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Diffstat (limited to 'src/cmd/compile/internal/ssa/gen/generic.rules')
| -rw-r--r-- | src/cmd/compile/internal/ssa/gen/generic.rules | 2542 |
1 files changed, 2542 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules new file mode 100644 index 0000000..b78d2aa --- /dev/null +++ b/src/cmd/compile/internal/ssa/gen/generic.rules @@ -0,0 +1,2542 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Simplifications that apply to all backend architectures. As an example, this +// Go source code +// +// y := 0 * x +// +// can be translated into y := 0 without losing any information, which saves a +// pointless multiplication instruction. Other .rules files in this directory +// (for example AMD64.rules) contain rules specific to the architecture in the +// filename. The rules here apply to every architecture. +// +// The code for parsing this file lives in rulegen.go; this file generates +// ssa/rewritegeneric.go. + +// values are specified using the following format: +// (op <type> [auxint] {aux} arg0 arg1 ...) +// the type, aux, and auxint fields are optional +// on the matching side +// - the type, aux, and auxint fields must match if they are specified. +// - the first occurrence of a variable defines that variable. Subsequent +// uses must match (be == to) the first use. +// - v is defined to be the value matched. +// - an additional conditional can be provided after the match pattern with "&&". +// on the generated side +// - the type of the top-level expression is the same as the one on the left-hand side. +// - the type of any subexpressions must be specified explicitly (or +// be specified in the op's type field). +// - auxint will be 0 if not specified. +// - aux will be nil if not specified. + +// blocks are specified using the following format: +// (kind controlvalue succ0 succ1 ...) +// controlvalue must be "nil" or a value expression +// succ* fields must be variables +// For now, the generated successors must be a permutation of the matched successors. + +// constant folding +(Trunc16to8 (Const16 [c])) => (Const8 [int8(c)]) +(Trunc32to8 (Const32 [c])) => (Const8 [int8(c)]) +(Trunc32to16 (Const32 [c])) => (Const16 [int16(c)]) +(Trunc64to8 (Const64 [c])) => (Const8 [int8(c)]) +(Trunc64to16 (Const64 [c])) => (Const16 [int16(c)]) +(Trunc64to32 (Const64 [c])) => (Const32 [int32(c)]) +(Cvt64Fto32F (Const64F [c])) => (Const32F [float32(c)]) +(Cvt32Fto64F (Const32F [c])) => (Const64F [float64(c)]) +(Cvt32to32F (Const32 [c])) => (Const32F [float32(c)]) +(Cvt32to64F (Const32 [c])) => (Const64F [float64(c)]) +(Cvt64to32F (Const64 [c])) => (Const32F [float32(c)]) +(Cvt64to64F (Const64 [c])) => (Const64F [float64(c)]) +(Cvt32Fto32 (Const32F [c])) => (Const32 [int32(c)]) +(Cvt32Fto64 (Const32F [c])) => (Const64 [int64(c)]) +(Cvt64Fto32 (Const64F [c])) => (Const32 [int32(c)]) +(Cvt64Fto64 (Const64F [c])) => (Const64 [int64(c)]) +(Round32F x:(Const32F)) => x +(Round64F x:(Const64F)) => x +(CvtBoolToUint8 (ConstBool [false])) => (Const8 [0]) +(CvtBoolToUint8 (ConstBool [true])) => (Const8 [1]) + +(Trunc16to8 (ZeroExt8to16 x)) => x +(Trunc32to8 (ZeroExt8to32 x)) => x +(Trunc32to16 (ZeroExt8to32 x)) => (ZeroExt8to16 x) +(Trunc32to16 (ZeroExt16to32 x)) => x +(Trunc64to8 (ZeroExt8to64 x)) => x +(Trunc64to16 (ZeroExt8to64 x)) => (ZeroExt8to16 x) +(Trunc64to16 (ZeroExt16to64 x)) => x +(Trunc64to32 (ZeroExt8to64 x)) => (ZeroExt8to32 x) +(Trunc64to32 (ZeroExt16to64 x)) => (ZeroExt16to32 x) +(Trunc64to32 (ZeroExt32to64 x)) => x +(Trunc16to8 (SignExt8to16 x)) => x +(Trunc32to8 (SignExt8to32 x)) => x +(Trunc32to16 (SignExt8to32 x)) => (SignExt8to16 x) +(Trunc32to16 (SignExt16to32 x)) => x +(Trunc64to8 (SignExt8to64 x)) => x +(Trunc64to16 (SignExt8to64 x)) => (SignExt8to16 x) +(Trunc64to16 (SignExt16to64 x)) => x +(Trunc64to32 (SignExt8to64 x)) => (SignExt8to32 x) +(Trunc64to32 (SignExt16to64 x)) => (SignExt16to32 x) +(Trunc64to32 (SignExt32to64 x)) => x + +(ZeroExt8to16 (Const8 [c])) => (Const16 [int16( uint8(c))]) +(ZeroExt8to32 (Const8 [c])) => (Const32 [int32( uint8(c))]) +(ZeroExt8to64 (Const8 [c])) => (Const64 [int64( uint8(c))]) +(ZeroExt16to32 (Const16 [c])) => (Const32 [int32(uint16(c))]) +(ZeroExt16to64 (Const16 [c])) => (Const64 [int64(uint16(c))]) +(ZeroExt32to64 (Const32 [c])) => (Const64 [int64(uint32(c))]) +(SignExt8to16 (Const8 [c])) => (Const16 [int16(c)]) +(SignExt8to32 (Const8 [c])) => (Const32 [int32(c)]) +(SignExt8to64 (Const8 [c])) => (Const64 [int64(c)]) +(SignExt16to32 (Const16 [c])) => (Const32 [int32(c)]) +(SignExt16to64 (Const16 [c])) => (Const64 [int64(c)]) +(SignExt32to64 (Const32 [c])) => (Const64 [int64(c)]) + +(Neg8 (Const8 [c])) => (Const8 [-c]) +(Neg16 (Const16 [c])) => (Const16 [-c]) +(Neg32 (Const32 [c])) => (Const32 [-c]) +(Neg64 (Const64 [c])) => (Const64 [-c]) +(Neg32F (Const32F [c])) && c != 0 => (Const32F [-c]) +(Neg64F (Const64F [c])) && c != 0 => (Const64F [-c]) + +(Add8 (Const8 [c]) (Const8 [d])) => (Const8 [c+d]) +(Add16 (Const16 [c]) (Const16 [d])) => (Const16 [c+d]) +(Add32 (Const32 [c]) (Const32 [d])) => (Const32 [c+d]) +(Add64 (Const64 [c]) (Const64 [d])) => (Const64 [c+d]) +(Add32F (Const32F [c]) (Const32F [d])) && c+d == c+d => (Const32F [c+d]) +(Add64F (Const64F [c]) (Const64F [d])) && c+d == c+d => (Const64F [c+d]) +(AddPtr <t> x (Const64 [c])) => (OffPtr <t> x [c]) +(AddPtr <t> x (Const32 [c])) => (OffPtr <t> x [int64(c)]) + +(Sub8 (Const8 [c]) (Const8 [d])) => (Const8 [c-d]) +(Sub16 (Const16 [c]) (Const16 [d])) => (Const16 [c-d]) +(Sub32 (Const32 [c]) (Const32 [d])) => (Const32 [c-d]) +(Sub64 (Const64 [c]) (Const64 [d])) => (Const64 [c-d]) +(Sub32F (Const32F [c]) (Const32F [d])) && c-d == c-d => (Const32F [c-d]) +(Sub64F (Const64F [c]) (Const64F [d])) && c-d == c-d => (Const64F [c-d]) + +(Mul8 (Const8 [c]) (Const8 [d])) => (Const8 [c*d]) +(Mul16 (Const16 [c]) (Const16 [d])) => (Const16 [c*d]) +(Mul32 (Const32 [c]) (Const32 [d])) => (Const32 [c*d]) +(Mul64 (Const64 [c]) (Const64 [d])) => (Const64 [c*d]) +(Mul32F (Const32F [c]) (Const32F [d])) && c*d == c*d => (Const32F [c*d]) +(Mul64F (Const64F [c]) (Const64F [d])) && c*d == c*d => (Const64F [c*d]) + +(And8 (Const8 [c]) (Const8 [d])) => (Const8 [c&d]) +(And16 (Const16 [c]) (Const16 [d])) => (Const16 [c&d]) +(And32 (Const32 [c]) (Const32 [d])) => (Const32 [c&d]) +(And64 (Const64 [c]) (Const64 [d])) => (Const64 [c&d]) + +(Or8 (Const8 [c]) (Const8 [d])) => (Const8 [c|d]) +(Or16 (Const16 [c]) (Const16 [d])) => (Const16 [c|d]) +(Or32 (Const32 [c]) (Const32 [d])) => (Const32 [c|d]) +(Or64 (Const64 [c]) (Const64 [d])) => (Const64 [c|d]) + +(Xor8 (Const8 [c]) (Const8 [d])) => (Const8 [c^d]) +(Xor16 (Const16 [c]) (Const16 [d])) => (Const16 [c^d]) +(Xor32 (Const32 [c]) (Const32 [d])) => (Const32 [c^d]) +(Xor64 (Const64 [c]) (Const64 [d])) => (Const64 [c^d]) + +(Ctz64 (Const64 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz64(c))]) +(Ctz32 (Const32 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz32(c))]) +(Ctz16 (Const16 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz16(c))]) +(Ctz8 (Const8 [c])) && config.PtrSize == 4 => (Const32 [int32(ntz8(c))]) + +(Ctz64 (Const64 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz64(c))]) +(Ctz32 (Const32 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz32(c))]) +(Ctz16 (Const16 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz16(c))]) +(Ctz8 (Const8 [c])) && config.PtrSize == 8 => (Const64 [int64(ntz8(c))]) + +(Div8 (Const8 [c]) (Const8 [d])) && d != 0 => (Const8 [c/d]) +(Div16 (Const16 [c]) (Const16 [d])) && d != 0 => (Const16 [c/d]) +(Div32 (Const32 [c]) (Const32 [d])) && d != 0 => (Const32 [c/d]) +(Div64 (Const64 [c]) (Const64 [d])) && d != 0 => (Const64 [c/d]) +(Div8u (Const8 [c]) (Const8 [d])) && d != 0 => (Const8 [int8(uint8(c)/uint8(d))]) +(Div16u (Const16 [c]) (Const16 [d])) && d != 0 => (Const16 [int16(uint16(c)/uint16(d))]) +(Div32u (Const32 [c]) (Const32 [d])) && d != 0 => (Const32 [int32(uint32(c)/uint32(d))]) +(Div64u (Const64 [c]) (Const64 [d])) && d != 0 => (Const64 [int64(uint64(c)/uint64(d))]) +(Div32F (Const32F [c]) (Const32F [d])) && c/d == c/d => (Const32F [c/d]) +(Div64F (Const64F [c]) (Const64F [d])) && c/d == c/d => (Const64F [c/d]) +(Select0 (Div128u (Const64 [0]) lo y)) => (Div64u lo y) +(Select1 (Div128u (Const64 [0]) lo y)) => (Mod64u lo y) + +(Not (ConstBool [c])) => (ConstBool [!c]) + +// Convert x * 1 to x. +(Mul(8|16|32|64) (Const(8|16|32|64) [1]) x) => x + +// Convert x * -1 to -x. +(Mul(8|16|32|64) (Const(8|16|32|64) [-1]) x) => (Neg(8|16|32|64) x) + +// Convert multiplication by a power of two to a shift. +(Mul8 <t> n (Const8 [c])) && isPowerOfTwo8(c) => (Lsh8x64 <t> n (Const64 <typ.UInt64> [log8(c)])) +(Mul16 <t> n (Const16 [c])) && isPowerOfTwo16(c) => (Lsh16x64 <t> n (Const64 <typ.UInt64> [log16(c)])) +(Mul32 <t> n (Const32 [c])) && isPowerOfTwo32(c) => (Lsh32x64 <t> n (Const64 <typ.UInt64> [log32(c)])) +(Mul64 <t> n (Const64 [c])) && isPowerOfTwo64(c) => (Lsh64x64 <t> n (Const64 <typ.UInt64> [log64(c)])) +(Mul8 <t> n (Const8 [c])) && t.IsSigned() && isPowerOfTwo8(-c) => (Neg8 (Lsh8x64 <t> n (Const64 <typ.UInt64> [log8(-c)]))) +(Mul16 <t> n (Const16 [c])) && t.IsSigned() && isPowerOfTwo16(-c) => (Neg16 (Lsh16x64 <t> n (Const64 <typ.UInt64> [log16(-c)]))) +(Mul32 <t> n (Const32 [c])) && t.IsSigned() && isPowerOfTwo32(-c) => (Neg32 (Lsh32x64 <t> n (Const64 <typ.UInt64> [log32(-c)]))) +(Mul64 <t> n (Const64 [c])) && t.IsSigned() && isPowerOfTwo64(-c) => (Neg64 (Lsh64x64 <t> n (Const64 <typ.UInt64> [log64(-c)]))) + +(Mod8 (Const8 [c]) (Const8 [d])) && d != 0 => (Const8 [c % d]) +(Mod16 (Const16 [c]) (Const16 [d])) && d != 0 => (Const16 [c % d]) +(Mod32 (Const32 [c]) (Const32 [d])) && d != 0 => (Const32 [c % d]) +(Mod64 (Const64 [c]) (Const64 [d])) && d != 0 => (Const64 [c % d]) + +(Mod8u (Const8 [c]) (Const8 [d])) && d != 0 => (Const8 [int8(uint8(c) % uint8(d))]) +(Mod16u (Const16 [c]) (Const16 [d])) && d != 0 => (Const16 [int16(uint16(c) % uint16(d))]) +(Mod32u (Const32 [c]) (Const32 [d])) && d != 0 => (Const32 [int32(uint32(c) % uint32(d))]) +(Mod64u (Const64 [c]) (Const64 [d])) && d != 0 => (Const64 [int64(uint64(c) % uint64(d))]) + +(Lsh64x64 (Const64 [c]) (Const64 [d])) => (Const64 [c << uint64(d)]) +(Rsh64x64 (Const64 [c]) (Const64 [d])) => (Const64 [c >> uint64(d)]) +(Rsh64Ux64 (Const64 [c]) (Const64 [d])) => (Const64 [int64(uint64(c) >> uint64(d))]) +(Lsh32x64 (Const32 [c]) (Const64 [d])) => (Const32 [c << uint64(d)]) +(Rsh32x64 (Const32 [c]) (Const64 [d])) => (Const32 [c >> uint64(d)]) +(Rsh32Ux64 (Const32 [c]) (Const64 [d])) => (Const32 [int32(uint32(c) >> uint64(d))]) +(Lsh16x64 (Const16 [c]) (Const64 [d])) => (Const16 [c << uint64(d)]) +(Rsh16x64 (Const16 [c]) (Const64 [d])) => (Const16 [c >> uint64(d)]) +(Rsh16Ux64 (Const16 [c]) (Const64 [d])) => (Const16 [int16(uint16(c) >> uint64(d))]) +(Lsh8x64 (Const8 [c]) (Const64 [d])) => (Const8 [c << uint64(d)]) +(Rsh8x64 (Const8 [c]) (Const64 [d])) => (Const8 [c >> uint64(d)]) +(Rsh8Ux64 (Const8 [c]) (Const64 [d])) => (Const8 [int8(uint8(c) >> uint64(d))]) + +// Fold IsInBounds when the range of the index cannot exceed the limit. +(IsInBounds (ZeroExt8to32 _) (Const32 [c])) && (1 << 8) <= c => (ConstBool [true]) +(IsInBounds (ZeroExt8to64 _) (Const64 [c])) && (1 << 8) <= c => (ConstBool [true]) +(IsInBounds (ZeroExt16to32 _) (Const32 [c])) && (1 << 16) <= c => (ConstBool [true]) +(IsInBounds (ZeroExt16to64 _) (Const64 [c])) && (1 << 16) <= c => (ConstBool [true]) +(IsInBounds x x) => (ConstBool [false]) +(IsInBounds (And8 (Const8 [c]) _) (Const8 [d])) && 0 <= c && c < d => (ConstBool [true]) +(IsInBounds (ZeroExt8to16 (And8 (Const8 [c]) _)) (Const16 [d])) && 0 <= c && int16(c) < d => (ConstBool [true]) +(IsInBounds (ZeroExt8to32 (And8 (Const8 [c]) _)) (Const32 [d])) && 0 <= c && int32(c) < d => (ConstBool [true]) +(IsInBounds (ZeroExt8to64 (And8 (Const8 [c]) _)) (Const64 [d])) && 0 <= c && int64(c) < d => (ConstBool [true]) +(IsInBounds (And16 (Const16 [c]) _) (Const16 [d])) && 0 <= c && c < d => (ConstBool [true]) +(IsInBounds (ZeroExt16to32 (And16 (Const16 [c]) _)) (Const32 [d])) && 0 <= c && int32(c) < d => (ConstBool [true]) +(IsInBounds (ZeroExt16to64 (And16 (Const16 [c]) _)) (Const64 [d])) && 0 <= c && int64(c) < d => (ConstBool [true]) +(IsInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c < d => (ConstBool [true]) +(IsInBounds (ZeroExt32to64 (And32 (Const32 [c]) _)) (Const64 [d])) && 0 <= c && int64(c) < d => (ConstBool [true]) +(IsInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c < d => (ConstBool [true]) +(IsInBounds (Const32 [c]) (Const32 [d])) => (ConstBool [0 <= c && c < d]) +(IsInBounds (Const64 [c]) (Const64 [d])) => (ConstBool [0 <= c && c < d]) +// (Mod64u x y) is always between 0 (inclusive) and y (exclusive). +(IsInBounds (Mod32u _ y) y) => (ConstBool [true]) +(IsInBounds (Mod64u _ y) y) => (ConstBool [true]) +// Right shifting an unsigned number limits its value. +(IsInBounds (ZeroExt8to64 (Rsh8Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d => (ConstBool [true]) +(IsInBounds (ZeroExt8to32 (Rsh8Ux64 _ (Const64 [c]))) (Const32 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d => (ConstBool [true]) +(IsInBounds (ZeroExt8to16 (Rsh8Ux64 _ (Const64 [c]))) (Const16 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d => (ConstBool [true]) +(IsInBounds (Rsh8Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 8 && 1<<uint( 8-c)-1 < d => (ConstBool [true]) +(IsInBounds (ZeroExt16to64 (Rsh16Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d => (ConstBool [true]) +(IsInBounds (ZeroExt16to32 (Rsh16Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d => (ConstBool [true]) +(IsInBounds (Rsh16Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 16 && 1<<uint(16-c)-1 < d => (ConstBool [true]) +(IsInBounds (ZeroExt32to64 (Rsh32Ux64 _ (Const64 [c]))) (Const64 [d])) && 0 < c && c < 32 && 1<<uint(32-c)-1 < d => (ConstBool [true]) +(IsInBounds (Rsh32Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 32 && 1<<uint(32-c)-1 < d => (ConstBool [true]) +(IsInBounds (Rsh64Ux64 _ (Const64 [c])) (Const64 [d])) && 0 < c && c < 64 && 1<<uint(64-c)-1 < d => (ConstBool [true]) + +(IsSliceInBounds x x) => (ConstBool [true]) +(IsSliceInBounds (And32 (Const32 [c]) _) (Const32 [d])) && 0 <= c && c <= d => (ConstBool [true]) +(IsSliceInBounds (And64 (Const64 [c]) _) (Const64 [d])) && 0 <= c && c <= d => (ConstBool [true]) +(IsSliceInBounds (Const32 [0]) _) => (ConstBool [true]) +(IsSliceInBounds (Const64 [0]) _) => (ConstBool [true]) +(IsSliceInBounds (Const32 [c]) (Const32 [d])) => (ConstBool [0 <= c && c <= d]) +(IsSliceInBounds (Const64 [c]) (Const64 [d])) => (ConstBool [0 <= c && c <= d]) +(IsSliceInBounds (SliceLen x) (SliceCap x)) => (ConstBool [true]) + +(Eq(64|32|16|8) x x) => (ConstBool [true]) +(EqB (ConstBool [c]) (ConstBool [d])) => (ConstBool [c == d]) +(EqB (ConstBool [false]) x) => (Not x) +(EqB (ConstBool [true]) x) => x + +(Neq(64|32|16|8) x x) => (ConstBool [false]) +(NeqB (ConstBool [c]) (ConstBool [d])) => (ConstBool [c != d]) +(NeqB (ConstBool [false]) x) => x +(NeqB (ConstBool [true]) x) => (Not x) +(NeqB (Not x) (Not y)) => (NeqB x y) + +(Eq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Eq64 (Const64 <t> [c-d]) x) +(Eq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Eq32 (Const32 <t> [c-d]) x) +(Eq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Eq16 (Const16 <t> [c-d]) x) +(Eq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) => (Eq8 (Const8 <t> [c-d]) x) + +(Neq64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Neq64 (Const64 <t> [c-d]) x) +(Neq32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Neq32 (Const32 <t> [c-d]) x) +(Neq16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Neq16 (Const16 <t> [c-d]) x) +(Neq8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) => (Neq8 (Const8 <t> [c-d]) x) + +// signed integer range: ( c <= x && x (<|<=) d ) -> ( unsigned(x-c) (<|<=) unsigned(d-c) ) +(AndB (Leq64 (Const64 [c]) x) ((Less|Leq)64 x (Const64 [d]))) && d >= c => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c])) (Const64 <x.Type> [d-c])) +(AndB (Leq32 (Const32 [c]) x) ((Less|Leq)32 x (Const32 [d]))) && d >= c => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c])) (Const32 <x.Type> [d-c])) +(AndB (Leq16 (Const16 [c]) x) ((Less|Leq)16 x (Const16 [d]))) && d >= c => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c])) (Const16 <x.Type> [d-c])) +(AndB (Leq8 (Const8 [c]) x) ((Less|Leq)8 x (Const8 [d]))) && d >= c => ((Less|Leq)8U (Sub8 <x.Type> x (Const8 <x.Type> [c])) (Const8 <x.Type> [d-c])) + +// signed integer range: ( c < x && x (<|<=) d ) -> ( unsigned(x-(c+1)) (<|<=) unsigned(d-(c+1)) ) +(AndB (Less64 (Const64 [c]) x) ((Less|Leq)64 x (Const64 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c+1])) (Const64 <x.Type> [d-c-1])) +(AndB (Less32 (Const32 [c]) x) ((Less|Leq)32 x (Const32 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c+1])) (Const32 <x.Type> [d-c-1])) +(AndB (Less16 (Const16 [c]) x) ((Less|Leq)16 x (Const16 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c+1])) (Const16 <x.Type> [d-c-1])) +(AndB (Less8 (Const8 [c]) x) ((Less|Leq)8 x (Const8 [d]))) && d >= c+1 && c+1 > c => ((Less|Leq)8U (Sub8 <x.Type> x (Const8 <x.Type> [c+1])) (Const8 <x.Type> [d-c-1])) + +// unsigned integer range: ( c <= x && x (<|<=) d ) -> ( x-c (<|<=) d-c ) +(AndB (Leq64U (Const64 [c]) x) ((Less|Leq)64U x (Const64 [d]))) && uint64(d) >= uint64(c) => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c])) (Const64 <x.Type> [d-c])) +(AndB (Leq32U (Const32 [c]) x) ((Less|Leq)32U x (Const32 [d]))) && uint32(d) >= uint32(c) => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c])) (Const32 <x.Type> [d-c])) +(AndB (Leq16U (Const16 [c]) x) ((Less|Leq)16U x (Const16 [d]))) && uint16(d) >= uint16(c) => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c])) (Const16 <x.Type> [d-c])) +(AndB (Leq8U (Const8 [c]) x) ((Less|Leq)8U x (Const8 [d]))) && uint8(d) >= uint8(c) => ((Less|Leq)8U (Sub8 <x.Type> x (Const8 <x.Type> [c])) (Const8 <x.Type> [d-c])) + +// unsigned integer range: ( c < x && x (<|<=) d ) -> ( x-(c+1) (<|<=) d-(c+1) ) +(AndB (Less64U (Const64 [c]) x) ((Less|Leq)64U x (Const64 [d]))) && uint64(d) >= uint64(c+1) && uint64(c+1) > uint64(c) => ((Less|Leq)64U (Sub64 <x.Type> x (Const64 <x.Type> [c+1])) (Const64 <x.Type> [d-c-1])) +(AndB (Less32U (Const32 [c]) x) ((Less|Leq)32U x (Const32 [d]))) && uint32(d) >= uint32(c+1) && uint32(c+1) > uint32(c) => ((Less|Leq)32U (Sub32 <x.Type> x (Const32 <x.Type> [c+1])) (Const32 <x.Type> [d-c-1])) +(AndB (Less16U (Const16 [c]) x) ((Less|Leq)16U x (Const16 [d]))) && uint16(d) >= uint16(c+1) && uint16(c+1) > uint16(c) => ((Less|Leq)16U (Sub16 <x.Type> x (Const16 <x.Type> [c+1])) (Const16 <x.Type> [d-c-1])) +(AndB (Less8U (Const8 [c]) x) ((Less|Leq)8U x (Const8 [d]))) && uint8(d) >= uint8(c+1) && uint8(c+1) > uint8(c) => ((Less|Leq)8U (Sub8 <x.Type> x (Const8 <x.Type> [c+1])) (Const8 <x.Type> [d-c-1])) + +// signed integer range: ( c (<|<=) x || x < d ) -> ( unsigned(c-d) (<|<=) unsigned(x-d) ) +(OrB ((Less|Leq)64 (Const64 [c]) x) (Less64 x (Const64 [d]))) && c >= d => ((Less|Leq)64U (Const64 <x.Type> [c-d]) (Sub64 <x.Type> x (Const64 <x.Type> [d]))) +(OrB ((Less|Leq)32 (Const32 [c]) x) (Less32 x (Const32 [d]))) && c >= d => ((Less|Leq)32U (Const32 <x.Type> [c-d]) (Sub32 <x.Type> x (Const32 <x.Type> [d]))) +(OrB ((Less|Leq)16 (Const16 [c]) x) (Less16 x (Const16 [d]))) && c >= d => ((Less|Leq)16U (Const16 <x.Type> [c-d]) (Sub16 <x.Type> x (Const16 <x.Type> [d]))) +(OrB ((Less|Leq)8 (Const8 [c]) x) (Less8 x (Const8 [d]))) && c >= d => ((Less|Leq)8U (Const8 <x.Type> [c-d]) (Sub8 <x.Type> x (Const8 <x.Type> [d]))) + +// signed integer range: ( c (<|<=) x || x <= d ) -> ( unsigned(c-(d+1)) (<|<=) unsigned(x-(d+1)) ) +(OrB ((Less|Leq)64 (Const64 [c]) x) (Leq64 x (Const64 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)64U (Const64 <x.Type> [c-d-1]) (Sub64 <x.Type> x (Const64 <x.Type> [d+1]))) +(OrB ((Less|Leq)32 (Const32 [c]) x) (Leq32 x (Const32 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)32U (Const32 <x.Type> [c-d-1]) (Sub32 <x.Type> x (Const32 <x.Type> [d+1]))) +(OrB ((Less|Leq)16 (Const16 [c]) x) (Leq16 x (Const16 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)16U (Const16 <x.Type> [c-d-1]) (Sub16 <x.Type> x (Const16 <x.Type> [d+1]))) +(OrB ((Less|Leq)8 (Const8 [c]) x) (Leq8 x (Const8 [d]))) && c >= d+1 && d+1 > d => ((Less|Leq)8U (Const8 <x.Type> [c-d-1]) (Sub8 <x.Type> x (Const8 <x.Type> [d+1]))) + +// unsigned integer range: ( c (<|<=) x || x < d ) -> ( c-d (<|<=) x-d ) +(OrB ((Less|Leq)64U (Const64 [c]) x) (Less64U x (Const64 [d]))) && uint64(c) >= uint64(d) => ((Less|Leq)64U (Const64 <x.Type> [c-d]) (Sub64 <x.Type> x (Const64 <x.Type> [d]))) +(OrB ((Less|Leq)32U (Const32 [c]) x) (Less32U x (Const32 [d]))) && uint32(c) >= uint32(d) => ((Less|Leq)32U (Const32 <x.Type> [c-d]) (Sub32 <x.Type> x (Const32 <x.Type> [d]))) +(OrB ((Less|Leq)16U (Const16 [c]) x) (Less16U x (Const16 [d]))) && uint16(c) >= uint16(d) => ((Less|Leq)16U (Const16 <x.Type> [c-d]) (Sub16 <x.Type> x (Const16 <x.Type> [d]))) +(OrB ((Less|Leq)8U (Const8 [c]) x) (Less8U x (Const8 [d]))) && uint8(c) >= uint8(d) => ((Less|Leq)8U (Const8 <x.Type> [c-d]) (Sub8 <x.Type> x (Const8 <x.Type> [d]))) + +// unsigned integer range: ( c (<|<=) x || x <= d ) -> ( c-(d+1) (<|<=) x-(d+1) ) +(OrB ((Less|Leq)64U (Const64 [c]) x) (Leq64U x (Const64 [d]))) && uint64(c) >= uint64(d+1) && uint64(d+1) > uint64(d) => ((Less|Leq)64U (Const64 <x.Type> [c-d-1]) (Sub64 <x.Type> x (Const64 <x.Type> [d+1]))) +(OrB ((Less|Leq)32U (Const32 [c]) x) (Leq32U x (Const32 [d]))) && uint32(c) >= uint32(d+1) && uint32(d+1) > uint32(d) => ((Less|Leq)32U (Const32 <x.Type> [c-d-1]) (Sub32 <x.Type> x (Const32 <x.Type> [d+1]))) +(OrB ((Less|Leq)16U (Const16 [c]) x) (Leq16U x (Const16 [d]))) && uint16(c) >= uint16(d+1) && uint16(d+1) > uint16(d) => ((Less|Leq)16U (Const16 <x.Type> [c-d-1]) (Sub16 <x.Type> x (Const16 <x.Type> [d+1]))) +(OrB ((Less|Leq)8U (Const8 [c]) x) (Leq8U x (Const8 [d]))) && uint8(c) >= uint8(d+1) && uint8(d+1) > uint8(d) => ((Less|Leq)8U (Const8 <x.Type> [c-d-1]) (Sub8 <x.Type> x (Const8 <x.Type> [d+1]))) + +// Canonicalize x-const to x+(-const) +(Sub64 x (Const64 <t> [c])) && x.Op != OpConst64 => (Add64 (Const64 <t> [-c]) x) +(Sub32 x (Const32 <t> [c])) && x.Op != OpConst32 => (Add32 (Const32 <t> [-c]) x) +(Sub16 x (Const16 <t> [c])) && x.Op != OpConst16 => (Add16 (Const16 <t> [-c]) x) +(Sub8 x (Const8 <t> [c])) && x.Op != OpConst8 => (Add8 (Const8 <t> [-c]) x) + +// fold negation into comparison operators +(Not (Eq(64|32|16|8|B|Ptr|64F|32F) x y)) => (Neq(64|32|16|8|B|Ptr|64F|32F) x y) +(Not (Neq(64|32|16|8|B|Ptr|64F|32F) x y)) => (Eq(64|32|16|8|B|Ptr|64F|32F) x y) + +(Not (Less(64|32|16|8) x y)) => (Leq(64|32|16|8) y x) +(Not (Less(64|32|16|8)U x y)) => (Leq(64|32|16|8)U y x) +(Not (Leq(64|32|16|8) x y)) => (Less(64|32|16|8) y x) +(Not (Leq(64|32|16|8)U x y)) => (Less(64|32|16|8)U y x) + +// Distribute multiplication c * (d+x) -> c*d + c*x. Useful for: +// a[i].b = ...; a[i+1].b = ... +(Mul64 (Const64 <t> [c]) (Add64 <t> (Const64 <t> [d]) x)) => + (Add64 (Const64 <t> [c*d]) (Mul64 <t> (Const64 <t> [c]) x)) +(Mul32 (Const32 <t> [c]) (Add32 <t> (Const32 <t> [d]) x)) => + (Add32 (Const32 <t> [c*d]) (Mul32 <t> (Const32 <t> [c]) x)) + +// Rewrite x*y ± x*z to x*(y±z) +(Add(64|32|16|8) <t> (Mul(64|32|16|8) x y) (Mul(64|32|16|8) x z)) + => (Mul(64|32|16|8) x (Add(64|32|16|8) <t> y z)) +(Sub(64|32|16|8) <t> (Mul(64|32|16|8) x y) (Mul(64|32|16|8) x z)) + => (Mul(64|32|16|8) x (Sub(64|32|16|8) <t> y z)) + +// rewrite shifts of 8/16/32 bit consts into 64 bit consts to reduce +// the number of the other rewrite rules for const shifts +(Lsh64x32 <t> x (Const32 [c])) => (Lsh64x64 x (Const64 <t> [int64(uint32(c))])) +(Lsh64x16 <t> x (Const16 [c])) => (Lsh64x64 x (Const64 <t> [int64(uint16(c))])) +(Lsh64x8 <t> x (Const8 [c])) => (Lsh64x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh64x32 <t> x (Const32 [c])) => (Rsh64x64 x (Const64 <t> [int64(uint32(c))])) +(Rsh64x16 <t> x (Const16 [c])) => (Rsh64x64 x (Const64 <t> [int64(uint16(c))])) +(Rsh64x8 <t> x (Const8 [c])) => (Rsh64x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh64Ux32 <t> x (Const32 [c])) => (Rsh64Ux64 x (Const64 <t> [int64(uint32(c))])) +(Rsh64Ux16 <t> x (Const16 [c])) => (Rsh64Ux64 x (Const64 <t> [int64(uint16(c))])) +(Rsh64Ux8 <t> x (Const8 [c])) => (Rsh64Ux64 x (Const64 <t> [int64(uint8(c))])) + +(Lsh32x32 <t> x (Const32 [c])) => (Lsh32x64 x (Const64 <t> [int64(uint32(c))])) +(Lsh32x16 <t> x (Const16 [c])) => (Lsh32x64 x (Const64 <t> [int64(uint16(c))])) +(Lsh32x8 <t> x (Const8 [c])) => (Lsh32x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh32x32 <t> x (Const32 [c])) => (Rsh32x64 x (Const64 <t> [int64(uint32(c))])) +(Rsh32x16 <t> x (Const16 [c])) => (Rsh32x64 x (Const64 <t> [int64(uint16(c))])) +(Rsh32x8 <t> x (Const8 [c])) => (Rsh32x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh32Ux32 <t> x (Const32 [c])) => (Rsh32Ux64 x (Const64 <t> [int64(uint32(c))])) +(Rsh32Ux16 <t> x (Const16 [c])) => (Rsh32Ux64 x (Const64 <t> [int64(uint16(c))])) +(Rsh32Ux8 <t> x (Const8 [c])) => (Rsh32Ux64 x (Const64 <t> [int64(uint8(c))])) + +(Lsh16x32 <t> x (Const32 [c])) => (Lsh16x64 x (Const64 <t> [int64(uint32(c))])) +(Lsh16x16 <t> x (Const16 [c])) => (Lsh16x64 x (Const64 <t> [int64(uint16(c))])) +(Lsh16x8 <t> x (Const8 [c])) => (Lsh16x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh16x32 <t> x (Const32 [c])) => (Rsh16x64 x (Const64 <t> [int64(uint32(c))])) +(Rsh16x16 <t> x (Const16 [c])) => (Rsh16x64 x (Const64 <t> [int64(uint16(c))])) +(Rsh16x8 <t> x (Const8 [c])) => (Rsh16x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh16Ux32 <t> x (Const32 [c])) => (Rsh16Ux64 x (Const64 <t> [int64(uint32(c))])) +(Rsh16Ux16 <t> x (Const16 [c])) => (Rsh16Ux64 x (Const64 <t> [int64(uint16(c))])) +(Rsh16Ux8 <t> x (Const8 [c])) => (Rsh16Ux64 x (Const64 <t> [int64(uint8(c))])) + +(Lsh8x32 <t> x (Const32 [c])) => (Lsh8x64 x (Const64 <t> [int64(uint32(c))])) +(Lsh8x16 <t> x (Const16 [c])) => (Lsh8x64 x (Const64 <t> [int64(uint16(c))])) +(Lsh8x8 <t> x (Const8 [c])) => (Lsh8x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh8x32 <t> x (Const32 [c])) => (Rsh8x64 x (Const64 <t> [int64(uint32(c))])) +(Rsh8x16 <t> x (Const16 [c])) => (Rsh8x64 x (Const64 <t> [int64(uint16(c))])) +(Rsh8x8 <t> x (Const8 [c])) => (Rsh8x64 x (Const64 <t> [int64(uint8(c))])) +(Rsh8Ux32 <t> x (Const32 [c])) => (Rsh8Ux64 x (Const64 <t> [int64(uint32(c))])) +(Rsh8Ux16 <t> x (Const16 [c])) => (Rsh8Ux64 x (Const64 <t> [int64(uint16(c))])) +(Rsh8Ux8 <t> x (Const8 [c])) => (Rsh8Ux64 x (Const64 <t> [int64(uint8(c))])) + +// shifts by zero +(Lsh(64|32|16|8)x64 x (Const64 [0])) => x +(Rsh(64|32|16|8)x64 x (Const64 [0])) => x +(Rsh(64|32|16|8)Ux64 x (Const64 [0])) => x + +// rotates by multiples of register width +(RotateLeft64 x (Const64 [c])) && c%64 == 0 => x +(RotateLeft32 x (Const32 [c])) && c%32 == 0 => x +(RotateLeft16 x (Const16 [c])) && c%16 == 0 => x +(RotateLeft8 x (Const8 [c])) && c%8 == 0 => x + +// zero shifted +(Lsh64x(64|32|16|8) (Const64 [0]) _) => (Const64 [0]) +(Rsh64x(64|32|16|8) (Const64 [0]) _) => (Const64 [0]) +(Rsh64Ux(64|32|16|8) (Const64 [0]) _) => (Const64 [0]) +(Lsh32x(64|32|16|8) (Const32 [0]) _) => (Const32 [0]) +(Rsh32x(64|32|16|8) (Const32 [0]) _) => (Const32 [0]) +(Rsh32Ux(64|32|16|8) (Const32 [0]) _) => (Const32 [0]) +(Lsh16x(64|32|16|8) (Const16 [0]) _) => (Const16 [0]) +(Rsh16x(64|32|16|8) (Const16 [0]) _) => (Const16 [0]) +(Rsh16Ux(64|32|16|8) (Const16 [0]) _) => (Const16 [0]) +(Lsh8x(64|32|16|8) (Const8 [0]) _) => (Const8 [0]) +(Rsh8x(64|32|16|8) (Const8 [0]) _) => (Const8 [0]) +(Rsh8Ux(64|32|16|8) (Const8 [0]) _) => (Const8 [0]) + +// large left shifts of all values, and right shifts of unsigned values +((Lsh64|Rsh64U)x64 _ (Const64 [c])) && uint64(c) >= 64 => (Const64 [0]) +((Lsh32|Rsh32U)x64 _ (Const64 [c])) && uint64(c) >= 32 => (Const32 [0]) +((Lsh16|Rsh16U)x64 _ (Const64 [c])) && uint64(c) >= 16 => (Const16 [0]) +((Lsh8|Rsh8U)x64 _ (Const64 [c])) && uint64(c) >= 8 => (Const8 [0]) + +// combine const shifts +(Lsh64x64 <t> (Lsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh64x64 x (Const64 <t> [c+d])) +(Lsh32x64 <t> (Lsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh32x64 x (Const64 <t> [c+d])) +(Lsh16x64 <t> (Lsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh16x64 x (Const64 <t> [c+d])) +(Lsh8x64 <t> (Lsh8x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Lsh8x64 x (Const64 <t> [c+d])) + +(Rsh64x64 <t> (Rsh64x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh64x64 x (Const64 <t> [c+d])) +(Rsh32x64 <t> (Rsh32x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh32x64 x (Const64 <t> [c+d])) +(Rsh16x64 <t> (Rsh16x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh16x64 x (Const64 <t> [c+d])) +(Rsh8x64 <t> (Rsh8x64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh8x64 x (Const64 <t> [c+d])) + +(Rsh64Ux64 <t> (Rsh64Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh64Ux64 x (Const64 <t> [c+d])) +(Rsh32Ux64 <t> (Rsh32Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh32Ux64 x (Const64 <t> [c+d])) +(Rsh16Ux64 <t> (Rsh16Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh16Ux64 x (Const64 <t> [c+d])) +(Rsh8Ux64 <t> (Rsh8Ux64 x (Const64 [c])) (Const64 [d])) && !uaddOvf(c,d) => (Rsh8Ux64 x (Const64 <t> [c+d])) + +// Remove signed right shift before an unsigned right shift that extracts the sign bit. +(Rsh8Ux64 (Rsh8x64 x _) (Const64 <t> [7] )) => (Rsh8Ux64 x (Const64 <t> [7] )) +(Rsh16Ux64 (Rsh16x64 x _) (Const64 <t> [15])) => (Rsh16Ux64 x (Const64 <t> [15])) +(Rsh32Ux64 (Rsh32x64 x _) (Const64 <t> [31])) => (Rsh32Ux64 x (Const64 <t> [31])) +(Rsh64Ux64 (Rsh64x64 x _) (Const64 <t> [63])) => (Rsh64Ux64 x (Const64 <t> [63])) + +// ((x >> c1) << c2) >> c3 +(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])) + && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) + => (Rsh(64|32|16|8)Ux64 x (Const64 <typ.UInt64> [c1-c2+c3])) + +// ((x << c1) >> c2) << c3 +(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])) + && uint64(c1) >= uint64(c2) && uint64(c3) >= uint64(c2) && !uaddOvf(c1-c2, c3) + => (Lsh(64|32|16|8)x64 x (Const64 <typ.UInt64> [c1-c2+c3])) + +// (x >> c) & uppermask = 0 +(And64 (Const64 [m]) (Rsh64Ux64 _ (Const64 [c]))) && c >= int64(64-ntz64(m)) => (Const64 [0]) +(And32 (Const32 [m]) (Rsh32Ux64 _ (Const64 [c]))) && c >= int64(32-ntz32(m)) => (Const32 [0]) +(And16 (Const16 [m]) (Rsh16Ux64 _ (Const64 [c]))) && c >= int64(16-ntz16(m)) => (Const16 [0]) +(And8 (Const8 [m]) (Rsh8Ux64 _ (Const64 [c]))) && c >= int64(8-ntz8(m)) => (Const8 [0]) + +// (x << c) & lowermask = 0 +(And64 (Const64 [m]) (Lsh64x64 _ (Const64 [c]))) && c >= int64(64-nlz64(m)) => (Const64 [0]) +(And32 (Const32 [m]) (Lsh32x64 _ (Const64 [c]))) && c >= int64(32-nlz32(m)) => (Const32 [0]) +(And16 (Const16 [m]) (Lsh16x64 _ (Const64 [c]))) && c >= int64(16-nlz16(m)) => (Const16 [0]) +(And8 (Const8 [m]) (Lsh8x64 _ (Const64 [c]))) && c >= int64(8-nlz8(m)) => (Const8 [0]) + +// replace shifts with zero extensions +(Rsh16Ux64 (Lsh16x64 x (Const64 [8])) (Const64 [8])) => (ZeroExt8to16 (Trunc16to8 <typ.UInt8> x)) +(Rsh32Ux64 (Lsh32x64 x (Const64 [24])) (Const64 [24])) => (ZeroExt8to32 (Trunc32to8 <typ.UInt8> x)) +(Rsh64Ux64 (Lsh64x64 x (Const64 [56])) (Const64 [56])) => (ZeroExt8to64 (Trunc64to8 <typ.UInt8> x)) +(Rsh32Ux64 (Lsh32x64 x (Const64 [16])) (Const64 [16])) => (ZeroExt16to32 (Trunc32to16 <typ.UInt16> x)) +(Rsh64Ux64 (Lsh64x64 x (Const64 [48])) (Const64 [48])) => (ZeroExt16to64 (Trunc64to16 <typ.UInt16> x)) +(Rsh64Ux64 (Lsh64x64 x (Const64 [32])) (Const64 [32])) => (ZeroExt32to64 (Trunc64to32 <typ.UInt32> x)) + +// replace shifts with sign extensions +(Rsh16x64 (Lsh16x64 x (Const64 [8])) (Const64 [8])) => (SignExt8to16 (Trunc16to8 <typ.Int8> x)) +(Rsh32x64 (Lsh32x64 x (Const64 [24])) (Const64 [24])) => (SignExt8to32 (Trunc32to8 <typ.Int8> x)) +(Rsh64x64 (Lsh64x64 x (Const64 [56])) (Const64 [56])) => (SignExt8to64 (Trunc64to8 <typ.Int8> x)) +(Rsh32x64 (Lsh32x64 x (Const64 [16])) (Const64 [16])) => (SignExt16to32 (Trunc32to16 <typ.Int16> x)) +(Rsh64x64 (Lsh64x64 x (Const64 [48])) (Const64 [48])) => (SignExt16to64 (Trunc64to16 <typ.Int16> x)) +(Rsh64x64 (Lsh64x64 x (Const64 [32])) (Const64 [32])) => (SignExt32to64 (Trunc64to32 <typ.Int32> x)) + +// constant comparisons +(Eq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c == d]) +(Neq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c != d]) +(Less(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c < d]) +(Leq(64|32|16|8) (Const(64|32|16|8) [c]) (Const(64|32|16|8) [d])) => (ConstBool [c <= d]) + +(Less64U (Const64 [c]) (Const64 [d])) => (ConstBool [uint64(c) < uint64(d)]) +(Less32U (Const32 [c]) (Const32 [d])) => (ConstBool [uint32(c) < uint32(d)]) +(Less16U (Const16 [c]) (Const16 [d])) => (ConstBool [uint16(c) < uint16(d)]) +(Less8U (Const8 [c]) (Const8 [d])) => (ConstBool [ uint8(c) < uint8(d)]) + +(Leq64U (Const64 [c]) (Const64 [d])) => (ConstBool [uint64(c) <= uint64(d)]) +(Leq32U (Const32 [c]) (Const32 [d])) => (ConstBool [uint32(c) <= uint32(d)]) +(Leq16U (Const16 [c]) (Const16 [d])) => (ConstBool [uint16(c) <= uint16(d)]) +(Leq8U (Const8 [c]) (Const8 [d])) => (ConstBool [ uint8(c) <= uint8(d)]) + +(Leq8 (Const8 [0]) (And8 _ (Const8 [c]))) && c >= 0 => (ConstBool [true]) +(Leq16 (Const16 [0]) (And16 _ (Const16 [c]))) && c >= 0 => (ConstBool [true]) +(Leq32 (Const32 [0]) (And32 _ (Const32 [c]))) && c >= 0 => (ConstBool [true]) +(Leq64 (Const64 [0]) (And64 _ (Const64 [c]))) && c >= 0 => (ConstBool [true]) + +(Leq8 (Const8 [0]) (Rsh8Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true]) +(Leq16 (Const16 [0]) (Rsh16Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true]) +(Leq32 (Const32 [0]) (Rsh32Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true]) +(Leq64 (Const64 [0]) (Rsh64Ux64 _ (Const64 [c]))) && c > 0 => (ConstBool [true]) + +(Less(64|32|16|8) (Const(64|32|16|8) <t> [0]) x) && isNonNegative(x) => (Neq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x) +(Less(64|32|16|8) x (Const(64|32|16|8) <t> [1])) && isNonNegative(x) => (Eq(64|32|16|8) (Const(64|32|16|8) <t> [0]) x) + +// constant floating point comparisons +(Eq32F (Const32F [c]) (Const32F [d])) => (ConstBool [c == d]) +(Eq64F (Const64F [c]) (Const64F [d])) => (ConstBool [c == d]) +(Neq32F (Const32F [c]) (Const32F [d])) => (ConstBool [c != d]) +(Neq64F (Const64F [c]) (Const64F [d])) => (ConstBool [c != d]) +(Less32F (Const32F [c]) (Const32F [d])) => (ConstBool [c < d]) +(Less64F (Const64F [c]) (Const64F [d])) => (ConstBool [c < d]) +(Leq32F (Const32F [c]) (Const32F [d])) => (ConstBool [c <= d]) +(Leq64F (Const64F [c]) (Const64F [d])) => (ConstBool [c <= d]) + +// simplifications +(Or(64|32|16|8) x x) => x +(Or(64|32|16|8) (Const(64|32|16|8) [0]) x) => x +(Or(64|32|16|8) (Const(64|32|16|8) [-1]) _) => (Const(64|32|16|8) [-1]) + +(And(64|32|16|8) x x) => x +(And(64|32|16|8) (Const(64|32|16|8) [-1]) x) => x +(And(64|32|16|8) (Const(64|32|16|8) [0]) _) => (Const(64|32|16|8) [0]) + +(Xor(64|32|16|8) x x) => (Const(64|32|16|8) [0]) +(Xor(64|32|16|8) (Const(64|32|16|8) [0]) x) => x + +(Add(64|32|16|8) (Const(64|32|16|8) [0]) x) => x +(Sub(64|32|16|8) x x) => (Const(64|32|16|8) [0]) +(Mul(64|32|16|8) (Const(64|32|16|8) [0]) _) => (Const(64|32|16|8) [0]) + +(Com(64|32|16|8) (Com(64|32|16|8) x)) => x +(Com(64|32|16|8) (Const(64|32|16|8) [c])) => (Const(64|32|16|8) [^c]) + +(Neg(64|32|16|8) (Sub(64|32|16|8) x y)) => (Sub(64|32|16|8) y x) + +// ^(x-1) == ^x+1 == -x +(Add(64|32|16|8) (Const(64|32|16|8) [1]) (Com(64|32|16|8) x)) => (Neg(64|32|16|8) x) +(Com(64|32|16|8) (Add(64|32|16|8) (Const(64|32|16|8) [-1]) x)) => (Neg(64|32|16|8) x) + +// -(-x) == x +(Neg(64|32|16|8) (Neg(64|32|16|8) x)) => x + +// -^x == x+1 +(Neg(64|32|16|8) <t> (Com(64|32|16|8) x)) => (Add(64|32|16|8) (Const(64|32|16|8) <t> [1]) x) + +(And(64|32|16|8) x (And(64|32|16|8) x y)) => (And(64|32|16|8) x y) +(Or(64|32|16|8) x (Or(64|32|16|8) x y)) => (Or(64|32|16|8) x y) +(Xor(64|32|16|8) x (Xor(64|32|16|8) x y)) => y + +// Unsigned comparisons to zero. +(Less(64U|32U|16U|8U) _ (Const(64|32|16|8) [0])) => (ConstBool [false]) +(Leq(64U|32U|16U|8U) (Const(64|32|16|8) [0]) _) => (ConstBool [true]) + +// Ands clear bits. Ors set bits. +// If a subsequent Or will set all the bits +// that an And cleared, we can skip the And. +// This happens in bitmasking code like: +// x &^= 3 << shift // clear two old bits +// x |= v << shift // set two new bits +// when shift is a small constant and v ends up a constant 3. +(Or8 (And8 x (Const8 [c2])) (Const8 <t> [c1])) && ^(c1 | c2) == 0 => (Or8 (Const8 <t> [c1]) x) +(Or16 (And16 x (Const16 [c2])) (Const16 <t> [c1])) && ^(c1 | c2) == 0 => (Or16 (Const16 <t> [c1]) x) +(Or32 (And32 x (Const32 [c2])) (Const32 <t> [c1])) && ^(c1 | c2) == 0 => (Or32 (Const32 <t> [c1]) x) +(Or64 (And64 x (Const64 [c2])) (Const64 <t> [c1])) && ^(c1 | c2) == 0 => (Or64 (Const64 <t> [c1]) x) + +(Trunc64to8 (And64 (Const64 [y]) x)) && y&0xFF == 0xFF => (Trunc64to8 x) +(Trunc64to16 (And64 (Const64 [y]) x)) && y&0xFFFF == 0xFFFF => (Trunc64to16 x) +(Trunc64to32 (And64 (Const64 [y]) x)) && y&0xFFFFFFFF == 0xFFFFFFFF => (Trunc64to32 x) +(Trunc32to8 (And32 (Const32 [y]) x)) && y&0xFF == 0xFF => (Trunc32to8 x) +(Trunc32to16 (And32 (Const32 [y]) x)) && y&0xFFFF == 0xFFFF => (Trunc32to16 x) +(Trunc16to8 (And16 (Const16 [y]) x)) && y&0xFF == 0xFF => (Trunc16to8 x) + +(ZeroExt8to64 (Trunc64to8 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 56 => x +(ZeroExt16to64 (Trunc64to16 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 48 => x +(ZeroExt32to64 (Trunc64to32 x:(Rsh64Ux64 _ (Const64 [s])))) && s >= 32 => x +(ZeroExt8to32 (Trunc32to8 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 24 => x +(ZeroExt16to32 (Trunc32to16 x:(Rsh32Ux64 _ (Const64 [s])))) && s >= 16 => x +(ZeroExt8to16 (Trunc16to8 x:(Rsh16Ux64 _ (Const64 [s])))) && s >= 8 => x + +(SignExt8to64 (Trunc64to8 x:(Rsh64x64 _ (Const64 [s])))) && s >= 56 => x +(SignExt16to64 (Trunc64to16 x:(Rsh64x64 _ (Const64 [s])))) && s >= 48 => x +(SignExt32to64 (Trunc64to32 x:(Rsh64x64 _ (Const64 [s])))) && s >= 32 => x +(SignExt8to32 (Trunc32to8 x:(Rsh32x64 _ (Const64 [s])))) && s >= 24 => x +(SignExt16to32 (Trunc32to16 x:(Rsh32x64 _ (Const64 [s])))) && s >= 16 => x +(SignExt8to16 (Trunc16to8 x:(Rsh16x64 _ (Const64 [s])))) && s >= 8 => x + +(Slicemask (Const32 [x])) && x > 0 => (Const32 [-1]) +(Slicemask (Const32 [0])) => (Const32 [0]) +(Slicemask (Const64 [x])) && x > 0 => (Const64 [-1]) +(Slicemask (Const64 [0])) => (Const64 [0]) + +// simplifications often used for lengths. e.g. len(s[i:i+5])==5 +(Sub(64|32|16|8) (Add(64|32|16|8) x y) x) => y +(Sub(64|32|16|8) (Add(64|32|16|8) x y) y) => x +(Sub(64|32|16|8) (Sub(64|32|16|8) x y) x) => (Neg(64|32|16|8) y) +(Sub(64|32|16|8) x (Add(64|32|16|8) x y)) => (Neg(64|32|16|8) y) +(Add(64|32|16|8) x (Sub(64|32|16|8) y x)) => y +(Add(64|32|16|8) x (Add(64|32|16|8) y (Sub(64|32|16|8) z x))) => (Add(64|32|16|8) y z) + +// basic phi simplifications +(Phi (Const8 [c]) (Const8 [c])) => (Const8 [c]) +(Phi (Const16 [c]) (Const16 [c])) => (Const16 [c]) +(Phi (Const32 [c]) (Const32 [c])) => (Const32 [c]) +(Phi (Const64 [c]) (Const64 [c])) => (Const64 [c]) + +// slice and interface comparisons +// The frontend ensures that we can only compare against nil, +// so we need only compare the first word (interface type or slice ptr). +(EqInter x y) => (EqPtr (ITab x) (ITab y)) +(NeqInter x y) => (NeqPtr (ITab x) (ITab y)) +(EqSlice x y) => (EqPtr (SlicePtr x) (SlicePtr y)) +(NeqSlice x y) => (NeqPtr (SlicePtr x) (SlicePtr y)) + +// Load of store of same address, with compatibly typed value and same size +(Load <t1> p1 (Store {t2} p2 x _)) + && isSamePtr(p1, p2) + && t1.Compare(x.Type) == types.CMPeq + && t1.Size() == t2.Size() + => x +(Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 x _))) + && isSamePtr(p1, p3) + && t1.Compare(x.Type) == types.CMPeq + && t1.Size() == t2.Size() + && disjoint(p3, t3.Size(), p2, t2.Size()) + => x +(Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 x _)))) + && isSamePtr(p1, p4) + && t1.Compare(x.Type) == types.CMPeq + && t1.Size() == t2.Size() + && disjoint(p4, t4.Size(), p2, t2.Size()) + && disjoint(p4, t4.Size(), p3, t3.Size()) + => x +(Load <t1> p1 (Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 _ (Store {t5} p5 x _))))) + && isSamePtr(p1, p5) + && t1.Compare(x.Type) == types.CMPeq + && t1.Size() == t2.Size() + && disjoint(p5, t5.Size(), p2, t2.Size()) + && disjoint(p5, t5.Size(), p3, t3.Size()) + && disjoint(p5, t5.Size(), p4, t4.Size()) + => x + +// Pass constants through math.Float{32,64}bits and math.Float{32,64}frombits + (Load <t1> p1 (Store {t2} p2 (Const64 [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 8 && is64BitFloat(t1) && !math.IsNaN(math.Float64frombits(uint64(x))) => (Const64F [math.Float64frombits(uint64(x))]) + (Load <t1> p1 (Store {t2} p2 (Const32 [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 4 && is32BitFloat(t1) && !math.IsNaN(float64(math.Float32frombits(uint32(x)))) => (Const32F [math.Float32frombits(uint32(x))]) +(Load <t1> p1 (Store {t2} p2 (Const64F [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 8 && is64BitInt(t1) => (Const64 [int64(math.Float64bits(x))]) +(Load <t1> p1 (Store {t2} p2 (Const32F [x]) _)) && isSamePtr(p1,p2) && sizeof(t2) == 4 && is32BitInt(t1) => (Const32 [int32(math.Float32bits(x))]) + +// Float Loads up to Zeros so they can be constant folded. +(Load <t1> op:(OffPtr [o1] p1) + (Store {t2} p2 _ + mem:(Zero [n] p3 _))) + && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p3) + && fe.CanSSA(t1) + && disjoint(op, t1.Size(), p2, t2.Size()) + => @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p3) mem) +(Load <t1> op:(OffPtr [o1] p1) + (Store {t2} p2 _ + (Store {t3} p3 _ + mem:(Zero [n] p4 _)))) + && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p4) + && fe.CanSSA(t1) + && disjoint(op, t1.Size(), p2, t2.Size()) + && disjoint(op, t1.Size(), p3, t3.Size()) + => @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p4) mem) +(Load <t1> op:(OffPtr [o1] p1) + (Store {t2} p2 _ + (Store {t3} p3 _ + (Store {t4} p4 _ + mem:(Zero [n] p5 _))))) + && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p5) + && fe.CanSSA(t1) + && disjoint(op, t1.Size(), p2, t2.Size()) + && disjoint(op, t1.Size(), p3, t3.Size()) + && disjoint(op, t1.Size(), p4, t4.Size()) + => @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p5) mem) +(Load <t1> op:(OffPtr [o1] p1) + (Store {t2} p2 _ + (Store {t3} p3 _ + (Store {t4} p4 _ + (Store {t5} p5 _ + mem:(Zero [n] p6 _)))))) + && o1 >= 0 && o1+t1.Size() <= n && isSamePtr(p1, p6) + && fe.CanSSA(t1) + && disjoint(op, t1.Size(), p2, t2.Size()) + && disjoint(op, t1.Size(), p3, t3.Size()) + && disjoint(op, t1.Size(), p4, t4.Size()) + && disjoint(op, t1.Size(), p5, t5.Size()) + => @mem.Block (Load <t1> (OffPtr <op.Type> [o1] p6) mem) + +// Zero to Load forwarding. +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && t1.IsBoolean() + && isSamePtr(p1, p2) + && n >= o + 1 + => (ConstBool [false]) +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && is8BitInt(t1) + && isSamePtr(p1, p2) + && n >= o + 1 + => (Const8 [0]) +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && is16BitInt(t1) + && isSamePtr(p1, p2) + && n >= o + 2 + => (Const16 [0]) +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && is32BitInt(t1) + && isSamePtr(p1, p2) + && n >= o + 4 + => (Const32 [0]) +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && is64BitInt(t1) + && isSamePtr(p1, p2) + && n >= o + 8 + => (Const64 [0]) +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && is32BitFloat(t1) + && isSamePtr(p1, p2) + && n >= o + 4 + => (Const32F [0]) +(Load <t1> (OffPtr [o] p1) (Zero [n] p2 _)) + && is64BitFloat(t1) + && isSamePtr(p1, p2) + && n >= o + 8 + => (Const64F [0]) + +// Eliminate stores of values that have just been loaded from the same location. +// We also handle the common case where there are some intermediate stores. +(Store {t1} p1 (Load <t2> p2 mem) mem) + && isSamePtr(p1, p2) + && t2.Size() == t1.Size() + => mem +(Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ oldmem)) + && isSamePtr(p1, p2) + && t2.Size() == t1.Size() + && disjoint(p1, t1.Size(), p3, t3.Size()) + => mem +(Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ (Store {t4} p4 _ oldmem))) + && isSamePtr(p1, p2) + && t2.Size() == t1.Size() + && disjoint(p1, t1.Size(), p3, t3.Size()) + && disjoint(p1, t1.Size(), p4, t4.Size()) + => mem +(Store {t1} p1 (Load <t2> p2 oldmem) mem:(Store {t3} p3 _ (Store {t4} p4 _ (Store {t5} p5 _ oldmem)))) + && isSamePtr(p1, p2) + && t2.Size() == t1.Size() + && disjoint(p1, t1.Size(), p3, t3.Size()) + && disjoint(p1, t1.Size(), p4, t4.Size()) + && disjoint(p1, t1.Size(), p5, t5.Size()) + => mem + +// Don't Store zeros to cleared variables. +(Store {t} (OffPtr [o] p1) x mem:(Zero [n] p2 _)) + && isConstZero(x) + && o >= 0 && t.Size() + o <= n && isSamePtr(p1, p2) + => mem +(Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Zero [n] p3 _))) + && isConstZero(x) + && o1 >= 0 && t1.Size() + o1 <= n && isSamePtr(p1, p3) + && disjoint(op, t1.Size(), p2, t2.Size()) + => mem +(Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Store {t3} p3 _ (Zero [n] p4 _)))) + && isConstZero(x) + && o1 >= 0 && t1.Size() + o1 <= n && isSamePtr(p1, p4) + && disjoint(op, t1.Size(), p2, t2.Size()) + && disjoint(op, t1.Size(), p3, t3.Size()) + => mem +(Store {t1} op:(OffPtr [o1] p1) x mem:(Store {t2} p2 _ (Store {t3} p3 _ (Store {t4} p4 _ (Zero [n] p5 _))))) + && isConstZero(x) + && o1 >= 0 && t1.Size() + o1 <= n && isSamePtr(p1, p5) + && disjoint(op, t1.Size(), p2, t2.Size()) + && disjoint(op, t1.Size(), p3, t3.Size()) + && disjoint(op, t1.Size(), p4, t4.Size()) + => mem + +// Collapse OffPtr +(OffPtr (OffPtr p [y]) [x]) => (OffPtr p [x+y]) +(OffPtr p [0]) && v.Type.Compare(p.Type) == types.CMPeq => p + +// indexing operations +// Note: bounds check has already been done +(PtrIndex <t> ptr idx) && config.PtrSize == 4 && is32Bit(t.Elem().Size()) => (AddPtr ptr (Mul32 <typ.Int> idx (Const32 <typ.Int> [int32(t.Elem().Size())]))) +(PtrIndex <t> ptr idx) && config.PtrSize == 8 => (AddPtr ptr (Mul64 <typ.Int> idx (Const64 <typ.Int> [t.Elem().Size()]))) + +// struct operations +(StructSelect (StructMake1 x)) => x +(StructSelect [0] (StructMake2 x _)) => x +(StructSelect [1] (StructMake2 _ x)) => x +(StructSelect [0] (StructMake3 x _ _)) => x +(StructSelect [1] (StructMake3 _ x _)) => x +(StructSelect [2] (StructMake3 _ _ x)) => x +(StructSelect [0] (StructMake4 x _ _ _)) => x +(StructSelect [1] (StructMake4 _ x _ _)) => x +(StructSelect [2] (StructMake4 _ _ x _)) => x +(StructSelect [3] (StructMake4 _ _ _ x)) => x + +(Load <t> _ _) && t.IsStruct() && t.NumFields() == 0 && fe.CanSSA(t) => + (StructMake0) +(Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 1 && fe.CanSSA(t) => + (StructMake1 + (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem)) +(Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 2 && fe.CanSSA(t) => + (StructMake2 + (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem) + (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem)) +(Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 3 && fe.CanSSA(t) => + (StructMake3 + (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem) + (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem) + (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem)) +(Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 4 && fe.CanSSA(t) => + (StructMake4 + (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0] ptr) mem) + (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem) + (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem) + (Load <t.FieldType(3)> (OffPtr <t.FieldType(3).PtrTo()> [t.FieldOff(3)] ptr) mem)) + +(StructSelect [i] x:(Load <t> ptr mem)) && !fe.CanSSA(t) => + @x.Block (Load <v.Type> (OffPtr <v.Type.PtrTo()> [t.FieldOff(int(i))] ptr) mem) + +(Store _ (StructMake0) mem) => mem +(Store dst (StructMake1 <t> f0) mem) => + (Store {t.FieldType(0)} (OffPtr <t.FieldType(0).PtrTo()> [0] dst) f0 mem) +(Store dst (StructMake2 <t> f0 f1) mem) => + (Store {t.FieldType(1)} + (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) + f1 + (Store {t.FieldType(0)} + (OffPtr <t.FieldType(0).PtrTo()> [0] dst) + f0 mem)) +(Store dst (StructMake3 <t> f0 f1 f2) mem) => + (Store {t.FieldType(2)} + (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] dst) + f2 + (Store {t.FieldType(1)} + (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) + f1 + (Store {t.FieldType(0)} + (OffPtr <t.FieldType(0).PtrTo()> [0] dst) + f0 mem))) +(Store dst (StructMake4 <t> f0 f1 f2 f3) mem) => + (Store {t.FieldType(3)} + (OffPtr <t.FieldType(3).PtrTo()> [t.FieldOff(3)] dst) + f3 + (Store {t.FieldType(2)} + (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] dst) + f2 + (Store {t.FieldType(1)} + (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] dst) + f1 + (Store {t.FieldType(0)} + (OffPtr <t.FieldType(0).PtrTo()> [0] dst) + f0 mem)))) + +// Putting struct{*byte} and similar into direct interfaces. +(IMake _typ (StructMake1 val)) => (IMake _typ val) +(StructSelect [0] (IData x)) => (IData x) + +// un-SSAable values use mem->mem copies +(Store {t} dst (Load src mem) mem) && !fe.CanSSA(t) => + (Move {t} [t.Size()] dst src mem) +(Store {t} dst (Load src mem) (VarDef {x} mem)) && !fe.CanSSA(t) => + (Move {t} [t.Size()] dst src (VarDef {x} mem)) + +// array ops +(ArraySelect (ArrayMake1 x)) => x + +(Load <t> _ _) && t.IsArray() && t.NumElem() == 0 => + (ArrayMake0) + +(Load <t> ptr mem) && t.IsArray() && t.NumElem() == 1 && fe.CanSSA(t) => + (ArrayMake1 (Load <t.Elem()> ptr mem)) + +(Store _ (ArrayMake0) mem) => mem +(Store dst (ArrayMake1 e) mem) => (Store {e.Type} dst e mem) + +// Putting [1]*byte and similar into direct interfaces. +(IMake _typ (ArrayMake1 val)) => (IMake _typ val) +(ArraySelect [0] (IData x)) => (IData x) + +// string ops +// Decomposing StringMake and lowering of StringPtr and StringLen +// happens in a later pass, dec, so that these operations are available +// to other passes for optimizations. +(StringPtr (StringMake (Addr <t> {s} base) _)) => (Addr <t> {s} base) +(StringLen (StringMake _ (Const64 <t> [c]))) => (Const64 <t> [c]) +(ConstString {str}) && config.PtrSize == 4 && str == "" => + (StringMake (ConstNil) (Const32 <typ.Int> [0])) +(ConstString {str}) && config.PtrSize == 8 && str == "" => + (StringMake (ConstNil) (Const64 <typ.Int> [0])) +(ConstString {str}) && config.PtrSize == 4 && str != "" => + (StringMake + (Addr <typ.BytePtr> {fe.StringData(str)} + (SB)) + (Const32 <typ.Int> [int32(len(str))])) +(ConstString {str}) && config.PtrSize == 8 && str != "" => + (StringMake + (Addr <typ.BytePtr> {fe.StringData(str)} + (SB)) + (Const64 <typ.Int> [int64(len(str))])) + +// slice ops +// Only a few slice rules are provided here. See dec.rules for +// a more comprehensive set. +(SliceLen (SliceMake _ (Const64 <t> [c]) _)) => (Const64 <t> [c]) +(SliceCap (SliceMake _ _ (Const64 <t> [c]))) => (Const64 <t> [c]) +(SliceLen (SliceMake _ (Const32 <t> [c]) _)) => (Const32 <t> [c]) +(SliceCap (SliceMake _ _ (Const32 <t> [c]))) => (Const32 <t> [c]) +(SlicePtr (SliceMake (SlicePtr x) _ _)) => (SlicePtr x) +(SliceLen (SliceMake _ (SliceLen x) _)) => (SliceLen x) +(SliceCap (SliceMake _ _ (SliceCap x))) => (SliceCap x) +(SliceCap (SliceMake _ _ (SliceLen x))) => (SliceLen x) +(ConstSlice) && config.PtrSize == 4 => + (SliceMake + (ConstNil <v.Type.Elem().PtrTo()>) + (Const32 <typ.Int> [0]) + (Const32 <typ.Int> [0])) +(ConstSlice) && config.PtrSize == 8 => + (SliceMake + (ConstNil <v.Type.Elem().PtrTo()>) + (Const64 <typ.Int> [0]) + (Const64 <typ.Int> [0])) + +// interface ops +(ConstInterface) => + (IMake + (ConstNil <typ.Uintptr>) + (ConstNil <typ.BytePtr>)) + +(NilCheck (GetG mem) mem) => mem + +(If (Not cond) yes no) => (If cond no yes) +(If (ConstBool [c]) yes no) && c => (First yes no) +(If (ConstBool [c]) yes no) && !c => (First no yes) + +// Get rid of Convert ops for pointer arithmetic on unsafe.Pointer. +(Convert (Add(64|32) (Convert ptr mem) off) mem) => (AddPtr ptr off) +(Convert (Convert ptr mem) mem) => ptr + +// strength reduction of divide by a constant. +// See ../magic.go for a detailed description of these algorithms. + +// Unsigned divide by power of 2. Strength reduce to a shift. +(Div8u n (Const8 [c])) && isPowerOfTwo8(c) => (Rsh8Ux64 n (Const64 <typ.UInt64> [log8(c)])) +(Div16u n (Const16 [c])) && isPowerOfTwo16(c) => (Rsh16Ux64 n (Const64 <typ.UInt64> [log16(c)])) +(Div32u n (Const32 [c])) && isPowerOfTwo32(c) => (Rsh32Ux64 n (Const64 <typ.UInt64> [log32(c)])) +(Div64u n (Const64 [c])) && isPowerOfTwo64(c) => (Rsh64Ux64 n (Const64 <typ.UInt64> [log64(c)])) +(Div64u n (Const64 [-1<<63])) => (Rsh64Ux64 n (Const64 <typ.UInt64> [63])) + +// Signed non-negative divide by power of 2. +(Div8 n (Const8 [c])) && isNonNegative(n) && isPowerOfTwo8(c) => (Rsh8Ux64 n (Const64 <typ.UInt64> [log8(c)])) +(Div16 n (Const16 [c])) && isNonNegative(n) && isPowerOfTwo16(c) => (Rsh16Ux64 n (Const64 <typ.UInt64> [log16(c)])) +(Div32 n (Const32 [c])) && isNonNegative(n) && isPowerOfTwo32(c) => (Rsh32Ux64 n (Const64 <typ.UInt64> [log32(c)])) +(Div64 n (Const64 [c])) && isNonNegative(n) && isPowerOfTwo64(c) => (Rsh64Ux64 n (Const64 <typ.UInt64> [log64(c)])) +(Div64 n (Const64 [-1<<63])) && isNonNegative(n) => (Const64 [0]) + +// Unsigned divide, not a power of 2. Strength reduce to a multiply. +// For 8-bit divides, we just do a direct 9-bit by 8-bit multiply. +(Div8u x (Const8 [c])) && umagicOK8(c) => + (Trunc32to8 + (Rsh32Ux64 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(1<<8+umagic8(c).m)]) + (ZeroExt8to32 x)) + (Const64 <typ.UInt64> [8+umagic8(c).s]))) + +// For 16-bit divides on 64-bit machines, we do a direct 17-bit by 16-bit multiply. +(Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 8 => + (Trunc64to16 + (Rsh64Ux64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(1<<16+umagic16(c).m)]) + (ZeroExt16to64 x)) + (Const64 <typ.UInt64> [16+umagic16(c).s]))) + +// For 16-bit divides on 32-bit machines +(Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 4 && umagic16(c).m&1 == 0 => + (Trunc32to16 + (Rsh32Ux64 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(1<<15+umagic16(c).m/2)]) + (ZeroExt16to32 x)) + (Const64 <typ.UInt64> [16+umagic16(c).s-1]))) +(Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 4 && c&1 == 0 => + (Trunc32to16 + (Rsh32Ux64 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(1<<15+(umagic16(c).m+1)/2)]) + (Rsh32Ux64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [1]))) + (Const64 <typ.UInt64> [16+umagic16(c).s-2]))) +(Div16u x (Const16 [c])) && umagicOK16(c) && config.RegSize == 4 && config.useAvg => + (Trunc32to16 + (Rsh32Ux64 <typ.UInt32> + (Avg32u + (Lsh32x64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [16])) + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(umagic16(c).m)]) + (ZeroExt16to32 x))) + (Const64 <typ.UInt64> [16+umagic16(c).s-1]))) + +// For 32-bit divides on 32-bit machines +(Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 4 && umagic32(c).m&1 == 0 && config.useHmul => + (Rsh32Ux64 <typ.UInt32> + (Hmul32u <typ.UInt32> + (Const32 <typ.UInt32> [int32(1<<31+umagic32(c).m/2)]) + x) + (Const64 <typ.UInt64> [umagic32(c).s-1])) +(Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 4 && c&1 == 0 && config.useHmul => + (Rsh32Ux64 <typ.UInt32> + (Hmul32u <typ.UInt32> + (Const32 <typ.UInt32> [int32(1<<31+(umagic32(c).m+1)/2)]) + (Rsh32Ux64 <typ.UInt32> x (Const64 <typ.UInt64> [1]))) + (Const64 <typ.UInt64> [umagic32(c).s-2])) +(Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 4 && config.useAvg && config.useHmul => + (Rsh32Ux64 <typ.UInt32> + (Avg32u + x + (Hmul32u <typ.UInt32> + (Const32 <typ.UInt32> [int32(umagic32(c).m)]) + x)) + (Const64 <typ.UInt64> [umagic32(c).s-1])) + +// For 32-bit divides on 64-bit machines +// We'll use a regular (non-hi) multiply for this case. +(Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 8 && umagic32(c).m&1 == 0 => + (Trunc64to32 + (Rsh64Ux64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(1<<31+umagic32(c).m/2)]) + (ZeroExt32to64 x)) + (Const64 <typ.UInt64> [32+umagic32(c).s-1]))) +(Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 8 && c&1 == 0 => + (Trunc64to32 + (Rsh64Ux64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(1<<31+(umagic32(c).m+1)/2)]) + (Rsh64Ux64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [1]))) + (Const64 <typ.UInt64> [32+umagic32(c).s-2]))) +(Div32u x (Const32 [c])) && umagicOK32(c) && config.RegSize == 8 && config.useAvg => + (Trunc64to32 + (Rsh64Ux64 <typ.UInt64> + (Avg64u + (Lsh64x64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [32])) + (Mul64 <typ.UInt64> + (Const64 <typ.UInt32> [int64(umagic32(c).m)]) + (ZeroExt32to64 x))) + (Const64 <typ.UInt64> [32+umagic32(c).s-1]))) + +// For unsigned 64-bit divides on 32-bit machines, +// if the constant fits in 16 bits (so that the last term +// fits in 32 bits), convert to three 32-bit divides by a constant. +// +// If 1<<32 = Q * c + R +// and x = hi << 32 + lo +// +// Then x = (hi/c*c + hi%c) << 32 + lo +// = hi/c*c<<32 + hi%c<<32 + lo +// = hi/c*c<<32 + (hi%c)*(Q*c+R) + lo/c*c + lo%c +// = hi/c*c<<32 + (hi%c)*Q*c + lo/c*c + (hi%c*R+lo%c) +// and x / c = (hi/c)<<32 + (hi%c)*Q + lo/c + (hi%c*R+lo%c)/c +(Div64u x (Const64 [c])) && c > 0 && c <= 0xFFFF && umagicOK32(int32(c)) && config.RegSize == 4 && config.useHmul => + (Add64 + (Add64 <typ.UInt64> + (Add64 <typ.UInt64> + (Lsh64x64 <typ.UInt64> + (ZeroExt32to64 + (Div32u <typ.UInt32> + (Trunc64to32 <typ.UInt32> (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [32]))) + (Const32 <typ.UInt32> [int32(c)]))) + (Const64 <typ.UInt64> [32])) + (ZeroExt32to64 (Div32u <typ.UInt32> (Trunc64to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(c)])))) + (Mul64 <typ.UInt64> + (ZeroExt32to64 <typ.UInt64> + (Mod32u <typ.UInt32> + (Trunc64to32 <typ.UInt32> (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [32]))) + (Const32 <typ.UInt32> [int32(c)]))) + (Const64 <typ.UInt64> [int64((1<<32)/c)]))) + (ZeroExt32to64 + (Div32u <typ.UInt32> + (Add32 <typ.UInt32> + (Mod32u <typ.UInt32> (Trunc64to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(c)])) + (Mul32 <typ.UInt32> + (Mod32u <typ.UInt32> + (Trunc64to32 <typ.UInt32> (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [32]))) + (Const32 <typ.UInt32> [int32(c)])) + (Const32 <typ.UInt32> [int32((1<<32)%c)]))) + (Const32 <typ.UInt32> [int32(c)])))) + +// For 64-bit divides on 64-bit machines +// (64-bit divides on 32-bit machines are lowered to a runtime call by the walk pass.) +(Div64u x (Const64 [c])) && umagicOK64(c) && config.RegSize == 8 && umagic64(c).m&1 == 0 && config.useHmul => + (Rsh64Ux64 <typ.UInt64> + (Hmul64u <typ.UInt64> + (Const64 <typ.UInt64> [int64(1<<63+umagic64(c).m/2)]) + x) + (Const64 <typ.UInt64> [umagic64(c).s-1])) +(Div64u x (Const64 [c])) && umagicOK64(c) && config.RegSize == 8 && c&1 == 0 && config.useHmul => + (Rsh64Ux64 <typ.UInt64> + (Hmul64u <typ.UInt64> + (Const64 <typ.UInt64> [int64(1<<63+(umagic64(c).m+1)/2)]) + (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [1]))) + (Const64 <typ.UInt64> [umagic64(c).s-2])) +(Div64u x (Const64 [c])) && umagicOK64(c) && config.RegSize == 8 && config.useAvg && config.useHmul => + (Rsh64Ux64 <typ.UInt64> + (Avg64u + x + (Hmul64u <typ.UInt64> + (Const64 <typ.UInt64> [int64(umagic64(c).m)]) + x)) + (Const64 <typ.UInt64> [umagic64(c).s-1])) + +// Signed divide by a negative constant. Rewrite to divide by a positive constant. +(Div8 <t> n (Const8 [c])) && c < 0 && c != -1<<7 => (Neg8 (Div8 <t> n (Const8 <t> [-c]))) +(Div16 <t> n (Const16 [c])) && c < 0 && c != -1<<15 => (Neg16 (Div16 <t> n (Const16 <t> [-c]))) +(Div32 <t> n (Const32 [c])) && c < 0 && c != -1<<31 => (Neg32 (Div32 <t> n (Const32 <t> [-c]))) +(Div64 <t> n (Const64 [c])) && c < 0 && c != -1<<63 => (Neg64 (Div64 <t> n (Const64 <t> [-c]))) + +// Dividing by the most-negative number. Result is always 0 except +// if the input is also the most-negative number. +// We can detect that using the sign bit of x & -x. +(Div8 <t> x (Const8 [-1<<7 ])) => (Rsh8Ux64 (And8 <t> x (Neg8 <t> x)) (Const64 <typ.UInt64> [7 ])) +(Div16 <t> x (Const16 [-1<<15])) => (Rsh16Ux64 (And16 <t> x (Neg16 <t> x)) (Const64 <typ.UInt64> [15])) +(Div32 <t> x (Const32 [-1<<31])) => (Rsh32Ux64 (And32 <t> x (Neg32 <t> x)) (Const64 <typ.UInt64> [31])) +(Div64 <t> x (Const64 [-1<<63])) => (Rsh64Ux64 (And64 <t> x (Neg64 <t> x)) (Const64 <typ.UInt64> [63])) + +// Signed divide by power of 2. +// n / c = n >> log(c) if n >= 0 +// = (n+c-1) >> log(c) if n < 0 +// We conditionally add c-1 by adding n>>63>>(64-log(c)) (first shift signed, second shift unsigned). +(Div8 <t> n (Const8 [c])) && isPowerOfTwo8(c) => + (Rsh8x64 + (Add8 <t> n (Rsh8Ux64 <t> (Rsh8x64 <t> n (Const64 <typ.UInt64> [ 7])) (Const64 <typ.UInt64> [int64( 8-log8(c))]))) + (Const64 <typ.UInt64> [int64(log8(c))])) +(Div16 <t> n (Const16 [c])) && isPowerOfTwo16(c) => + (Rsh16x64 + (Add16 <t> n (Rsh16Ux64 <t> (Rsh16x64 <t> n (Const64 <typ.UInt64> [15])) (Const64 <typ.UInt64> [int64(16-log16(c))]))) + (Const64 <typ.UInt64> [int64(log16(c))])) +(Div32 <t> n (Const32 [c])) && isPowerOfTwo32(c) => + (Rsh32x64 + (Add32 <t> n (Rsh32Ux64 <t> (Rsh32x64 <t> n (Const64 <typ.UInt64> [31])) (Const64 <typ.UInt64> [int64(32-log32(c))]))) + (Const64 <typ.UInt64> [int64(log32(c))])) +(Div64 <t> n (Const64 [c])) && isPowerOfTwo64(c) => + (Rsh64x64 + (Add64 <t> n (Rsh64Ux64 <t> (Rsh64x64 <t> n (Const64 <typ.UInt64> [63])) (Const64 <typ.UInt64> [int64(64-log64(c))]))) + (Const64 <typ.UInt64> [int64(log64(c))])) + +// Signed divide, not a power of 2. Strength reduce to a multiply. +(Div8 <t> x (Const8 [c])) && smagicOK8(c) => + (Sub8 <t> + (Rsh32x64 <t> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(smagic8(c).m)]) + (SignExt8to32 x)) + (Const64 <typ.UInt64> [8+smagic8(c).s])) + (Rsh32x64 <t> + (SignExt8to32 x) + (Const64 <typ.UInt64> [31]))) +(Div16 <t> x (Const16 [c])) && smagicOK16(c) => + (Sub16 <t> + (Rsh32x64 <t> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(smagic16(c).m)]) + (SignExt16to32 x)) + (Const64 <typ.UInt64> [16+smagic16(c).s])) + (Rsh32x64 <t> + (SignExt16to32 x) + (Const64 <typ.UInt64> [31]))) +(Div32 <t> x (Const32 [c])) && smagicOK32(c) && config.RegSize == 8 => + (Sub32 <t> + (Rsh64x64 <t> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(smagic32(c).m)]) + (SignExt32to64 x)) + (Const64 <typ.UInt64> [32+smagic32(c).s])) + (Rsh64x64 <t> + (SignExt32to64 x) + (Const64 <typ.UInt64> [63]))) +(Div32 <t> x (Const32 [c])) && smagicOK32(c) && config.RegSize == 4 && smagic32(c).m&1 == 0 && config.useHmul => + (Sub32 <t> + (Rsh32x64 <t> + (Hmul32 <t> + (Const32 <typ.UInt32> [int32(smagic32(c).m/2)]) + x) + (Const64 <typ.UInt64> [smagic32(c).s-1])) + (Rsh32x64 <t> + x + (Const64 <typ.UInt64> [31]))) +(Div32 <t> x (Const32 [c])) && smagicOK32(c) && config.RegSize == 4 && smagic32(c).m&1 != 0 && config.useHmul => + (Sub32 <t> + (Rsh32x64 <t> + (Add32 <t> + (Hmul32 <t> + (Const32 <typ.UInt32> [int32(smagic32(c).m)]) + x) + x) + (Const64 <typ.UInt64> [smagic32(c).s])) + (Rsh32x64 <t> + x + (Const64 <typ.UInt64> [31]))) +(Div64 <t> x (Const64 [c])) && smagicOK64(c) && smagic64(c).m&1 == 0 && config.useHmul => + (Sub64 <t> + (Rsh64x64 <t> + (Hmul64 <t> + (Const64 <typ.UInt64> [int64(smagic64(c).m/2)]) + x) + (Const64 <typ.UInt64> [smagic64(c).s-1])) + (Rsh64x64 <t> + x + (Const64 <typ.UInt64> [63]))) +(Div64 <t> x (Const64 [c])) && smagicOK64(c) && smagic64(c).m&1 != 0 && config.useHmul => + (Sub64 <t> + (Rsh64x64 <t> + (Add64 <t> + (Hmul64 <t> + (Const64 <typ.UInt64> [int64(smagic64(c).m)]) + x) + x) + (Const64 <typ.UInt64> [smagic64(c).s])) + (Rsh64x64 <t> + x + (Const64 <typ.UInt64> [63]))) + +// Unsigned mod by power of 2 constant. +(Mod8u <t> n (Const8 [c])) && isPowerOfTwo8(c) => (And8 n (Const8 <t> [c-1])) +(Mod16u <t> n (Const16 [c])) && isPowerOfTwo16(c) => (And16 n (Const16 <t> [c-1])) +(Mod32u <t> n (Const32 [c])) && isPowerOfTwo32(c) => (And32 n (Const32 <t> [c-1])) +(Mod64u <t> n (Const64 [c])) && isPowerOfTwo64(c) => (And64 n (Const64 <t> [c-1])) +(Mod64u <t> n (Const64 [-1<<63])) => (And64 n (Const64 <t> [1<<63-1])) + +// Signed non-negative mod by power of 2 constant. +(Mod8 <t> n (Const8 [c])) && isNonNegative(n) && isPowerOfTwo8(c) => (And8 n (Const8 <t> [c-1])) +(Mod16 <t> n (Const16 [c])) && isNonNegative(n) && isPowerOfTwo16(c) => (And16 n (Const16 <t> [c-1])) +(Mod32 <t> n (Const32 [c])) && isNonNegative(n) && isPowerOfTwo32(c) => (And32 n (Const32 <t> [c-1])) +(Mod64 <t> n (Const64 [c])) && isNonNegative(n) && isPowerOfTwo64(c) => (And64 n (Const64 <t> [c-1])) +(Mod64 n (Const64 [-1<<63])) && isNonNegative(n) => n + +// Signed mod by negative constant. +(Mod8 <t> n (Const8 [c])) && c < 0 && c != -1<<7 => (Mod8 <t> n (Const8 <t> [-c])) +(Mod16 <t> n (Const16 [c])) && c < 0 && c != -1<<15 => (Mod16 <t> n (Const16 <t> [-c])) +(Mod32 <t> n (Const32 [c])) && c < 0 && c != -1<<31 => (Mod32 <t> n (Const32 <t> [-c])) +(Mod64 <t> n (Const64 [c])) && c < 0 && c != -1<<63 => (Mod64 <t> n (Const64 <t> [-c])) + +// All other mods by constants, do A%B = A-(A/B*B). +// This implements % with two * and a bunch of ancillary ops. +// One of the * is free if the user's code also computes A/B. +(Mod8 <t> x (Const8 [c])) && x.Op != OpConst8 && (c > 0 || c == -1<<7) + => (Sub8 x (Mul8 <t> (Div8 <t> x (Const8 <t> [c])) (Const8 <t> [c]))) +(Mod16 <t> x (Const16 [c])) && x.Op != OpConst16 && (c > 0 || c == -1<<15) + => (Sub16 x (Mul16 <t> (Div16 <t> x (Const16 <t> [c])) (Const16 <t> [c]))) +(Mod32 <t> x (Const32 [c])) && x.Op != OpConst32 && (c > 0 || c == -1<<31) + => (Sub32 x (Mul32 <t> (Div32 <t> x (Const32 <t> [c])) (Const32 <t> [c]))) +(Mod64 <t> x (Const64 [c])) && x.Op != OpConst64 && (c > 0 || c == -1<<63) + => (Sub64 x (Mul64 <t> (Div64 <t> x (Const64 <t> [c])) (Const64 <t> [c]))) +(Mod8u <t> x (Const8 [c])) && x.Op != OpConst8 && c > 0 && umagicOK8( c) + => (Sub8 x (Mul8 <t> (Div8u <t> x (Const8 <t> [c])) (Const8 <t> [c]))) +(Mod16u <t> x (Const16 [c])) && x.Op != OpConst16 && c > 0 && umagicOK16(c) + => (Sub16 x (Mul16 <t> (Div16u <t> x (Const16 <t> [c])) (Const16 <t> [c]))) +(Mod32u <t> x (Const32 [c])) && x.Op != OpConst32 && c > 0 && umagicOK32(c) + => (Sub32 x (Mul32 <t> (Div32u <t> x (Const32 <t> [c])) (Const32 <t> [c]))) +(Mod64u <t> x (Const64 [c])) && x.Op != OpConst64 && c > 0 && umagicOK64(c) + => (Sub64 x (Mul64 <t> (Div64u <t> x (Const64 <t> [c])) (Const64 <t> [c]))) + +// For architectures without rotates on less than 32-bits, promote these checks to 32-bit. +(Eq8 (Mod8u x (Const8 [c])) (Const8 [0])) && x.Op != OpConst8 && udivisibleOK8(c) && !hasSmallRotate(config) => + (Eq32 (Mod32u <typ.UInt32> (ZeroExt8to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(uint8(c))])) (Const32 <typ.UInt32> [0])) +(Eq16 (Mod16u x (Const16 [c])) (Const16 [0])) && x.Op != OpConst16 && udivisibleOK16(c) && !hasSmallRotate(config) => + (Eq32 (Mod32u <typ.UInt32> (ZeroExt16to32 <typ.UInt32> x) (Const32 <typ.UInt32> [int32(uint16(c))])) (Const32 <typ.UInt32> [0])) +(Eq8 (Mod8 x (Const8 [c])) (Const8 [0])) && x.Op != OpConst8 && sdivisibleOK8(c) && !hasSmallRotate(config) => + (Eq32 (Mod32 <typ.Int32> (SignExt8to32 <typ.Int32> x) (Const32 <typ.Int32> [int32(c)])) (Const32 <typ.Int32> [0])) +(Eq16 (Mod16 x (Const16 [c])) (Const16 [0])) && x.Op != OpConst16 && sdivisibleOK16(c) && !hasSmallRotate(config) => + (Eq32 (Mod32 <typ.Int32> (SignExt16to32 <typ.Int32> x) (Const32 <typ.Int32> [int32(c)])) (Const32 <typ.Int32> [0])) + +// Divisibility checks x%c == 0 convert to multiply and rotate. +// Note, x%c == 0 is rewritten as x == c*(x/c) during the opt pass +// where (x/c) is performed using multiplication with magic constants. +// To rewrite x%c == 0 requires pattern matching the rewritten expression +// and checking that the division by the same constant wasn't already calculated. +// This check is made by counting uses of the magic constant multiplication. +// Note that if there were an intermediate opt pass, this rule could be applied +// directly on the Div op and magic division rewrites could be delayed to late opt. + +// Unsigned divisibility checks convert to multiply and rotate. +(Eq8 x (Mul8 (Const8 [c]) + (Trunc32to8 + (Rsh32Ux64 + mul:(Mul32 + (Const32 [m]) + (ZeroExt8to32 x)) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(1<<8+umagic8(c).m) && s == 8+umagic8(c).s + && x.Op != OpConst8 && udivisibleOK8(c) + => (Leq8U + (RotateLeft8 <typ.UInt8> + (Mul8 <typ.UInt8> + (Const8 <typ.UInt8> [int8(udivisible8(c).m)]) + x) + (Const8 <typ.UInt8> [int8(8-udivisible8(c).k)]) + ) + (Const8 <typ.UInt8> [int8(udivisible8(c).max)]) + ) + +(Eq16 x (Mul16 (Const16 [c]) + (Trunc64to16 + (Rsh64Ux64 + mul:(Mul64 + (Const64 [m]) + (ZeroExt16to64 x)) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(1<<16+umagic16(c).m) && s == 16+umagic16(c).s + && x.Op != OpConst16 && udivisibleOK16(c) + => (Leq16U + (RotateLeft16 <typ.UInt16> + (Mul16 <typ.UInt16> + (Const16 <typ.UInt16> [int16(udivisible16(c).m)]) + x) + (Const16 <typ.UInt16> [int16(16-udivisible16(c).k)]) + ) + (Const16 <typ.UInt16> [int16(udivisible16(c).max)]) + ) + +(Eq16 