github.com/megatontech/mynoteforgo@v0.0.0-20200507084910-5d0c6ea6e890/源码/cmd/compile/internal/ssa/gen/generic.rules (about) 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 [int64(int8(c))]) 42 (Trunc32to8 (Const32 [c])) -> (Const8 [int64(int8(c))]) 43 (Trunc32to16 (Const32 [c])) -> (Const16 [int64(int16(c))]) 44 (Trunc64to8 (Const64 [c])) -> (Const8 [int64(int8(c))]) 45 (Trunc64to16 (Const64 [c])) -> (Const16 [int64(int16(c))]) 46 (Trunc64to32 (Const64 [c])) -> (Const32 [int64(int32(c))]) 47 (Cvt64Fto32F (Const64F [c])) -> (Const32F [auxFrom32F(float32(auxTo64F(c)))]) 48 (Cvt32Fto64F (Const32F [c])) -> (Const64F [c]) // c is already a 64 bit float 49 (Cvt32to32F (Const32 [c])) -> (Const32F [auxFrom32F(float32(int32(c)))]) 50 (Cvt32to64F (Const32 [c])) -> (Const64F [auxFrom64F(float64(int32(c)))]) 51 (Cvt64to32F (Const64 [c])) -> (Const32F [auxFrom32F(float32(c))]) 52 (Cvt64to64F (Const64 [c])) -> (Const64F [auxFrom64F(float64(c))]) 53 (Cvt32Fto32 (Const32F [c])) -> (Const32 [int64(int32(auxTo32F(c)))]) 54 (Cvt32Fto64 (Const32F [c])) -> (Const64 [int64(auxTo32F(c))]) 55 (Cvt64Fto32 (Const64F [c])) -> (Const32 [int64(int32(auxTo64F(c)))]) 56 (Cvt64Fto64 (Const64F [c])) -> (Const64 [int64(auxTo64F(c))]) 57 (Round32F x:(Const32F)) -> x 58 (Round64F x:(Const64F)) -> x 59 60 (Trunc16to8 (ZeroExt8to16 x)) -> x 61 (Trunc32to8 (ZeroExt8to32 x)) -> x 62 (Trunc32to16 (ZeroExt8to32 x)) -> (ZeroExt8to16 x) 63 (Trunc32to16 (ZeroExt16to32 x)) -> x 64 (Trunc64to8 (ZeroExt8to64 x)) -> x 65 (Trunc64to16 (ZeroExt8to64 x)) -> (ZeroExt8to16 x) 66 (Trunc64to16 (ZeroExt16to64 x)) -> x 67 (Trunc64to32 (ZeroExt8to64 x)) -> (ZeroExt8to32 x) 68 (Trunc64to32 (ZeroExt16to64 x)) -> (ZeroExt16to32 x) 69 (Trunc64to32 (ZeroExt32to64 x)) -> x 70 (Trunc16to8 (SignExt8to16 x)) -> x 71 (Trunc32to8 (SignExt8to32 x)) -> x 72 (Trunc32to16 (SignExt8to32 x)) -> (SignExt8to16 x) 73 (Trunc32to16 (SignExt16to32 x)) -> x 74 (Trunc64to8 (SignExt8to64 x)) -> x 75 (Trunc64to16 (SignExt8to64 x)) -> (SignExt8to16 x) 76 (Trunc64to16 (SignExt16to64 x)) -> x 77 (Trunc64to32 (SignExt8to64 x)) -> (SignExt8to32 x) 78 (Trunc64to32 (SignExt16to64 x)) -> (SignExt16to32 x) 79 (Trunc64to32 (SignExt32to64 x)) -> x 80 81 (ZeroExt8to16 (Const8 [c])) -> (Const16 [int64( uint8(c))]) 82 (ZeroExt8to32 (Const8 [c])) -> (Const32 [int64( uint8(c))]) 83 (ZeroExt8to64 (Const8 [c])) -> (Const64 [int64( uint8(c))]) 84 (ZeroExt16to32 (Const16 [c])) -> (Const32 [int64(uint16(c))]) 85 (ZeroExt16to64 (Const16 [c])) -> (Const64 [int64(uint16(c))]) 86 (ZeroExt32to64 (Const32 [c])) -> (Const64 [int64(uint32(c))]) 87 (SignExt8to16 (Const8 [c])) -> (Const16 [int64( int8(c))]) 88 (SignExt8to32 (Const8 [c])) -> (Const32 [int64( int8(c))]) 89 (SignExt8to64 (Const8 [c])) -> (Const64 [int64( int8(c))]) 90 (SignExt16to32 (Const16 [c])) -> (Const32 [int64( int16(c))]) 91 (SignExt16to64 (Const16 [c])) -> (Const64 [int64( int16(c))]) 92 (SignExt32to64 (Const32 [c])) -> (Const64 [int64( int32(c))]) 93 94 (Neg8 (Const8 [c])) -> (Const8 [int64( -int8(c))]) 95 (Neg16 (Const16 [c])) -> (Const16 [int64(-int16(c))]) 96 (Neg32 (Const32 [c])) -> (Const32 [int64(-int32(c))]) 97 (Neg64 (Const64 [c])) -> (Const64 [-c]) 98 (Neg32F (Const32F [c])) && auxTo32F(c) != 0 -> (Const32F [auxFrom32F(-auxTo32F(c))]) 99 (Neg64F (Const64F [c])) && auxTo64F(c) != 0 -> (Const64F [auxFrom64F(-auxTo64F(c))]) 100 101 (Add8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c+d))]) 102 (Add16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c+d))]) 103 (Add32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c+d))]) 104 (Add64 (Const64 [c]) (Const64 [d])) -> (Const64 [c+d]) 105 (Add32F (Const32F [c]) (Const32F [d])) -> (Const32F [auxFrom32F(auxTo32F(c) + auxTo32F(d))]) 106 (Add64F (Const64F [c]) (Const64F [d])) -> (Const64F [auxFrom64F(auxTo64F(c) + auxTo64F(d))]) 107 (AddPtr <t> x (Const64 [c])) -> (OffPtr <t> x [c]) 108 (AddPtr <t> x (Const32 [c])) -> (OffPtr <t> x [c]) 109 110 (Sub8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c-d))]) 111 (Sub16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c-d))]) 112 (Sub32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c-d))]) 113 (Sub64 (Const64 [c]) (Const64 [d])) -> (Const64 [c-d]) 114 (Sub32F (Const32F [c]) (Const32F [d])) -> (Const32F [auxFrom32F(auxTo32F(c) - auxTo32F(d))]) 115 (Sub64F (Const64F [c]) (Const64F [d])) -> (Const64F [auxFrom64F(auxTo64F(c) - auxTo64F(d))]) 116 117 (Mul8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c*d))]) 118 (Mul16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c*d))]) 119 (Mul32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c*d))]) 120 (Mul64 (Const64 [c]) (Const64 [d])) -> (Const64 [c*d]) 121 (Mul32F (Const32F [c]) (Const32F [d])) -> (Const32F [auxFrom32F(auxTo32F(c) * auxTo32F(d))]) 122 (Mul64F (Const64F [c]) (Const64F [d])) -> (Const64F [auxFrom64F(auxTo64F(c) * auxTo64F(d))]) 123 124 (And8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c&d))]) 125 (And16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c&d))]) 126 (And32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c&d))]) 127 (And64 (Const64 [c]) (Const64 [d])) -> (Const64 [c&d]) 128 129 (Or8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c|d))]) 130 (Or16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c|d))]) 131 (Or32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c|d))]) 132 (Or64 (Const64 [c]) (Const64 [d])) -> (Const64 [c|d]) 133 134 (Xor8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c^d))]) 135 (Xor16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c^d))]) 136 (Xor32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c^d))]) 137 (Xor64 (Const64 [c]) (Const64 [d])) -> (Const64 [c^d]) 138 139 (Div8 (Const8 [c]) (Const8 [d])) && d != 0 -> (Const8 [int64(int8(c)/int8(d))]) 140 (Div16 (Const16 [c]) (Const16 [d])) && d != 0 -> (Const16 [int64(int16(c)/int16(d))]) 141 (Div32 (Const32 [c]) (Const32 [d])) && d != 0 -> (Const32 [int64(int32(c)/int32(d))]) 142 (Div64 (Const64 [c]) (Const64 [d])) && d != 0 -> (Const64 [c/d]) 143 (Div8u (Const8 [c]) (Const8 [d])) && d != 0 -> (Const8 [int64(int8(uint8(c)/uint8(d)))]) 144 (Div16u (Const16 [c]) (Const16 [d])) && d != 0 -> (Const16 [int64(int16(uint16(c)/uint16(d)))]) 145 (Div32u (Const32 [c]) (Const32 [d])) && d != 0 -> (Const32 [int64(int32(uint32(c)/uint32(d)))]) 146 (Div64u (Const64 [c]) (Const64 [d])) && d != 0 -> (Const64 [int64(uint64(c)/uint64(d))]) 147 (Div32F (Const32F [c]) (Const32F [d])) -> (Const32F [auxFrom32F(auxTo32F(c) / auxTo32F(d))]) 148 (Div64F (Const64F [c]) (Const64F [d])) -> (Const64F [auxFrom64F(auxTo64F(c) / auxTo64F(d))]) 149 150 (Not (ConstBool [c])) -> (ConstBool [1-c]) 151 152 // Convert x * 1 to x. 153 (Mul(8|16|32|64) (Const(8|16|32|64) [1]) x) -> x 154 155 // Convert x * -1 to -x. 156 (Mul(8|16|32|64) (Const(8|16|32|64) [-1]) x) -> (Neg(8|16|32|64) x) 157 158 // Convert multiplication by a power of two to a shift. 159 (Mul8 <t> n (Const8 [c])) && isPowerOfTwo(c) -> (Lsh8x64 <t> n (Const64 <typ.UInt64> [log2(c)])) 160 (Mul16 <t> n (Const16 [c])) && isPowerOfTwo(c) -> (Lsh16x64 <t> n (Const64 <typ.UInt64> [log2(c)])) 161 (Mul32 <t> n (Const32 [c])) && isPowerOfTwo(c) -> (Lsh32x64 <t> n (Const64 <typ.UInt64> [log2(c)])) 162 (Mul64 <t> n (Const64 [c])) && isPowerOfTwo(c) -> (Lsh64x64 <t> n (Const64 <typ.UInt64> [log2(c)])) 163 (Mul8 <t> n (Const8 [c])) && t.IsSigned() && isPowerOfTwo(-c) -> (Neg8 (Lsh8x64 <t> n (Const64 <typ.UInt64> [log2(-c)]))) 164 (Mul16 <t> n (Const16 [c])) && t.IsSigned() && isPowerOfTwo(-c) -> (Neg16 (Lsh16x64 <t> n (Const64 <typ.UInt64> [log2(-c)]))) 165 (Mul32 <t> n (Const32 [c])) && t.IsSigned() && isPowerOfTwo(-c) -> (Neg32 (Lsh32x64 <t> n (Const64 <typ.UInt64> [log2(-c)]))) 166 (Mul64 <t> n (Const64 [c])) && t.IsSigned() && isPowerOfTwo(-c) -> (Neg64 (Lsh64x64 <t> n (Const64 <typ.UInt64> [log2(-c)]))) 167 168 (Mod8 (Const8 [c]) (Const8 [d])) && d != 0 -> (Const8 [int64(int8(c % d))]) 169 (Mod16 (Const16 [c]) (Const16 [d])) && d != 0 -> (Const16 [int64(int16(c % d))]) 170 (Mod32 (Const32 [c]) (Const32 [d])) && d != 0 -> (Const32 [int64(int32(c % d))]) 171 (Mod64 (Const64 [c]) (Const64 [d])) && d != 0 -> (Const64 [c % d]) 172 173 (Mod8u (Const8 [c]) (Const8 [d])) && d != 0 -> (Const8 [int64(uint8(c) % uint8(d))]) 174 (Mod16u (Const16 [c]) (Const16 [d])) && d != 0 -> (Const16 [int64(uint16(c) % uint16(d))]) 175 (Mod32u (Const32 [c]) (Const32 [d])) && d != 0 -> (Const32 [int64(uint32(c) % uint32(d))]) 176 (Mod64u (Const64 [c]) (Const64 [d])) && d != 0 -> (Const64 [int64(uint64(c) % uint64(d))]) 177 178 (Lsh64x64 (Const64 [c]) (Const64 [d])) -> (Const64 [c << uint64(d)]) 179 (Rsh64x64 (Const64 [c]) (Const64 [d])) -> (Const64 [c >> uint64(d)]) 180 (Rsh64Ux64 (Const64 [c]) (Const64 [d])) -> (Const64 [int64(uint64(c) >> uint64(d))]) 181 (Lsh32x64 (Const32 [c]) (Const64 [d])) -> (Const32 [int64(int32(c) << uint64(d))]) 182 (Rsh32x64 (Const32 [c]) (Const64 [d])) -> (Const32 [int64(int32(c) >> uint64(d))]) 183 (Rsh32Ux64 (Const32 [c]) (Const64 [d])) -> (Const32 [int64(int32(uint32(c) >> uint64(d)))]) 184 (Lsh16x64 (Const16 [c]) (Const64 [d])) -> (Const16 [int64(int16(c) << uint64(d))]) 185 (Rsh16x64 (Const16 [c]) (Const64 [d])) -> (Const16 [int64(int16(c) >> uint64(d))]) 186 (Rsh16Ux64 (Const16 [c]) (Const64 [d])) -> (Const16 [int64(int16(uint16(c) >> uint64(d)))]) 187 (Lsh8x64 (Const8 [c]) (Const64 [d])) -> (Const8 [int64(int8(c) << uint64(d))]) 188 (Rsh8x64 (Const8 [c]) (Const64 [d])) -> (Const8 [int64(int8(c) >> uint64(d))]) 189 (Rsh8Ux64 (Const8 [c]) (Const64 [d])) -> (Const8 [int64(int8(uint8(c) >> uint64(d)))]) 190 191 // Fold IsInBounds when the range of the index cannot exceed the limit. 192 (IsInBounds (ZeroExt8to32 _) (Const32 [c])) && (1 << 8) <= c -> (ConstBool [1]) 193 (IsInBounds (ZeroExt8to64 _) (Const64 [c])) && (1 << 8) <= c -> (ConstBool [1]) 194 (IsInBounds (ZeroExt16to32 _) (Const32 [c])) && (1 << 16) <= c -> (ConstBool [1]) 195 (IsInBounds (ZeroExt16to64 _) (Const64 [c])) && (1 << 16) <= c -> (ConstBool [1]) 196 (IsInBounds x x) -> (ConstBool [0]) 197 (IsInBounds (And8 (Const8 [c]) _) (Const8 [d])) && 0 <= c && c < d -> (ConstBool [1]) 198 (IsInBounds (ZeroExt8to16 (And8 (Const8 [c]) _)) (Const16 [d])) && 0 <= c && c < d -> (ConstBool [1]) 199 (IsInBounds (ZeroExt8to32 (And8 (Const8 [c]) _)) (Const32 [d])) && 0 <= c && c < d -> (ConstBool [1]) 200 (IsInBounds (ZeroExt8to64 (And8 (Const8 [c]) _)) (Const64 [d])) && 0 <= c && c < d -> (ConstBool [1]) 201 (IsInBounds (And16 (Const16 [c]) _) (Const16 [d])) && 0 <= c && c < d -> (ConstBool [1]) 202 (IsInBounds (ZeroExt16to32 (And16 (Const16 [c]) _)) (Const32 [d])) && 0 <= c && c < d -> (ConstBool [1]) 203 (IsInBounds (ZeroExt16to64 (And16 (Const16 [c]) _)) (Const64 [d])) && 0 <= c && c < d -> (ConstBool [1]) 204 (IsInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c < d -> (ConstBool [1]) 205 (IsInBounds (ZeroExt32to64 (And32 (Const32 [c]) _)) (Const64 [d])) && 0 <= c && c < d -> (ConstBool [1]) 206 (IsInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c < d -> (ConstBool [1]) 207 (IsInBounds (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(0 <= c && c < d)]) 208 (IsInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(0 <= c && c < d)]) 209 // (Mod64u x y) is always between 0 (inclusive) and y (exclusive). 