alignment()
  2459  	&& t4.Alignment() <= t1.Alignment()
  2460  	&& registerizable(b, t2)
  2461  	&& registerizable(b, t3)
  2462  	&& registerizable(b, t4)
  2463  	&& o3 == t4.Size()
  2464  	&& o2-o3 == t3.Size()
  2465  	&& n == t2.Size() + t3.Size() + t4.Size()
  2466  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2467  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2468  			(Store {t4} (OffPtr <tt4> [0] dst) d3 mem)))
  2469  (Move {t1} [n] dst p1
  2470  	mem:(VarDef
  2471  		(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2472  			(Store {t3} op3:(OffPtr <tt3> [o3] p3) d2
  2473  				(Store {t4} op4:(OffPtr <tt4> [o4] p4) d3
  2474  					(Store {t5} op5:(OffPtr <tt5> [0] p5) d4 _))))))
  2475  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5)
  2476  	&& t2.Alignment() <= t1.Alignment()
  2477  	&& t3.Alignment() <= t1.Alignment()
  2478  	&& t4.Alignment() <= t1.Alignment()
  2479  	&& t5.Alignment() <= t1.Alignment()
  2480  	&& registerizable(b, t2)
  2481  	&& registerizable(b, t3)
  2482  	&& registerizable(b, t4)
  2483  	&& registerizable(b, t5)
  2484  	&& o4 == t5.Size()
  2485  	&& o3-o4 == t4.Size()
  2486  	&& o2-o3 == t3.Size()
  2487  	&& n == t2.Size() + t3.Size() + t4.Size() + t5.Size()
  2488  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2489  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2490  			(Store {t4} (OffPtr <tt4> [o4] dst) d3
  2491  				(Store {t5} (OffPtr <tt5> [0] dst) d4 mem))))
  2492  
  2493  // Prefer to Zero and Store than to Move.
  2494  (Move {t1} [n] dst p1
  2495  	mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2496  		(Zero {t3} [n] p3 _)))
  2497  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3)
  2498  	&& t2.Alignment() <= t1.Alignment()
  2499  	&& t3.Alignment() <= t1.Alignment()
  2500  	&& registerizable(b, t2)
  2501  	&& n >= o2 + t2.Size()
  2502  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2503  		(Zero {t1} [n] dst mem))
  2504  (Move {t1} [n] dst p1
  2505  	mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1
  2506  		(Store {t3} (OffPtr <tt3> [o3] p3) d2
  2507  			(Zero {t4} [n] p4 _))))
  2508  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4)
  2509  	&& t2.Alignment() <= t1.Alignment()
  2510  	&& t3.Alignment() <= t1.Alignment()
  2511  	&& t4.Alignment() <= t1.Alignment()
  2512  	&& registerizable(b, t2)
  2513  	&& registerizable(b, t3)
  2514  	&& n >= o2 + t2.Size()
  2515  	&& n >= o3 + t3.Size()
  2516  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2517  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2518  			(Zero {t1} [n] dst mem)))
  2519  (Move {t1} [n] dst p1
  2520  	mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1
  2521  		(Store {t3} (OffPtr <tt3> [o3] p3) d2
  2522  			(Store {t4} (OffPtr <tt4> [o4] p4) d3
  2523  				(Zero {t5} [n] p5 _)))))
  2524  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5)
  2525  	&& t2.Alignment() <= t1.Alignment()
  2526  	&& t3.Alignment() <= t1.Alignment()
  2527  	&& t4.Alignment() <= t1.Alignment()
  2528  	&& t5.Alignment() <= t1.Alignment()
  2529  	&& registerizable(b, t2)
  2530  	&& registerizable(b, t3)
  2531  	&& registerizable(b, t4)
  2532  	&& n >= o2 + t2.Size()
  2533  	&& n >= o3 + t3.Size()
  2534  	&& n >= o4 + t4.Size()
