github.com/sbinet/go@v0.0.0-20160827155028-54d7de7dd62b/src/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 [f2i(float64(i2f32(c)))]) 48 (Cvt32Fto64F (Const32F [c])) -> (Const64F [c]) // c is already a 64 bit float 49 50 // const negation is currently handled by frontend 51 //(Neg8 (Const8 [c])) -> (Const8 [-c]) 52 //(Neg16 (Const16 [c])) -> (Const16 [-c]) 53 //(Neg32 (Const32 [c])) -> (Const32 [-c]) 54 //(Neg64 (Const64 [c])) -> (Const64 [-c]) 55 //(Neg32F (Const32F [c])) -> (Const32F [f2i(-i2f(c))]) 56 //(Neg64F (Const64F [c])) -> (Const64F [f2i(-i2f(c))]) 57 58 (Add8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c+d))]) 59 (Add16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c+d))]) 60 (Add32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c+d))]) 61 (Add64 (Const64 [c]) (Const64 [d])) -> (Const64 [c+d]) 62 (Add32F (Const32F [c]) (Const32F [d])) -> 63 (Const32F [f2i(float64(i2f32(c) + i2f32(d)))]) // ensure we combine the operands with 32 bit precision 64 (Add64F (Const64F [c]) (Const64F [d])) -> (Const64F [f2i(i2f(c) + i2f(d))]) 65 (AddPtr <t> x (Const64 [c])) -> (OffPtr <t> x [c]) 66 67 (Sub8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c-d))]) 68 (Sub16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c-d))]) 69 (Sub32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c-d))]) 70 (Sub64 (Const64 [c]) (Const64 [d])) -> (Const64 [c-d]) 71 (Sub32F (Const32F [c]) (Const32F [d])) -> 72 (Const32F [f2i(float64(i2f32(c) - i2f32(d)))]) 73 (Sub64F (Const64F [c]) (Const64F [d])) -> (Const64F [f2i(i2f(c) - i2f(d))]) 74 75 (Mul8 (Const8 [c]) (Const8 [d])) -> (Const8 [int64(int8(c*d))]) 76 (Mul16 (Const16 [c]) (Const16 [d])) -> (Const16 [int64(int16(c*d))]) 77 (Mul32 (Const32 [c]) (Const32 [d])) -> (Const32 [int64(int32(c*d))]) 78 (Mul64 (Const64 [c]) (Const64 [d])) -> (Const64 [c*d]) 79 (Mul32F (Const32F [c]) (Const32F [d])) -> 80 (Const32F [f2i(float64(i2f32(c) * i2f32(d)))]) 81 (Mul64F (Const64F [c]) (Const64F [d])) -> (Const64F [f2i(i2f(c) * i2f(d))]) 82 83 // Convert x * -1 to -x. The front-end catches some but not all of these. 84 (Mul8 (Const8 [-1]) x) -> (Neg8 x) 85 (Mul16 (Const16 [-1]) x) -> (Neg16 x) 86 (Mul32 (Const32 [-1]) x) -> (Neg32 x) 87 (Mul64 (Const64 [-1]) x) -> (Neg64 x) 88 89 (Mod8 (Const8 [c]) (Const8 [d])) && d != 0 -> (Const8 [int64(int8(c % d))]) 90 (Mod16 (Const16 [c]) (Const16 [d])) && d != 0 -> (Const16 [int64(int16(c % d))]) 91 (Mod32 (Const32 [c]) (Const32 [d])) && d != 0 -> (Const32 [int64(int32(c % d))]) 92 (Mod64 (Const64 [c]) (Const64 [d])) && d != 0 -> (Const64 [c % d]) 93 94 (Mod8u (Const8 [c]) (Const8 [d])) && d != 0 -> (Const8 [int64(uint8(c) % uint8(d))]) 95 (Mod16u (Const16 [c]) (Const16 [d])) && d != 0 -> (Const16 [int64(uint16(c) % uint16(d))]) 96 (Mod32u (Const32 [c]) (Const32 [d])) && d != 0 -> (Const32 [int64(uint32(c) % uint32(d))]) 97 (Mod64u (Const64 [c]) (Const64 [d])) && d != 0 -> (Const64 [int64(uint64(c) % uint64(d))]) 98 99 (Lsh64x64 (Const64 [c]) (Const64 [d])) -> (Const64 [c << uint64(d)]) 100 (Rsh64x64 (Const64 [c]) (Const64 [d])) -> (Const64 [c >> uint64(d)]) 101 (Rsh64Ux64 (Const64 [c]) (Const64 [d])) -> (Const64 [int64(uint64(c) >> uint64(d))]) 102 (Lsh32x64 (Const32 [c]) (Const64 [d])) -> (Const32 [int64(int32(c) << uint64(d))]) 103 (Rsh32x64 (Const32 [c]) (Const64 [d])) -> (Const32 [int64(int32(c) >> uint64(d))]) 104 (Rsh32Ux64 (Const32 [c]) (Const64 [d])) -> (Const32 [int64(int32(uint32(c) >> uint64(d)))]) 105 (Lsh16x64 (Const16 [c]) (Const64 [d])) -> (Const16 [int64(int16(c) << uint64(d))]) 106 (Rsh16x64 (Const16 [c]) (Const64 [d])) -> (Const16 [int64(int16(c) >> uint64(d))]) 107 (Rsh16Ux64 (Const16 [c]) (Const64 [d])) -> (Const16 [int64(int16(uint16(c) >> uint64(d)))]) 108 (Lsh8x64 (Const8 [c]) (Const64 [d])) -> (Const8 [int64(int8(c) << uint64(d))]) 109 (Rsh8x64 (Const8 [c]) (Const64 [d])) -> (Const8 [int64(int8(c) >> uint64(d))]) 110 (Rsh8Ux64 (Const8 [c]) (Const64 [d])) -> (Const8 [int64(int8(uint8(c) >> uint64(d)))]) 111 112 // Fold IsInBounds when the range of the index cannot exceed the limit. 113 (IsInBounds (ZeroExt8to32 _) (Const32 [c])) && (1 << 8) <= c -> (ConstBool [1]) 114 (IsInBounds (ZeroExt8to64 _) (Const64 [c])) && (1 << 8) <= c -> (ConstBool [1]) 115 (IsInBounds (ZeroExt16to32 _) (Const32 [c])) && (1 << 16) <= c -> (ConstBool [1]) 116 (IsInBounds (ZeroExt16to64 _) (Const64 [c])) && (1 << 16) <= c -> (ConstBool [1]) 117 (IsInBounds x x) -> (ConstBool [0]) 118 (IsInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c < d -> (ConstBool [1]) 119 (IsInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c < d -> (ConstBool [1]) 120 (IsInBounds (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(0 <= c && c < d)]) 121 (IsInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(0 <= c && c < d)]) 122 // (Mod64u x y) is always between 0 (inclusive) and y (exclusive). 