210 (IsInBounds (Mod32u _ y) y) -> (ConstBool [1]) 211 (IsInBounds (Mod64u _ y) y) -> (ConstBool [1]) 212 // Right shifting an unsigned number limits its value. 213 (IsInBounds (ZeroExt8to64 (Rsh8Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1]) 214 (IsInBounds (ZeroExt8to32 (Rsh8Ux64 _ (Const64 [c]))) (Const32 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1]) 215 (IsInBounds (ZeroExt8to16 (Rsh8Ux64 _ (Const64 [c]))) (Const16 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1]) 216 (IsInBounds (Rsh8Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1]) 217 (IsInBounds (ZeroExt16to64 (Rsh16Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d -> (ConstBool [1]) 218 (IsInBounds (ZeroExt16to32 (Rsh16Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d -> (ConstBool [1]) 219 (IsInBounds (Rsh16Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d -> (ConstBool [1]) 220 (IsInBounds (ZeroExt32to64 (Rsh32Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 32 && 1<<uint(32-c)-1 < d -> (ConstBool [1]) 221 (IsInBounds (Rsh32Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 32 && 1<<uint(32-c)-1 < d -> (ConstBool [1]) 222 (IsInBounds (Rsh64Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 64 && 1<<uint(64-c)-1 < d -> (ConstBool [1]) 223 224 (IsSliceInBounds x x) -> (ConstBool [1]) 225 (IsSliceInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c <= d -> (ConstBool [1]) 226 (IsSliceInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c <= d -> (ConstBool [1]) 227 (IsSliceInBounds (Const32 [0]) _) -> (ConstBool [1]) 228 (IsSliceInBounds (Const64 [0]) _) -> (ConstBool [1]) 229 (IsSliceInBounds (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(0 <= c && c <= d)]) 230 (IsSliceInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(0 <= c && c <= d)]) 231 (IsSliceInBounds (SliceLen x) (SliceCap x)) -> (ConstBool [1]) 232 233 (Eq(64|32|16|8) x x) -> (ConstBool [1]) 234 (EqB (ConstBool [c]) (ConstBool [d])) -> (ConstBool [b2i(c == d)]) 235 (EqB (ConstBool [0]) x) -> (Not x) 236 (EqB (ConstBool [1]) x) -> x 237 238 (Neq(64|32|16|8) x x) -> (ConstBool [0]) 239 (NeqB (ConstBool [c]) (ConstBool [d])) -> (ConstBool [b2i(c != d)]) 240 (NeqB (ConstBool [0]) x) -> x 241 (NeqB (ConstBool [1]) x) -> (Not x) 242 (NeqB (Not x) (Not y)) -> (NeqB x y) 243 244 (Eq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) -> (Eq64 (Const64 <t> [c-d]) x) 245 (Eq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) -> (Eq32 (Const32 <t> [int64(int32(c-d))]) x) 246 (Eq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) -> (Eq16 (Const16 <t> [int64(int16(c-d))]) x) 247 (Eq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) -> (Eq8 (Const8 <t> [int64(int8(c-d))]) x) 248 249 (Neq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) -> (Neq64 (Const64 <t> [c-d]) x) 250 (Neq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) -> (Neq32 (Const32 <t> [int64(int32(c-d))]) x) 251 (Neq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) -> (Neq16 (Const16 <t> [int64(int16(c-d))]) x) 252 (Neq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) -> (Neq8 (Const8 <t> [int64(int8(c-d))]) x) 253 254 // Canonicalize x-const to x+(-const) 255 (Sub64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Add64 (Const64 <t> [-c]) x) 256 (Sub32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Add32 (Const32 <t> [int64(int32(-c))]) x) 257 (Sub16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Add16 (Const16 <t> [int64(int16(-c))]) x) 258 (Sub8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Add8 (Const8 <t> [int64(int8(-c))]) x) 259 260 // fold negation into comparison operators 261 (Not (Eq(64|32|16|8|B) x y)) -> (Neq(64|32|16|8|B) x y) 262 (Not (Neq(64|32|16|8|B) x y)) -> (Eq(64|32|16|8|B) x y) 263 264 (Not (Greater(64|32|16|8) x y)) -> (Leq(64|32|16|8) x y) 265 (Not (Greater(64|32|16|8)U x y)) -> (Leq(64|32|16|8)U x y) 266 (Not (Geq(64|32|16|8) x y)) -> (Less(64|32|16|8) x y) 267 (Not (Geq(64|32|16|8)U x y)) -> (Less(64|32|16|8)U x y) 268 269 (Not (Less(64|32|16|8) x y)) -> (Geq(64|32|16|8) x y) 270 (Not (Less(64|32|16|8)U x y)) -> (Geq(64|32|16|8)U x y) 271 (Not (Leq(64|32|16|8) x y)) -> (Greater(64|32|16|8) x y) 272 (Not (Leq(64|32|16|8)U x y)) -> (Greater(64|32|16|8)U x y) 273 274 275 // Distribute multiplication c * (d+x) -> c*d + c*x. Useful for: 276 // a[i].b = ...; a[i+1].b = ... 277 (Mul64 (Const64 <t> [c]) (Add64 <t> (Const64 <t> [d]) x)) -> 278 (Add64 (Const64 <t> [c*d]) (Mul64 <t> (Const64 <t> [c]) x)) 279 (Mul32 (Const32 <t> [c]) (Add32 <t> (Const32 <t> [d]) x)) -> 280 (Add32 (Const32 <t> [int64(int32(c*d))]) (Mul32 <t> (Const32 <t> [c]) x)) 281 282 // Rewrite x*y ± x*z to x*(y±z) 283 (Add(64|32|16|8) <t> (Mul(64|32|16|8) x y) (Mul(64|32|16|8) x z)) 284 -> (Mul(64|32|16|8) x (Add(64|32|16|8) <t> y z)) 285 (Sub(64|32|16|8) <t> (Mul(64|32|16|8) x y) (Mul(64|32|16|8) x z)) 286 -> (Mul(64|32|16|8) x (Sub(64|32|16|8) <t> y z)) 287 288 // rewrite shifts of 8/16/32 bit consts into 64 bit consts to reduce 289 // the number of the other rewrite rules for const shifts 290 (Lsh64x32 <t> x (Const32 [c])) -> (Lsh64x64 x (Const64 <t> [int64(uint32(c))])) 291 (Lsh64x16 <t> x (Const16 [c])) -> (Lsh64x64 x (Const64 <t> [int64(uint16(c))])) 292 (Lsh64x8 <t> x (Const8 [c])) -> (Lsh64x64 x (Const64 <t> [int64(uint8(c))])) 293 (Rsh64x32 <t> x (Const32 [c])) -> (Rsh64x64 x (Const64 <t> [int64(uint32(c))])) 294 (Rsh64x16 <t> x (Const16 [c])) -> (Rsh64x64 x (Const64 <t> [int64(uint16(c))])) 295 (Rsh64x8 <t> x (Const8 [c])) -> (Rsh64x64 x (Const64 <t> [int64(uint8(c))])) 296 (Rsh64Ux32 <t> x (Const32 [c])) -> (Rsh64Ux64 x (Const64 <t> [int64(uint32(c))])) 297 (Rsh64Ux16 <t> x (Const16 [c])) -> (Rsh64Ux64 x (Const64 <t> [int64(uint16(c))])) 298 (Rsh64Ux8 <t> x (Const8 [c])) -> (Rsh64Ux64 x (Const64 <t> [int64(uint8(c))])) 299 300 (Lsh32x32 <t> x (Const32 [c])) -> (Lsh32x64 x (Const64 <t> [int64(uint32(c))])) 301 (Lsh32x16 <t> x (Const16 [c])) -> (Lsh32x64 x (Const64 <t> [int64(uint16(c))])) 302 (Lsh32x8 <t> x (Const8 [c])) -> (Lsh32x64 x (Const64 <t> [int64(uint8(c))])) 303 (Rsh32x32 <t> x (Const32 [c])) -> (Rsh32x64 x (Const64 <t> [int64(uint32(c))])) 304 (Rsh32x16 <t> x (Const16 [c])) -> (Rsh32x64 x (Const64 <t> [int64(uint16(c))])) 305 (Rsh32x8 <t> x (Const8 [c])) -> (Rsh32x64 x (Const64 <t> [int64(uint8(c))])) 306 (Rsh32Ux32 <t> x (Const32 [c])) -> (Rsh32Ux64 x (Const64 <t> [int64(uint32(c))])) 307 (Rsh32Ux16 <t> x (Const16 [c])) -> (Rsh32Ux64 x (Const64 <t> [int64(uint16(c))])) 308 (Rsh32Ux8 <t> x (Const8 [c])) -> (Rsh32Ux64 x (Const64 <t> [int64(uint8(c))])) 309 310 (Lsh16x32 <t> x (Const32 [c])) -> (Lsh16x64 x (Const64 <t> [int64(uint32(c))])) 311 (Lsh16x16 <t> x (Const16 [c])) -> (Lsh16x64 x (Const64 <t> [int64(uint16(c))])) 312 (Lsh16x8 <t> x (Const8 [c])) -> (Lsh16x64 x (Const64 <t> [int64(uint8(c))])) 313 (Rsh16x32 <t> x (Const32 [c])) -> (Rsh16x64 x (Const64 <t> [int64(uint32(c))])) 314 (Rsh16x16 <t> x (Const16 [c])) -> (Rsh16x64 x (Const64 <t> [int64(uint16(c))])) 315 (Rsh16x8 <t> x (Const8 [c])) -> (Rsh16x64 x (Const64 <t> [int64(uint8(c))])) 316 (Rsh16Ux32 <t> x (Const32 [c])) -> (Rsh16Ux64 x (Const64 <t> [int64(uint32(c))])) 317 (Rsh16Ux16 <t> x (Const16 [c])) -> (Rsh16Ux64 x (Const64 <t> [int64(uint16(c))])) 318 (Rsh16Ux8 <t> x (Const8 [c])) -> (Rsh16Ux64 x (Const64 <t> [int64(uint8(c))])) 319 320 (Lsh8x32 <t> x (Const32 [c])) -> (Lsh8x64 x (Const64 <t> [int64(uint32(c))])) 321 (Lsh8x16 <t> x (Const16 [c])) -> (Lsh8x64 x (Const64 <t> [int64(uint16(c))])) 322 (Lsh8x8 <t> x (Const8 [c])) -> (Lsh8x64 x (Const64 <t> [int64(uint8(c))])) 323 (Rsh8x32 <t> x (Const32 [c])) -> (Rsh8x64 x (Const64 <t> [int64(uint32(c))])) 324 (Rsh8x16 <t> x (Const16 [c])) -> (Rsh8x64 x (Const64 <t> [int64(uint16(c))])) 325 (Rsh8x8 <t> x (Const8 [c])) -> (Rsh8x64 x (Const64 <t> [int64(uint8(c))])) 326 (Rsh8Ux32 <t> x (Const32 [c])) -> (Rsh8Ux64 x (Const64 <t> [int64(uint32(c))])) 327 (Rsh8Ux16 <t> x (Const16 [c])) -> (Rsh8Ux64 x (Const64 <t> [int64(uint16(c))])) 328 (Rsh8Ux8 <t> x (Const8 [c])) -> (Rsh8Ux64 x (Const64 <t> [int64(uint8(c))])) 329 330 // shifts by zero 331 (Lsh(64|32|16|8)x64 x (Const64 [0])) -> x 332 (Rsh(64|32|16|8)x64 x (Const64 [0])) -> x 333 (Rsh(64|32|16|8)Ux64 x (Const64 [0])) -> x 334 335 // zero shifted 336 (Lsh64x(64|32|16|8) (Const64 [0]) _) -> (Const64 [0]) 337 (Rsh64x(64|32|16|8) (Const64 [0]) _) -> (Const64 [0]) 338 (Rsh64Ux(64|32|16|8) (Const64 [0]) _) -> (Const64 [0]) 339 (Lsh32x(64|32|16|8) (Const32 [0]) _) -> (Const32 [0]) 340 (Rsh32x(64|32|16|8) (Const32 [0]) _) -> (Const32 [0]) 341 (Rsh32Ux(64|32|16|8) (Const32 [0]) _) -> (Const32 [0]) 342 (Lsh16x(64|32|16|8) (Const16 [0]) _) -> (Const16 [0]) 343 (Rsh16x(64|32|16|8) (Const16 [0]) _) -> (Const16 [0]) 344 (Rsh16Ux(64|32|16|8) (Const16 [0]) _) -> (Const16 [0]) 345 (Lsh8x(64|32|16|8) (Const8 [0]) _) -> (Const8 [0]) 346 (Rsh8x(64|32|16|8) (Const8 [0]) _) -> (Const8 [0]) 347 (Rsh8Ux(64|32|16|8) (Const8 [0]) _) -> (Const8 [0]) 348 349 // large left shifts of all values, and right shifts of unsigned values 350 ((Lsh64|Rsh64U)x64 _ (Const64 [c])) && uint64(c) >= 64 -> (Const64 [0]) 351 ((Lsh32|Rsh32U)x64 _ (Const64 [c])) && uint64(c) >= 32 -> (Const32 [0]) 352 ((Lsh16|Rsh16U)x64 _ (Const64 [c])) && uint64(c) >= 16 -> (Const16 [0]) 353 ((Lsh8|Rsh8U)x64 _ (Const64 [c])) && uint64(c) >= 8 -> (Const8 [0]) 354 355 // combine const shifts 356 (Lsh64x64 <t> (Lsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh64x64 x (Const64 <t> [c+d])) 357 (Lsh32x64 <t> (Lsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh32x64 x (Const64 <t> [c+d])) 358 (Lsh16x64 <t> (Lsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh16x64 x (Const64 <t> [c+d])) 359 (Lsh8x64 <t> (Lsh8x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh8x64 x (Const64 <t> [c+d])) 360 361 (Rsh64x64 <t> (Rsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh64x64 x (Const64 <t> [c+d])) 362 (Rsh32x64 <t> (Rsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh32x64 x (Const64 <t> [c+d])) 363 (Rsh16x64 <t> (Rsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh16x64 x (Const64 <t> [c+d])) 364 (Rsh8x64 <t> (Rsh8x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh8x64 x (Const64 <t> [c+d])) 365 366 (Rsh64Ux64 <t> (Rsh64Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh64Ux64 x (Const64 <t> [c+d])) 367 (Rsh32Ux64 <t> (Rsh32Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh32Ux64 x (Const64 <t> [c+d])) 368 (Rsh16Ux64 <t> (Rsh16Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh16Ux64 x (Const64 <t> [c+d])) 369 (Rsh8Ux64 <t> (Rsh8Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh8Ux64 x (Const64 <t> [c+d])) 370 371 // Remove signed right shift before an unsigned right shift that extracts the sign bit. 372 (Rsh8Ux64 (Rsh8x64 x _) (Const64 <t> [7] )) -> (Rsh8Ux64 x (Const64 <t> [7] )) 373 (Rsh16Ux64 (Rsh16x64 x _) (Const64 <t> [15])) -> (Rsh16Ux64 x (Const64 <t> [15])) 374 (Rsh32Ux64 (Rsh32x64 x _) (Const64 <t> [31])) -> (Rsh32Ux64 x (Const64 <t> [31])) 375 (Rsh64Ux64 (Rsh64x64 x _) (Const64 <t> [63])) -> (Rsh64Ux64 x (Const64 <t> [63])) 376 377 // ((x >> c1) << c2) >> c3 378 (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])) 379 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 380 -> (Rsh(64|32|16|8)Ux64 x (Const64 <typ.UInt64> [c1-c2+c3])) 381 382 // ((x << c1) >> c2) << c3 383 (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])) 384 