  2535  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2536  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2537  			(Store {t4} (OffPtr <tt4> [o4] dst) d3
  2538  				(Zero {t1} [n] dst mem))))
  2539  (Move {t1} [n] dst p1
  2540  	mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1
  2541  		(Store {t3} (OffPtr <tt3> [o3] p3) d2
  2542  			(Store {t4} (OffPtr <tt4> [o4] p4) d3
  2543  				(Store {t5} (OffPtr <tt5> [o5] p5) d4
  2544  					(Zero {t6} [n] p6 _))))))
  2545  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) && isSamePtr(p5, p6)
  2546  	&& t2.Alignment() <= t1.Alignment()
  2547  	&& t3.Alignment() <= t1.Alignment()
  2548  	&& t4.Alignment() <= t1.Alignment()
  2549  	&& t5.Alignment() <= t1.Alignment()
  2550  	&& t6.Alignment() <= t1.Alignment()
  2551  	&& registerizable(b, t2)
  2552  	&& registerizable(b, t3)
  2553  	&& registerizable(b, t4)
  2554  	&& registerizable(b, t5)
  2555  	&& n >= o2 + t2.Size()
  2556  	&& n >= o3 + t3.Size()
  2557  	&& n >= o4 + t4.Size()
  2558  	&& n >= o5 + t5.Size()
  2559  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2560  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2561  			(Store {t4} (OffPtr <tt4> [o4] dst) d3
  2562  				(Store {t5} (OffPtr <tt5> [o5] dst) d4
  2563  					(Zero {t1} [n] dst mem)))))
  2564  (Move {t1} [n] dst p1
  2565  	mem:(VarDef
  2566  		(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1
  2567  			(Zero {t3} [n] p3 _))))
  2568  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3)
  2569  	&& t2.Alignment() <= t1.Alignment()
  2570  	&& t3.Alignment() <= t1.Alignment()
  2571  	&& registerizable(b, t2)
  2572  	&& n >= o2 + t2.Size()
  2573  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2574  		(Zero {t1} [n] dst mem))
  2575  (Move {t1} [n] dst p1
  2576  	mem:(VarDef
  2577  		(Store {t2} (OffPtr <tt2> [o2] p2) d1
  2578  			(Store {t3} (OffPtr <tt3> [o3] p3) d2
  2579  				(Zero {t4} [n] p4 _)))))
  2580  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4)
  2581  	&& t2.Alignment() <= t1.Alignment()
  2582  	&& t3.Alignment() <= t1.Alignment()
  2583  	&& t4.Alignment() <= t1.Alignment()
  2584  	&& registerizable(b, t2)
  2585  	&& registerizable(b, t3)
  2586  	&& n >= o2 + t2.Size()
  2587  	&& n >= o3 + t3.Size()
  2588  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2589  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2590  			(Zero {t1} [n] dst mem)))
  2591  (Move {t1} [n] dst p1
  2592  	mem:(VarDef
  2593  		(Store {t2} (OffPtr <tt2> [o2] p2) d1
  2594  			(Store {t3} (OffPtr <tt3> [o3] p3) d2
  2595  				(Store {t4} (OffPtr <tt4> [o4] p4) d3
  2596  					(Zero {t5} [n] p5 _))))))
  2597  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5)
  2598  	&& t2.Alignment() <= t1.Alignment()
  2599  	&& t3.Alignment() <= t1.Alignment()
  2600  	&& t4.Alignment() <= t1.Alignment()
  2601  	&& t5.Alignment() <= t1.Alignment()
  2602  	&& registerizable(b, t2)
  2603  	&& registerizable(b, t3)
  2604  	&& registerizable(b, t4)
  2605  	&& n >= o2 + t2.Size()
  2606  	&& n >= o3 + t3.Size()
  2607  	&& n >= o4 + t4.Size()
  2608  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2609  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2610  			(Store {t4} (OffPtr <tt4> [o4] dst) d3
  2611  				(Zero {t1} [n] dst mem))))
  2612  (Move {t1} [n] dst p1
  2613  	mem:(VarDef
  2614  		(Store {t2} (OffPtr <tt2> [o2] p2) d1
  2615  			(Store {t3} (OffPtr <tt3> [o3] p3) d2