123 (IsInBounds (Mod32u _ y) y) -> (ConstBool [1]) 124 (IsInBounds (Mod64u _ y) y) -> (ConstBool [1]) 125 126 (IsSliceInBounds x x) -> (ConstBool [1]) 127 (IsSliceInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c <= d -> (ConstBool [1]) 128 (IsSliceInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c <= d -> (ConstBool [1]) 129 (IsSliceInBounds (Const32 [0]) _) -> (ConstBool [1]) 130 (IsSliceInBounds (Const64 [0]) _) -> (ConstBool [1]) 131 (IsSliceInBounds (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(0 <= c && c <= d)]) 132 (IsSliceInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(0 <= c && c <= d)]) 133 (IsSliceInBounds (SliceLen x) (SliceCap x)) -> (ConstBool [1]) 134 135 (Eq64 x x) -> (ConstBool [1]) 136 (Eq32 x x) -> (ConstBool [1]) 137 (Eq16 x x) -> (ConstBool [1]) 138 (Eq8 x x) -> (ConstBool [1]) 139 (EqB (ConstBool [c]) (ConstBool [d])) -> (ConstBool [b2i(c == d)]) 140 (EqB (ConstBool [0]) x) -> (Not x) 141 (EqB (ConstBool [1]) x) -> x 142 143 (Neq64 x x) -> (ConstBool [0]) 144 (Neq32 x x) -> (ConstBool [0]) 145 (Neq16 x x) -> (ConstBool [0]) 146 (Neq8 x x) -> (ConstBool [0]) 147 (NeqB (ConstBool [c]) (ConstBool [d])) -> (ConstBool [b2i(c != d)]) 148 (NeqB (ConstBool [0]) x) -> x 149 (NeqB (ConstBool [1]) x) -> (Not x) 150 151 (Eq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) -> (Eq64 (Const64 <t> [c-d]) x) 152 (Eq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) -> (Eq32 (Const32 <t> [int64(int32(c-d))]) x) 153 (Eq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) -> (Eq16 (Const16 <t> [int64(int16(c-d))]) x) 154 (Eq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) -> (Eq8 (Const8 <t> [int64(int8(c-d))]) x) 155 156 (Neq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) -> (Neq64 (Const64 <t> [c-d]) x) 157 (Neq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) -> (Neq32 (Const32 <t> [int64(int32(c-d))]) x) 158 (Neq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) -> (Neq16 (Const16 <t> [int64(int16(c-d))]) x) 159 (Neq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) -> (Neq8 (Const8 <t> [int64(int8(c-d))]) x) 160 161 // canonicalize: swap arguments for commutative operations when one argument is a constant. 162 (Eq64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Eq64 (Const64 <t> [c]) x) 163 (Eq32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Eq32 (Const32 <t> [c]) x) 164 (Eq16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Eq16 (Const16 <t> [c]) x) 165 (Eq8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Eq8 (Const8 <t> [c]) x) 166 167 (Neq64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Neq64 (Const64 <t> [c]) x) 168 (Neq32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Neq32 (Const32 <t> [c]) x) 169 (Neq16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Neq16 (Const16 <t> [c]) x) 170 (Neq8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Neq8 (Const8 <t> [c]) x) 171 172 // AddPtr is not canonicalized because nilcheck ptr checks the first argument to be non-nil. 173 (Add64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Add64 (Const64 <t> [c]) x) 174 (Add32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Add32 (Const32 <t> [c]) x) 175 (Add16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Add16 (Const16 <t> [c]) x) 176 (Add8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Add8 (Const8 <t> [c]) x) 177 178 (Mul64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Mul64 (Const64 <t> [c]) x) 179 (Mul32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Mul32 (Const32 <t> [c]) x) 180 (Mul16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Mul16 (Const16 <t> [c]) x) 181 (Mul8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Mul8 (Const8 <t> [c]) x) 182 183 (Sub64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Add64 (Const64 <t> [-c]) x) 184 (Sub32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Add32 (Const32 <t> [int64(int32(-c))]) x) 185 (Sub16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Add16 (Const16 <t> [int64(int16(-c))]) x) 186 (Sub8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Add8 (Const8 <t> [int64(int8(-c))]) x) 187 188 (And64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (And64 (Const64 <t> [c]) x) 189 (And32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (And32 (Const32 <t> [c]) x) 190 (And16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (And16 (Const16 <t> [c]) x) 191 (And8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (And8 (Const8 <t> [c]) x) 192 193 (Or64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Or64 (Const64 <t> [c]) x) 194 (Or32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Or32 (Const32 <t> [c]) x) 195 (Or16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Or16 (Const16 <t> [c]) x) 196 (Or8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Or8 (Const8 <t> [c]) x) 197 198 (Xor64 x (Const64 <t> [c])) && x.Op != OpConst64 -> (Xor64 (Const64 <t> [c]) x) 199 (Xor32 x (Const32 <t> [c])) && x.Op != OpConst32 -> (Xor32 (Const32 <t> [c]) x) 200 (Xor16 x (Const16 <t> [c])) && x.Op != OpConst16 -> (Xor16 (Const16 <t> [c]) x) 201 (Xor8 x (Const8 <t> [c])) && x.Op != OpConst8 -> (Xor8 (Const8 <t> [c]) x) 202 203 // Distribute multiplication c * (d+x) -> c*d + c*x. Useful for: 204 // a[i].b = ...; a[i+1].b = ... 