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 385 -> (Lsh(64|32|16|8)x64 x (Const64 <typ.UInt64> [c1-c2+c3])) 386 387 // (x >> c) & uppermask = 0 388 (And64 (Const64 [m]) (Rsh64Ux64 _ (Const64 [c]))) && c >= 64-ntz(m) -> (Const64 [0]) 389 (And32 (Const32 [m]) (Rsh32Ux64 _ (Const64 [c]))) && c >= 64-ntz(m) -> (Const32 [0]) 390 (And16 (Const16 [m]) (Rsh16Ux64 _ (Const64 [c]))) && c >= 64-ntz(m) -> (Const16 [0]) 391 (And8 (Const8 [m]) (Rsh8Ux64 _ (Const64 [c]))) && c >= 64-ntz(m) -> (Const8 [0]) 392 393 // (x << c) & lowermask = 0 394 (And64 (Const64 [m]) (Lsh64x64 _ (Const64 [c]))) && c >= 64-nlz(m) -> (Const64 [0]) 395 (And32 (Const32 [m]) (Lsh32x64 _ (Const64 [c]))) && c >= 64-nlz(m) -> (Const32 [0]) 396 (And16 (Const16 [m]) (Lsh16x64 _ (Const64 [c]))) && c >= 64-nlz(m) -> (Const16 [0]) 397 (And8 (Const8 [m]) (Lsh8x64 _ (Const64 [c]))) && c >= 64-nlz(m) -> (Const8 [0]) 398 399 // replace shifts with zero extensions 400 (Rsh16Ux64 (Lsh16x64 x (Const64 [8])) (Const64 [8])) -> (ZeroExt8to16 (Trunc16to8 <typ.UInt8> x)) 401 (Rsh32Ux64 (Lsh32x64 x (Const64 [24])) (Const64 [24])) -> (ZeroExt8to32 (Trunc32to8 <typ.UInt8> x)) 402 (Rsh64Ux64 (Lsh64x64 x (Const64 [56])) (Const64 [56])) -> (ZeroExt8to64 (Trunc64to8 <typ.UInt8> x)) 403 (Rsh32Ux64 (Lsh32x64 x (Const64 [16])) (Const64 [16])) -> (ZeroExt16to32 (Trunc32to16 <typ.UInt16> x)) 404 (Rsh64Ux64 (Lsh64x64 x (Const64 [48])) (Const64 [48])) -> (ZeroExt16to64 (Trunc64to16 <typ.UInt16> x)) 405 (Rsh64Ux64 (Lsh64x64 x (Const64 [32])) (Const64 [32])) -> (ZeroExt32to64 (Trunc64to32 <typ.UInt32> x)) 406 407 // replace shifts with sign extensions 408 (Rsh16x64 (Lsh16x64 x (Const64 [8])) (Const64 [8])) -> (SignExt8to16 (Trunc16to8 <typ.Int8> x)) 409 (Rsh32x64 (Lsh32x64 x (Const64 [24])) (Const64 [24])) -> (SignExt8to32 (Trunc32to8 <typ.Int8> x)) 410 (Rsh64x64 (Lsh64x64 x (Const64 [56])) (Const64 [56])) -> (SignExt8to64 (Trunc64to8 <typ.Int8> x)) 411 (Rsh32x64 (Lsh32x64 x (Const64 [16])) (Const64 [16])) -> (SignExt16to32 (Trunc32to16 <typ.Int16> x)) 412 (Rsh64x64 (Lsh64x64 x (Const64 [48])) (Const64 [48])) -> (SignExt16to64 (Trunc64to16 <typ.Int16> x)) 413 (Rsh64x64 (Lsh64x64 x (Const64 [32])) (Const64 [32])) -> (SignExt32to64 (Trunc64to32 <typ.Int32> x)) 414 415 // constant comparisons 416 (Eq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) -> (ConstBool [b2i(c == d)]) 417 (Neq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) -> (ConstBool [b2i(c != d)]) 418 (Greater(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) -> (ConstBool [b2i(c > d)]) 419 (Geq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) -> (ConstBool [b2i(c >= d)]) 420 (Less(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) -> (ConstBool [b2i(c < d)]) 421 (Leq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) -> (ConstBool [b2i(c <= d)]) 422 423 (Greater64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) > uint64(d))]) 424 (Greater32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) > uint32(d))]) 425 (Greater16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) > uint16(d))]) 426 (Greater8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) > uint8(d))]) 427 428 (Geq64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) >= uint64(d))]) 429 (Geq32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) >= uint32(d))]) 430 (Geq16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) >= uint16(d))]) 431 (Geq8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) >= uint8(d))]) 432 433 (Less64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) < uint64(d))]) 434 (Less32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) < uint32(d))]) 435 (Less16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) < uint16(d))]) 436 (Less8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) < uint8(d))]) 437 438 (Leq64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) <= uint64(d))]) 439 (Leq32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) <= uint32(d))]) 440 (Leq16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) <= uint16(d))]) 441 (Leq8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) <= uint8(d))]) 442 443 // constant floating point comparisons 444 (Eq32F (Const32F [c]) (Const32F [d])) -> (ConstBool [b2i(auxTo32F(c) == auxTo32F(d))]) 445 (Eq64F (Const64F [c]) (Const64F [d])) -> (ConstBool [b2i(auxTo64F(c) == auxTo64F(d))]) 446 (Neq32F (Const32F [c]) (Const32F [d])) -> (ConstBool [b2i(auxTo32F(c) != auxTo32F(d))]) 447 (Neq64F (Const64F [c]) (Const64F [d])) -> (ConstBool [b2i(auxTo64F(c) != auxTo64F(d))]) 448 (Greater32F (Const32F [c]) (Const32F [d])) -> (ConstBool [b2i(auxTo32F(c) > auxTo32F(d))]) 449 (Greater64F (Const64F [c]) (Const64F [d])) -> (ConstBool [b2i(auxTo64F(c) > auxTo64F(d))]) 450 (Geq32F (Const32F [c]) (Const32F [d])) -> (ConstBool [b2i(auxTo32F(c) >= auxTo32F(d))]) 451 (Geq64F (Const64F [c]) (Const64F [d])) -> (ConstBool [b2i(auxTo64F(c) >= auxTo64F(d))]) 452 (Less32F (Const32F [c]) (Const32F [d])) -> (ConstBool [b2i(auxTo32F(c) < auxTo32F(d))]) 453 (Less64F (Const64F [c]) (Const64F [d])) -> (ConstBool [b2i(auxTo64F(c) < auxTo64F(d))]) 454 (Leq32F (Const32F [c]) (Const32F [d])) -> (ConstBool [b2i(auxTo32F(c) <= auxTo32F(d))]) 455 (Leq64F (Const64F [c]) (Const64F [d])) -> (ConstBool [b2i(auxTo64F(c) <= auxTo64F(d))]) 456 457 // simplifications 458 (Or(64|32|16|8) x x) -> x 459 (Or(64|32|16|8) (Const(64|32|16|8) [0]) x) -> x 460 (Or(64|32|16|8) (Const(64|32|16|8) [-1]) _) -> (Const(64|32|16|8) [-1]) 461 462 (And(64|32|16|8) x x) -> x 463 (And(64|32|16|8) (Const(64|32|16|8) [-1]) x) -> x 464 (And(64|32|16|8) (Const(64|32|16|8) [0]) _) -> (Const(64|32|16|8) [0]) 465 466 (Xor(64|32|16|8) x x) -> (Const(64|32|16|8) [0]) 467 (Xor(64|32|16|8) (Const(64|32|16|8) [0]) x) -> x 468 469 (Add(64|32|16|8) (Const(64|32|16|8) [0]) x) -> x 470 (Sub(64|32|16|8) x x) -> (Const(64|32|16|8) [0]) 471 (Mul(64|32|16|8) (Const(64|32|16|8) [0]) _) -> (Const(64|32|16|8) [0]) 472 473 (Com(64|32|16|8) (Com(64|32|16|8) x)) -> x 474 (Com(64|32|16|8) (Const(64|32|16|8) [c])) -> (Const(64|32|16|8) [^c]) 475 476 (Neg(64|32|16|8) (Sub(64|32|16|8) x y)) -> (Sub(64|32|16|8) y x) 477 478 (Add(64|32|16|8) (Const(64|32|16|8) [1]) (Com(64|32|16|8) x)) -> (Neg(64|32|16|8) x) 479 480 (And(64|32|16|8) x (And(64|32|16|8) x y)) -> (And(64|32|16|8) x y) 481 (Or(64|32|16|8) x (Or(64|32|16|8) x y)) -> (Or(64|32|16|8) x y) 482 (Xor(64|32|16|8) x (Xor(64|32|16|8) x y)) -> y 483 484 // Ands clear bits. Ors set bits. 485 // If a subsequent Or will set all the bits 486 // that an And cleared, we can skip the And. 487 // This happens in bitmasking code like: 488 // x &^= 3 << shift // clear two old bits 489 // x |= v << shift // set two new bits 490 // when shift is a small constant and v ends up a constant 3. 491 (Or8 (And8 x (Const8 [c2])) (Const8 <t> [c1])) && ^(c1 | c2) == 0 -> (Or8 (Const8 <t> [c1]) x) 492 (Or16 (And16 x (Const16 [c2])) (Const16 <t> [c1])) && ^(c1 | c2) == 0 -> (Or16 (Const16 <t> [c1]) x) 493 (Or32 (And32 x (Const32 [c2])) (Const32 <t> [c1])) && ^(c1 | c2) == 0 -> (Or32 (Const32 <t> [c1]) x) 494 (Or64 (And64 x (Const64 [c2])) (Const64 <t> [c1])) && ^(c1 | c2) == 0 -> (Or64 (Const64 <t> [c1]) x) 495 496 (Trunc64to8 (And64 (Const64 [y]) x)) && y&0xFF == 0xFF -> (Trunc64to8 x) 497 (Trunc64to16 (And64 (Const64 [y]) x)) && y&0xFFFF == 0xFFFF -> (Trunc64to16 x) 498 (Trunc64to32 (And64 (Const64 [y]) x)) && y&0xFFFFFFFF == 0xFFFFFFFF -> (Trunc64to32 x) 499 (Trunc32to8 (And32 (Const32 [y]) x)) && y&0xFF == 0xFF -> (Trunc32to8 x) 500 (Trunc32to16 (And32 (Const32 [y]) x)) && y&0xFFFF == 0xFFFF -> (Trunc32to16 x) 501 (Trunc16to8 (And16 (Const16 [y]) x)) && y&0xFF == 0xFF -> (Trunc16to8 x) 502 503 (ZeroExt8to64 (Trunc64to8 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 56 -> x 504 (ZeroExt16to64 (Trunc64to16 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 48 -> x 505 (ZeroExt32to64 (Trunc64to32 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 32 -> x 506 (ZeroExt8to32 (Trunc32to8 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 24 -> x 507 (ZeroExt16to32 (Trunc32to16 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 16 -> x 508 (ZeroExt8to16 (Trunc16to8 x:(Rsh16Ux64 _ (Const64 [s])))) && s >= 8 -> x 509 510 (SignExt8to64 (Trunc64to8 x:(Rsh64x64 _ (Const64 [s])))) && s >= 56 -> x 511 (SignExt16to64 (Trunc64to16 x:(Rsh64x64 _ (Const64 [s])))) && s >= 48 -> x 512 (SignExt32to64 (Trunc64to32 x:(Rsh64x64 _ (Const64 [s])))) && s >= 32 -> x 513 (SignExt8to32 (Trunc32to8 x:(Rsh32x64 _ (Const64 [s])))) && s >= 24 -> x 514 (SignExt16to32 (Trunc32to16 x:(Rsh32x64 _ (Const64 [s])))) && s >= 16 -> x 515 (SignExt8to16 (Trunc16to8 x:(Rsh16x64 _ (Const64 [s])))) && s >= 8 -> x 516 517 (Slicemask (Const32 [x])) && x > 0 -> (Const32 [-1]) 518 (Slicemask (Const32 [0])) -> (Const32 [0]) 519 (Slicemask (Const64 [x])) && x > 0 -> (Const64 [-1]) 520 (Slicemask (Const64 [0])) -> (Const64 [0]) 521 522 // Rewrite AND of consts as shifts if possible, slightly faster for 64 bit operands 523 // leading zeros can be shifted left, then right 524 (And64 <t> (Const64 [y]) x) && nlz(y) + nto(y) == 64 && nto(y) >= 32 525 -> (Rsh64Ux64 (Lsh64x64 <t> x (Const64 <t> [nlz(y)])) (Const64 <t> [nlz(y)])) 526 // trailing zeros can be shifted right, then left 527 (And64 <t> (Const64 [y]) x) && nlo(y) + ntz(y) == 64 && ntz(y) >= 32 528 -> (Lsh64x64 (Rsh64Ux64 <t> x (Const64 <t> [ntz(y)])) (Const64 <t> [ntz(y)])) 529 530 // simplifications often used for lengths. e.g. len(s[i:i+5])==5 531 (Sub(64|32|16|8) (Add(64|32|16|8) x y) x) -> y 532 (Sub(64|32|16|8) (Add(64|32|16|8) x y) y) -> x 533 534 // basic phi simplifications 535 (Phi (Const8 [c]) (Const8 [c])) -> (Const8 [c]) 536 (Phi (Const16 [c]) (Const16 [c])) -> (Const16 [c]) 537 (Phi (Const32 [c]) (Const32 [c])) -> (Const32 [c]) 538 (Phi (Const64 [c]) (Const64 [c])) -> (Const64 [c]) 539 540 // slice and interface comparisons 541 // The frontend ensures that we can only compare against nil, 542 // so we need only compare the first word (interface type or slice ptr). 543 (EqInter x y) -> (EqPtr (ITab x) (ITab y)) 544 (NeqInter x y) -> (NeqPtr (ITab x) (ITab y)) 545 (EqSlice x y) -> (EqPtr (SlicePtr x) (SlicePtr y)) 546 (NeqSlice x y) -> (NeqPtr (SlicePtr x) (SlicePtr y)) 547 548 // Load of store of same address, with compatibly typed value and same size 549 (Load <t1> p1 (Store {t2} p2 x _)) 550 && isSamePtr(p1, p2) 551 && t1.Compare(x.Type) == types.CMPeq 552 && t1.Size() == sizeof(t2) 553 -> x 554 (Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 x _))) 555 && isSamePtr(p1, p3) 556 && t1.Compare(x.Type) == types.CMPeq 557 && t1.Size() == sizeof(t2) 558 && disjoint(p3, sizeof(t3), p2, sizeof(t2)) 559 -> x 560 (Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 x _)))) 561 && isSamePtr(p1, p4) 562 && t1.Compare(x.Type) == types.CMPeq 563 && t1.Size() == sizeof(t2) 564 && disjoint(p4, sizeof(t4), p2, sizeof(t2)) 565 && disjoint(p4, sizeof(t4), p3, sizeof(t3)) 566 -> x 567 (Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 _ (Store {t5} p5 x _))))) 568 && isSamePtr(p1, p5) 569 && t1.Compare(x.Type) == types.CMPeq 570 && t1.Size() == sizeof(t2) 571 && disjoint(p5, sizeof(t5), p2, sizeof(t2)) 572 && disjoint(p5, sizeof(t5), p3, sizeof(t3)) 573 && disjoint(p5, sizeof(t5), p4, sizeof(t4)) 574 -> x 575 576 // Pass constants through math.Float{32,64}bits and math.Float{32,64}frombits 577 (Load <t1> p1 (Store {t2} p2 (Const64 [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 8 && is64BitFloat(t1) -> (Const64F [x]) 578 (Load <t1> p1 (Store {t2} p2 (Const32 [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 4 && is32BitFloat(t1) -> (Const32F [auxFrom32F(math.Float32frombits(uint32(x)))]) 579 (Load <t1> p1 (Store {t2} p2 (Const64F [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 8 && is64BitInt(t1) -> (Const64 [x]) 580 (Load <t1> p1 (Store {t2} p2 (Const32F [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 4 && is32BitInt(t1) -> (Const32 [int64(int32(math.Float32bits(auxTo32F(x))))]) 581 582 // Float Loads up to Zeros so they can be constant folded. 