  2616  				(Store {t4} (OffPtr <tt4> [o4] p4) d3
  2617  					(Store {t5} (OffPtr <tt5> [o5] p5) d4
  2618  						(Zero {t6} [n] p6 _)))))))
  2619  	&& isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) && isSamePtr(p5, p6)
  2620  	&& t2.Alignment() <= t1.Alignment()
  2621  	&& t3.Alignment() <= t1.Alignment()
  2622  	&& t4.Alignment() <= t1.Alignment()
  2623  	&& t5.Alignment() <= t1.Alignment()
  2624  	&& t6.Alignment() <= t1.Alignment()
  2625  	&& registerizable(b, t2)
  2626  	&& registerizable(b, t3)
  2627  	&& registerizable(b, t4)
  2628  	&& registerizable(b, t5)
  2629  	&& n >= o2 + t2.Size()
  2630  	&& n >= o3 + t3.Size()
  2631  	&& n >= o4 + t4.Size()
  2632  	&& n >= o5 + t5.Size()
  2633  	=> (Store {t2} (OffPtr <tt2> [o2] dst) d1
  2634  		(Store {t3} (OffPtr <tt3> [o3] dst) d2
  2635  			(Store {t4} (OffPtr <tt4> [o4] dst) d3
  2636  				(Store {t5} (OffPtr <tt5> [o5] dst) d4
  2637  					(Zero {t1} [n] dst mem)))))
  2638  
  2639  (SelectN [0] call:(StaticLECall {sym} a x)) && needRaceCleanup(sym, call) && clobber(call) => x
  2640  (SelectN [0] call:(StaticLECall {sym} x)) && needRaceCleanup(sym, call) && clobber(call) => x
  2641  
  2642  // When rewriting append to growslice, we use as the new length the result of
  2643  // growslice so that we don't have to spill/restore the new length around the growslice call.
  2644  // The exception here is that if the new length is a constant, avoiding spilling it
  2645  // is pointless and its constantness is sometimes useful for subsequent optimizations.
  2646  // See issue 56440.
  2647  // Note there are 2 rules here, one for the pre-decomposed []T result and one for
  2648  // the post-decomposed (*T,int,int) result. (The latter is generated after call expansion.)
  2649  (SliceLen (SelectN [0] (StaticLECall {sym} _ newLen:(Const(64|32)) _ _ _ _))) && isSameCall(sym, "runtime.growslice") => newLen
  2650  (SelectN [1] (StaticCall {sym} _ newLen:(Const(64|32)) _ _ _ _)) && v.Type.IsInteger() && isSameCall(sym, "runtime.growslice") => newLen
  2651  
  2652  // Collapse moving A -> B -> C into just A -> C.
  2653  // Later passes (deadstore, elim unread auto) will remove the A -> B move, if possible.
  2654  // This happens most commonly when B is an autotmp inserted earlier
  2655  // during compilation to ensure correctness.
  2656  // Take care that overlapping moves are preserved.
  2657  // Restrict this optimization to the stack, to avoid duplicating loads from the heap;
  2658  // see CL 145208 for discussion.
  2659  (Move {t1} [s] dst tmp1 midmem:(Move {t2} [s] tmp2 src _))
  2660  	&& t1.Compare(t2) == types.CMPeq
  2661  	&& isSamePtr(tmp1, tmp2)
  2662  	&& isStackPtr(src) && !isVolatile(src)
  2663  	&& disjoint(src, s, tmp2, s)
  2664  	&& (disjoint(src, s, dst, s) || isInlinableMemmove(dst, src, s, config))
  2665  	=> (Move {t1} [s] dst src midmem)
  2666  
  2667  // Same, but for large types that require VarDefs.
  2668  (Move {t1} [s] dst tmp1 midmem:(VarDef (Move {t2} [s] tmp2 src _)))
  2669  	&& t1.Compare(t2) == types.CMPeq
  2670  	&& isSamePtr(tmp1, tmp2)
  2671  	&& isStackPtr(src) && !isVolatile(src)
  2672  	&& disjoint(src, s, tmp2, s)
  2673  	&& (disjoint(src, s, dst, s) || isInlinableMemmove(dst, src, s, config))
  2674  	=> (Move {t1} [s] dst src midmem)
  2675  
  2676  // Don't zero the same bits twice.