205 (Mul64 (Const64 <t> [c]) (Add64 <t> (Const64 <t> [d]) x)) -> 206 (Add64 (Const64 <t> [c*d]) (Mul64 <t> (Const64 <t> [c]) x)) 207 (Mul32 (Const32 <t> [c]) (Add32 <t> (Const32 <t> [d]) x)) -> 208 (Add32 (Const32 <t> [int64(int32(c*d))]) (Mul32 <t> (Const32 <t> [c]) x)) 209 210 // rewrite shifts of 8/16/32 bit consts into 64 bit consts to reduce 211 // the number of the other rewrite rules for const shifts 212 (Lsh64x32 <t> x (Const32 [c])) -> (Lsh64x64 x (Const64 <t> [int64(uint32(c))])) 213 (Lsh64x16 <t> x (Const16 [c])) -> (Lsh64x64 x (Const64 <t> [int64(uint16(c))])) 214 (Lsh64x8 <t> x (Const8 [c])) -> (Lsh64x64 x (Const64 <t> [int64(uint8(c))])) 215 (Rsh64x32 <t> x (Const32 [c])) -> (Rsh64x64 x (Const64 <t> [int64(uint32(c))])) 216 (Rsh64x16 <t> x (Const16 [c])) -> (Rsh64x64 x (Const64 <t> [int64(uint16(c))])) 217 (Rsh64x8 <t> x (Const8 [c])) -> (Rsh64x64 x (Const64 <t> [int64(uint8(c))])) 218 (Rsh64Ux32 <t> x (Const32 [c])) -> (Rsh64Ux64 x (Const64 <t> [int64(uint32(c))])) 219 (Rsh64Ux16 <t> x (Const16 [c])) -> (Rsh64Ux64 x (Const64 <t> [int64(uint16(c))])) 220 (Rsh64Ux8 <t> x (Const8 [c])) -> (Rsh64Ux64 x (Const64 <t> [int64(uint8(c))])) 221 222 (Lsh32x32 <t> x (Const32 [c])) -> (Lsh32x64 x (Const64 <t> [int64(uint32(c))])) 223 (Lsh32x16 <t> x (Const16 [c])) -> (Lsh32x64 x (Const64 <t> [int64(uint16(c))])) 224 (Lsh32x8 <t> x (Const8 [c])) -> (Lsh32x64 x (Const64 <t> [int64(uint8(c))])) 225 (Rsh32x32 <t> x (Const32 [c])) -> (Rsh32x64 x (Const64 <t> [int64(uint32(c))])) 226 (Rsh32x16 <t> x (Const16 [c])) -> (Rsh32x64 x (Const64 <t> [int64(uint16(c))])) 227 (Rsh32x8 <t> x (Const8 [c])) -> (Rsh32x64 x (Const64 <t> [int64(uint8(c))])) 228 (Rsh32Ux32 <t> x (Const32 [c])) -> (Rsh32Ux64 x (Const64 <t> [int64(uint32(c))])) 229 (Rsh32Ux16 <t> x (Const16 [c])) -> (Rsh32Ux64 x (Const64 <t> [int64(uint16(c))])) 230 (Rsh32Ux8 <t> x (Const8 [c])) -> (Rsh32Ux64 x (Const64 <t> [int64(uint8(c))])) 231 232 (Lsh16x32 <t> x (Const32 [c])) -> (Lsh16x64 x (Const64 <t> [int64(uint32(c))])) 233 (Lsh16x16 <t> x (Const16 [c])) -> (Lsh16x64 x (Const64 <t> [int64(uint16(c))])) 234 (Lsh16x8 <t> x (Const8 [c])) -> (Lsh16x64 x (Const64 <t> [int64(uint8(c))])) 235 (Rsh16x32 <t> x (Const32 [c])) -> (Rsh16x64 x (Const64 <t> [int64(uint32(c))])) 236 (Rsh16x16 <t> x (Const16 [c])) -> (Rsh16x64 x (Const64 <t> [int64(uint16(c))])) 237 (Rsh16x8 <t> x (Const8 [c])) -> (Rsh16x64 x (Const64 <t> [int64(uint8(c))])) 238 (Rsh16Ux32 <t> x (Const32 [c])) -> (Rsh16Ux64 x (Const64 <t> [int64(uint32(c))])) 239 (Rsh16Ux16 <t> x (Const16 [c])) -> (Rsh16Ux64 x (Const64 <t> [int64(uint16(c))])) 240 (Rsh16Ux8 <t> x (Const8 [c])) -> (Rsh16Ux64 x (Const64 <t> [int64(uint8(c))])) 241 242 (Lsh8x32 <t> x (Const32 [c])) -> (Lsh8x64 x (Const64 <t> [int64(uint32(c))])) 243 (Lsh8x16 <t> x (Const16 [c])) -> (Lsh8x64 x (Const64 <t> [int64(uint16(c))])) 244 (Lsh8x8 <t> x (Const8 [c])) -> (Lsh8x64 x (Const64 <t> [int64(uint8(c))])) 245 (Rsh8x32 <t> x (Const32 [c])) -> (Rsh8x64 x (Const64 <t> [int64(uint32(c))])) 246 (Rsh8x16 <t> x (Const16 [c])) -> (Rsh8x64 x (Const64 <t> [int64(uint16(c))])) 247 (Rsh8x8 <t> x (Const8 [c])) -> (Rsh8x64 x (Const64 <t> [int64(uint8(c))])) 248 (Rsh8Ux32 <t> x (Const32 [c])) -> (Rsh8Ux64 x (Const64 <t> [int64(uint32(c))])) 249 (Rsh8Ux16 <t> x (Const16 [c])) -> (Rsh8Ux64 x (Const64 <t> [int64(uint16(c))])) 250 (Rsh8Ux8 <t> x (Const8 [c])) -> (Rsh8Ux64 x (Const64 <t> [int64(uint8(c))])) 251 252 // shifts by zero 253 (Lsh64x64 x (Const64 [0])) -> x 254 (Rsh64x64 x (Const64 [0])) -> x 255 (Rsh64Ux64 x (Const64 [0])) -> x 256 (Lsh32x64 x (Const64 [0])) -> x 257 (Rsh32x64 x (Const64 [0])) -> x 258 (Rsh32Ux64 x (Const64 [0])) -> x 259 (Lsh16x64 x (Const64 [0])) -> x 260 (Rsh16x64 x (Const64 [0])) -> x 261 (Rsh16Ux64 x (Const64 [0])) -> x 262 (Lsh8x64 x (Const64 [0])) -> x 263 (Rsh8x64 x (Const64 [0])) -> x 264 (Rsh8Ux64 x (Const64 [0])) -> x 265 266 // zero shifted. 267 (Lsh64x64 (Const64 [0]) _) -> (Const64 [0]) 268 (Lsh64x32 (Const64 [0]) _) -> (Const64 [0]) 269 (Lsh64x16 (Const64 [0]) _) -> (Const64 [0]) 270 (Lsh64x8 (Const64 [0]) _) -> (Const64 [0]) 271 (Rsh64x64 (Const64 [0]) _) -> (Const64 [0]) 272 (Rsh64x32 (Const64 [0]) _) -> (Const64 [0]) 273 (Rsh64x16 (Const64 [0]) _) -> (Const64 [0]) 274 (Rsh64x8 (Const64 [0]) _) -> (Const64 [0]) 275 (Rsh64Ux64 (Const64 [0]) _) -> (Const64 [0]) 276 (Rsh64Ux32 (Const64 [0]) _) -> (Const64 [0]) 277 (Rsh64Ux16 (Const64 [0]) _) -> (Const64 [0]) 278 (Rsh64Ux8 (Const64 [0]) _) -> (Const64 [0]) 279 (Lsh32x64 (Const32 [0]) _) -> (Const32 [0]) 280 (Lsh32x32 (Const32 [0]) _) -> (Const32 [0]) 281 (Lsh32x16 (Const32 [0]) _) -> (Const32 [0]) 282 (Lsh32x8 (Const32 [0]) _) -> (Const32 [0]) 283 (Rsh32x64 (Const32 [0]) _) -> (Const32 [0]) 284 (Rsh32x32 (Const32 [0]) _) -> (Const32 [0]) 285 (Rsh32x16 (Const32 [0]) _) -> (Const32 [0]) 286 (Rsh32x8 (Const32 [0]) _) -> (Const32 [0]) 287 (Rsh32Ux64 (Const32 [0]) _) -> (Const32 [0]) 288 (Rsh32Ux32 (Const32 [0]) _) -> (Const32 [0]) 289 (Rsh32Ux16 (Const32 [0]) _) -> (Const32 [0]) 290 (Rsh32Ux8 (Const32 [0]) _) -> (Const32 [0]) 291 (Lsh16x64 (Const16 [0]) _) -> (Const16 [0]) 292 (Lsh16x32 (Const16 [0]) _) -> (Const16 [0]) 293 (Lsh16x16 (Const16 [0]) _) -> (Const16 [0]) 294 (Lsh16x8 (Const16 [0]) _) -> (Const16 [0]) 295 (Rsh16x64 (Const16 [0]) _) -> (Const16 [0]) 296 (Rsh16x32 (Const16 [0]) _) -> (Const16 [0]) 297 (Rsh16x16 (Const16 [0]) _) -> (Const16 [0]) 298 (Rsh16x8 (Const16 [0]) _) -> (Const16 [0]) 299 (Rsh16Ux64 (Const16 [0]) _) -> (Const16 [0]) 300 (Rsh16Ux32 (Const16 [0]) _) -> (Const16 [0]) 301 (Rsh16Ux16 (Const16 [0]) _) -> (Const16 [0]) 302 (Rsh16Ux8 (Const16 [0]) _) -> (Const16 [0]) 303 (Lsh8x64 (Const8 [0]) _) -> (Const8 [0]) 304 (Lsh8x32 (Const8 [0]) _) -> (Const8 [0]) 305 (Lsh8x16 (Const8 [0]) _) -> (Const8 [0]) 306 (Lsh8x8 (Const8 [0]) _) -> (Const8 [0]) 307 (Rsh8x64 (Const8 [0]) _) -> (Const8 [0]) 308 (Rsh8x32 (Const8 [0]) _) -> (Const8 [0]) 309 (Rsh8x16 (Const8 [0]) _) -> (Const8 [0]) 310 (Rsh8x8 (Const8 [0]) _) -> (Const8 [0]) 311 (Rsh8Ux64 (Const8 [0]) _) -> (Const8 [0]) 312 (Rsh8Ux32 (Const8 [0]) _) -> (Const8 [0]) 313 (Rsh8Ux16 (Const8 [0]) _) -> (Const8 [0]) 314 (Rsh8Ux8 (Const8 [0]) _) -> (Const8 [0]) 315 316 // large left shifts of all values, and right shifts of unsigned values 317 (Lsh64x64 _ (Const64 [c])) && uint64(c) >= 64 -> (Const64 [0]) 318 (Rsh64Ux64 _ (Const64 [c])) && uint64(c) >= 64 -> (Const64 [0]) 319 (Lsh32x64 _ (Const64 [c])) && uint64(c) >= 32 -> (Const32 [0]) 320 (Rsh32Ux64 _ (Const64 [c])) && uint64(c) >= 32 -> (Const32 [0]) 321 (Lsh16x64 _ (Const64 [c])) && uint64(c) >= 16 -> (Const16 [0]) 322 (Rsh16Ux64 _ (Const64 [c])) && uint64(c) >= 16 -> (Const16 [0]) 323 (Lsh8x64 _ (Const64 [c])) && uint64(c) >= 8 -> (Const8 [0]) 324 (Rsh8Ux64 _ (Const64 [c])) && uint64(c) >= 8 -> (Const8 [0]) 325 326 // combine const shifts 327 (Lsh64x64 <t> (Lsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh64x64 x (Const64 <t> [c+d])) 328 (Lsh32x64 <t> (Lsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh32x64 x (Const64 <t> [c+d])) 329 (Lsh16x64 <t> (Lsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh16x64 x (Const64 <t> [c+d])) 330 (Lsh8x64 <t> (Lsh8x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Lsh8x64 x (Const64 <t> [c+d])) 331 332 (Rsh64x64 <t> (Rsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh64x64 x (Const64 <t> [c+d])) 333 (Rsh32x64 <t> (Rsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh32x64 x (Const64 <t> [c+d])) 334 (Rsh16x64 <t> (Rsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh16x64 x (Const64 <t> [c+d])) 335 (Rsh8x64 <t> (Rsh8x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh8x64 x (Const64 <t> [c+d])) 336 337 (Rsh64Ux64 <t> (Rsh64Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh64Ux64 x (Const64 <t> [c+d])) 338 (Rsh32Ux64 <t> (Rsh32Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh32Ux64 x (Const64 <t> [c+d])) 339 (Rsh16Ux64 <t> (Rsh16Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh16Ux64 x (Const64 <t> [c+d])) 340 (Rsh8Ux64 <t> (Rsh8Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) -> (Rsh8Ux64 x (Const64 <t> [c+d])) 341 342 // ((x >> c1) << c2) >> c3 343 (Rsh64Ux64 (Lsh64x64 (Rsh64Ux64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 344 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 345 -> (Rsh64Ux64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 346 (Rsh32Ux64 (Lsh32x64 (Rsh32Ux64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 347 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 348 -> (Rsh32Ux64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 349 (Rsh16Ux64 (Lsh16x64 (Rsh16Ux64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 350 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 351 -> (Rsh16Ux64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 352 (Rsh8Ux64 (Lsh8x64 (Rsh8Ux64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 353 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 354 -> (Rsh8Ux64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 355 356 // ((x << c1) >> c2) << c3 357 (Lsh64x64 (Rsh64Ux64 (Lsh64x64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 358 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 359 -> (Lsh64x64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 360 (Lsh32x64 (Rsh32Ux64 (Lsh32x64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 361 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 362 -> (Lsh32x64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 363 (Lsh16x64 (Rsh16Ux64 (Lsh16x64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 364 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 365 -> (Lsh16x64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 366 (Lsh8x64 (Rsh8Ux64 (Lsh8x64 x (Const64 [c1])) (Const64 [c2])) (Const64 [c3])) 367 && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) 368 -> (Lsh8x64 x (Const64 <config.fe.TypeUInt64()> [c1-c2+c3])) 369 370 // constant comparisons 371 (Eq64 (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(c == d)]) 372 (Eq32 (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(c == d)]) 373 (Eq16 (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(c == d)]) 374 (Eq8 (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(c == d)]) 375 376 (Neq64 (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(c != d)]) 377 (Neq32 (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(c != d)]) 378 (Neq16 (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(c != d)]) 379 (Neq8 (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(c != d)]) 380 381 (Greater64 (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(c > d)]) 382 (Greater32 (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(c > d)]) 383 (Greater16 (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(c > d)]) 384 (Greater8 (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(c > d)]) 385 386 (Greater64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) > uint64(d))]) 387 (Greater32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) > uint32(d))]) 388 (Greater16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) > uint16(d))]) 389 (Greater8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) > uint8(d))]) 390 391 (Geq64 (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(c >= d)]) 392 (Geq32 (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(c >= d)]) 393 (Geq16 (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(c >= d)]) 394 (Geq8 (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(c >= d)]) 395 396 (Geq64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) >= uint64(d))]) 397 (Geq32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) >= uint32(d))]) 398 (Geq16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) >= uint16(d))]) 399 (Geq8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) >= uint8(d))]) 400 401 (Less64 (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(c < d)]) 402 (Less32 (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(c < d)]) 403 (Less16 (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(c < d)]) 404 (Less8 (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(c < d)]) 405 406 (Less64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) < uint64(d))]) 407 (Less32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) < uint32(d))]) 408 (Less16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) < uint16(d))]) 409 (Less8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) < uint8(d))]) 410 411 (Leq64 (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(c <= d)]) 412 (Leq32 (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(c <= d)]) 413 (Leq16 (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(c <= d)]) 414 (Leq8 (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(c <= d)]) 415 416 (Leq64U (Const64 [c]) (Const64 [d])) -> (ConstBool [b2i(uint64(c) <= uint64(d))]) 417 (Leq32U (Const32 [c]) (Const32 [d])) -> (ConstBool [b2i(uint32(c) <= uint32(d))]) 418 (Leq16U (Const16 [c]) (Const16 [d])) -> (ConstBool [b2i(uint16(c) <= uint16(d))]) 419 (Leq8U (Const8 [c]) (Const8 [d])) -> (ConstBool [b2i(uint8(c) <= uint8(d))]) 420 421 // simplifications 422 (Or64 x x) -> x 423 (Or32 x x) -> x 424 (Or16 x x) -> x 425 (Or8 x x) -> x 426 (Or64 (Const64 [0]) x) -> x 427 (Or32 (Const32 [0]) x) -> x 428 (Or16 (Const16 [0]) x) -> x 429 (Or8 (Const8 [0]) x) -> x 430 (Or64 (Const64 [-1]) _) -> (Const64 [-1]) 431 (Or32 (Const32 [-1]) _) -> (Const32 [-1]) 432 (Or16 (Const16 [-1]) _) -> (Const16 [-1]) 433 (Or8 (Const8 [-1]) _) -> (Const8 [-1]) 434 (And64 x x) -> x 435 (And32 x x) -> x 436 (And16 x x) -> x 437 (And8 x x) -> x 438 (And64 (Const64 [-1]) x) -> x 439 (And32 (Const32 [-1]) x) -> x 440 (And16 (Const16 [-1]) x) -> x 441 (And8 (Const8 [-1]) x) -> x 442 (And64 (Const64 [0]) _) -> (Const64 [0]) 443 (And32 (Const32 [0]) _) -> (Const32 [0]) 444 (And16 (Const16 [0]) _) -> (Const16 [0]) 445 (And8 (Const8 [0]) _) -> (Const8 [0]) 446 (Xor64 x x) -> (Const64 [0]) 447 (Xor32 x x) -> (Const32 [0]) 448 (Xor16 x x) -> (Const16 [0]) 449 (Xor8 x x) -> (Const8 [0]) 450 (Xor64 (Const64 [0]) x) -> x 451 (Xor32 (Const32 [0]) x) -> x 452 (Xor16 (Const16 [0]) x) -> x 453 (Xor8 (Const8 [0]) x) -> x 454 (Add64 (Const64 [0]) x) -> x 455 (Add32 (Const32 [0]) x) -> x 456 (Add16 (Const16 [0]) x) -> x 457 (Add8 (Const8 [0]) x) -> x 458 (Sub64 x x) -> (Const64 [0]) 459 (Sub32 x x) -> (Const32 [0]) 460 (Sub16 x x) -> (Const16 [0]) 461 (Sub8 x x) -> (Const8 [0]) 462 (Mul64 (Const64 [0]) _) -> (Const64 [0]) 463 (Mul32 (Const32 [0]) _) -> (Const32 [0]) 464 (Mul16 (Const16 [0]) _) -> (Const16 [0]) 465 (Mul8 (Const8 [0]) _) -> (Const8 [0]) 466 (Com8 (Com8 x)) -> x 467 (Com16 (Com16 x)) -> x 468 (Com32 (Com32 x)) -> x 469 (Com64 (Com64 x)) -> x 470 (Neg8 (Sub8 x y)) -> (Sub8 y x) 471 (Neg16 (Sub16 x y)) -> (Sub16 y x) 472 (Neg32 (Sub32 x y)) -> (Sub32 y x) 473 (Neg64 (Sub64 x y)) -> (Sub64 y x) 474 475 (And64 x (And64 x y)) -> (And64 x y) 476 (And32 x (And32 x y)) -> (And32 x y) 477 (And16 x (And16 x y)) -> (And16 x y) 478 (And8 x (And8 x y)) -> (And8 x y) 479 (And64 x (And64 y x)) -> (And64 x y) 480 (And32 x (And32 y x)) -> (And32 x y) 481 (And16 x (And16 y x)) -> (And16 x y) 482 (And8 x (And8 y x)) -> (And8 x y) 483 (And64 (And64 x y) x) -> (And64 x y) 484 (And32 (And32 x y) x) -> (And32 x y) 485 (And16 (And16 x y) x) -> (And16 x y) 486 (And8 (And8 x y) x) -> (And8 x y) 487 (And64 (And64 x y) y) -> (And64 x y) 488 (And32 (And32 x y) y) -> (And32 x y) 489 (And16 (And16 x y) y) -> (And16 x y) 490 (And8 (And8 x y) y) -> (And8 x y) 491 (Or64 x (Or64 x y)) -> (Or64 x y) 492 (Or32 x (Or32 x y)) -> (Or32 x y) 493 (Or16 x (Or16 x y)) -> (Or16 x y) 494 (Or8 x (Or8 x y)) -> (Or8 x y) 495 (Or64 x (Or64 y x)) -> (Or64 x y) 496 (Or32 x (Or32 y x)) -> (Or32 x y) 497 (Or16 x (Or16 y x)) -> (Or16 