583 (Load <t1> op:(OffPtr [o1] p1) 584 (Store {t2} p2 _ 585 mem:(Zero [n] p3 _))) 586 && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p3) 587 && fe.CanSSA(t1) 588 && disjoint(op, t1.Size(), p2, sizeof(t2)) 589 -> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p3) mem) 590 (Load <t1> op:(OffPtr [o1] p1) 591 (Store {t2} p2 _ 592 (Store {t3} p3 _ 593 mem:(Zero [n] p4 _)))) 594 && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p4) 595 && fe.CanSSA(t1) 596 && disjoint(op, t1.Size(), p2, sizeof(t2)) 597 && disjoint(op, t1.Size(), p3, sizeof(t3)) 598 -> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p4) mem) 599 (Load <t1> op:(OffPtr [o1] p1) 600 (Store {t2} p2 _ 601 (Store {t3} p3 _ 602 (Store {t4} p4 _ 603 mem:(Zero [n] p5 _))))) 604 && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p5) 605 && fe.CanSSA(t1) 606 && disjoint(op, t1.Size(), p2, sizeof(t2)) 607 && disjoint(op, t1.Size(), p3, sizeof(t3)) 608 && disjoint(op, t1.Size(), p4, sizeof(t4)) 609 -> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p5) mem) 610 (Load <t1> op:(OffPtr [o1] p1) 611 (Store {t2} p2 _ 612 (Store {t3} p3 _ 613 (Store {t4} p4 _ 614 (Store {t5} p5 _ 615 mem:(Zero [n] p6 _)))))) 616 && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p6) 617 && fe.CanSSA(t1) 618 && disjoint(op, t1.Size(), p2, sizeof(t2)) 619 && disjoint(op, t1.Size(), p3, sizeof(t3)) 620 && disjoint(op, t1.Size(), p4, sizeof(t4)) 621 && disjoint(op, t1.Size(), p5, sizeof(t5)) 622 -> @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p6) mem) 623 624 // Zero to Load forwarding. 625 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 626 && t1.IsBoolean() 627 && isSamePtr(p1, p2) 628 && n >= o + 1 629 -> (ConstBool [0]) 630 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 631 && is8BitInt(t1) 632 && isSamePtr(p1, p2) 633 && n >= o + 1 634 -> (Const8 [0]) 635 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 636 && is16BitInt(t1) 637 && isSamePtr(p1, p2) 638 && n >= o + 2 639 -> (Const16 [0]) 640 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 641 && is32BitInt(t1) 642 && isSamePtr(p1, p2) 643 && n >= o + 4 644 -> (Const32 [0]) 645 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 646 && is64BitInt(t1) 647 && isSamePtr(p1, p2) 648 && n >= o + 8 649 -> (Const64 [0]) 650 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 651 && is32BitFloat(t1) 652 && isSamePtr(p1, p2) 653 && n >= o + 4 654 -> (Const32F [0]) 655 (Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) 656 && is64BitFloat(t1) 657 && isSamePtr(p1, p2) 658 && n >= o + 8 659 -> (Const64F [0]) 660 661 // Eliminate stores of values that have just been loaded from the same location. 662 // We also handle the common case where there are some intermediate stores. 663 (Store {t1} p1 (Load <t2> p2 mem) mem) 664 && isSamePtr(p1, p2) 665 && t2.Size() == sizeof(t1) 666 -> mem 667 (Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ oldmem)) 668 && isSamePtr(p1, p2) 669 && t2.Size() == sizeof(t1) 670 && disjoint(p1, sizeof(t1), p3, sizeof(t3)) 671 -> mem 672 (Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ (Store {t4} p4 _ oldmem))) 673 && isSamePtr(p1, p2) 674 && t2.Size() == sizeof(t1) 675 && disjoint(p1, sizeof(t1), p3, sizeof(t3)) 676 && disjoint(p1, sizeof(t1), p4, sizeof(t4)) 677 -> mem 678 (Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ (Store {t4} p4 _ (Store {t5} p5 _ oldmem)))) 679 && isSamePtr(p1, p2) 680 && t2.Size() == sizeof(t1) 681 && disjoint(p1, sizeof(t1), p3, sizeof(t3)) 682 && disjoint(p1, sizeof(t1), p4, sizeof(t4)) 683 && disjoint(p1, sizeof(t1), p5, sizeof(t5)) 684 -> mem 685 686 // Don't Store zeros to cleared variables. 687 (Store {t} (OffPtr [o] p1) x mem:(Zero [n] p2 _)) 688 && isConstZero(x) 689 && o >= 0 && sizeof(t) + o <= n && isSamePtr(p1, p2) 690 -> mem 691 (Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Zero [n] p3 _))) 692 && isConstZero(x) 693 && o1 >= 0 && sizeof(t1) + o1 <= n && isSamePtr(p1, p3) 694 && disjoint(op, sizeof(t1), p2, sizeof(t2)) 695 -> mem 696 (Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Store {t3} p3 _ (Zero [n] p4 _)))) 697 && isConstZero(x) 698 && o1 >= 0 && sizeof(t1) + o1 <= n && isSamePtr(p1, p4) 699 && disjoint(op, sizeof(t1), p2, sizeof(t2)) 700 && disjoint(op, sizeof(t1), p3, sizeof(t3)) 701 -> mem 702 (Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 _ (Zero [n] p5 _))))) 703 && isConstZero(x) 704 && o1 >= 0 && sizeof(t1) + o1 <= n && isSamePtr(p1, p5) 705 && disjoint(op, sizeof(t1), p2, sizeof(t2)) 706 && disjoint(op, sizeof(t1), p3, sizeof(t3)) 707 && disjoint(op, sizeof(t1), p4, sizeof(t4)) 708 -> mem 709 710 // Collapse OffPtr 711 (OffPtr (OffPtr p [b]) [a]) -> (OffPtr p [a+b]) 712 (OffPtr p [0]) && v.Type.Compare(p.Type) == types.CMPeq -> p 713 714 // indexing operations 715 // Note: bounds check has already been done 716 (PtrIndex <t> ptr idx) && config.PtrSize == 4 -> (AddPtr ptr (Mul32 <typ.Int> idx (Const32 <typ.Int> [t.Elem().Size()]))) 717 (PtrIndex <t> ptr idx) && config.PtrSize == 8 -> (AddPtr ptr (Mul64 <typ.Int> idx (Const64 <typ.Int> [t.Elem().Size()]))) 718 719 // struct operations 720 (StructSelect (StructMake1 x)) -> x 721 (StructSelect [0] (StructMake2 x _)) -> x 722 (StructSelect [1] (StructMake2 _ x)) -> x 723 (StructSelect [0] (StructMake3 x _ _)) -> x 724 (StructSelect [1] (StructMake3 _ x _)) -> x 725 (StructSelect [2] (StructMake3 _ _ x)) -> x 726 (StructSelect [0] (StructMake4 x _ _ _)) -> x 727 (StructSelect [1] (StructMake4 _ x _ _)) -> x 728 (StructSelect [2] (StructMake4 _ _ x _)) -> x 729 (StructSelect [3] (StructMake4 _ _ _ x)) -> x 730 731 (Load <t> _ _) && t.IsStruct() && t.NumFields() == 0 && fe.CanSSA(t) -> 732 (StructMake0) 733 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 1 && fe.CanSSA(t) -> 734 (StructMake1 735 (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem)) 736 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 2 && fe.CanSSA(t) -> 737 (StructMake2 738 (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem) 739 (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem)) 740 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 3 && fe.CanSSA(t) -> 741 (StructMake3 742 (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem) 743 (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem) 744 (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem)) 745 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 4 && fe.CanSSA(t) -> 746 (StructMake4 747 (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem) 748 (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem) 749 (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem) 750 (Load <t.FieldType(3)> (OffPtr <t.FieldType(3).PtrTo()> [t.FieldOff(3)] ptr) mem)) 751 752 (StructSelect [i] x:(Load <t> ptr mem)) && !fe.CanSSA(t) -> 753 @x.Block (Load <v.Type> (OffPtr <v.Type.PtrTo()> [t.FieldOff(int(i))] ptr) mem) 754 755 (Store _ (StructMake0) mem) -> mem 756 (Store dst (StructMake1 <t> f0) mem) -> 757 (Store {t.FieldType(0)} (OffPtr <t.FieldType(0).PtrTo()> [0] dst) f0 mem) 758 (Store dst (StructMake2 <t> f0 f1) mem) -> 759 (Store {t.FieldType(1)} 760 (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) 761 f1 762 (Store {t.FieldType(0)} 763 (OffPtr <t.FieldType(0).PtrTo()> [0] dst) 764 f0 mem)) 765 (Store dst (StructMake3 <t> f0 f1 f2) mem) -> 766 (Store {t.FieldType(2)} 767 (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] dst) 768 f2 769 (Store {t.FieldType(1)} 770 (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) 771 f1 772 (Store {t.FieldType(0)} 773 (OffPtr <t.FieldType(0).PtrTo()> [0] dst) 774 f0 mem))) 775 (Store dst (StructMake4 <t> f0 f1 f2 f3) mem) -> 776 (Store {t.FieldType(3)} 777 (OffPtr <t.FieldType(3).PtrTo()> [t.FieldOff(3)] dst) 778 f3 779 (Store {t.FieldType(2)} 780 (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] dst) 781 f2 782 (Store {t.FieldType(1)} 783 (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) 784 f1 785 (Store {t.FieldType(0)} 786 (OffPtr <t.FieldType(0).PtrTo()> [0] dst) 787 f0 mem)))) 788 789 // Putting struct{*byte} and similar into direct interfaces. 790 (IMake typ (StructMake1 val)) -> (IMake typ val) 791 (StructSelect [0] x:(IData _)) -> x 792 793 // un-SSAable values use mem->mem copies 794 (Store {t} dst (Load src mem) mem) && !fe.CanSSA(t.(*types.Type)) -> 795 (Move {t} [sizeof(t)] dst src mem) 796 (Store {t} dst (Load src mem) (VarDef {x} mem)) && !fe.CanSSA(t.(*types.Type)) -> 797 (Move {t} [sizeof(t)] dst src (VarDef {x} mem)) 798 799 // array ops 800 (ArraySelect (ArrayMake1 x)) -> x 801 802 (Load <t> _ _) && t.IsArray() && t.NumElem() == 0 -> 803 (ArrayMake0) 804 805 (Load <t> ptr mem) && t.IsArray() && t.NumElem() == 1 && fe.CanSSA(t) -> 806 (ArrayMake1 (Load <t.Elem()> ptr mem)) 807 808 (Store _ (ArrayMake0) mem) -> mem 809 (Store dst (ArrayMake1 e) mem) -> (Store {e.Type} dst e mem) 810 811 // Putting [1]{*byte} and similar into direct interfaces. 812 (IMake typ (ArrayMake1 val)) -> (IMake typ val) 813 (ArraySelect [0] x:(IData _)) -> x 814 815 // string ops 816 // Decomposing StringMake and lowering of StringPtr and StringLen 817 // happens in a later pass, dec, so that these operations are available 818 // to other passes for optimizations. 819 (StringPtr (StringMake (Addr <t> {s} base) _)) -> (Addr <t> {s} base) 820 (StringLen (StringMake _ (Const64 <t> [c]))) -> (Const64 <t> [c]) 821 (ConstString {s}) && config.PtrSize == 4 && s.(string) == "" -> 822 (StringMake (ConstNil) (Const32 <typ.Int> [0])) 823 (ConstString {s}) && config.PtrSize == 8 && s.(string) == "" -> 824 (StringMake (ConstNil) (Const64 <typ.Int> [0])) 825 (ConstString {s}) && config.PtrSize == 4 && s.(string) != "" -> 826 (StringMake 827 (Addr <typ.BytePtr> {fe.StringData(s.(string))} 828 (SB)) 829 (Const32 <typ.Int> [int64(len(s.(string)))])) 830 (ConstString {s}) && config.PtrSize == 8 && s.(string) != "" -> 831 (StringMake 832 (Addr <typ.BytePtr> {fe.StringData(s.(string))} 833 (SB)) 834 (Const64 <typ.Int> [int64(len(s.