  2677  (Zero {t} [s] dst1 zero:(Zero {t} [s] dst2 _)) && isSamePtr(dst1, dst2) => zero
  2678  (Zero {t} [s] dst1 vardef:(VarDef (Zero {t} [s] dst2 _))) && isSamePtr(dst1, dst2) => vardef
  2679  
  2680  // Elide self-moves. This only happens rarely (e.g test/fixedbugs/bug277.go).
  2681  // However, this rule is needed to prevent the previous rule from looping forever in such cases.
  2682  (Move dst src mem) && isSamePtr(dst, src) => mem
  2683  
  2684  // Constant rotate detection.
  2685  ((Add64|Or64|Xor64) (Lsh64x64 x z:(Const64 <t> [c])) (Rsh64Ux64 x (Const64 [d]))) && c < 64 && d == 64-c && canRotate(config, 64) => (RotateLeft64 x z)
  2686  ((Add32|Or32|Xor32) (Lsh32x64 x z:(Const64 <t> [c])) (Rsh32Ux64 x (Const64 [d]))) && c < 32 && d == 32-c && canRotate(config, 32) => (RotateLeft32 x z)
  2687  ((Add16|Or16|Xor16) (Lsh16x64 x z:(Const64 <t> [c])) (Rsh16Ux64 x (Const64 [d]))) && c < 16 && d == 16-c && canRotate(config, 16) => (RotateLeft16 x z)
  2688  ((Add8|Or8|Xor8) (Lsh8x64 x z:(Const64 <t> [c])) (Rsh8Ux64 x (Const64 [d]))) && c < 8 && d == 8-c && canRotate(config, 8) => (RotateLeft8 x z)
  2689  
  2690  // Non-constant rotate detection.
  2691  // We use shiftIsBounded to make sure that neither of the shifts are >64.
  2692  // Note: these rules are subtle when the shift amounts are 0/64, as Go shifts
  2693  // are different from most native shifts. But it works out.
  2694  ((Add64|Or64|Xor64) left:(Lsh64x64 x y) right:(Rsh64Ux64 x (Sub64 (Const64 [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x y)
  2695  ((Add64|Or64|Xor64) left:(Lsh64x32 x y) right:(Rsh64Ux32 x (Sub32 (Const32 [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x y)
  2696  ((Add64|Or64|Xor64) left:(Lsh64x16 x y) right:(Rsh64Ux16 x (Sub16 (Const16 [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x y)
  2697  ((Add64|Or64|Xor64) left:(Lsh64x8  x y) right:(Rsh64Ux8  x (Sub8  (Const8  [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x y)
  2698  
  2699  ((Add64|Or64|Xor64) right:(Rsh64Ux64 x y) left:(Lsh64x64 x z:(Sub64 (Const64 [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x z)
  2700  ((Add64|Or64|Xor64) right:(Rsh64Ux32 x y) left:(Lsh64x32 x z:(Sub32 (Const32 [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x z)
  2701  ((Add64|Or64|Xor64) right:(Rsh64Ux16 x y) left:(Lsh64x16 x z:(Sub16 (Const16 [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x z)
  2702  ((Add64|Or64|Xor64) right:(Rsh64Ux8  x y) left:(Lsh64x8  x z:(Sub8  (Const8  [64]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 64) => (RotateLeft64 x z)
  2703  
  2704  ((Add32|Or32|Xor32) left:(Lsh32x64 x y) right:(Rsh32Ux64 x (Sub64 (Const64 [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x y)
  2705  ((Add32|Or32|Xor32) left:(Lsh32x32 x y) right:(Rsh32Ux32 x (Sub32 (Const32 [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x y)
  2706  ((Add32|Or32|Xor32) left:(Lsh32x16 x y) right:(Rsh32Ux16 x (Sub16 (Const16 [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x y)
  2707  ((Add32|Or32|Xor32) left:(Lsh32x8  x y) right:(Rsh32Ux8  x (Sub8  (Const8  [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x y)
  2708  
  2709  ((Add32|Or32|Xor32) right:(Rsh32Ux64 x y) left:(Lsh32x64 x z:(Sub64 (Const64 [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x z)
  2710  ((Add32|Or32|Xor32) right:(Rsh32Ux32 x y) left:(Lsh32x32 x z:(Sub32 (Const32 [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x z)