x (Mul16 (Const16 [c]) + (Trunc32to16 + (Rsh32Ux64 + mul:(Mul32 + (Const32 [m]) + (ZeroExt16to32 x)) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(1<<15+umagic16(c).m/2) && s == 16+umagic16(c).s-1 + && x.Op != OpConst16 && udivisibleOK16(c) + => (Leq16U + (RotateLeft16 <typ.UInt16> + (Mul16 <typ.UInt16> + (Const16 <typ.UInt16> [int16(udivisible16(c).m)]) + x) + (Const16 <typ.UInt16> [int16(16-udivisible16(c).k)]) + ) + (Const16 <typ.UInt16> [int16(udivisible16(c).max)]) + ) + +(Eq16 x (Mul16 (Const16 [c]) + (Trunc32to16 + (Rsh32Ux64 + mul:(Mul32 + (Const32 [m]) + (Rsh32Ux64 (ZeroExt16to32 x) (Const64 [1]))) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(1<<15+(umagic16(c).m+1)/2) && s == 16+umagic16(c).s-2 + && x.Op != OpConst16 && udivisibleOK16(c) + => (Leq16U + (RotateLeft16 <typ.UInt16> + (Mul16 <typ.UInt16> + (Const16 <typ.UInt16> [int16(udivisible16(c).m)]) + x) + (Const16 <typ.UInt16> [int16(16-udivisible16(c).k)]) + ) + (Const16 <typ.UInt16> [int16(udivisible16(c).max)]) + ) + +(Eq16 x (Mul16 (Const16 [c]) + (Trunc32to16 + (Rsh32Ux64 + (Avg32u + (Lsh32x64 (ZeroExt16to32 x) (Const64 [16])) + mul:(Mul32 + (Const32 [m]) + (ZeroExt16to32 x))) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(umagic16(c).m) && s == 16+umagic16(c).s-1 + && x.Op != OpConst16 && udivisibleOK16(c) + => (Leq16U + (RotateLeft16 <typ.UInt16> + (Mul16 <typ.UInt16> + (Const16 <typ.UInt16> [int16(udivisible16(c).m)]) + x) + (Const16 <typ.UInt16> [int16(16-udivisible16(c).k)]) + ) + (Const16 <typ.UInt16> [int16(udivisible16(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Rsh32Ux64 + mul:(Hmul32u + (Const32 [m]) + x) + (Const64 [s])) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(1<<31+umagic32(c).m/2) && s == umagic32(c).s-1 + && x.Op != OpConst32 && udivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(udivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(32-udivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(udivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Rsh32Ux64 + mul:(Hmul32u + (Const32 <typ.UInt32> [m]) + (Rsh32Ux64 x (Const64 [1]))) + (Const64 [s])) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(1<<31+(umagic32(c).m+1)/2) && s == umagic32(c).s-2 + && x.Op != OpConst32 && udivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(udivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(32-udivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(udivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Rsh32Ux64 + (Avg32u + x + mul:(Hmul32u + (Const32 [m]) + x)) + (Const64 [s])) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(umagic32(c).m) && s == umagic32(c).s-1 + && x.Op != OpConst32 && udivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(udivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(32-udivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(udivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Trunc64to32 + (Rsh64Ux64 + mul:(Mul64 + (Const64 [m]) + (ZeroExt32to64 x)) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(1<<31+umagic32(c).m/2) && s == 32+umagic32(c).s-1 + && x.Op != OpConst32 && udivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(udivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(32-udivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(udivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Trunc64to32 + (Rsh64Ux64 + mul:(Mul64 + (Const64 [m]) + (Rsh64Ux64 (ZeroExt32to64 x) (Const64 [1]))) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(1<<31+(umagic32(c).m+1)/2) && s == 32+umagic32(c).s-2 + && x.Op != OpConst32 && udivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(udivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(32-udivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(udivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Trunc64to32 + (Rsh64Ux64 + (Avg64u + (Lsh64x64 (ZeroExt32to64 x) (Const64 [32])) + mul:(Mul64 + (Const64 [m]) + (ZeroExt32to64 x))) + (Const64 [s]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(umagic32(c).m) && s == 32+umagic32(c).s-1 + && x.Op != OpConst32 && udivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(udivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(32-udivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(udivisible32(c).max)]) + ) + +(Eq64 x (Mul64 (Const64 [c]) + (Rsh64Ux64 + mul:(Hmul64u + (Const64 [m]) + x) + (Const64 [s])) + ) +) && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(1<<63+umagic64(c).m/2) && s == umagic64(c).s-1 + && x.Op != OpConst64 && udivisibleOK64(c) + => (Leq64U + (RotateLeft64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(udivisible64(c).m)]) + x) + (Const64 <typ.UInt64> [64-udivisible64(c).k]) + ) + (Const64 <typ.UInt64> [int64(udivisible64(c).max)]) + ) +(Eq64 x (Mul64 (Const64 [c]) + (Rsh64Ux64 + mul:(Hmul64u + (Const64 [m]) + (Rsh64Ux64 x (Const64 [1]))) + (Const64 [s])) + ) +) && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(1<<63+(umagic64(c).m+1)/2) && s == umagic64(c).s-2 + && x.Op != OpConst64 && udivisibleOK64(c) + => (Leq64U + (RotateLeft64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(udivisible64(c).m)]) + x) + (Const64 <typ.UInt64> [64-udivisible64(c).k]) + ) + (Const64 <typ.UInt64> [int64(udivisible64(c).max)]) + ) +(Eq64 x (Mul64 (Const64 [c]) + (Rsh64Ux64 + (Avg64u + x + mul:(Hmul64u + (Const64 [m]) + x)) + (Const64 [s])) + ) +) && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(umagic64(c).m) && s == umagic64(c).s-1 + && x.Op != OpConst64 && udivisibleOK64(c) + => (Leq64U + (RotateLeft64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(udivisible64(c).m)]) + x) + (Const64 <typ.UInt64> [64-udivisible64(c).k]) + ) + (Const64 <typ.UInt64> [int64(udivisible64(c).max)]) + ) + +// Signed divisibility checks convert to multiply, add and rotate. +(Eq8 x (Mul8 (Const8 [c]) + (Sub8 + (Rsh32x64 + mul:(Mul32 + (Const32 [m]) + (SignExt8to32 x)) + (Const64 [s])) + (Rsh32x64 + (SignExt8to32 x) + (Const64 [31]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(smagic8(c).m) && s == 8+smagic8(c).s + && x.Op != OpConst8 && sdivisibleOK8(c) + => (Leq8U + (RotateLeft8 <typ.UInt8> + (Add8 <typ.UInt8> + (Mul8 <typ.UInt8> + (Const8 <typ.UInt8> [int8(sdivisible8(c).m)]) + x) + (Const8 <typ.UInt8> [int8(sdivisible8(c).a)]) + ) + (Const8 <typ.UInt8> [int8(8-sdivisible8(c).k)]) + ) + (Const8 <typ.UInt8> [int8(sdivisible8(c).max)]) + ) + +(Eq16 x (Mul16 (Const16 [c]) + (Sub16 + (Rsh32x64 + mul:(Mul32 + (Const32 [m]) + (SignExt16to32 x)) + (Const64 [s])) + (Rsh32x64 + (SignExt16to32 x) + (Const64 [31]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(smagic16(c).m) && s == 16+smagic16(c).s + && x.Op != OpConst16 && sdivisibleOK16(c) + => (Leq16U + (RotateLeft16 <typ.UInt16> + (Add16 <typ.UInt16> + (Mul16 <typ.UInt16> + (Const16 <typ.UInt16> [int16(sdivisible16(c).m)]) + x) + (Const16 <typ.UInt16> [int16(sdivisible16(c).a)]) + ) + (Const16 <typ.UInt16> [int16(16-sdivisible16(c).k)]) + ) + (Const16 <typ.UInt16> [int16(sdivisible16(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Sub32 + (Rsh64x64 + mul:(Mul64 + (Const64 [m]) + (SignExt32to64 x)) + (Const64 [s])) + (Rsh64x64 + (SignExt32to64 x) + (Const64 [63]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(smagic32(c).m) && s == 32+smagic32(c).s + && x.Op != OpConst32 && sdivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Add32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(sdivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(sdivisible32(c).a)]) + ) + (Const32 <typ.UInt32> [int32(32-sdivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(sdivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Sub32 + (Rsh32x64 + mul:(Hmul32 + (Const32 [m]) + x) + (Const64 [s])) + (Rsh32x64 + x + (Const64 [31]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(smagic32(c).m/2) && s == smagic32(c).s-1 + && x.Op != OpConst32 && sdivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Add32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(sdivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(sdivisible32(c).a)]) + ) + (Const32 <typ.UInt32> [int32(32-sdivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(sdivisible32(c).max)]) + ) + +(Eq32 x (Mul32 (Const32 [c]) + (Sub32 + (Rsh32x64 + (Add32 + mul:(Hmul32 + (Const32 [m]) + x) + x) + (Const64 [s])) + (Rsh32x64 + x + (Const64 [31]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int32(smagic32(c).m) && s == smagic32(c).s + && x.Op != OpConst32 && sdivisibleOK32(c) + => (Leq32U + (RotateLeft32 <typ.UInt32> + (Add32 <typ.UInt32> + (Mul32 <typ.UInt32> + (Const32 <typ.UInt32> [int32(sdivisible32(c).m)]) + x) + (Const32 <typ.UInt32> [int32(sdivisible32(c).a)]) + ) + (Const32 <typ.UInt32> [int32(32-sdivisible32(c).k)]) + ) + (Const32 <typ.UInt32> [int32(sdivisible32(c).max)]) + ) + +(Eq64 x (Mul64 (Const64 [c]) + (Sub64 + (Rsh64x64 + mul:(Hmul64 + (Const64 [m]) + x) + (Const64 [s])) + (Rsh64x64 + x + (Const64 [63]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(smagic64(c).m/2) && s == smagic64(c).s-1 + && x.Op != OpConst64 && sdivisibleOK64(c) + => (Leq64U + (RotateLeft64 <typ.UInt64> + (Add64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(sdivisible64(c).m)]) + x) + (Const64 <typ.UInt64> [int64(sdivisible64(c).a)]) + ) + (Const64 <typ.UInt64> [64-sdivisible64(c).k]) + ) + (Const64 <typ.UInt64> [int64(sdivisible64(c).max)]) + ) + +(Eq64 x (Mul64 (Const64 [c]) + (Sub64 + (Rsh64x64 + (Add64 + mul:(Hmul64 + (Const64 [m]) + x) + x) + (Const64 [s])) + (Rsh64x64 + x + (Const64 [63]))) + ) +) + && v.Block.Func.pass.name != "opt" && mul.Uses == 1 + && m == int64(smagic64(c).m) && s == smagic64(c).s + && x.Op != OpConst64 && sdivisibleOK64(c) + => (Leq64U + (RotateLeft64 <typ.UInt64> + (Add64 <typ.UInt64> + (Mul64 <typ.UInt64> + (Const64 <typ.UInt64> [int64(sdivisible64(c).m)]) + x) + (Const64 <typ.UInt64> [int64(sdivisible64(c).a)]) + ) + (Const64 <typ.UInt64> [64-sdivisible64(c).k]) + ) + (Const64 <typ.UInt64> [int64(sdivisible64(c).max)]) + ) + +// Divisibility check for signed integers for power of two constant are simple mask. +// However, we must match against the rewritten n%c == 0 -> n - c*(n/c) == 0 -> n == c*(n/c) +// where n/c contains fixup code to handle signed n. +((Eq8|Neq8) n (Lsh8x64 + (Rsh8x64 + (Add8 <t> n (Rsh8Ux64 <t> (Rsh8x64 <t> n (Const64 <typ.UInt64> [ 7])) (Const64 <typ.UInt64> [kbar]))) + (Const64 <typ.UInt64> [k])) + (Const64 <typ.UInt64> [k])) +) && k > 0 && k < 7 && kbar == 8 - k + => ((Eq8|Neq8) (And8 <t> n (Const8 <t> [1<<uint(k)-1])) (Const8 <t> [0])) + +((Eq16|Neq16) n (Lsh16x64 + (Rsh16x64 + (Add16 <t> n (Rsh16Ux64 <t> (Rsh16x64 <t> n (Const64 <typ.UInt64> [15])) (Const64 <typ.UInt64> [kbar]))) + (Const64 <typ.UInt64> [k])) + (Const64 <typ.UInt64> [k])) +) && k > 0 && k < 15 && kbar == 16 - k + => ((Eq16|Neq16) (And16 <t> n (Const16 <t> [1<<uint(k)-1])) (Const16 <t> [0])) + +((Eq32|Neq32) n (Lsh32x64 + (Rsh32x64 + (Add32 <t> n (Rsh32Ux64 <t> (Rsh32x64 <t> n (Const64 <typ.UInt64> [31])) (Const64 <typ.UInt64> [kbar]))) + (Const64 <typ.UInt64> [k])) + (Const64 <typ.UInt64> [k])) +) && k > 0 && k < 31 && kbar == 32 - k + => ((Eq32|Neq32) (And32 <t> n (Const32 <t> [1<<uint(k)-1])) (Const32 <t> [0])) + +((Eq64|Neq64) n (Lsh64x64 + (Rsh64x64 + (Add64 <t> n (Rsh64Ux64 <t> (Rsh64x64 <t> n (Const64 <typ.UInt64> [63])) (Const64 <typ.UInt64> [kbar]))) + (Const64 <typ.UInt64> [k])) + (Const64 <typ.UInt64> [k])) +) && k > 0 && k < 63 && kbar == 64 - k + => ((Eq64|Neq64) (And64 <t> n (Const64 <t> [1<<uint(k)-1])) (Const64 <t> [0])) + +(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) +(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) + +// Optimize bitsets +(Eq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [y])) && oneBit8(y) + => (Neq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [0])) +(Eq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [y])) && oneBit16(y) + => (Neq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [0])) +(Eq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [y])) && oneBit32(y) + => (Neq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [0])) +(Eq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [y])) && oneBit64(y) + => (Neq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [0])) +(Neq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [y])) && oneBit8(y) + => (Eq8 (And8 <t> x (Const8 <t> [y])) (Const8 <t> [0])) +(Neq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [y])) && oneBit16(y) + => (Eq16 (And16 <t> x (Const16 <t> [y])) (Const16 <t> [0])) +(Neq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [y])) && oneBit32(y) + => (Eq32 (And32 <t> x (Const32 <t> [y])) (Const32 <t> [0])) +(Neq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [y])) && oneBit64(y) + => (Eq64 (And64 <t> x (Const64 <t> [y])) (Const64 <t> [0])) + +// Reassociate expressions involving +// constants such that constants come first, +// exposing obvious constant-folding opportunities. +// Reassociate (op (op y C) x) to (op C (op x y)) or similar, where C +// is constant, which pushes constants to the outside +// of the expression. At that point, any constant-folding +// opportunities should be obvious. +// Note: don't include AddPtr here! In order to maintain the +// invariant that pointers must stay within the pointed-to object, +// we can't pull part of a pointer computation above the AddPtr. +// See issue 37881. +// Note: we don't need to handle any (x-C) cases because we already rewrite +// (x-C) to (x+(-C)). + +// x + (C + z) -> C + (x + z) +(Add64 (Add64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Add64 i (Add64 <t> z x)) +(Add32 (Add32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Add32 i (Add32 <t> z x)) +(Add16 (Add16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Add16 i (Add16 <t> z x)) +(Add8 (Add8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Add8 i (Add8 <t> z