(string)))])) 835 836 // slice ops 837 // Only a few slice rules are provided here. See dec.rules for 838 // a more comprehensive set. 839 (SliceLen (SliceMake _ (Const64 <t> [c]) _)) -> (Const64 <t> [c]) 840 (SliceCap (SliceMake _ _ (Const64 <t> [c]))) -> (Const64 <t> [c]) 841 (SliceLen (SliceMake _ (Const32 <t> [c]) _)) -> (Const32 <t> [c]) 842 (SliceCap (SliceMake _ _ (Const32 <t> [c]))) -> (Const32 <t> [c]) 843 (SlicePtr (SliceMake (SlicePtr x) _ _)) -> (SlicePtr x) 844 (SliceLen (SliceMake _ (SliceLen x) _)) -> (SliceLen x) 845 (SliceCap (SliceMake _ _ (SliceCap x))) -> (SliceCap x) 846 (SliceCap (SliceMake _ _ (SliceLen x))) -> (SliceLen x) 847 (ConstSlice) && config.PtrSize == 4 -> 848 (SliceMake 849 (ConstNil <v.Type.Elem().PtrTo()>) 850 (Const32 <typ.Int> [0]) 851 (Const32 <typ.Int> [0])) 852 (ConstSlice) && config.PtrSize == 8 -> 853 (SliceMake 854 (ConstNil <v.Type.Elem().PtrTo()>) 855 (Const64 <typ.Int> [0]) 856 (Const64 <typ.Int> [0])) 857 858 // interface ops 859 (ConstInterface) -> 860 (IMake 861 (ConstNil <typ.Uintptr>) 862 (ConstNil <typ.BytePtr>)) 863 864 (NilCheck (GetG mem) mem) -> mem 865 866 (If (Not cond) yes no) -> (If cond no yes) 867 (If (ConstBool [c]) yes no) && c == 1 -> (First nil yes no) 868 (If (ConstBool [c]) yes no) && c == 0 -> (First nil no yes) 869 870 // Get rid of Convert ops for pointer arithmetic on unsafe.Pointer. 871 (Convert (Add(64|32) (Convert ptr mem) off) mem) -> (Add(64|32) ptr off) 872 (Convert (Convert ptr mem) mem) -> ptr 873 874 // strength reduction of divide by a constant. 875 // See ../magic.go for a detailed description of these algorithms. 876 877 // Unsigned divide by power of 2. Strength reduce to a shift. 878 (Div8u n (Const8 [c])) && isPowerOfTwo(c&0xff) -> (Rsh8Ux64 n (Const64 <typ.UInt64> [log2(c&0xff)])) 879 (Div16u n (Const16 [c])) && isPowerOfTwo(c&0xffff) -> (Rsh16Ux64 n (Const64 <typ.UInt64> [log2(c&0xffff)])) 880 (Div32u n (Const32 [c])) && isPowerOfTwo(c&0xffffffff) -> (Rsh32Ux64 n (Const64 <typ.UInt64> [log2(c&0xffffffff)])) 881 (Div64u n (Const64 [c])) && isPowerOfTwo(c) -> (Rsh64Ux64 n (Const64 <typ.UInt64> [log2(c)])) 882 (Div64u n (Const64 [-1<<63])) -> (Rsh64Ux64 n (Const64 <typ.UInt64> [63])) 883 884 // Signed non-negative divide by power of 2. 885 (Div8 n (Const8 [c])) && isNonNegative(n) && isPowerOfTwo(c&0xff) -> (Rsh8Ux64 n (Const64 <typ.UInt64> [log2(c&0xff)])) 886 (Div16 n (Const16 [c])) && isNonNegative(n) && isPowerOfTwo(c&0xffff) -> (Rsh16Ux64 n (Const64 <typ.UInt64> [log2(c&0xffff)])) 887 (Div32 n (Const32 [c])) && isNonNegative(n) && isPowerOfTwo(c&0xffffffff) -> (Rsh32Ux64 n (Const64 <typ.UInt64> [log2(c&0xffffffff)])) 888 (Div64 n (Const64 [c])) && isNonNegative(n) && isPowerOfTwo(c) -> (Rsh64Ux64 n (Const64 <typ.UInt64> [log2(c)])) 889 (Div64 n (Const64 [-1<<63])) && isNonNegative(n) -> (Const64 [0]) 890 891 // Unsigned divide, not a power of 2. Strength reduce to a multiply. 892 // For 8-bit divides, we just do a direct 9-bit by 8-bit multiply. 893 (Div8u x (Const8 [c])) && umagicOK(8, c) -> 894 (Trunc32to8 895 (Rsh32Ux64 <typ.UInt32> 896 (Mul32 <typ.UInt32> 897 (Const32 <typ.UInt32> [int64(1<<8+umagic(8,c).m)]) 898 (ZeroExt8to32 x)) 899 (Const64 <typ.UInt64> [8+umagic(8,c).s]))) 900 901 // For 16-bit divides on 64-bit machines, we do a direct 17-bit by 16-bit multiply. 902 (Div16u x (Const16 [c])) && umagicOK(16, c) && config.RegSize == 8 -> 903 (Trunc64to16 904 (Rsh64Ux64 <typ.UInt64> 905 (Mul64 <typ.UInt64> 906 (Const64 <typ.UInt64> [int64(1<<16+umagic(16,c).m)]) 907 (ZeroExt16to64 x)) 908 (Const64 <typ.UInt64> [16+umagic(16,c).s]))) 909 910 // For 16-bit divides on 32-bit machines 911 (Div16u x (Const16 [c])) && umagicOK(16, c) && config.RegSize == 4 && umagic(16,c).m&1 == 0 -> 912 (Trunc32to16 913 (Rsh32Ux64 <typ.UInt32> 914 (Mul32 <typ.UInt32> 915 (Const32 <typ.UInt32> [int64(1<<15+umagic(16,c).m/2)]) 916 (ZeroExt16to32 x)) 917 (Const64 <typ.UInt64> [16+umagic(16,c).s-1]))) 918 (Div16u x (Const16 [c])) && umagicOK(16, c) && config.RegSize == 4 && c&1 == 0 -> 919 (Trunc32to16 920 (Rsh32Ux64 <typ.UInt32> 921 (Mul32 <typ.UInt32> 922 (Const32 <typ.UInt32> [int64(1<<15+(umagic(16,c).m+1)/2)]) 923 (Rsh32Ux64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [1]))) 924 (Const64 <typ.UInt64> [16+umagic(16,c).s-2]))) 925 (Div16u x (Const16 [c])) && umagicOK(16, c) && config.RegSize == 4 && config.useAvg -> 926 (Trunc32to16 927 (Rsh32Ux64 <typ.UInt32> 928 (Avg32u 929 (Lsh32x64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [16])) 930 (Mul32 <typ.UInt32> 931 (Const32 <typ.UInt32> [int64(umagic(16,c).m)]) 932 (ZeroExt16to32 x))) 933 (Const64 <typ.UInt64> [16+umagic(16,c).s-1]))) 934 935 // For 32-bit divides on 32-bit machines 936 (Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && umagic(32,c).m&1 == 0 && config.useHmul -> 937 (Rsh32Ux64 <typ.UInt32> 938 (Hmul32u <typ.UInt32> 939 (Const32 <typ.UInt32> [int64(int32(1<<31+umagic(32,c).m/2))]) 940 x) 941 (Const64 <typ.UInt64> [umagic(32,c).s-1])) 942 (Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && c&1 == 0 && config.useHmul -> 943 (Rsh32Ux64 <typ.UInt32> 944 (Hmul32u <typ.UInt32> 945 (Const32 <typ.UInt32> [int64(int32(1<<31+(umagic(32,c).m+1)/2))]) 946 (Rsh32Ux64 <typ.UInt32> x (Const64 <typ.UInt64> [1]))) 947 (Const64 <typ.UInt64> [umagic(32,c).s-2])) 948 (Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && config.useAvg && config.useHmul -> 949 (Rsh32Ux64 <typ.UInt32> 950 (Avg32u 951 x 952 (Hmul32u <typ.UInt32> 953 (Const32 <typ.UInt32> [int64(int32(umagic(32,c).m))]) 954 x)) 955 (Const64 <typ.UInt64> [umagic(32,c).s-1])) 956 957 // For 32-bit divides on 64-bit machines 958 // We'll use a regular (non-hi) multiply for this case. 959 (Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 8 && umagic(32,c).m&1 == 0 -> 960 (Trunc64to32 961 (Rsh64Ux64 <typ.UInt64> 962 (Mul64 <typ.UInt64> 963 (Const64 <typ.UInt64> [int64(1<<31+umagic(32,c).m/2)]) 964 (ZeroExt32to64 x)) 965 (Const64 <typ.UInt64> [32+umagic(32,c).s-1]))) 966 (Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 8 && c&1 == 0 -> 967 (Trunc64to32 968 (Rsh64Ux64 <typ.UInt64> 969 (Mul64 <typ.UInt64> 970 (Const64 <typ.UInt64> [int64(1<<31+(umagic(32,c).m+1)/2)]) 971 (Rsh64Ux64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [1]))) 972 (Const64 <typ.UInt64> [32+umagic(32,c).s-2]))) 973 (Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 8 && config.useAvg -> 974 (Trunc64to32 975 (Rsh64Ux64 <typ.UInt64> 976 (Avg64u 977 (Lsh64x64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [32])) 978 (Mul64 <typ.UInt64> 979 (Const64 <typ.UInt32> [int64(umagic(32,c).m)]) 980 (ZeroExt32to64 x))) 981 (Const64 <typ.UInt64> [32+umagic(32,c).s-1]))) 982 983 // For 64-bit divides on 64-bit machines 984 // (64-bit divides on 32-bit machines are lowered to a runtime call by the walk pass.) 985 (Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && umagic(64,c).m&1 == 0 && config.useHmul -> 986 (Rsh64Ux64 <typ.UInt64> 987 (Hmul64u <typ.UInt64> 988 (Const64 <typ.UInt64> [int64(1<<63+umagic(64,c).m/2)]) 989 x) 990 (Const64 <typ.UInt64> [umagic(64,c).s-1])) 991 (Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && c&1 == 0 && config.useHmul -> 992 (Rsh64Ux64 <typ.UInt64> 993 (Hmul64u <typ.UInt64> 994 (Const64 <typ.UInt64> [int64(1<<63+(umagic(64,c).m+1)/2)]) 995 (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [1]))) 996 (Const64 <typ.UInt64> [umagic(64,c).s-2])) 997 (Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && config.useAvg && config.useHmul -> 998 (Rsh64Ux64 <typ.UInt64> 999 (Avg64u 1000 x 1001 (Hmul64u <typ.UInt64> 1002 (Const64 <typ.UInt64> [int64(umagic(64,c).m)]) 1003 x)) 1004 (Const64 <typ.UInt64> [umagic(64,c).s-1])) 1005 1006 // Signed divide by a negative constant. Rewrite to divide by a positive constant. 1007 (Div8 <t> n (Const8 [c])) && c < 0 && c != -1<<7 -> (Neg8 (Div8 <t> n (Const8 <t> [-c]))) 1008 (Div16 <t> n (Const16 [c])) && c < 0 && c != -1<<15 -> (Neg16 (Div16 <t> n (Const16 <t> [-c]))) 1009 (Div32 <t> n (Const32 [c])) && c < 0 && c != -1<<31 -> (Neg32 (Div32 <t> n (Const32 <t> [-c]))) 1010 (Div64 <t> n (Const64 [c])) && c < 0 && c != -1<<63 -> (Neg64 (Div64 <t> n (Const64 <t> [-c]))) 1011 1012 // Dividing by the most-negative number. Result is always 0 except 1013 // if the input is also the most-negative number. 1014 // We can detect that using the sign bit of x & -x. 1015 (Div8 <t> x (Const8 [-1<<7 ])) -> (Rsh8Ux64 (And8 <t> x (Neg8 <t> x)) (Const64 <typ.UInt64> [7 ])) 1016 (Div16 <t> x (Const16 [-1<<15])) -> (Rsh16Ux64 (And16 <t> x (Neg16 <t> x)) (Const64 <typ.UInt64> [15])) 1017 (Div32 <t> x (Const32 [-1<<31])) -> (Rsh32Ux64 (And32 <t> x (Neg32 <t> x)) (Const64 <typ.UInt64> [31])) 1018 (Div64 <t> x (Const64 [-1<<63])) -> (Rsh64Ux64 (And64 <t> x (Neg64 <t> x)) (Const64 <typ.UInt64> [63])) 1019 1020 // Signed divide by power of 2. 1021 // n / c = n >> log(c) if n >= 0 1022 // = (n+c-1) >> log(c) if n < 0 1023 // We conditionally add c-1 by adding n>>63>>(64-log(c)) (first shift signed, second shift unsigned). 1024 (Div8 <t> n (Const8 [c])) && isPowerOfTwo(c) -> 1025 (Rsh8x64 1026 (Add8 <t> n (Rsh8Ux64 <t> (Rsh8x64 <t> n (Const64 <typ.UInt64> [ 7])) (Const64 <typ.UInt64> [ 8-log2(c)]))) 1027 (Const64 <typ.UInt64> [log2(c)])) 1028 (Div16 <t> n (Const16 [c])) && isPowerOfTwo(c) -> 1029 (Rsh16x64 1030 (Add16 <t> n (Rsh16Ux64 <t> (Rsh16x64 <t> n (Const64 <typ.UInt64> [15])) (Const64 <typ.UInt64> [16-log2(c)]))) 1031 (Const64 <typ.UInt64> [log2(c)])) 1032 (Div32 <t> n (Const32 [c])) && isPowerOfTwo(c) -> 1033 (Rsh32x64 1034 (Add32 <t> n (Rsh32Ux64 <t> (Rsh32x64 <t> n (Const64 <typ.UInt64> [31])) (Const64 <typ.UInt64> [32-log2(c)]))) 1035 (Const64 <typ.UInt64> [log2(c)])) 1036 (Div64 <t> n (Const64 [c])) && isPowerOfTwo(c) -> 1037 (Rsh64x64 1038 (Add64 <t> n (Rsh64Ux64 <t> (Rsh64x64 <t> n (Const64 <typ.UInt64> [63])) (Const64 <typ.UInt64> [64-log2(c)]))) 1039 (Const64 <typ.UInt64> [log2(c)])) 1040 1041 // Signed divide, not a power of 2. Strength reduce to a multiply. 1042 (Div8 <t> x (Const8 [c])) && smagicOK(8,c) -> 1043 (Sub8 <t> 1044 (Rsh32x64 <t> 1045 (Mul32 <typ.UInt32> 1046 (Const32 <typ.UInt32> [int64(smagic(8,c).m)]) 1047 (SignExt8to32 x)) 1048 (Const64 <typ.UInt64> [8+smagic(8,c).s])) 1049 (Rsh32x64 <t> 1050 (SignExt8to32 x) 1051 (Const64 <typ.UInt64> [31]))) 1052 (Div16 <t> x (Const16 [c])) && smagicOK(16,c) -> 1053 (Sub16 <t> 1054 (Rsh32x64 <t> 1055 (Mul32 <typ.UInt32> 1056 (Const32 <typ.UInt32> [int64(smagic(16,c).m)]) 1057 (SignExt16to32 x)) 1058 (Const64 <typ.UInt64> [16+smagic(16,c).s])) 1059 (Rsh32x64 <t> 1060 (SignExt16to32 x) 1061 (Const64 <typ.UInt64> [31]))) 1062 (Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 8 -> 1063 (Sub32 <t> 1064 (Rsh64x64 <t> 1065 (Mul64 <typ.UInt64> 1066 (Const64 <typ.UInt64> [int64(smagic(32,c).m)]) 1067 (SignExt32to64 x)) 1068 (Const64 <typ.UInt64> [32+smagic(32,c).s])) 1069 (Rsh64x64 <t> 1070 (SignExt32to64 x) 1071 (Const64 <typ.UInt64> [63]))) 1072 (Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 == 0 && config.useHmul -> 1073 (Sub32 <t> 1074 (Rsh32x64 <t> 1075 (Hmul32 <t> 1076 (Const32 <typ.UInt32> [int64(int32(smagic(32,c).m/2))]) 1077 x) 1078 (Const64 <typ.UInt64> [smagic(32,c).s-1])) 1079 (Rsh32x64 <t> 1080 x 1081 (Const64 <typ.UInt64> [31]))) 1082 (Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 != 0 && config.useHmul -> 1083 (Sub32 <t> 1084 (Rsh32x64 <t> 1085 (Add32 <t> 1086 (Hmul32 <t> 1087 (Const32 <typ.UInt32> [int64(int32(smagic(32,c).m))]) 1088 x) 1089 x) 1090 (Const64 <typ.UInt64> [smagic(32,c).s])) 1091 (Rsh32x64 <t> 1092 x 1093 (Const64 <typ.UInt64> [31]))) 1094 (Div64 <t> x (Const64 [c])) && smagicOK(64,c) && smagic(64,c).m&1 == 0 && config.useHmul -> 1095 (Sub64 <t> 1096 (Rsh64x64 <t> 1097 (Hmul64 <t> 1098 (Const64 <typ.UInt64> [int64(smagic(64,c).m/2)]) 1099 x) 1100 (Const64 <typ.UInt64> [smagic(64,c).s-1])) 1101 (Rsh64x64 <t> 1102 x 1103 (Const64 <typ.UInt64> [63]))) 1104 (Div64 <t> x (Const64 [c])) && smagicOK(64,c) && smagic(64,c).m&1 != 0 && config.useHmul -> 1105 (Sub64 <t> 1106 (Rsh64x64 <t> 1107 (Add64 <t> 1108 (Hmul64 <t> 1109 (Const64 <typ.UInt64> [int64(smagic(64,c).m)]) 1110 x) 1111 x) 1112 (Const64 <typ.UInt64> [smagic(64,c).s])) 1113 (Rsh64x64 <t> 1114 x 1115 (Const64 <typ.UInt64> [63]))) 1116 1117 // Unsigned mod by power of 2 constant. 