  2711  ((Add32|Or32|Xor32) right:(Rsh32Ux16 x y) left:(Lsh32x16 x z:(Sub16 (Const16 [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x z)
  2712  ((Add32|Or32|Xor32) right:(Rsh32Ux8  x y) left:(Lsh32x8  x z:(Sub8  (Const8  [32]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 32) => (RotateLeft32 x z)
  2713  
  2714  ((Add16|Or16|Xor16) left:(Lsh16x64 x y) right:(Rsh16Ux64 x (Sub64 (Const64 [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x y)
  2715  ((Add16|Or16|Xor16) left:(Lsh16x32 x y) right:(Rsh16Ux32 x (Sub32 (Const32 [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x y)
  2716  ((Add16|Or16|Xor16) left:(Lsh16x16 x y) right:(Rsh16Ux16 x (Sub16 (Const16 [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x y)
  2717  ((Add16|Or16|Xor16) left:(Lsh16x8  x y) right:(Rsh16Ux8  x (Sub8  (Const8  [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x y)
  2718  
  2719  ((Add16|Or16|Xor16) right:(Rsh16Ux64 x y) left:(Lsh16x64 x z:(Sub64 (Const64 [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x z)
  2720  ((Add16|Or16|Xor16) right:(Rsh16Ux32 x y) left:(Lsh16x32 x z:(Sub32 (Const32 [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x z)
  2721  ((Add16|Or16|Xor16) right:(Rsh16Ux16 x y) left:(Lsh16x16 x z:(Sub16 (Const16 [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x z)
  2722  ((Add16|Or16|Xor16) right:(Rsh16Ux8  x y) left:(Lsh16x8  x z:(Sub8  (Const8  [16]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 16) => (RotateLeft16 x z)
  2723  
  2724  ((Add8|Or8|Xor8) left:(Lsh8x64 x y) right:(Rsh8Ux64 x (Sub64 (Const64 [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x y)
  2725  ((Add8|Or8|Xor8) left:(Lsh8x32 x y) right:(Rsh8Ux32 x (Sub32 (Const32 [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x y)
  2726  ((Add8|Or8|Xor8) left:(Lsh8x16 x y) right:(Rsh8Ux16 x (Sub16 (Const16 [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x y)
  2727  ((Add8|Or8|Xor8) left:(Lsh8x8  x y) right:(Rsh8Ux8  x (Sub8  (Const8  [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x y)
  2728  
  2729  ((Add8|Or8|Xor8) right:(Rsh8Ux64 x y) left:(Lsh8x64 x z:(Sub64 (Const64 [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x z)
  2730  ((Add8|Or8|Xor8) right:(Rsh8Ux32 x y) left:(Lsh8x32 x z:(Sub32 (Const32 [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x z)
  2731  ((Add8|Or8|Xor8) right:(Rsh8Ux16 x y) left:(Lsh8x16 x z:(Sub16 (Const16 [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x z)
  2732  ((Add8|Or8|Xor8) right:(Rsh8Ux8  x y) left:(Lsh8x8  x z:(Sub8  (Const8  [8]) y))) && (shiftIsBounded(left) || shiftIsBounded(right)) && canRotate(config, 8) => (RotateLeft8 x z)
  2733  
  2734  // Rotating by y&c, with c a mask that doesn't change the bottom bits, is the same as rotating by y.
  2735  (RotateLeft64 x (And(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&63 == 63 => (RotateLeft64 x y)
  2736  (RotateLeft32 x (And(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&31 == 31 => (RotateLeft32 x y)
  2737  (RotateLeft16 x (And(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&15 == 15 => (RotateLeft16 x y)
  2738  (RotateLeft8  x (And(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&7  == 7  => (RotateLeft8  x y)
  2739  
  2740  // Rotating by -(y&c), with c a mask that doesn't change the bottom bits, is the same as rotating by -y.