x)) + +// x + (C - z) -> C + (x - z) +(Add64 (Sub64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Add64 i (Sub64 <t> x z)) +(Add32 (Sub32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Add32 i (Sub32 <t> x z)) +(Add16 (Sub16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Add16 i (Sub16 <t> x z)) +(Add8 (Sub8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Add8 i (Sub8 <t> x z)) + +// x - (C - z) -> x + (z - C) -> (x + z) - C +(Sub64 x (Sub64 i:(Const64 <t>) z)) && (z.Op != OpConst64 && x.Op != OpConst64) => (Sub64 (Add64 <t> x z) i) +(Sub32 x (Sub32 i:(Const32 <t>) z)) && (z.Op != OpConst32 && x.Op != OpConst32) => (Sub32 (Add32 <t> x z) i) +(Sub16 x (Sub16 i:(Const16 <t>) z)) && (z.Op != OpConst16 && x.Op != OpConst16) => (Sub16 (Add16 <t> x z) i) +(Sub8 x (Sub8 i:(Const8 <t>) z)) && (z.Op != OpConst8 && x.Op != OpConst8) => (Sub8 (Add8 <t> x z) i) + +// x - (z + C) -> x + (-z - C) -> (x - z) - C +(Sub64 x (Add64 z i:(Const64 <t>))) && (z.Op != OpConst64 && x.Op != OpConst64) => (Sub64 (Sub64 <t> x z) i) +(Sub32 x (Add32 z i:(Const32 <t>))) && (z.Op != OpConst32 && x.Op != OpConst32) => (Sub32 (Sub32 <t> x z) i) +(Sub16 x (Add16 z i:(Const16 <t>))) && (z.Op != OpConst16 && x.Op != OpConst16) => (Sub16 (Sub16 <t> x z) i) +(Sub8 x (Add8 z i:(Const8 <t>))) && (z.Op != OpConst8 && x.Op != OpConst8) => (Sub8 (Sub8 <t> x z) i) + +// (C - z) - x -> C - (z + x) +(Sub64 (Sub64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Sub64 i (Add64 <t> z x)) +(Sub32 (Sub32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Sub32 i (Add32 <t> z x)) +(Sub16 (Sub16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Sub16 i (Add16 <t> z x)) +(Sub8 (Sub8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Sub8 i (Add8 <t> z x)) + +// (z + C) -x -> C + (z - x) +(Sub64 (Add64 z i:(Const64 <t>)) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Add64 i (Sub64 <t> z x)) +(Sub32 (Add32 z i:(Const32 <t>)) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Add32 i (Sub32 <t> z x)) +(Sub16 (Add16 z i:(Const16 <t>)) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Add16 i (Sub16 <t> z x)) +(Sub8 (Add8 z i:(Const8 <t>)) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Add8 i (Sub8 <t> z x)) + +// x & (C & z) -> C & (x & z) +(And64 (And64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (And64 i (And64 <t> z x)) +(And32 (And32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (And32 i (And32 <t> z x)) +(And16 (And16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (And16 i (And16 <t> z x)) +(And8 (And8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (And8 i (And8 <t> z x)) + +// x | (C | z) -> C | (x | z) +(Or64 (Or64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Or64 i (Or64 <t> z x)) +(Or32 (Or32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Or32 i (Or32 <t> z x)) +(Or16 (Or16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Or16 i (Or16 <t> z x)) +(Or8 (Or8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Or8 i (Or8 <t> z x)) + +// x ^ (C ^ z) -> C ^ (x ^ z) +(Xor64 (Xor64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Xor64 i (Xor64 <t> z x)) +(Xor32 (Xor32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Xor32 i (Xor32 <t> z x)) +(Xor16 (Xor16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Xor16 i (Xor16 <t> z x)) +(Xor8 (Xor8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Xor8 i (Xor8 <t> z x)) + +// x * (D * z) = D * (x * z) +(Mul64 (Mul64 i:(Const64 <t>) z) x) && (z.Op != OpConst64 && x.Op != OpConst64) => (Mul64 i (Mul64 <t> x z)) +(Mul32 (Mul32 i:(Const32 <t>) z) x) && (z.Op != OpConst32 && x.Op != OpConst32) => (Mul32 i (Mul32 <t> x z)) +(Mul16 (Mul16 i:(Const16 <t>) z) x) && (z.Op != OpConst16 && x.Op != OpConst16) => (Mul16 i (Mul16 <t> x z)) +(Mul8 (Mul8 i:(Const8 <t>) z) x) && (z.Op != OpConst8 && x.Op != OpConst8) => (Mul8 i (Mul8 <t> x z)) + +// C + (D + x) -> (C + D) + x +(Add64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Add64 (Const64 <t> [c+d]) x) +(Add32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Add32 (Const32 <t> [c+d]) x) +(Add16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Add16 (Const16 <t> [c+d]) x) +(Add8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) => (Add8 (Const8 <t> [c+d]) x) + +// C + (D - x) -> (C + D) - x +(Add64 (Const64 <t> [c]) (Sub64 (Const64 <t> [d]) x)) => (Sub64 (Const64 <t> [c+d]) x) +(Add32 (Const32 <t> [c]) (Sub32 (Const32 <t> [d]) x)) => (Sub32 (Const32 <t> [c+d]) x) +(Add16 (Const16 <t> [c]) (Sub16 (Const16 <t> [d]) x)) => (Sub16 (Const16 <t> [c+d]) x) +(Add8 (Const8 <t> [c]) (Sub8 (Const8 <t> [d]) x)) => (Sub8 (Const8 <t> [c+d]) x) + +// C - (D - x) -> (C - D) + x +(Sub64 (Const64 <t> [c]) (Sub64 (Const64 <t> [d]) x)) => (Add64 (Const64 <t> [c-d]) x) +(Sub32 (Const32 <t> [c]) (Sub32 (Const32 <t> [d]) x)) => (Add32 (Const32 <t> [c-d]) x) +(Sub16 (Const16 <t> [c]) (Sub16 (Const16 <t> [d]) x)) => (Add16 (Const16 <t> [c-d]) x) +(Sub8 (Const8 <t> [c]) (Sub8 (Const8 <t> [d]) x)) => (Add8 (Const8 <t> [c-d]) x) + +// C - (D + x) -> (C - D) - x +(Sub64 (Const64 <t> [c]) (Add64 (Const64 <t> [d]) x)) => (Sub64 (Const64 <t> [c-d]) x) +(Sub32 (Const32 <t> [c]) (Add32 (Const32 <t> [d]) x)) => (Sub32 (Const32 <t> [c-d]) x) +(Sub16 (Const16 <t> [c]) (Add16 (Const16 <t> [d]) x)) => (Sub16 (Const16 <t> [c-d]) x) +(Sub8 (Const8 <t> [c]) (Add8 (Const8 <t> [d]) x)) => (Sub8 (Const8 <t> [c-d]) x) + +// C & (D & x) -> (C & D) & x +(And64 (Const64 <t> [c]) (And64 (Const64 <t> [d]) x)) => (And64 (Const64 <t> [c&d]) x) +(And32 (Const32 <t> [c]) (And32 (Const32 <t> [d]) x)) => (And32 (Const32 <t> [c&d]) x) +(And16 (Const16 <t> [c]) (And16 (Const16 <t> [d]) x)) => (And16 (Const16 <t> [c&d]) x) +(And8 (Const8 <t> [c]) (And8 (Const8 <t> [d]) x)) => (And8 (Const8 <t> [c&d]) x) + +// C | (D | x) -> (C | D) | x +(Or64 (Const64 <t> [c]) (Or64 (Const64 <t> [d]) x)) => (Or64 (Const64 <t> [c|d]) x) +(Or32 (Const32 <t> [c]) (Or32 (Const32 <t> [d]) x)) => (Or32 (Const32 <t> [c|d]) x) +(Or16 (Const16 <t> [c]) (Or16 (Const16 <t> [d]) x)) => (Or16 (Const16 <t> [c|d]) x) +(Or8 (Const8 <t> [c]) (Or8 (Const8 <t> [d]) x)) => (Or8 (Const8 <t> [c|d]) x) + +// C ^ (D ^ x) -> (C ^ D) ^ x +(Xor64 (Const64 <t> [c]) (Xor64 (Const64 <t> [d]) x)) => (Xor64 (Const64 <t> [c^d]) x) +(Xor32 (Const32 <t> [c]) (Xor32 (Const32 <t> [d]) x)) => (Xor32 (Const32 <t> [c^d]) x) +(Xor16 (Const16 <t> [c]) (Xor16 (Const16 <t> [d]) x)) => (Xor16 (Const16 <t> [c^d]) x) +(Xor8 (Const8 <t> [c]) (Xor8 (Const8 <t> [d]) x)) => (Xor8 (Const8 <t> [c^d]) x) + +// C * (D * x) = (C * D) * x +(Mul64 (Const64 <t> [c]) (Mul64 (Const64 <t> [d]) x)) => (Mul64 (Const64 <t> [c*d]) x) +(Mul32 (Const32 <t> [c]) (Mul32 (Const32 <t> [d]) x)) => (Mul32 (Const32 <t> [c*d]) x) +(Mul16 (Const16 <t> [c]) (Mul16 (Const16 <t> [d]) x)) => (Mul16 (Const16 <t> [c*d]) x) +(Mul8 (Const8 <t> [c]) (Mul8 (Const8 <t> [d]) x)) => (Mul8 (Const8 <t> [c*d]) x) + +// floating point optimizations +(Mul(32|64)F x (Const(32|64)F [1])) => x +(Mul32F x (Const32F [-1])) => (Neg32F x) +(Mul64F x (Const64F [-1])) => (Neg64F x) +(Mul32F x (Const32F [2])) => (Add32F x x) +(Mul64F x (Const64F [2])) => (Add64F x x) + +(Div32F x (Const32F <t> [c])) && reciprocalExact32(c) => (Mul32F x (Const32F <t> [1/c])) +(Div64F x (Const64F <t> [c])) && reciprocalExact64(c) => (Mul64F x (Const64F <t> [1/c])) + +// rewrite single-precision sqrt expression "float32(math.Sqrt(float64(x)))" +(Cvt64Fto32F sqrt0:(Sqrt (Cvt32Fto64F x))) && sqrt0.Uses==1 => (Sqrt32 x) + +(Sqrt (Const64F [c])) && !math.IsNaN(math.Sqrt(c)) => (Const64F [math.Sqrt(c)]) + +// for rewriting results of some late-expanded rewrites (below) +(SelectN [0] (MakeResult x ___)) => x +(SelectN [1] (MakeResult x y ___)) => y +(SelectN [2] (MakeResult x y z ___)) => z + +// for late-expanded calls, recognize newobject and remove zeroing and nilchecks +(Zero (SelectN [0] call:(StaticLECall _ _)) mem:(SelectN [1] call)) + && isSameCall(call.Aux, "runtime.newobject") + => mem + +(Store (SelectN [0] call:(StaticLECall _ _)) x mem:(SelectN [1] call)) + && isConstZero(x) + && isSameCall(call.Aux, "runtime.newobject") + => mem + +(Store (OffPtr (SelectN [0] call:(StaticLECall _ _))) x mem:(SelectN [1] call)) + && isConstZero(x) + && isSameCall(call.Aux, "runtime.newobject") + => mem + +(NilCheck (SelectN [0] call:(StaticLECall _ _)) _) + && isSameCall(call.Aux, "runtime.newobject") + && warnRule(fe.Debug_checknil(), v, "removed nil check") + => (Invalid) + +(NilCheck (OffPtr (SelectN [0] call:(StaticLECall _ _))) _) + && isSameCall(call.Aux, "runtime.newobject") + && warnRule(fe.Debug_checknil(), v, "removed nil check") + => (Invalid) + +// for late-expanded calls, recognize memequal applied to a single constant byte +// Support is limited by 1, 2, 4, 8 byte sizes +(StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [1]) mem) + && isSameCall(callAux, "runtime.memequal") + && symIsRO(scon) + => (MakeResult (Eq8 (Load <typ.Int8> sptr mem) (Const8 <typ.Int8> [int8(read8(scon,0))])) mem) + +(StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [2]) mem) + && isSameCall(callAux, "runtime.memequal") + && symIsRO(scon) + && canLoadUnaligned(config) + => (MakeResult (Eq16 (Load <typ.Int16> sptr mem) (Const16 <typ.Int16> [int16(read16(scon,0,config.ctxt.Arch.ByteOrder))])) mem) + +(StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [4]) mem) + && isSameCall(callAux, "runtime.memequal") + && symIsRO(scon) + && canLoadUnaligned(config) + => (MakeResult (Eq32 (Load <typ.Int32> sptr mem) (Const32 <typ.Int32> [int32(read32(scon,0,config.ctxt.Arch.ByteOrder))])) mem) + +(StaticLECall {callAux} sptr (Addr {scon} (SB)) (Const64 [8]) mem) + && isSameCall(callAux, "runtime.memequal") + && symIsRO(scon) + && canLoadUnaligned(config) && config.PtrSize == 8 + => (MakeResult (Eq64 (Load <typ.Int64> sptr mem) (Const64 <typ.Int64> [int64(read64(scon,0,config.ctxt.Arch.ByteOrder))])) mem) + +// Evaluate constant address comparisons. +(EqPtr x x) => (ConstBool [true]) +(NeqPtr x x) => (ConstBool [false]) +(EqPtr (Addr {x} _) (Addr {y} _)) => (ConstBool [x == y]) +(EqPtr (Addr {x} _) (OffPtr [o] (Addr {y} _))) => (ConstBool [x == y && o == 0]) +(EqPtr (OffPtr [o1] (Addr {x} _)) (OffPtr [o2] (Addr {y} _))) => (ConstBool [x == y && o1 == o2]) +(NeqPtr (Addr {x} _) (Addr {y} _)) => (ConstBool [x != y]) +(NeqPtr (Addr {x} _) (OffPtr [o] (Addr {y} _))) => (ConstBool [x != y || o != 0]) +(NeqPtr (OffPtr [o1] (Addr {x} _)) (OffPtr [o2] (Addr {y} _))) => (ConstBool [x != y || o1 != o2]) +(EqPtr (LocalAddr {x} _ _) (LocalAddr {y} _ _)) => (ConstBool [x == y]) +(EqPtr (LocalAddr {x} _ _) (OffPtr [o] (LocalAddr {y} _ _))) => (ConstBool [x == y && o == 0]) +(EqPtr (OffPtr [o1] (LocalAddr {x} _ _)) (OffPtr [o2] (LocalAddr {y} _ _))) => (ConstBool [x == y && o1 == o2]) +(NeqPtr (LocalAddr {x} _ _) (LocalAddr {y} _ _)) => (ConstBool [x != y]) +(NeqPtr (LocalAddr {x} _ _) (OffPtr [o] (LocalAddr {y} _ _))) => (ConstBool [x != y || o != 0]) +(NeqPtr (OffPtr [o1] (LocalAddr {x} _ _)) (OffPtr [o2] (LocalAddr {y} _ _))) => (ConstBool [x != y || o1 != o2]) +(EqPtr (OffPtr [o1] p1) p2) && isSamePtr(p1, p2) => (ConstBool [o1 == 0]) +(NeqPtr (OffPtr [o1] p1) p2) && isSamePtr(p1, p2) => (ConstBool [o1 != 0]) +(EqPtr (OffPtr [o1] p1) (OffPtr [o2] p2)) && isSamePtr(p1, p2) => (ConstBool [o1 == o2]) +(NeqPtr (OffPtr [o1] p1) (OffPtr [o2] p2)) && isSamePtr(p1, p2) => (ConstBool [o1 != o2]) +(EqPtr (Const(32|64) [c]) (Const(32|64) [d])) => (ConstBool [c == d]) +(NeqPtr (Const(32|64) [c]) (Const(32|64) [d])) => (ConstBool [c != d]) + +(EqPtr (LocalAddr _ _) (Addr _)) => (ConstBool [false]) +(EqPtr (OffPtr (LocalAddr _ _)) (Addr _)) => (ConstBool [false]) +(EqPtr (LocalAddr _ _) (OffPtr (Addr _))) => (ConstBool [false]) +(EqPtr (OffPtr (LocalAddr _ _)) (OffPtr (Addr _))) => (ConstBool [false]) +(NeqPtr (LocalAddr _ _) (Addr _)) => (ConstBool [true]) +(NeqPtr (OffPtr (LocalAddr _ _)) (Addr _)) => (ConstBool [true]) +(NeqPtr (LocalAddr _ _) (OffPtr (Addr _))) => (ConstBool [true]) +(NeqPtr (OffPtr (LocalAddr _ _)) (OffPtr (Addr _))) => (ConstBool [true]) + +// Simplify address comparisons. +(EqPtr (AddPtr p1 o1) p2) && isSamePtr(p1, p2) => (Not (IsNonNil o1)) +(NeqPtr (AddPtr p1 o1) p2) && isSamePtr(p1, p2) => (IsNonNil o1) +(EqPtr (Const(32|64) [0]) p) => (Not (IsNonNil p)) +(NeqPtr (Const(32|64) [0]) p) => (IsNonNil p) +(EqPtr (ConstNil) p) => (Not (IsNonNil p)) +(NeqPtr (ConstNil) p) => (IsNonNil p) + +// Evaluate constant user nil checks. +(IsNonNil (ConstNil)) => (ConstBool [false]) +(IsNonNil (Const(32|64) [c])) => (ConstBool [c != 0]) +(IsNonNil (Addr _)) => (ConstBool [true]) +(IsNonNil (LocalAddr _ _)) => (ConstBool [true]) + +// Inline small or disjoint runtime.memmove calls with constant length. +// See the comment in op Move in genericOps.go for discussion of the type. +// +// Note that we've lost any knowledge of the type and alignment requirements +// of the source and destination. We only know the size, and that the type +// contains no pointers. +// The type of the move is not necessarily v.Args[0].Type().Elem()! +// See issue 55122 for details. +// +// Because expand calls runs after prove, constants useful to this pattern may not appear. +// Both versions need to exist; the memory and register variants. +// +// Match post-expansion calls, memory version. +(SelectN [0] call:(StaticCall {sym} s1:(Store _ (Const(64|32) [sz]) s2:(Store _ src s3:(Store {t} _ dst mem))))) + && sz >= 0 + && isSameCall(sym, "runtime.memmove") + && s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1 + && isInlinableMemmove(dst, src, int64(sz), config) + && clobber(s1, s2, s3, call) + => (Move {types.Types[types.TUINT8]} [int64(sz)] dst src mem) + +// Match post-expansion calls, register version. +(SelectN [0] call:(StaticCall {sym} dst src (Const(64|32) [sz]) mem)) + && sz >= 0 + && call.Uses == 1 // this will exclude all calls with