x y) 498 (Or8 x (Or8 y x)) -> (Or8 x y) 499 (Or64 (Or64 x y) x) -> (Or64 x y) 500 (Or32 (Or32 x y) x) -> (Or32 x y) 501 (Or16 (Or16 x y) x) -> (Or16 x y) 502 (Or8 (Or8 x y) x) -> (Or8 x y) 503 (Or64 (Or64 x y) y) -> (Or64 x y) 504 (Or32 (Or32 x y) y) -> (Or32 x y) 505 (Or16 (Or16 x y) y) -> (Or16 x y) 506 (Or8 (Or8 x y) y) -> (Or8 x y) 507 (Xor64 x (Xor64 x y)) -> y 508 (Xor32 x (Xor32 x y)) -> y 509 (Xor16 x (Xor16 x y)) -> y 510 (Xor8 x (Xor8 x y)) -> y 511 (Xor64 x (Xor64 y x)) -> y 512 (Xor32 x (Xor32 y x)) -> y 513 (Xor16 x (Xor16 y x)) -> y 514 (Xor8 x (Xor8 y x)) -> y 515 (Xor64 (Xor64 x y) x) -> y 516 (Xor32 (Xor32 x y) x) -> y 517 (Xor16 (Xor16 x y) x) -> y 518 (Xor8 (Xor8 x y) x) -> y 519 (Xor64 (Xor64 x y) y) -> x 520 (Xor32 (Xor32 x y) y) -> x 521 (Xor16 (Xor16 x y) y) -> x 522 (Xor8 (Xor8 x y) y) -> x 523 524 (Trunc64to8 (And64 (Const64 [y]) x)) && y&0xFF == 0xFF -> (Trunc64to8 x) 525 (Trunc64to16 (And64 (Const64 [y]) x)) && y&0xFFFF == 0xFFFF -> (Trunc64to16 x) 526 (Trunc64to32 (And64 (Const64 [y]) x)) && y&0xFFFFFFFF == 0xFFFFFFFF -> (Trunc64to32 x) 527 (Trunc32to8 (And32 (Const32 [y]) x)) && y&0xFF == 0xFF -> (Trunc32to8 x) 528 (Trunc32to16 (And32 (Const32 [y]) x)) && y&0xFFFF == 0xFFFF -> (Trunc32to16 x) 529 (Trunc16to8 (And16 (Const16 [y]) x)) && y&0xFF == 0xFF -> (Trunc16to8 x) 530 531 // Rewrite AND of consts as shifts if possible, slightly faster for 64 bit operands 532 // leading zeros can be shifted left, then right 533 (And64 <t> (Const64 [y]) x) && nlz(y) + nto(y) == 64 && nto(y) >= 32 534 -> (Rsh64Ux64 (Lsh64x64 <t> x (Const64 <t> [nlz(y)])) (Const64 <t> [nlz(y)])) 535 // trailing zeros can be shifted right, then left 536 (And64 <t> (Const64 [y]) x) && nlo(y) + ntz(y) == 64 && ntz(y) >= 32 537 -> (Lsh64x64 (Rsh64Ux64 <t> x (Const64 <t> [ntz(y)])) (Const64 <t> [ntz(y)])) 538 539 // simplifications often used for lengths. e.g. len(s[i:i+5])==5 540 (Sub64 (Add64 x y) x) -> y 541 (Sub64 (Add64 x y) y) -> x 542 (Sub32 (Add32 x y) x) -> y 543 (Sub32 (Add32 x y) y) -> x 544 (Sub16 (Add16 x y) x) -> y 545 (Sub16 (Add16 x y) y) -> x 546 (Sub8 (Add8 x y) x) -> y 547 (Sub8 (Add8 x y) y) -> x 548 549 // basic phi simplifications 550 (Phi (Const8 [c]) (Const8 [c])) -> (Const8 [c]) 551 (Phi (Const16 [c]) (Const16 [c])) -> (Const16 [c]) 552 (Phi (Const32 [c]) (Const32 [c])) -> (Const32 [c]) 553 (Phi (Const64 [c]) (Const64 [c])) -> (Const64 [c]) 554 555 // user nil checks 556 (NeqPtr p (ConstNil)) -> (IsNonNil p) 557 (NeqPtr (ConstNil) p) -> (IsNonNil p) 558 (EqPtr p (ConstNil)) -> (Not (IsNonNil p)) 559 (EqPtr (ConstNil) p) -> (Not (IsNonNil p)) 560 561 // slice and interface comparisons 562 // The frontend ensures that we can only compare against nil, 563 // so we need only compare the first word (interface type or slice ptr). 564 (EqInter x y) -> (EqPtr (ITab x) (ITab y)) 565 (NeqInter x y) -> (NeqPtr (ITab x) (ITab y)) 566 (EqSlice x y) -> (EqPtr (SlicePtr x) (SlicePtr y)) 567 (NeqSlice x y) -> (NeqPtr (SlicePtr x) (SlicePtr y)) 568 569 // Load of store of same address, with compatibly typed value and same size 570 (Load <t1> p1 (Store [w] p2 x _)) && isSamePtr(p1,p2) && t1.Compare(x.Type)==CMPeq && w == t1.Size() -> x 571 572 // Collapse OffPtr 573 (OffPtr (OffPtr p [b]) [a]) -> (OffPtr p [a+b]) 574 (OffPtr p [0]) && v.Type.Compare(p.Type) == CMPeq -> p 575 576 // indexing operations 577 // Note: bounds check has already been done 578 (ArrayIndex <t> [0] x:(Load ptr mem)) -> @x.Block (Load <t> ptr mem) 579 (PtrIndex <t> ptr idx) && config.PtrSize == 4 -> (AddPtr ptr (Mul32 <config.fe.TypeInt()> idx (Const32 <config.fe.TypeInt()> [t.ElemType().Size()]))) 580 (PtrIndex <t> ptr idx) && config.PtrSize == 8 -> (AddPtr ptr (Mul64 <config.fe.TypeInt()> idx (Const64 <config.fe.TypeInt()> [t.ElemType().Size()]))) 581 582 // struct operations 583 (StructSelect (StructMake1 x)) -> x 584 (StructSelect [0] (StructMake2 x _)) -> x 585 (StructSelect [1] (StructMake2 _ x)) -> x 586 (StructSelect [0] (StructMake3 x _ _)) -> x 587 (StructSelect [1] (StructMake3 _ x _)) -> x 588 (StructSelect [2] (StructMake3 _ _ x)) -> x 589 (StructSelect [0] (StructMake4 x _ _ _)) -> x 590 (StructSelect [1] (StructMake4 _ x _ _)) -> x 591 (StructSelect [2] (StructMake4 _ _ x _)) -> x 592 (StructSelect [3] (StructMake4 _ _ _ x)) -> x 593 594 (Load <t> _ _) && t.IsStruct() && t.NumFields() == 0 && config.fe.CanSSA(t) -> 595 (StructMake0) 596 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 1 && config.fe.CanSSA(t) -> 597 (StructMake1 598 (Load <t.FieldType(0)> ptr mem)) 599 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 2 && config.fe.CanSSA(t) -> 600 (StructMake2 601 (Load <t.FieldType(0)> ptr mem) 602 (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem)) 603 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 3 && config.fe.CanSSA(t) -> 604 (StructMake3 605 (Load <t.FieldType(0)> ptr mem) 606 (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem) 607 (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem)) 608 (Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 4 && config.fe.CanSSA(t) -> 609 (StructMake4 610 (Load <t.FieldType(0)> ptr mem) 611 (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem) 