  2741  (RotateLeft64 x (Neg(64|32|16|8) (And(64|32|16|8) y (Const(64|32|16|8) [c])))) && c&63 == 63 => (RotateLeft64 x (Neg(64|32|16|8) <y.Type> y))
  2742  (RotateLeft32 x (Neg(64|32|16|8) (And(64|32|16|8) y (Const(64|32|16|8) [c])))) && c&31 == 31 => (RotateLeft32 x (Neg(64|32|16|8) <y.Type> y))
  2743  (RotateLeft16 x (Neg(64|32|16|8) (And(64|32|16|8) y (Const(64|32|16|8) [c])))) && c&15 == 15 => (RotateLeft16 x (Neg(64|32|16|8) <y.Type> y))
  2744  (RotateLeft8  x (Neg(64|32|16|8) (And(64|32|16|8) y (Const(64|32|16|8) [c])))) && c&7  == 7  => (RotateLeft8  x (Neg(64|32|16|8) <y.Type> y))
  2745  
  2746  // Rotating by y+c, with c a multiple of the value width, is the same as rotating by y.
  2747  (RotateLeft64 x (Add(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&63 == 0 => (RotateLeft64 x y)
  2748  (RotateLeft32 x (Add(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&31 == 0 => (RotateLeft32 x y)
  2749  (RotateLeft16 x (Add(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&15 == 0 => (RotateLeft16 x y)
  2750  (RotateLeft8  x (Add(64|32|16|8) y (Const(64|32|16|8) [c]))) && c&7  == 0 => (RotateLeft8  x y)
  2751  
  2752  // Rotating by c-y, with c a multiple of the value width, is the same as rotating by -y.
  2753  (RotateLeft64 x (Sub(64|32|16|8) (Const(64|32|16|8) [c]) y)) && c&63 == 0 => (RotateLeft64 x (Neg(64|32|16|8) <y.Type> y))
  2754  (RotateLeft32 x (Sub(64|32|16|8) (Const(64|32|16|8) [c]) y)) && c&31 == 0 => (RotateLeft32 x (Neg(64|32|16|8) <y.Type> y))
  2755  (RotateLeft16 x (Sub(64|32|16|8) (Const(64|32|16|8) [c]) y)) && c&15 == 0 => (RotateLeft16 x (Neg(64|32|16|8) <y.Type> y))
  2756  (RotateLeft8  x (Sub(64|32|16|8) (Const(64|32|16|8) [c]) y)) && c&7  == 0 => (RotateLeft8  x (Neg(64|32|16|8) <y.Type> y))
  2757  
  2758  // Ensure we don't do Const64 rotates in a 32-bit system.
  2759  (RotateLeft64 x (Const64 <t> [c])) && config.PtrSize == 4 => (RotateLeft64 x (Const32 <t> [int32(c)]))
  2760  (RotateLeft32 x (Const64 <t> [c])) && config.PtrSize == 4 => (RotateLeft32 x (Const32 <t> [int32(c)]))
  2761  (RotateLeft16 x (Const64 <t> [c])) && config.PtrSize == 4 => (RotateLeft16 x (Const32 <t> [int32(c)]))
  2762  (RotateLeft8  x (Const64 <t> [c])) && config.PtrSize == 4 => (RotateLeft8  x (Const32 <t> [int32(c)]))
  2763  
  2764  // Rotating by c, then by d, is the same as rotating by c+d.
  2765  // We're trading a rotate for an add, which seems generally a good choice. It is especially good when c and d are constants.
  2766  // This rule is a bit tricky as c and d might be different widths. We handle only cases where they are the same width.