results + && isSameCall(sym, "runtime.memmove") + && isInlinableMemmove(dst, src, int64(sz), config) + && clobber(call) + => (Move {types.Types[types.TUINT8]} [int64(sz)] dst src mem) + +// Match pre-expansion calls. +(SelectN [0] call:(StaticLECall {sym} dst src (Const(64|32) [sz]) mem)) + && sz >= 0 + && call.Uses == 1 // this will exclude all calls with results + && isSameCall(sym, "runtime.memmove") + && isInlinableMemmove(dst, src, int64(sz), config) + && clobber(call) + => (Move {types.Types[types.TUINT8]} [int64(sz)] dst src mem) + +// De-virtualize late-expanded interface calls into late-expanded static calls. +// Note that (ITab (IMake)) doesn't get rewritten until after the first opt pass, +// so this rule should trigger reliably. +// devirtLECall removes the first argument, adds the devirtualized symbol to the AuxCall, and changes the opcode +(InterLECall [argsize] {auxCall} (Load (OffPtr [off] (ITab (IMake (Addr {itab} (SB)) _))) _) ___) && devirtLESym(v, auxCall, itab, off) != + nil => devirtLECall(v, devirtLESym(v, auxCall, itab, off)) + +// Move and Zero optimizations. +// Move source and destination may overlap. + +// Convert Moves into Zeros when the source is known to be zeros. +(Move {t} [n] dst1 src mem:(Zero {t} [n] dst2 _)) && isSamePtr(src, dst2) + => (Zero {t} [n] dst1 mem) +(Move {t} [n] dst1 src mem:(VarDef (Zero {t} [n] dst0 _))) && isSamePtr(src, dst0) + => (Zero {t} [n] dst1 mem) +(Move {t} [n] dst (Addr {sym} (SB)) mem) && symIsROZero(sym) => (Zero {t} [n] dst mem) + +// Don't Store to variables that are about to be overwritten by Move/Zero. +(Zero {t1} [n] p1 store:(Store {t2} (OffPtr [o2] p2) _ mem)) + && isSamePtr(p1, p2) && store.Uses == 1 + && n >= o2 + t2.Size() + && clobber(store) + => (Zero {t1} [n] p1 mem) +(Move {t1} [n] dst1 src1 store:(Store {t2} op:(OffPtr [o2] dst2) _ mem)) + && isSamePtr(dst1, dst2) && store.Uses == 1 + && n >= o2 + t2.Size() + && disjoint(src1, n, op, t2.Size()) + && clobber(store) + => (Move {t1} [n] dst1 src1 mem) + +// Don't Move to variables that are immediately completely overwritten. +(Zero {t} [n] dst1 move:(Move {t} [n] dst2 _ mem)) + && move.Uses == 1 + && isSamePtr(dst1, dst2) + && clobber(move) + => (Zero {t} [n] dst1 mem) +(Move {t} [n] dst1 src1 move:(Move {t} [n] dst2 _ mem)) + && move.Uses == 1 + && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) + && clobber(move) + => (Move {t} [n] dst1 src1 mem) +(Zero {t} [n] dst1 vardef:(VarDef {x} move:(Move {t} [n] dst2 _ mem))) + && move.Uses == 1 && vardef.Uses == 1 + && isSamePtr(dst1, dst2) + && clobber(move, vardef) + => (Zero {t} [n] dst1 (VarDef {x} mem)) +(Move {t} [n] dst1 src1 vardef:(VarDef {x} move:(Move {t} [n] dst2 _ mem))) + && move.Uses == 1 && vardef.Uses == 1 + && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) + && clobber(move, vardef) + => (Move {t} [n] dst1 src1 (VarDef {x} mem)) +(Store {t1} op1:(OffPtr [o1] p1) d1 + m2:(Store {t2} op2:(OffPtr [0] p2) d2 + m3:(Move [n] p3 _ mem))) + && m2.Uses == 1 && m3.Uses == 1 + && o1 == t2.Size() + && n == t2.Size() + t1.Size() + && isSamePtr(p1, p2) && isSamePtr(p2, p3) + && clobber(m2, m3) + => (Store {t1} op1 d1 (Store {t2} op2 d2 mem)) +(Store {t1} op1:(OffPtr [o1] p1) d1 + m2:(Store {t2} op2:(OffPtr [o2] p2) d2 + m3:(Store {t3} op3:(OffPtr [0] p3) d3 + m4:(Move [n] p4 _ mem)))) + && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 + && o2 == t3.Size() + && o1-o2 == t2.Size() + && n == t3.Size() + t2.Size() + t1.Size() + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) + && clobber(m2, m3, m4) + => (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 mem))) +(Store {t1} op1:(OffPtr [o1] p1) d1 + m2:(Store {t2} op2:(OffPtr [o2] p2) d2 + m3:(Store {t3} op3:(OffPtr [o3] p3) d3 + m4:(Store {t4} op4:(OffPtr [0] p4) d4 + m5:(Move [n] p5 _ mem))))) + && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 && m5.Uses == 1 + && o3 == t4.Size() + && o2-o3 == t3.Size() + && o1-o2 == t2.Size() + && n == t4.Size() + t3.Size() + t2.Size() + t1.Size() + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) + && clobber(m2, m3, m4, m5) + => (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 (Store {t4} op4 d4 mem)))) + +// Don't Zero variables that are immediately completely overwritten +// before being accessed. +(Move {t} [n] dst1 src1 zero:(Zero {t} [n] dst2 mem)) + && zero.Uses == 1 + && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) + && clobber(zero) + => (Move {t} [n] dst1 src1 mem) +(Move {t} [n] dst1 src1 vardef:(VarDef {x} zero:(Zero {t} [n] dst2 mem))) + && zero.Uses == 1 && vardef.Uses == 1 + && isSamePtr(dst1, dst2) && disjoint(src1, n, dst2, n) + && clobber(zero, vardef) + => (Move {t} [n] dst1 src1 (VarDef {x} mem)) +(Store {t1} op1:(OffPtr [o1] p1) d1 + m2:(Store {t2} op2:(OffPtr [0] p2) d2 + m3:(Zero [n] p3 mem))) + && m2.Uses == 1 && m3.Uses == 1 + && o1 == t2.Size() + && n == t2.Size() + t1.Size() + && isSamePtr(p1, p2) && isSamePtr(p2, p3) + && clobber(m2, m3) + => (Store {t1} op1 d1 (Store {t2} op2 d2 mem)) +(Store {t1} op1:(OffPtr [o1] p1) d1 + m2:(Store {t2} op2:(OffPtr [o2] p2) d2 + m3:(Store {t3} op3:(OffPtr [0] p3) d3 + m4:(Zero [n] p4 mem)))) + && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 + && o2 == t3.Size() + && o1-o2 == t2.Size() + && n == t3.Size() + t2.Size() + t1.Size() + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) + && clobber(m2, m3, m4) + => (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 mem))) +(Store {t1} op1:(OffPtr [o1] p1) d1 + m2:(Store {t2} op2:(OffPtr [o2] p2) d2 + m3:(Store {t3} op3:(OffPtr [o3] p3) d3 + m4:(Store {t4} op4:(OffPtr [0] p4) d4 + m5:(Zero [n] p5 mem))))) + && m2.Uses == 1 && m3.Uses == 1 && m4.Uses == 1 && m5.Uses == 1 + && o3 == t4.Size() + && o2-o3 == t3.Size() + && o1-o2 == t2.Size() + && n == t4.Size() + t3.Size() + t2.Size() + t1.Size() + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) + && clobber(m2, m3, m4, m5) + => (Store {t1} op1 d1 (Store {t2} op2 d2 (Store {t3} op3 d3 (Store {t4} op4 d4 mem)))) + +// Don't Move from memory if the values are likely to already be +// in registers. +(Move {t1} [n] dst p1 + mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Store {t3} op3:(OffPtr <tt3> [0] p3) d2 _))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && o2 == t3.Size() + && n == t2.Size() + t3.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [0] dst) d2 mem)) +(Move {t1} [n] dst p1 + mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 + (Store {t4} op4:(OffPtr <tt4> [0] p4) d3 _)))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && o3 == t4.Size() + && o2-o3 == t3.Size() + && n == t2.Size() + t3.Size() + t4.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [0] dst) d3 mem))) +(Move {t1} [n] dst p1 + mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 + (Store {t4} op4:(OffPtr <tt4> [o4] p4) d3 + (Store {t5} op5:(OffPtr <tt5> [0] p5) d4 _))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && t5.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && registerizable(b, t5) + && o4 == t5.Size() + && o3-o4 == t4.Size() + && o2-o3 == t3.Size() + && n == t2.Size() + t3.Size() + t4.Size() + t5.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [o4] dst) d3 + (Store {t5} (OffPtr <tt5> [0] dst) d4 mem)))) + +// Same thing but with VarDef in the middle. +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Store {t3} op3:(OffPtr <tt3> [0] p3) d2 _)))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && o2 == t3.Size() + && n == t2.Size() + t3.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [0] dst) d2 mem)) +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 + (Store {t4} op4:(OffPtr <tt4> [0] p4) d3 _))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && o3 == t4.Size() + && o2-o3 == t3.Size() + && n == t2.Size() + t3.Size() + t4.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [0] dst) d3 mem))) +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Store {t3} op3:(OffPtr <tt3> [o3] p3) d2 + (Store {t4} op4:(OffPtr <tt4> [o4] p4) d3 + (Store {t5} op5:(OffPtr <tt5> [0] p5) d4 _)))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && t5.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && registerizable(b, t5) + && o4 == t5.Size() + && o3-o4 == t4.Size() + && o2-o3 == t3.Size() + && n == t2.Size() + t3.Size() + t4.Size() + t5.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [o4] dst) d3 + (Store {t5} (OffPtr <tt5> [0] dst) d4 mem)))) + +// Prefer to Zero and Store than to Move. +(Move {t1} [n] dst p1 + mem:(Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Zero {t3} [n] p3 _))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && n >= o2 + t2.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Zero {t1} [n] dst mem)) +(Move {t1} [n] dst p1 + mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1 + (Store {t3} (OffPtr <tt3> [o3] p3) d2 + (Zero {t4} [n] p4 _)))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && n >= o2 + t2.Size() + && n >= o3 + t3.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Zero {t1} [n] dst mem))) +(Move {t1} [n] dst p1 + mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1 + (Store {t3} (OffPtr <tt3> [o3] p3) d2 + (Store {t4} (OffPtr <tt4> [o4] p4) d3 + (Zero {t5} [n] p5 _))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && t5.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && n >= o2 + t2.Size() + && n >= o3 + t3.Size() + && n >= o4 + t4.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [o4] dst) d3 + (Zero {t1} [n] dst mem)))) +(Move {t1} [n] dst p1 + mem:(Store {t2} (OffPtr <tt2> [o2] p2) d1 + (Store {t3} (OffPtr <tt3> [o3] p3) d2 + (Store {t4} (OffPtr <tt4> [o4] p4) d3 + (Store {t5} (OffPtr <tt5> [o5] p5) d4 + (Zero {t6} [n] p6 _)))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) && isSamePtr(p5, p6) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && t5.Alignment() <= t1.Alignment() + && t6.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && registerizable(b, t5) + && n >= o2 + t2.Size() + && n >= o3 + t3.Size() + && n >= o4 + t4.Size() + && n >= o5 + t5.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [o4] dst) d3 + (Store {t5} (OffPtr <tt5> [o5] dst) d4 + (Zero {t1} [n] dst mem))))) +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} op2:(OffPtr <tt2> [o2] p2) d1 + (Zero {t3} [n] p3 _)))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && n >= o2 + t2.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Zero {t1} [n] dst mem)) +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} (OffPtr <tt2> [o2] p2) d1 + (Store {t3} (OffPtr <tt3> [o3] p3) d2 + (Zero {t4} [n] p4 _))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && n >= o2 + t2.Size() + && n >= o3 + t3.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Zero {t1} [n] dst mem))) +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} (OffPtr <tt2> [o2] p2) d1 + (Store {t3} (OffPtr <tt3> [o3] p3) d2 + (Store {t4} (OffPtr <tt4> [o4] p4) d3 + (Zero {t5} [n] p5 _)))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && t5.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && n >= o2 + t2.Size() + && n >= o3 + t3.Size() + && n >= o4 + t4.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [o4] dst) d3 + (Zero {t1} [n] dst mem)))) +(Move {t1} [n] dst p1 + mem:(VarDef + (Store {t2} (OffPtr <tt2> [o2] p2) d1 + (Store {t3} (OffPtr <tt3> [o3] p3) d2 + (Store {t4} (OffPtr <tt4> [o4] p4) d3 + (Store {t5} (OffPtr <tt5> [o5] p5) d4 + (Zero {t6} [n] p6 _))))))) + && isSamePtr(p1, p2) && isSamePtr(p2, p3) && isSamePtr(p3, p4) && isSamePtr(p4, p5) && isSamePtr(p5, p6) + && t2.Alignment() <= t1.Alignment() + && t3.Alignment() <= t1.Alignment() + && t4.Alignment() <= t1.Alignment() + && t5.Alignment() <= t1.Alignment() + && t6.Alignment() <= t1.Alignment() + && registerizable(b, t2) + && registerizable(b, t3) + && registerizable(b, t4) + && registerizable(b, t5) + && n >= o2 + t2.Size() + && n >= o3 + t3.Size() + && n >= o4 + t4.Size() + && n >= o5 + t5.Size() + => (Store {t2} (OffPtr <tt2> [o2] dst) d1 + (Store {t3} (OffPtr <tt3> [o3] dst) d2 + (Store {t4} (OffPtr <tt4> [o4] dst) d3 + (Store {t5} (OffPtr <tt5> [o5] dst) d4 + (Zero {t1} [n] dst mem))))) + +(SelectN [0] call:(StaticLECall {sym} a x)) && needRaceCleanup(sym, call) && clobber(call) => x +(SelectN [0] call:(StaticLECall {sym} x)) && needRaceCleanup(sym, call) && clobber(call) => x + +// Collapse moving A -> B -> C into just A -> C. +// Later passes (deadstore, elim unread auto) will remove the A -> B move, if possible. +// This happens most commonly when B is an autotmp inserted earlier +// during compilation to ensure correctness. +// Take care that overlapping moves are preserved. +// Restrict this optimization to the stack, to avoid duplicating loads from the heap; +// see CL 145208 for discussion. +(Move {t1} [s] dst tmp1 midmem:(Move {t2} [s] tmp2 src _)) + && t1.Compare(t2) == types.CMPeq + && isSamePtr(tmp1, tmp2) + && isStackPtr(src) && !isVolatile(src) + && disjoint(src, s, tmp2, s) + && (disjoint(src, s, dst, s) || isInlinableMemmove(dst, src, s, config)) + => (Move {t1} [s] dst src midmem) + +// Same, but for large types that require VarDefs. +(Move {t1} [s] dst tmp1 midmem:(VarDef (Move {t2} [s] tmp2 src _))) + && t1.Compare(t2) == types.CMPeq + && isSamePtr(tmp1, tmp2) + && isStackPtr(src) && !isVolatile(src) + && disjoint(src, s, tmp2, s) + && (disjoint(src, s, dst, s) || isInlinableMemmove(dst, src, s, config)) + => (Move {t1} [s] dst src midmem) + +// Don't zero the same bits twice. +(Zero {t} [s] dst1 zero:(Zero {t} [s] dst2 _)) && isSamePtr(dst1, dst2) => zero +(Zero {t} [s] dst1 vardef:(VarDef (Zero {t} [s] dst2 _))) && isSamePtr(dst1, dst2) => vardef + +// Elide self-moves. This only happens rarely (e.g test/fixedbugs/bug277.go). +// However, this rule is needed to prevent the previous rule from looping forever in such cases. +(Move dst src mem) && isSamePtr(dst, src) => mem |