1118 (Mod8u <t> n (Const8 [c])) && isPowerOfTwo(c&0xff) -> (And8 n (Const8 <t> [(c&0xff)-1])) 1119 (Mod16u <t> n (Const16 [c])) && isPowerOfTwo(c&0xffff) -> (And16 n (Const16 <t> [(c&0xffff)-1])) 1120 (Mod32u <t> n (Const32 [c])) && isPowerOfTwo(c&0xffffffff) -> (And32 n (Const32 <t> [(c&0xffffffff)-1])) 1121 (Mod64u <t> n (Const64 [c])) && isPowerOfTwo(c) -> (And64 n (Const64 <t> [c-1])) 1122 (Mod64u <t> n (Const64 [-1<<63])) -> (And64 n (Const64 <t> [1<<63-1])) 1123 1124 // Signed non-negative mod by power of 2 constant. 1125 (Mod8 <t> n (Const8 [c])) && isNonNegative(n) && isPowerOfTwo(c&0xff) -> (And8 n (Const8 <t> [(c&0xff)-1])) 1126 (Mod16 <t> n (Const16 [c])) && isNonNegative(n) && isPowerOfTwo(c&0xffff) -> (And16 n (Const16 <t> [(c&0xffff)-1])) 1127 (Mod32 <t> n (Const32 [c])) && isNonNegative(n) && isPowerOfTwo(c&0xffffffff) -> (And32 n (Const32 <t> [(c&0xffffffff)-1])) 1128 (Mod64 <t> n (Const64 [c])) && isNonNegative(n) && isPowerOfTwo(c) -> (And64 n (Const64 <t> [c-1])) 1129 (Mod64 n (Const64 [-1<<63])) && isNonNegative(n) -> n 1130 1131 // Signed mod by negative constant. 1132 (Mod8 <t> n (Const8 [c])) && c < 0 && c != -1<<7 -> (Mod8 <t> n (Const8 <t> [-c])) 1133 (Mod16 <t> n (Const16 [c])) && c < 0 && c != -1<<15 -> (Mod16 <t> n (Const16 <t> [-c])) 1134 (Mod32 <t> n (Const32 [c])) && c < 0 && c != -1<<31 -> (Mod32 <t> n (Const32 <t> [-c])) 1135 (Mod64 <t> n (Const64 [c])) && c < 0 && c != -1<<63 -> (Mod64 <t> n (Const64 <t> [-c])) 1136 1137 // All other mods by constants, do A%B = A-(A/B*B). 1138 // This implements % with two * and a bunch of ancillary ops. 1139 // One of the * is free if the user's code also computes A/B. 1140 (Mod8 <t> x (Const8 [c])) && x.Op != OpConst8 && (c > 0 || c == -1<<7) 1141 -> (Sub8 x (Mul8 <t> (Div8 <t> x (Const8 <t> [c])) (Const8 <t> [c]))) 1142 (Mod16 <t> x (Const16 [c])) && x.Op != OpConst16 && (c > 0 || c == -1<<15) 1143 -> (Sub16 x (Mul16 <t> (Div16 <t> x (Const16 <t> [c])) (Const16 <t> [c]))) 1144 (Mod32 <t> x (Const32 [c])) && x.Op != OpConst32 && (c > 0 || c == -1<<31) 1145 -> (Sub32 x (Mul32 <t> (Div32 <t> x (Const32 <t> [c])) (Const32 <t> [c]))) 1146 (Mod64 <t> x (Const64 [c])) && x.Op != OpConst64 && (c > 0 || c == -1<<63) 1147 -> (Sub64 x (Mul64 <t> (Div64 <t> x (Const64 <t> [c])) (Const64 <t> [c]))) 1148 (Mod8u <t> x (Const8 [c])) && x.Op != OpConst8 && c > 0 && umagicOK(8 ,c) 1149 -> (Sub8 x (Mul8 <t> (Div8u <t> x (Const8 <t> [c])) (Const8 <t> [c]))) 1150 (Mod16u <t> x (Const16 [c])) && x.Op != OpConst16 && c > 0 && umagicOK(16,c) 1151 -> (Sub16 x (Mul16 <t> (Div16u <t> x (Const16 <t> [c])) (Const16 <t> [c]))) 1152 (Mod32u <t> x (Const32 [c])) && x.Op != OpConst32 && c > 0 && umagicOK(32,c) 1153 -> (Sub32 x (Mul32 <t> (Div32u <t> x (Const32 <t> [c])) (Const32 <t> [c]))) 1154 (Mod64u <t> x (Const64 [c])) && x.Op != OpConst64 && c > 0 && umagicOK(64,c) 1155 -> (Sub64 x (Mul64 <t> (Div64u <t> x (Const64 <t> [c])) (Const64 <t> [c]))) 1156 1157 (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) 1158 (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) 1159 1160 // Reassociate expressions involving 1161 // constants such that constants come first, 1162 // exposing obvious constant-folding opportunities. 1163 // Reassociate (op (op y C) x) to (op C (op x y)) or similar, where C 1164 // is constant, which pushes constants to the outside 1165 // of the expression. At that point, any constant-folding 1166 // opportunities should be obvious. 1167 1168 // x + (C + z) -> C + (x + z) 1169 (Add64 (Add64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Add64 i (Add64 <t> z x)) 1170 (Add32 (Add32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Add32 i (Add32 <t> z x)) 1171 (Add16 (Add16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Add16 i (Add16 <t> z x)) 1172 (Add8 (Add8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Add8 i (Add8 <t> z x)) 1173 1174 // x + (C - z) -> C + (x - z) 1175 (Add64 (Sub64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Add64 i (Sub64 <t> x z)) 1176 (Add32 (Sub32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Add32 i (Sub32 <t> x z)) 1177 (Add16 (Sub16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Add16 i (Sub16 <t> x z)) 1178 (Add8 (Sub8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Add8 i (Sub8 <t> x z)) 1179 (Add64 x (Sub64 i:(Const64 <t>) z)) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Add64 i (Sub64 <t> x z)) 1180 (Add32 x (Sub32 i:(Const32 <t>) z)) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Add32 i (Sub32 <t> x z)) 1181 (Add16 x (Sub16 i:(Const16 <t>) z)) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Add16 i (Sub16 <t> x z)) 1182 (Add8 x (Sub8 i:(Const8 <t>) z)) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Add8 i (Sub8 <t> x z)) 1183 1184 // x + (z - C) -> (x + z) - C 1185 (Add64 (Sub64 z i:(Const64 <t>)) x) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Sub64 (Add64 <t> x z) i) 1186 (Add32 (Sub32 z i:(Const32 <t>)) x) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Sub32 (Add32 <t> x z) i) 1187 (Add16 (Sub16 z i:(Const16 <t>)) x) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Sub16 (Add16 <t> x z) i) 1188 (Add8 (Sub8 z i:(Const8 <t>)) x) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Sub8 (Add8 <t> x z) i) 1189 (Add64 x (Sub64 z i:(Const64 <t>))) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Sub64 (Add64 <t> x z) i) 1190 (Add32 x (Sub32 z i:(Const32 <t>))) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Sub32 (Add32 <t> x z) i) 1191 (Add16 x (Sub16 z i:(Const16 <t>))) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Sub16 (Add16 <t> x z) i) 1192 (Add8 x (Sub8 z i:(Const8 <t>))) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Sub8 (Add8 <t> x z) i) 1193 1194 // x - (C - z) -> x + (z - C) -> (x + z) - C 1195 (Sub64 x (Sub64 i:(Const64 <t>) z)) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Sub64 (Add64 <t> x z) i) 1196 (Sub32 x (Sub32 i:(Const32 <t>) z)) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Sub32 (Add32 <t> x z) i) 1197 (Sub16 x (Sub16 i:(Const16 <t>) z)) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Sub16 (Add16 <t> x z) i) 1198 (Sub8 x (Sub8 i:(Const8 <t>) z)) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Sub8 (Add8 <t> x z) i) 1199 1200 // x - (z - C) -> x + (C - z) -> (x - z) + C 1201 (Sub64 x (Sub64 z i:(Const64 <t>))) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Add64 i (Sub64 <t> x z)) 1202 (Sub32 x (Sub32 z i:(Const32 <t>))) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Add32 i (Sub32 <t> x z)) 1203 (Sub16 x (Sub16 z i:(Const16 <t>))) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Add16 i (Sub16 <t> x z)) 1204 (Sub8 x (Sub8 z i:(Const8 <t>))) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Add8 i (Sub8 <t> x z)) 1205 1206 // x & (C & z) -> C & (x & z) 1207 (And64 (And64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) -> (And64 i (And64 <t> z x)) 1208 (And32 (And32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) -> (And32 i (And32 <t> z x)) 1209 (And16 (And16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) -> (And16 i (And16 <t> z x)) 1210 (And8 (And8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) -> (And8 i (And8 <t> z x)) 1211 1212 // x | (C | z) -> C | (x | z) 1213 (Or64 (Or64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Or64 i (Or64 <t> z x)) 1214 (Or32 (Or32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Or32 i (Or32 <t> z x)) 1215 (Or16 (Or16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Or16 i (Or16 <t> z x)) 1216 (Or8 (Or8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Or8 i (Or8 <t> z x)) 1217 1218 // x ^ (C ^ z) -> C ^ (x ^ z) 1219 (Xor64 (Xor64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) -> (Xor64 i (Xor64 <t> z x)) 1220 (Xor32 (Xor32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) -> (Xor32 i (Xor32 <t> z x)) 1221 (Xor16 (Xor16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) -> (Xor16 i (Xor16 <t> z x)) 1222 (Xor8 (Xor8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) -> (Xor8 i (Xor8 <t> z x)) 1223 1224 // C + (D + x) -> (C + D) + x 1225 (Add64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) -> (Add64 (Const64 <t> [c+d]) x) 1226 (Add32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) -> (Add32 (Const32 <t> [int64(int32(c+d))]) x) 1227 (Add16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) -> (Add16 (Const16 <t> [int64(int16(c+d))]) x) 1228 (Add8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) -> (Add8 (Const8 <t> [int64(int8(c+d))]) x) 1229 1230 // C + (D - x) -> (C + D) - x 1231 (Add64 (Const64 <t> [c]) (Sub64 (Const64 <t> [d]) x)) -> (Sub64 (Const64 <t> [c+d]) x) 1232 (Add32 (Const32 <t> [c]) (Sub32 (Const32 <t> [d]) x)) -> (Sub32 (Const32 <t> [int64(int32(c+d))]) x) 1233 (Add16 (Const16 <t> [c]) (Sub16 (Const16 <t> [d]) x)) -> (Sub16 (Const16 <t> [int64(int16(c+d))]) x) 1234 (Add8 (Const8 <t> [c]) (Sub8 (Const8 <t> [d]) x)) -> (Sub8 (Const8 <t> [int64(int8(c+d))]) x) 1235 1236 // C + (x - D) -> (C - D) + x 1237 (Add64 (Const64 <t> [c]) (Sub64 x (Const64 <t> [d]))) -> (Add64 (Const64 <t> [c-d]) x) 1238 (Add32 (Const32 <t> [c]) (Sub32 x (Const32 <t> [d]))) -> (Add32 (Const32 <t> [int64(int32(c-d))]) x) 1239 (Add16 (Const16 <t> [c]) (Sub16 x (Const16 <t> [d]))) -> (Add16 (Const16 <t> [int64(int16(c-d))]) x) 1240 (Add8 (Const8 <t> [c]) (Sub8 x (Const8 <t> [d]))) -> (Add8 (Const8 <t> [int64(int8(c-d))]) x) 1241 1242 // C - (x - D) -> (C + D) - x 1243 (Sub64 (Const64 <t> [c]) (Sub64 x (Const64 <t> [d]))) -> (Sub64 (Const64 <t> [c+d]) x) 1244 (Sub32 (Const32 <t> [c]) (Sub32 x (Const32 <t> [d]))) -> (Sub32 (Const32 <t> [int64(int32(c+d))]) x) 1245 (Sub16 (Const16 <t> [c]) (Sub16 x (Const16 <t> [d]))) -> (Sub16 (Const16 <t> [int64(int16(c+d))]) x) 1246 (Sub8 (Const8 <t> [c]) (Sub8 x (Const8 <t> [d]))) -> (Sub8 (Const8 <t> [int64(int8(c+d))]) x) 1247 1248 // C - (D - x) -> (C - D) + x 1249 (Sub64 (Const64 <t> [c]) (Sub64 (Const64 <t> [d]) x)) -> (Add64 (Const64 <t> [c-d]) x) 1250 (Sub32 (Const32 <t> [c]) (Sub32 (Const32 <t> [d]) x)) -> (Add32 (Const32 <t> [int64(int32(c-d))]) x) 1251 (Sub16 (Const16 <t> [c]) (Sub16 (Const16 <t> [d]) x)) -> (Add16 (Const16 <t> [int64(int16(c-d))]) x) 1252 (Sub8 (Const8 <t> [c]) (Sub8 (Const8 <t> [d]) x)) -> (Add8 (Const8 <t> [int64(int8(c-d))]) x) 1253 1254 // C & (D & x) -> (C & D) & x 1255 (And64 (Const64 <t> [c]) (And64 (Const64 <t> [d]) x)) -> (And64 (Const64 <t> [c&d]) x) 1256 (And32 (Const32 <t> [c]) (And32 (Const32 <t> [d]) x)) -> (And32 (Const32 <t> [int64(int32(c&d))]) x) 1257 (And16 (Const16 <t> [c]) (And16 (Const16 <t> [d]) x)) -> (And16 (Const16 <t> [int64(int16(c&d))]) x) 1258 (And8 (Const8 <t> [c]) (And8 (Const8 <t> [d]) x)) -> (And8 (Const8 <t> [int64(int8(c&d))]) x) 1259 1260 // C | (D | x) -> (C | D) | x 1261 (Or64 (Const64 <t> [c]) (Or64 (Const64 <t> [d]) x)) -> (Or64 (Const64 <t> [c|d]) x) 1262 (Or32 (Const32 <t> [c]) (Or32 (Const32 <t> [d]) x)) -> (Or32 (Const32 <t> [int64(int32(c|d))]) x) 1263 (Or16 (Const16 <t> [c]) (Or16 (Const16 <t> [d]) x)) -> (Or16 (Const16 <t> [int64(int16(c|d))]) x) 1264 (Or8 (Const8 <t> [c]) (Or8 (Const8 <t> [d]) x)) -> (Or8 (Const8 <t> [int64(int8(c|d))]) x) 1265 1266 // C ^ (D ^ x) -> (C ^ D) ^ x 1267 (Xor64 (Const64 <t> [c]) (Xor64 (Const64 <t> [d]) x)) -> (Xor64 (Const64 <t> [c^d]) x) 1268 (Xor32 (Const32 <t> [c]) (Xor32 (Const32 <t> [d]) x)) -> (Xor32 (Const32 <t> [int64(int32(c^d))]) x) 1269 (Xor16 (Const16 <t> [c]) (Xor16 (Const16 <t> [d]) x)) -> (Xor16 (Const16 <t> [int64(int16(c^d))]) x) 1270 (Xor8 (Const8 <t> [c]) (Xor8 (Const8 <t> [d]) x)) -> (Xor8 (Const8 <t> [int64(int8(c^d))]) x) 1271 1272 // C * (D * x) = (C * D) * x 1273 (Mul64 (Const64 <t> [c]) (Mul64 (Const64 <t> [d]) x)) -> (Mul64 (Const64 <t> [c*d]) x) 1274 (Mul32 (Const32 <t> [c]) (Mul32 (Const32 <t> [d]) x)) -> (Mul32 (Const32 <t> [int64(int32(c*d))]) x) 1275 (Mul16 (Const16 <t> [c]) (Mul16 (Const16 <t> [d]) x)) -> (Mul16 (Const16 <t> [int64(int16(c*d))]) x) 1276 (Mul8 (Const8 <t> [c]) (Mul8 (Const8 <t> [d]) x)) -> (Mul8 (Const8 <t> [int64(int8(c*d))]) x) 1277 1278 // floating point optimizations 1279 (Mul(32|64)F x (Const(32|64)F [auxFrom64F(1)])) -> x 1280 (Mul32F x (Const32F [auxFrom32F(-1)])) -> (Neg32F x) 1281 (Mul64F x (Const64F [auxFrom64F(-1)])) -> (Neg64F x) 1282 (Mul32F x (Const32F [auxFrom32F(2)])) -> (Add32F x x) 1283 (Mul64F x (Const64F [auxFrom64F(2)])) -> (Add64F x x) 1284 1285 (Div32F x (Const32F <t> [c])) && reciprocalExact32(auxTo32F(c)) -> (Mul32F x (Const32F <t> [auxFrom32F(1/auxTo32F(c))])) 1286 (Div64F x (Const64F <t> [c])) && reciprocalExact64(auxTo64F(c)) -> (Mul64F x (Const64F <t> [auxFrom64F(1/auxTo64F(c))])) 1287 1288 (Sqrt (Const64F [c])) -> (Const64F [auxFrom64F(math.Sqrt(auxTo64F(c)))]) 1289 1290 // recognize runtime.newobject and don't Zero/Nilcheck it 1291 (Zero (Load (OffPtr [c] (SP)) mem) mem) 1292 && mem.Op == OpStaticCall 1293 && isSameSym(mem.Aux, "runtime.newobject") 1294 && c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value 1295 -> mem 1296 (Store (Load (OffPtr [c] (SP)) mem) x mem) 1297 && isConstZero(x) 1298 && mem.Op == OpStaticCall 1299 && isSameSym(mem.Aux, "runtime.newobject") 1300 && c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value 1301 -> mem 1302 (Store (OffPtr (Load (OffPtr [c] (SP)) mem)) x mem) 1303 && isConstZero(x) 1304 && mem.Op == OpStaticCall 1305 && isSameSym(mem.Aux, "runtime.newobject") 1306 && c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value 1307 -> mem 1308 // nil checks just need to rewrite to something useless. 1309 // they will be deadcode eliminated soon afterwards. 1310 (NilCheck (Load (OffPtr [c] (SP)) (StaticCall {sym} _)) _) 1311 && isSameSym(sym, "runtime.newobject") 1312 && c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value 1313 && warnRule(fe.Debug_checknil(), v, "removed nil check") 1314 -> (Invalid) 1315 (NilCheck (OffPtr (Load (OffPtr [c] (SP)) (StaticCall {sym} _))) _) 1316 && isSameSym(sym, "runtime.newobject") 1317 && c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value 1318 && warnRule(fe.Debug_checknil(), v, "removed nil check") 1319 -> (Invalid) 1320 1321 // Evaluate constant address comparisons. 1322 (EqPtr x x) -> (ConstBool [1]) 1323 (NeqPtr x x) -> (ConstBool [0]) 1324 (EqPtr (Addr {a} _) (Addr {b} _)) -> (ConstBool [b2i(a == b)]) 1325 (NeqPtr (Addr {a} _) (Addr {b} _)) -> (ConstBool [b2i(a != b)]) 1326 (EqPtr (LocalAddr {a} _ _) (LocalAddr {b} _ _)) -> (ConstBool [b2i(a == b)]) 1327 (NeqPtr (LocalAddr {a} _ _) (LocalAddr {b} _ _)) -> (ConstBool [b2i(a != b)]) 1328 (EqPtr (OffPtr [o1] p1) p2) && isSamePtr(p1, p2) -> (ConstBool [b2i(o1 == 0)]) 1329 (NeqPtr (OffPtr [o1] p1) p2) && isSamePtr(p1, p2) -> (ConstBool [b2i(o1 != 0)]) 1330 (EqPtr (OffPtr [o1] p1) (OffPtr [o2] p2)) && isSamePtr(p1, p2) -> (ConstBool [b2i(o1 == o2)]) 1331 (NeqPtr (OffPtr [o1] p1) (OffPtr [o2] p2)) && isSamePtr(p1, p2) -> (ConstBool [b2i(o1 != o2)]) 1332 (EqPtr (Const(32|64) [c]) (Const(32|64) [d])) -> (ConstBool [b2i(c == d)]) 1333 (NeqPtr (Const(32|64) [c]) (Const(32|64) [d])) -> (ConstBool [b2i(c != d)]) 1334 1335 (EqPtr (LocalAddr _ _) (Addr _)) -> (ConstBool [0]) 1336 (NeqPtr (LocalAddr _ _) (Addr _)) -> (ConstBool [1]) 1337 (EqPtr (Addr _) (LocalAddr _ _)) -> (ConstBool [0]) 1338 (NeqPtr (Addr _) (LocalAddr _ _)) -> (ConstBool [1]) 1339 1340 // Simplify address comparisons. 1341 (EqPtr (AddPtr p1 o1) p2) && isSamePtr(p1, p2) -> (Not (IsNonNil o1)) 1342 (NeqPtr (AddPtr p1 o1) p2) && isSamePtr(p1, p2) -> (IsNonNil o1) 1343 (EqPtr (Const(32|64) [0]) p) -> (Not (IsNonNil p)) 1344 (NeqPtr (Const(32|64) [0]) p) -> (IsNonNil p) 1345 (EqPtr (ConstNil) p) -> (Not (IsNonNil p)) 1346 (NeqPtr (ConstNil) p) -> (IsNonNil p) 1347 1348 // Evaluate constant user nil checks. 1349 (IsNonNil (ConstNil)) -> (ConstBool [0]) 1350 (IsNonNil (Const(32|64) [c])) -> (ConstBool [b2i(c != 0)]) 1351 (IsNonNil (Addr _)) -> (ConstBool [1]) 1352 (IsNonNil (LocalAddr _ _)) -> (ConstBool [1]) 1353 1354 // Inline small or disjoint runtime.memmove calls with constant length. 1355 (StaticCall {sym} s1:(Store _ (Const(64|32) [sz]) s2:(Store _ src s3:(Store {t} _ dst mem)))) 1356 && isSameSym(sym,"runtime.memmove") 1357 && t.(*types.Type).IsPtr() // avoids TUINTPTR, see issue 30061 1358 && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 1359 && isInlinableMemmove(dst,src,sz,config) 1360 && clobber(s1) && clobber(s2) && clobber(s3) 1361 -> (Move {t.(*types.Type).Elem()} [sz] dst src mem) 1362 1363 // De-virtualize interface calls into static calls. 1364 // Note that (ITab (IMake)) doesn't get 1365 // rewritten until after the first opt pass, 1366 // so this rule should trigger reliably. 1367 (InterCall [argsize] (Load (OffPtr [off] (ITab (IMake (Addr {itab} (SB)) _))) _) mem) && devirt(v, itab, off) != nil -> 1368 (StaticCall [argsize] {devirt(v, itab, off)} mem) 1369 1370 // Move and Zero optimizations. 1371 // Move source and destination may overlap. 1372 1373 // Convert Moves into Zeros when the source is known to be zeros. 1374 (Move {t} [n] dst1 src mem:(Zero {t} [n] dst2 _)) && isSamePtr(src, dst2) 1375 -> (Zero {t} [n] dst1 mem) 1376 (Move {t} [n] dst1 src mem:(VarDef (Zero {t} [n] dst0 _))) && isSamePtr(src, dst0) 1377 -> (Zero {t} [n] dst1 mem) 1378 1379 // Don't Store to variables that are about to be overwritten by Move/Zero. 1380 (Zero {t1} [n] p1 store:(Store {t2} (OffPtr [o2] p2) _ mem)) 1381 && isSamePtr(p1, p2) && store.Uses == 1 1382 && n >= o2 + sizeof(t2) 1383 && clobber(store) 1384 -> (Zero {t1} [n] p1 mem) 1385 (Move {t1} [n] dst1 src1 store:(Store {t2} op:(OffPtr [o2] dst2) _ mem)) 1386 && isSamePtr(dst1, dst2) && store.Uses == 1 1387 && n >= o2 + sizeof(t2) 1388 && disjoint(src1, n, op, sizeof(t2)) 1389 && clobber(store) 1390 -> (Move {t1} [n] dst1 src1 mem) 1391 1392 // Don't Move to variables that are immediately completely overwritten. 1393 (Zero {t} [n] dst1 move:(Move {t} [n] dst2 _ mem)) 1394 && move.Uses == 1 1395 && isSamePtr(dst1, dst2) 1396 && clobber(move) 1397 -> (Zero {t} [n] dst1 mem) 1398 (Move {t} [n] dst1 src1 move:(Move {t} [n] dst2 _ mem)) 1399 && move.Uses == 1 1400 && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) 1401 && clobber(move) 1402 -> (Move {t} [n] dst1 src1 mem) 1403 (Zero {t} [n] dst1 vardef:(VarDef {x} move:(Move {t} [n] dst2 _ mem))) 1404 && move.Uses == 1 && vardef.Uses == 1 1405 && isSamePtr(dst1, dst2) 1406 && clobber(move) && clobber(vardef) 1407 -> (Zero {t} [n] dst1 (VarDef {x} mem)) 1408 (Move {t} [n] dst1 src1 vardef:(VarDef {x} move:(Move {t} [n] dst2 _ mem))) 1409 && move.Uses == 1 && vardef.Uses == 1 1410 && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) 1411 && clobber(move) && clobber(vardef) 1412 -> (Move {t} [n] dst1 src1 (VarDef {x} mem)) 1413 (Store {t1} op1:(OffPtr [o1] p1) d1 1414 m2:(Store {t2} op2:(OffPtr [0] p2) d2 1415 m3:(Move [n] p3 _ mem))) 1416 && m2.Uses == 1 && m3.Uses == 1 1417 && o1 == sizeof(t2) 1418 && n == sizeof(t2) + sizeof(t1) 1419 && isSamePtr(p1, p2) && isSamePtr(p2, p3) 1420 && clobber(m2) && clobber(m3) 1421 -> (Store {t1} op1 d1 (Store {t2} op2 d2 mem)) 1422 (Store {t1} op1:(OffPtr [o1] p1) d1 1423 m2:(Store {t2} op2:(OffPtr [o2] p2) d2 1424 m3:(Store {t3} op3:(OffPtr [0] p3) d3 1425 m4:(Move [n] p4 _ mem)))) 1426 && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 1427 && o2 == sizeof(t3) 1428 && o1-o2 == sizeof(t2) 1429 && n == sizeof(t3) + sizeof(t2) + sizeof(t1) 1430 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) 1431 && clobber(m2) && clobber(m3) && clobber(m4) 1432 -> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 mem))) 1433 (Store {t1} op1:(OffPtr [o1] p1) d1 1434 m2:(Store {t2} op2:(OffPtr [o2] p2) d2 1435 m3:(Store {t3} op3:(OffPtr [o3] p3) d3 1436 m4:(Store {t4} op4:(OffPtr [0] p4) d4 1437 m5:(Move [n] p5 _ mem))))) 1438 && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 && m5.Uses == 1 1439 && o3 == sizeof(t4) 1440 && o2-o3 == sizeof(t3) 1441 && o1-o2 == sizeof(t2) 1442 && n == sizeof(t4) + sizeof(t3) + sizeof(t2) + sizeof(t1) 1443 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) 1444 && clobber(m2) && clobber(m3) && clobber(m4) && clobber(m5) 1445 -> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 (Store {t4} op4 d4 mem)))) 1446 1447 // Don't Zero variables that are immediately completely overwritten 1448 // before being accessed. 1449 (Move {t} [n] dst1 src1 zero:(Zero {t} [n] dst2 mem)) 1450 && zero.Uses == 1 1451 && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) 1452 && clobber(zero) 1453 -> (Move {t} [n] dst1 src1 mem) 1454 (Move {t} [n] dst1 src1 vardef:(VarDef {x} zero:(Zero {t} [n] dst2 mem))) 1455 && zero.Uses == 1 && vardef.Uses == 1 1456 && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) 1457 && clobber(zero) && clobber(vardef) 1458 -> (Move {t} [n] dst1 src1 (VarDef {x} mem)) 1459 (Store {t1} op1:(OffPtr [o1] p1) d1 1460 m2:(Store {t2} op2:(OffPtr [0] p2) d2 1461 m3:(Zero [n] p3 mem))) 1462 && m2.Uses == 1 && m3.Uses == 1 1463 && o1 == sizeof(t2) 1464 && n == sizeof(t2) + sizeof(t1) 1465 && isSamePtr(p1, p2) && isSamePtr(p2, p3) 1466 && clobber(m2) && clobber(m3) 1467 -> (Store {t1} op1 d1 (Store {t2} op2 d2 mem)) 1468 (Store {t1} op1:(OffPtr [o1] p1) d1 1469 m2:(Store {t2} op2:(OffPtr [o2] p2) d2 1470 m3:(Store {t3} op3:(OffPtr [0] p3) d3 1471 m4:(Zero [n] p4 mem)))) 1472 && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 1473 && o2 == sizeof(t3) 1474 && o1-o2 == sizeof(t2) 1475 && n == sizeof(t3) + sizeof(t2) + sizeof(t1) 1476 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) 1477 && clobber(m2) && clobber(m3) && clobber(m4) 1478 -> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 mem))) 1479 (Store {t1} op1:(OffPtr [o1] p1) d1 1480 m2:(Store {t2} op2:(OffPtr [o2] p2) d2 1481 m3:(Store {t3} op3:(OffPtr [o3] p3) d3 1482 m4:(Store {t4} op4:(OffPtr [0] p4) d4 1483 m5:(Zero [n] p5 mem))))) 1484 && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 && m5.Uses == 1 1485 && o3 == sizeof(t4) 1486 && o2-o3 == sizeof(t3) 1487 && o1-o2 == sizeof(t2) 1488 && n == sizeof(t4) + sizeof(t3) + sizeof(t2) + sizeof(t1) 1489 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) 1490 && clobber(m2) && clobber(m3) && clobber(m4) && clobber(m5) 1491 -> (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 (Store {t4} op4 d4 mem)))) 1492 1493 // Don't Move from memory if the values are likely to already be 1494 // in registers. 