  2767  (RotateLeft(64|32|16|8) (RotateLeft(64|32|16|8) x c) d) && c.Type.Size() == 8 && d.Type.Size() == 8 => (RotateLeft(64|32|16|8) x (Add64 <c.Type> c d))
  2768  (RotateLeft(64|32|16|8) (RotateLeft(64|32|16|8) x c) d) && c.Type.Size() == 4 && d.Type.Size() == 4 => (RotateLeft(64|32|16|8) x (Add32 <c.Type> c d))
  2769  (RotateLeft(64|32|16|8) (RotateLeft(64|32|16|8) x c) d) && c.Type.Size() == 2 && d.Type.Size() == 2 => (RotateLeft(64|32|16|8) x (Add16 <c.Type> c d))
  2770  (RotateLeft(64|32|16|8) (RotateLeft(64|32|16|8) x c) d) && c.Type.Size() == 1 && d.Type.Size() == 1 => (RotateLeft(64|32|16|8) x (Add8  <c.Type> c d))
  2771  
  2772  // Loading constant values from dictionaries and itabs.
  2773  (Load <typ.BytePtr> (OffPtr [off]                       (Addr {s} sb)       ) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2774  (Load <typ.BytePtr> (OffPtr [off]              (Convert (Addr {s} sb) _)    ) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2775  (Load <typ.BytePtr> (OffPtr [off] (ITab (IMake          (Addr {s} sb)    _))) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2776  (Load <typ.BytePtr> (OffPtr [off] (ITab (IMake (Convert (Addr {s} sb) _) _))) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2777  (Load <typ.Uintptr> (OffPtr [off]                       (Addr {s} sb)       ) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2778  (Load <typ.Uintptr> (OffPtr [off]              (Convert (Addr {s} sb) _)    ) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2779  (Load <typ.Uintptr> (OffPtr [off] (ITab (IMake          (Addr {s} sb)    _))) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2780  (Load <typ.Uintptr> (OffPtr [off] (ITab (IMake (Convert (Addr {s} sb) _) _))) _)  && isFixedSym(s, off) => (Addr {fixedSym(b.Func, s, off)} sb)
  2781  
  2782  // Loading constant values from runtime._type.hash.
  2783  (Load <t> (OffPtr [off]                       (Addr {sym} _)       ) _) && t.IsInteger() && t.Size() == 4 && isFixed32(config, sym, off) => (Const32 [fixed32(config, sym, off)])
  2784  (Load <t> (OffPtr [off]              (Convert (Addr {sym} _) _)    ) _) && t.IsInteger() && t.Size() == 4 && isFixed32(config, sym, off) => (Const32 [fixed32(config, sym, off)])
  2785  (Load <t> (OffPtr [off] (ITab (IMake          (Addr {sym} _)    _))) _) && t.IsInteger() && t.Size() == 4 && isFixed32(config, sym, off) => (Const32 [fixed32(config, sym, off)])
  2786  (Load <t> (OffPtr [off] (ITab (IMake (Convert (Addr {sym} _) _) _))) _) && t.IsInteger() && t.Size() == 4 && isFixed32(config, sym, off) => (Const32 [fixed32(config, sym, off)])
  2787  
  2788  // Calling cmpstring a second time with the same arguments in the
  2789  // same memory state can reuse the results of the first call.
  2790  // See issue 61725.
  2791  // Note that this could pretty easily generalize to any pure function.
  2792  (SelectN [0] (StaticLECall {f} x y (SelectN [1] c:(StaticLECall {g} x y mem))))
  2793    && isSameCall(f, "runtime.cmpstring")
  2794    && isSameCall(g, "runtime.cmpstring")
  2795  => @c.Block (SelectN [0] <typ.Int> c)
  2796  
  2797  // If we don't use the result of cmpstring, might as well not call it.
  2798  // Note that this could pretty easily generalize to any pure function.
  2799  (SelectN [1] c:(StaticLECall {f} _ _ mem)) && c.Uses == 1 && isSameCall(f, "runtime.cmpstring") && clobber(c) => mem
  2800  
  2801  // We can easily compute the result of efaceeq if
  2802  // we know the underlying type is pointer-ish.
  2803  (StaticLECall {f} typ_ x y mem)
  2804  	&& isSameCall(f, "runtime.efaceeq")
  2805  	&& isDirectType(typ_)
  2806  	&& clobber(v)
  2807  	=> (MakeResult (EqPtr x y) mem)
  2808  
  2809  // We can easily compute the result of ifaceeq if
  2810  // we know the underlying type is pointer-ish.