612 (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem) 613 (Load <t.FieldType(3)> (OffPtr <t.FieldType(3).PtrTo()> [t.FieldOff(3)] ptr) mem)) 614 615 (StructSelect [i] x:(Load <t> ptr mem)) && !config.fe.CanSSA(t) -> 616 @x.Block (Load <v.Type> (OffPtr <v.Type.PtrTo()> [t.FieldOff(int(i))] ptr) mem) 617 618 (Store _ (StructMake0) mem) -> mem 619 (Store dst (StructMake1 <t> f0) mem) -> 620 (Store [t.FieldType(0).Size()] dst f0 mem) 621 (Store dst (StructMake2 <t> f0 f1) mem) -> 622 (Store [t.FieldType(1).Size()] 623 (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) 624 f1 625 (Store [t.FieldType(0).Size()] dst f0 mem)) 626 (Store dst (StructMake3 <t> f0 f1 f2) mem) -> 627 (Store [t.FieldType(2).Size()] 628 (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] dst) 629 f2 630 (Store [t.FieldType(1).Size()] 631 (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) 632 f1 633 (Store [t.FieldType(0).Size()] dst f0 mem))) 634 (Store dst (StructMake4 <t> f0 f1 f2 f3) mem) -> 635 (Store [t.FieldType(3).Size()] 636 (OffPtr <t.FieldType(3).PtrTo()> [t.FieldOff(3)] dst) 637 f3 638 (Store [t.FieldType(2).Size()] 639 (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] dst) 640 f2 641 (Store [t.FieldType(1).Size()] 642 (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) 643 f1 644 (Store [t.FieldType(0).Size()] dst f0 mem)))) 645 646 // un-SSAable values use mem->mem copies 647 (Store [size] dst (Load <t> src mem) mem) && !config.fe.CanSSA(t) -> 648 (Move [MakeSizeAndAlign(size, t.Alignment()).Int64()] dst src mem) 649 (Store [size] dst (Load <t> src mem) (VarDef {x} mem)) && !config.fe.CanSSA(t) -> 650 (Move [MakeSizeAndAlign(size, t.Alignment()).Int64()] dst src (VarDef {x} mem)) 651 652 // string ops 653 // Decomposing StringMake and lowering of StringPtr and StringLen 654 // happens in a later pass, dec, so that these operations are available 655 // to other passes for optimizations. 656 (StringPtr (StringMake (Const64 <t> [c]) _)) -> (Const64 <t> [c]) 657 (StringLen (StringMake _ (Const64 <t> [c]))) -> (Const64 <t> [c]) 658 (ConstString {s}) && config.PtrSize == 4 && s.(string) == "" -> 659 (StringMake (ConstNil) (Const32 <config.fe.TypeInt()> [0])) 660 (ConstString {s}) && config.PtrSize == 8 && s.(string) == "" -> 661 (StringMake (ConstNil) (Const64 <config.fe.TypeInt()> [0])) 662 (ConstString {s}) && config.PtrSize == 4 && s.(string) != "" -> 663 (StringMake 664 (Addr <config.fe.TypeBytePtr()> {config.fe.StringData(s.(string))} 665 (SB)) 666 (Const32 <config.fe.TypeInt()> [int64(len(s.(string)))])) 667 (ConstString {s}) && config.PtrSize == 8 && s.(string) != "" -> 668 (StringMake 669 (Addr <config.fe.TypeBytePtr()> {config.fe.StringData(s.(string))} 670 (SB)) 671 (Const64 <config.fe.TypeInt()> [int64(len(s.(string)))])) 672 673 // slice ops 674 // Only a few slice rules are provided here. See dec.rules for 675 // a more comprehensive set. 676 (SliceLen (SliceMake _ (Const64 <t> [c]) _)) -> (Const64 <t> [c]) 677 (SliceCap (SliceMake _ _ (Const64 <t> [c]))) -> (Const64 <t> [c]) 678 (SlicePtr (SliceMake (SlicePtr x) _ _)) -> (SlicePtr x) 679 (SliceLen (SliceMake _ (SliceLen x) _)) -> (SliceLen x) 680 (SliceCap (SliceMake _ _ (SliceCap x))) -> (SliceCap x) 681 (SliceCap (SliceMake _ _ (SliceLen x))) -> (SliceLen x) 682 (ConstSlice) && config.PtrSize == 4 -> 683 (SliceMake 684 (ConstNil <v.Type.ElemType().PtrTo()>) 685 (Const32 <config.fe.TypeInt()> [0]) 686 (Const32 <config.fe.TypeInt()> [0])) 687 (ConstSlice) && config.PtrSize == 8 -> 688 (SliceMake 689 (ConstNil <v.Type.ElemType().PtrTo()>) 690 (Const64 <config.fe.TypeInt()> [0]) 691 (Const64 <config.fe.TypeInt()> [0])) 692 693 // interface ops 694 (ConstInterface) -> 695 (IMake 696 (ConstNil <config.fe.TypeBytePtr()>) 697 (ConstNil <config.fe.TypeBytePtr()>)) 698 699 (Check (NilCheck (GetG _) _) next) -> (Plain nil next) 700 701 (If (Not cond) yes no) -> (If cond no yes) 702 (If (ConstBool [c]) yes no) && c == 1 -> (First nil yes no) 703 (If (ConstBool [c]) yes no) && c == 0 -> (First nil no yes) 704 705 // Get rid of Convert ops for pointer arithmetic on unsafe.Pointer. 706 (Convert (Add64 (Convert ptr mem) off) mem) -> (Add64 ptr off) 707 (Convert (Add64 off (Convert ptr mem)) mem) -> (Add64 ptr off) 708 (Convert (Convert ptr mem) mem) -> ptr 709 710 // Decompose compound argument values 711 (Arg {n} [off]) && v.Type.IsString() -> 712 (StringMake 713 (Arg <config.fe.TypeBytePtr()> {n} [off]) 714 (Arg <config.fe.TypeInt()> {n} [off+config.PtrSize])) 715 716 (Arg {n} [off]) && v.Type.IsSlice() -> 717 (SliceMake 718 (Arg <v.Type.ElemType().PtrTo()> {n} [off]) 719 (Arg <config.fe.TypeInt()> {n} [off+config.PtrSize]) 720 (Arg <config.fe.TypeInt()> {n} [off+2*config.PtrSize])) 721 722 (Arg {n} [off]) && v.Type.IsInterface() -> 723 (IMake 724 (Arg <config.fe.TypeBytePtr()> {n} [off]) 725 (Arg <config.fe.TypeBytePtr()> {n} [off+config.PtrSize])) 726 727 (Arg {n} [off]) && v.Type.IsComplex() && v.Type.Size() == 16 -> 728 (ComplexMake 729 (Arg <config.fe.TypeFloat64()> {n} [off]) 730 (Arg <config.fe.TypeFloat64()> {n} [off+8])) 731 732 (Arg {n} [off]) && v.Type.IsComplex() && v.Type.Size() == 8 -> 733 (ComplexMake 