1495 (Move {t1} [n] dst p1 1496 mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1497 (Store {t3} op3:(OffPtr <tt3> [0] p3) d2 _))) 1498 && isSamePtr(p1, p2) && isSamePtr(p2, p3) 1499 && alignof(t2) <= alignof(t1) 1500 && alignof(t3) <= alignof(t1) 1501 && registerizable(b, t2) 1502 && registerizable(b, t3) 1503 && o2 == sizeof(t3) 1504 && n == sizeof(t2) + sizeof(t3) 1505 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1506 (Store {t3} (OffPtr <tt3> [0] dst) d2 mem)) 1507 (Move {t1} [n] dst p1 1508 mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1509 (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 1510 (Store {t4} op4:(OffPtr <tt4> [0] p4) d3 _)))) 1511 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) 1512 && alignof(t2) <= alignof(t1) 1513 && alignof(t3) <= alignof(t1) 1514 && alignof(t4) <= alignof(t1) 1515 && registerizable(b, t2) 1516 && registerizable(b, t3) 1517 && registerizable(b, t4) 1518 && o3 == sizeof(t4) 1519 && o2-o3 == sizeof(t3) 1520 && n == sizeof(t2) + sizeof(t3) + sizeof(t4) 1521 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1522 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1523 (Store {t4} (OffPtr <tt4> [0] dst) d3 mem))) 1524 (Move {t1} [n] dst p1 1525 mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1526 (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 1527 (Store {t4} op4:(OffPtr <tt4> [o4] p4) d3 1528 (Store {t5} op5:(OffPtr <tt5> [0] p5) d4 _))))) 1529 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) 1530 && alignof(t2) <= alignof(t1) 1531 && alignof(t3) <= alignof(t1) 1532 && alignof(t4) <= alignof(t1) 1533 && alignof(t5) <= alignof(t1) 1534 && registerizable(b, t2) 1535 && registerizable(b, t3) 1536 && registerizable(b, t4) 1537 && registerizable(b, t5) 1538 && o4 == sizeof(t5) 1539 && o3-o4 == sizeof(t4) 1540 && o2-o3 == sizeof(t3) 1541 && n == sizeof(t2) + sizeof(t3) + sizeof(t4) + sizeof(t5) 1542 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1543 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1544 (Store {t4} (OffPtr <tt4> [o4] dst) d3 1545 (Store {t5} (OffPtr <tt5> [0] dst) d4 mem)))) 1546 1547 // Same thing but with VarDef in the middle. 1548 (Move {t1} [n] dst p1 1549 mem:(VarDef 1550 (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1551 (Store {t3} op3:(OffPtr <tt3> [0] p3) d2 _)))) 1552 && isSamePtr(p1, p2) && isSamePtr(p2, p3) 1553 && alignof(t2) <= alignof(t1) 1554 && alignof(t3) <= alignof(t1) 1555 && registerizable(b, t2) 1556 && registerizable(b, t3) 1557 && o2 == sizeof(t3) 1558 && n == sizeof(t2) + sizeof(t3) 1559 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1560 (Store {t3} (OffPtr <tt3> [0] dst) d2 mem)) 1561 (Move {t1} [n] dst p1 1562 mem:(VarDef 1563 (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1564 (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 1565 (Store {t4} op4:(OffPtr <tt4> [0] p4) d3 _))))) 1566 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) 1567 && alignof(t2) <= alignof(t1) 1568 && alignof(t3) <= alignof(t1) 1569 && alignof(t4) <= alignof(t1) 1570 && registerizable(b, t2) 1571 && registerizable(b, t3) 1572 && registerizable(b, t4) 1573 && o3 == sizeof(t4) 1574 && o2-o3 == sizeof(t3) 1575 && n == sizeof(t2) + sizeof(t3) + sizeof(t4) 1576 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1577 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1578 (Store {t4} (OffPtr <tt4> [0] dst) d3 mem))) 1579 (Move {t1} [n] dst p1 1580 mem:(VarDef 1581 (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1582 (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 1583 (Store {t4} op4:(OffPtr <tt4> [o4] p4) d3 1584 (Store {t5} op5:(OffPtr <tt5> [0] p5) d4 _)))))) 1585 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) 1586 && alignof(t2) <= alignof(t1) 1587 && alignof(t3) <= alignof(t1) 1588 && alignof(t4) <= alignof(t1) 1589 && alignof(t5) <= alignof(t1) 1590 && registerizable(b, t2) 1591 && registerizable(b, t3) 1592 && registerizable(b, t4) 1593 && registerizable(b, t5) 1594 && o4 == sizeof(t5) 1595 && o3-o4 == sizeof(t4) 1596 && o2-o3 == sizeof(t3) 1597 && n == sizeof(t2) + sizeof(t3) + sizeof(t4) + sizeof(t5) 1598 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1599 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1600 (Store {t4} (OffPtr <tt4> [o4] dst) d3 1601 (Store {t5} (OffPtr <tt5> [0] dst) d4 mem)))) 1602 1603 // Prefer to Zero and Store than to Move. 1604 (Move {t1} [n] dst p1 1605 mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1606 (Zero {t3} [n] p3 _))) 1607 && isSamePtr(p1, p2) && isSamePtr(p2, p3) 1608 && alignof(t2) <= alignof(t1) 1609 && alignof(t3) <= alignof(t1) 1610 && registerizable(b, t2) 1611 && n >= o2 + sizeof(t2) 1612 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1613 (Zero {t1} [n] dst mem)) 1614 (Move {t1} [n] dst p1 1615 mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1 1616 (Store {t3} (OffPtr <tt3> [o3] p3) d2 1617 (Zero {t4} [n] p4 _)))) 1618 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) 1619 && alignof(t2) <= alignof(t1) 1620 && alignof(t3) <= alignof(t1) 1621 && alignof(t4) <= alignof(t1) 1622 && registerizable(b, t2) 1623 && registerizable(b, t3) 1624 && n >= o2 + sizeof(t2) 1625 && n >= o3 + sizeof(t3) 1626 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1627 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1628 (Zero {t1} [n] dst mem))) 1629 (Move {t1} [n] dst p1 1630 mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1 1631 (Store {t3} (OffPtr <tt3> [o3] p3) d2 1632 (Store {t4} (OffPtr <tt4> [o4] p4) d3 1633 (Zero {t5} [n] p5 _))))) 1634 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) 1635 && alignof(t2) <= alignof(t1) 1636 && alignof(t3) <= alignof(t1) 1637 && alignof(t4) <= alignof(t1) 1638 && alignof(t5) <= alignof(t1) 1639 && registerizable(b, t2) 1640 && registerizable(b, t3) 1641 && registerizable(b, t4) 1642 && n >= o2 + sizeof(t2) 1643 && n >= o3 + sizeof(t3) 1644 && n >= o4 + sizeof(t4) 1645 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1646 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1647 (Store {t4} (OffPtr <tt4> [o4] dst) d3 1648 (Zero {t1} [n] dst mem)))) 1649 (Move {t1} [n] dst p1 1650 mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1 1651 (Store {t3} (OffPtr <tt3> [o3] p3) d2 1652 (Store {t4} (OffPtr <tt4> [o4] p4) d3 1653 (Store {t5} (OffPtr <tt5> [o5] p5) d4 1654 (Zero {t6} [n] p6 _)))))) 1655 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) && isSamePtr(p5, p6) 1656 && alignof(t2) <= alignof(t1) 1657 && alignof(t3) <= alignof(t1) 1658 && alignof(t4) <= alignof(t1) 1659 && alignof(t5) <= alignof(t1) 1660 && alignof(t6) <= alignof(t1) 1661 && registerizable(b, t2) 1662 && registerizable(b, t3) 1663 && registerizable(b, t4) 1664 && registerizable(b, t5) 1665 && n >= o2 + sizeof(t2) 1666 && n >= o3 + sizeof(t3) 1667 && n >= o4 + sizeof(t4) 1668 && n >= o5 + sizeof(t5) 1669 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1670 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1671 (Store {t4} (OffPtr <tt4> [o4] dst) d3 1672 (Store {t5} (OffPtr <tt5> [o5] dst) d4 1673 (Zero {t1} [n] dst mem))))) 1674 (Move {t1} [n] dst p1 1675 mem:(VarDef 1676 (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 1677 (Zero {t3} [n] p3 _)))) 1678 && isSamePtr(p1, p2) && isSamePtr(p2, p3) 1679 && alignof(t2) <= alignof(t1) 1680 && alignof(t3) <= alignof(t1) 1681 && registerizable(b, t2) 1682 && n >= o2 + sizeof(t2) 1683 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1684 (Zero {t1} [n] dst mem)) 1685 (Move {t1} [n] dst p1 1686 mem:(VarDef 1687 (Store {t2} (OffPtr <tt2> [o2] p2) d1 1688 (Store {t3} (OffPtr <tt3> [o3] p3) d2 1689 (Zero {t4} [n] p4 _))))) 1690 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) 1691 && alignof(t2) <= alignof(t1) 1692 && alignof(t3) <= alignof(t1) 1693 && alignof(t4) <= alignof(t1) 1694 && registerizable(b, t2) 1695 && registerizable(b, t3) 1696 && n >= o2 + sizeof(t2) 1697 && n >= o3 + sizeof(t3) 1698 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1699 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1700 (Zero {t1} [n] dst mem))) 1701 (Move {t1} [n] dst p1 1702 mem:(VarDef 1703 (Store {t2} (OffPtr <tt2> [o2] p2) d1 1704 (Store {t3} (OffPtr <tt3> [o3] p3) d2 1705 (Store {t4} (OffPtr <tt4> [o4] p4) d3 1706 (Zero {t5} [n] p5 _)))))) 1707 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) 1708 && alignof(t2) <= alignof(t1) 1709 && alignof(t3) <= alignof(t1) 1710 && alignof(t4) <= alignof(t1) 1711 && alignof(t5) <= alignof(t1) 1712 && registerizable(b, t2) 1713 && registerizable(b, t3) 1714 && registerizable(b, t4) 1715 && n >= o2 + sizeof(t2) 1716 && n >= o3 + sizeof(t3) 1717 && n >= o4 + sizeof(t4) 1718 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1719 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1720 (Store {t4} (OffPtr <tt4> [o4] dst) d3 1721 (Zero {t1} [n] dst mem)))) 1722 (Move {t1} [n] dst p1 1723 mem:(VarDef 1724 (Store {t2} (OffPtr <tt2> [o2] p2) d1 1725 (Store {t3} (OffPtr <tt3> [o3] p3) d2 1726 (Store {t4} (OffPtr <tt4> [o4] p4) d3 1727 (Store {t5} (OffPtr <tt5> [o5] p5) d4 1728 (Zero {t6} [n] p6 _))))))) 1729 && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) && isSamePtr(p5, p6) 1730 && alignof(t2) <= alignof(t1) 1731 && alignof(t3) <= alignof(t1) 1732 && alignof(t4) <= alignof(t1) 1733 && alignof(t5) <= alignof(t1) 1734 && alignof(t6) <= alignof(t1) 1735 && registerizable(b, t2) 1736 && registerizable(b, t3) 1737 && registerizable(b, t4) 1738 && registerizable(b, t5) 1739 && n >= o2 + sizeof(t2) 1740 && n >= o3 + sizeof(t3) 1741 && n >= o4 + sizeof(t4) 1742 && n >= o5 + sizeof(t5) 1743 -> (Store {t2} (OffPtr <tt2> [o2] dst) d1 1744 (Store {t3} (OffPtr <tt3> [o3] dst) d2 1745 (Store {t4} (OffPtr <tt4> [o4] dst) d3 1746 (Store {t5} (OffPtr <tt5> [o5] dst) d4 1747 (Zero {t1} [n] dst mem))))) 1748 1749 (StaticCall {sym} x) && needRaceCleanup(sym,v) -> x 1750 1751 // Collapse moving A -> B -> C into just A -> C. 1752 // Later passes (deadstore, elim unread auto) will remove the A -> B move, if possible. 1753 // This happens most commonly when B is an autotmp inserted earlier 1754 // during compilation to ensure correctness. 1755 // Take care that overlapping moves are preserved. 1756 // Restrict this optimization to the stack, to avoid duplicating loads from the heap; 1757 // see CL 145208 for discussion. 1758 (Move {t1} [s] dst tmp1 midmem:(Move {t2} [s] tmp2 src _)) 1759 && t1.(*types.Type).Compare(t2.(*types.Type)) == types.CMPeq 1760 && isSamePtr(tmp1, tmp2) 1761 && isStackPtr(src) 1762 && disjoint(src, s, tmp2, s) 1763 && (disjoint(src, s, dst, s) || isInlinableMemmove(dst, src, s, config)) 1764 -> (Move {t1} [s] dst src midmem) 1765 1766 // Same, but for large types that require VarDefs. 1767 (Move {t1} [s] dst tmp1 midmem:(VarDef (Move {t2} [s] tmp2 src _))) 1768 && t1.(*types.Type).Compare(t2.(*types.Type)) == types.CMPeq 1769 && isSamePtr(tmp1, tmp2) 1770 && isStackPtr(src) 1771 && disjoint(src, s, tmp2, s) 1772 && (disjoint(src, s, dst, s) || isInlinableMemmove(dst, src, s, config)) 1773 -> (Move {t1} [s] dst src midmem) 1774 1775 // Elide self-moves. This only happens rarely (e.g test/fixedbugs/bug277.go). 1776 // However, this rule is needed to prevent the previous rule from looping forever in such cases. 1777 (Move dst src mem) && isSamePtr(dst, src) -> mem