// Copyright 2016 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. (Add(Ptr|32|16|8) ...) => (ADD ...) (Add(32|64)F ...) => (ADD(F|D) ...) (Select0 (Add32carry x y)) => (ADD x y) (Select1 (Add32carry x y)) => (SGTU x (ADD x y)) (Add32withcarry x y c) => (ADD c (ADD x y)) (Sub(Ptr|32|16|8) ...) => (SUB ...) (Sub(32|64)F ...) => (SUB(F|D) ...) (Select0 (Sub32carry x y)) => (SUB x y) (Select1 (Sub32carry x y)) => (SGTU (SUB x y) x) (Sub32withcarry x y c) => (SUB (SUB x y) c) (Mul(32|16|8) ...) => (MUL ...) (Mul(32|64)F ...) => (MUL(F|D) ...) (Hmul(32|32u) x y) => (Select0 (MUL(T|TU) x y)) (Mul32uhilo ...) => (MULTU ...) (Div32 x y) => (Select1 (DIV x y)) (Div32u x y) => (Select1 (DIVU x y)) (Div16 x y) => (Select1 (DIV (SignExt16to32 x) (SignExt16to32 y))) (Div16u x y) => (Select1 (DIVU (ZeroExt16to32 x) (ZeroExt16to32 y))) (Div8 x y) => (Select1 (DIV (SignExt8to32 x) (SignExt8to32 y))) (Div8u x y) => (Select1 (DIVU (ZeroExt8to32 x) (ZeroExt8to32 y))) (Div(32|64)F ...) => (DIV(F|D) ...) (Mod32 x y) => (Select0 (DIV x y)) (Mod32u x y) => (Select0 (DIVU x y)) (Mod16 x y) => (Select0 (DIV (SignExt16to32 x) (SignExt16to32 y))) (Mod16u x y) => (Select0 (DIVU (ZeroExt16to32 x) (ZeroExt16to32 y))) (Mod8 x y) => (Select0 (DIV (SignExt8to32 x) (SignExt8to32 y))) (Mod8u x y) => (Select0 (DIVU (ZeroExt8to32 x) (ZeroExt8to32 y))) // (x + y) / 2 with x>=y becomes (x - y) / 2 + y (Avg32u x y) => (ADD (SRLconst (SUB x y) [1]) y) (And(32|16|8) ...) => (AND ...) (Or(32|16|8) ...) => (OR ...) (Xor(32|16|8) ...) => (XOR ...) // constant shifts // generic opt rewrites all constant shifts to shift by Const64 (Lsh32x64 x (Const64 [c])) && uint32(c) < 32 => (SLLconst x [int32(c)]) (Rsh32x64 x (Const64 [c])) && uint32(c) < 32 => (SRAconst x [int32(c)]) (Rsh32Ux64 x (Const64 [c])) && uint32(c) < 32 => (SRLconst x [int32(c)]) (Lsh16x64 x (Const64 [c])) && uint32(c) < 16 => (SLLconst x [int32(c)]) (Rsh16x64 x (Const64 [c])) && uint32(c) < 16 => (SRAconst (SLLconst x [16]) [int32(c+16)]) (Rsh16Ux64 x (Const64 [c])) && uint32(c) < 16 => (SRLconst (SLLconst x [16]) [int32(c+16)]) (Lsh8x64 x (Const64 [c])) && uint32(c) < 8 => (SLLconst x [int32(c)]) (Rsh8x64 x (Const64 [c])) && uint32(c) < 8 => (SRAconst (SLLconst x [24]) [int32(c+24)]) (Rsh8Ux64 x (Const64 [c])) && uint32(c) < 8 => (SRLconst (SLLconst x [24]) [int32(c+24)]) // large constant shifts (Lsh32x64 _ (Const64 [c])) && uint32(c) >= 32 => (MOVWconst [0]) (Rsh32Ux64 _ (Const64 [c])) && uint32(c) >= 32 => (MOVWconst [0]) (Lsh16x64 _ (Const64 [c])) && uint32(c) >= 16 => (MOVWconst [0]) (Rsh16Ux64 _ (Const64 [c])) && uint32(c) >= 16 => (MOVWconst [0]) (Lsh8x64 _ (Const64 [c])) && uint32(c) >= 8 => (MOVWconst [0]) (Rsh8Ux64 _ (Const64 [c])) && uint32(c) >= 8 => (MOVWconst [0]) // large constant signed right shift, we leave the sign bit (Rsh32x64 x (Const64 [c])) && uint32(c) >= 32 => (SRAconst x [31]) (Rsh16x64 x (Const64 [c])) && uint32(c) >= 16 => (SRAconst (SLLconst x [16]) [31]) (Rsh8x64 x (Const64 [c])) && uint32(c) >= 8 => (SRAconst (SLLconst x [24]) [31]) // shifts // hardware instruction uses only the low 5 