  2811  (StaticLECall {f} itab x y mem)
  2812  	&& isSameCall(f, "runtime.ifaceeq")
  2813  	&& isDirectIface(itab)
  2814  	&& clobber(v)
  2815  	=> (MakeResult (EqPtr x y) mem)
  2816  
  2817  // If we use the result of slicebytetostring in a map lookup operation,
  2818  // then we don't need to actually do the []byte->string conversion.
  2819  // We can just use the ptr/len of the byte slice directly as a (temporary) string.
  2820  //
  2821  // Note that this does not handle some obscure cases like
  2822  // m[[2]string{string(b1), string(b2)}]. There is code in ../walk/order.go
  2823  // which handles some of those cases.
  2824  (StaticLECall {f} [argsize] typ_ map_ key:(SelectN [0] sbts:(StaticLECall {g} _ ptr len mem)) m:(SelectN [1] sbts))
  2825    &&    (isSameCall(f, "runtime.mapaccess1_faststr")
  2826        || isSameCall(f, "runtime.mapaccess2_faststr")
  2827        || isSameCall(f, "runtime.mapdelete_faststr"))
  2828    && isSameCall(g, "runtime.slicebytetostring")
  2829    && key.Uses == 1
  2830    && sbts.Uses == 2
  2831    && resetCopy(m, mem)
  2832    && clobber(sbts)
  2833    && clobber(key)
  2834  => (StaticLECall {f} [argsize] typ_ map_ (StringMake <typ.String> ptr len) mem)
  2835  
  2836  // Similarly to map lookups, also handle unique.Make for strings, which unique.Make will clone.
  2837  (StaticLECall {f} [argsize] dict_ key:(SelectN [0] sbts:(StaticLECall {g} _ ptr len mem)) m:(SelectN [1] sbts))
  2838    && isSameCall(f, "unique.Make[go.shape.string]")
  2839    && isSameCall(g, "runtime.slicebytetostring")
  2840    && key.Uses == 1
  2841    && sbts.Uses == 2
  2842    && resetCopy(m, mem)
  2843    && clobber(sbts)
  2844    && clobber(key)
  2845  => (StaticLECall {f} [argsize] dict_ (StringMake <typ.String> ptr len) mem)
  2846  
  2847  // Transform some CondSelect into math operations.
  2848  // if b { x++ } => x += b // but not on arm64 because it has CSINC
  2849  (CondSelect (Add8 <t> x (Const8 [1])) x bool) && config.arch != "arm64" => (Add8 x (CvtBoolToUint8 <t> bool))
  2850  (CondSelect (Add(64|32|16) <t> x (Const(64|32|16) [1])) x bool) && config.arch != "arm64" => (Add(64|32|16) x (ZeroExt8to(64|32|16) <t> (CvtBoolToUint8 <types.Types[types.TUINT8]> bool)))
  2851  
  2852  // if b { x-- } => x -= b
  2853  (CondSelect (Add8 <t> x (Const8 [-1])) x bool) => (Sub8 x (CvtBoolToUint8 <t> bool))
  2854  (CondSelect (Add(64|32|16) <t> x (Const(64|32|16) [-1])) x bool) => (Sub(64|32|16) x (ZeroExt8to(64|32|16) <t> (CvtBoolToUint8 <types.Types[types.TUINT8]> bool)))
  2855  
  2856  // if b { x <<= 1 } => x <<= b
  2857  (CondSelect (Lsh(64|32|16|8)x64 x (Const64 [1])) x bool) => (Lsh(64|32|16|8)x8 [true] x (CvtBoolToUint8 <types.Types[types.TUINT8]> bool))
  2858  
  2859  // if b { x >>= 1 } => x >>= b
  2860  (CondSelect (Rsh(64|32|16|8)x64 x (Const64 [1])) x bool) => (Rsh(64|32|16|8)x8 [true] x (CvtBoolToUint8 <types.Types[types.TUINT8]> bool))
  2861  (CondSelect (Rsh(64|32|16|8)Ux64 x (Const64 [1])) x bool) => (Rsh(64|32|16|8)Ux8 [true] x (CvtBoolToUint8 <types.Types[types.TUINT8]> bool))
  2862  

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