734 (Arg <config.fe.TypeFloat32()> {n} [off]) 735 (Arg <config.fe.TypeFloat32()> {n} [off+4])) 736 737 (Arg <t>) && t.IsStruct() && t.NumFields() == 0 && config.fe.CanSSA(t) -> 738 (StructMake0) 739 (Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 1 && config.fe.CanSSA(t) -> 740 (StructMake1 741 (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)])) 742 (Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 2 && config.fe.CanSSA(t) -> 743 (StructMake2 744 (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)]) 745 (Arg <t.FieldType(1)> {n} [off+t.FieldOff(1)])) 746 (Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 3 && config.fe.CanSSA(t) -> 747 (StructMake3 748 (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)]) 749 (Arg <t.FieldType(1)> {n} [off+t.FieldOff(1)]) 750 (Arg <t.FieldType(2)> {n} [off+t.FieldOff(2)])) 751 (Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 4 && config.fe.CanSSA(t) -> 752 (StructMake4 753 (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)]) 754 (Arg <t.FieldType(1)> {n} [off+t.FieldOff(1)]) 755 (Arg <t.FieldType(2)> {n} [off+t.FieldOff(2)]) 756 (Arg <t.FieldType(3)> {n} [off+t.FieldOff(3)])) 757 758 // strength reduction of divide by a constant. 759 // Note: frontend does <=32 bits. We only need to do 64 bits here. 760 // TODO: Do them all here? 761 762 // Div/mod by 1. Currently handled by frontend. 763 //(Div64 n (Const64 [1])) -> n 764 //(Div64u n (Const64 [1])) -> n 765 //(Mod64 n (Const64 [1])) -> (Const64 [0]) 766 //(Mod64u n (Const64 [1])) -> (Const64 [0]) 767 768 // Unsigned divide by power of 2. 769 (Div64u <t> n (Const64 [c])) && isPowerOfTwo(c) -> (Rsh64Ux64 n (Const64 <t> [log2(c)])) 770 (Mod64u <t> n (Const64 [c])) && isPowerOfTwo(c) -> (And64 n (Const64 <t> [c-1])) 771 772 // Signed divide by power of 2. Currently handled by frontend. 773 // n / c = n >> log(c) if n >= 0 774 // = (n+c-1) >> log(c) if n < 0 775 // We conditionally add c-1 by adding n>>63>>(64-log(c)) (first shift signed, second shift unsigned). 776 //(Div64 <t> n (Const64 [c])) && isPowerOfTwo(c) -> 777 // (Rsh64x64 778 // (Add64 <t> 779 // n 780 // (Rsh64Ux64 <t> 781 // (Rsh64x64 <t> n (Const64 <t> [63])) 782 // (Const64 <t> [64-log2(c)]))) 783 // (Const64 <t> [log2(c)])) 784 785 // Unsigned divide, not a power of 2. Strength reduce to a multiply. 786 (Div64u <t> x (Const64 [c])) && umagic64ok(c) && !umagic64a(c) -> 787 (Rsh64Ux64 788 (Hmul64u <t> 789 (Const64 <t> [umagic64m(c)]) 790 x) 791 (Const64 <t> [umagic64s(c)])) 792 (Div64u <t> x (Const64 [c])) && umagic64ok(c) && umagic64a(c) -> 793 (Rsh64Ux64 794 (Avg64u <t> 795 (Hmul64u <t> 796 x 797 (Const64 <t> [umagic64m(c)])) 798 x) 799 (Const64 <t> [umagic64s(c)-1])) 800 801 // Signed divide, not a power of 2. Strength reduce to a multiply. 802 (Div64 <t> x (Const64 [c])) && c > 0 && smagic64ok(c) && smagic64m(c) > 0 -> 803 (Sub64 <t> 804 (Rsh64x64 <t> 805 (Hmul64 <t> 806 (Const64 <t> [smagic64m(c)]) 807 x) 808 (Const64 <t> [smagic64s(c)])) 809 (Rsh64x64 <t> 810 x 811 (Const64 <t> [63]))) 812 (Div64 <t> x (Const64 [c])) && c > 0 && smagic64ok(c) && smagic64m(c) < 0 -> 813 (Sub64 <t> 814 (Rsh64x64 <t> 815 (Add64 <t> 816 (Hmul64 <t> 817 (Const64 <t> [smagic64m(c)]) 818 x) 819 x) 820 (Const64 <t> [smagic64s(c)])) 821 (Rsh64x64 <t> 822 x 823 (Const64 <t> [63]))) 824 (Div64 <t> x (Const64 [c])) && c < 0 && smagic64ok(c) && smagic64m(c) > 0 -> 825 (Neg64 <t> 826 (Sub64 <t> 827 (Rsh64x64 <t> 828 (Hmul64 <t> 829 (Const64 <t> [smagic64m(c)]) 830 x) 831 (Const64 <t> [smagic64s(c)])) 832 (Rsh64x64 <t> 833 x 834 (Const64 <t> [63])))) 835 (Div64 <t> x (Const64 [c])) && c < 0 && smagic64ok(c) && smagic64m(c) < 0 -> 836 (Neg64 <t> 837 (Sub64 <t> 838 (Rsh64x64 <t> 839 (Add64 <t> 840 (Hmul64 <t> 841 (Const64 <t> [smagic64m(c)]) 842 x) 843 x) 844 (Const64 <t> [smagic64s(c)])) 845 (Rsh64x64 <t> 846 x 847 (Const64 <t> [63])))) 848 849 // A%B = A-(A/B*B). 850 // This implements % with two * and a bunch of ancillary ops. 851 // One of the * is free if the user's code also computes A/B. 852 (Mod64 <t> x (Const64 [c])) && x.Op != OpConst64 && smagic64ok(c) 853 -> (Sub64 x (Mul64 <t> (Div64 <t> x (Const64 <t> [c])) (Const64 <t> [c]))) 854 (Mod64u <t> x (Const64 [c])) && x.Op != OpConst64 && umagic64ok(c) 855 -> (Sub64 x (Mul64 <t> (Div64u <t> x (Const64 <t> [c])) (Const64 <t> [c]))) 856 857 // floating point optimizations 858 (Add32F x (Const32F [0])) -> x 859 (Add32F (Const32F [0]) x) -> x 860 (Add64F x (Const64F [0])) -> x 861 (Add64F (Const64F [0]) x) -> x 862 (Sub32F x (Const32F [0])) -> x 863 (Sub64F x (Const64F [0])) -> x 864 (Mul32F x (Const32F [f2i(1)])) -> x 865 (Mul32F (Const32F [f2i(1)]) x) -> x 866 (Mul64F x (Const64F [f2i(1)])) -> x 867 (Mul64F (Const64F [f2i(1)]) x) -> x 868 (Mul32F x (Const32F [f2i(-1)])) -> (Neg32F x) 869 (Mul32F (Const32F [f2i(-1)]) x) -> (Neg32F x) 870 (Mul64F x (Const64F [f2i(-1)])) -> (Neg64F x) 871 (Mul64F (Const64F [f2i(-1)]) x) -> (Neg64F x) 872 (Div32F x (Const32F [f2i(1)])) -> x 873 (Div64F x (Const64F [f2i(1)])) -> x 874 (Div32F x (Const32F [f2i(-1)])) -> (Neg32F x) 875 (Div64F x (Const64F [f2i(-1)])) -> (Neg32F x) 876 877 (Sqrt (Const64F [c])) -> (Const64F [f2i(math.Sqrt(i2f(c)))])