bits of the shift // we compare to 32 to ensure Go semantics for large shifts (Lsh32x32 x y) => (CMOVZ (SLL x y) (MOVWconst [0]) (SGTUconst [32] y)) (Lsh32x16 x y) => (CMOVZ (SLL x (ZeroExt16to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt16to32 y))) (Lsh32x8 x y) => (CMOVZ (SLL x (ZeroExt8to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt8to32 y))) (Lsh16x32 x y) => (CMOVZ (SLL x y) (MOVWconst [0]) (SGTUconst [32] y)) (Lsh16x16 x y) => (CMOVZ (SLL x (ZeroExt16to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt16to32 y))) (Lsh16x8 x y) => (CMOVZ (SLL x (ZeroExt8to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt8to32 y))) (Lsh8x32 x y) => (CMOVZ (SLL x y) (MOVWconst [0]) (SGTUconst [32] y)) (Lsh8x16 x y) => (CMOVZ (SLL x (ZeroExt16to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt16to32 y))) (Lsh8x8 x y) => (CMOVZ (SLL x (ZeroExt8to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt8to32 y))) (Rsh32Ux32 x y) => (CMOVZ (SRL x y) (MOVWconst [0]) (SGTUconst [32] y)) (Rsh32Ux16 x y) => (CMOVZ (SRL x (ZeroExt16to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt16to32 y))) (Rsh32Ux8 x y) => (CMOVZ (SRL x (ZeroExt8to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt8to32 y))) (Rsh16Ux32 x y) => (CMOVZ (SRL (ZeroExt16to32 x) y) (MOVWconst [0]) (SGTUconst [32] y)) (Rsh16Ux16 x y) => (CMOVZ (SRL (ZeroExt16to32 x) (ZeroExt16to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt16to32 y))) (Rsh16Ux8 x y) => (CMOVZ (SRL (ZeroExt16to32 x) (ZeroExt8to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt8to32 y))) (Rsh8Ux32 x y) => (CMOVZ (SRL (ZeroExt8to32 x) y) (MOVWconst [0]) (SGTUconst [32] y)) (Rsh8Ux16 x y) => (CMOVZ (SRL (ZeroExt8to32 x) (ZeroExt16to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt16to32 y))) (Rsh8Ux8 x y) => (CMOVZ (SRL (ZeroExt8to32 x) (ZeroExt8to32 y) ) (MOVWconst [0]) (SGTUconst [32] (ZeroExt8to32 y))) (Rsh32x32 x y) => (SRA x ( CMOVZ y (MOVWconst [31]) (SGTUconst [32] y))) (Rsh32x16 x y) => (SRA x ( CMOVZ (ZeroExt16to32 y) (MOVWconst [31]) (SGTUconst [32] (ZeroExt16to32 y)))) (Rsh32x8 x y) => (SRA x ( CMOVZ (ZeroExt8to32 y) (MOVWconst [31]) (SGTUconst [32] (ZeroExt8to32 y)))) (Rsh16x32 x y) => (SRA (SignExt16to32 x) ( CMOVZ y (MOVWconst [31]) (SGTUconst [32] y))) (Rsh16x16 x y) => (SRA (SignExt16to32 x) ( CMOVZ (ZeroExt16to32 y) (MOVWconst [31]) (SGTUconst [32] (ZeroExt16to32 y)))) (Rsh16x8 x y) => (SRA (SignExt16to32 x) ( CMOVZ (ZeroExt8to32 y) (MOVWconst [31]) (SGTUconst [32] (ZeroExt8to32 y)))) (Rsh8x32 x y) => (SRA (SignExt16to32 x) ( CMOVZ y (MOVWconst [31]) (SGTUconst [32] y))) (Rsh8x16 x y) => (SRA (SignExt16to32 x) ( CMOVZ (ZeroExt16to32 y) (MOVWconst [31]) (SGTUconst [32] (ZeroExt16to32 y)))) (Rsh8x8 x y) => (SRA (SignExt16to32 x) ( CMOVZ (ZeroExt8to32 y) (MOVWconst [31]) (SGTUconst [32] (ZeroExt8to32 y)))) // rotates (RotateLeft8 x (MOVWconst [c])) => (Or8 (Lsh8x32 x (MOVWconst [c&7])) (Rsh8Ux32 x (MOVWconst [-c&7]))) (RotateLeft16 x (MOVWconst [c])) => (Or16 (Lsh16x32 x (MOVWconst [c&15])) (Rsh16Ux32 x (MOVWconst [-c&15]))) (RotateLeft32 x (MOVWconst [c])) => (Or32 (Lsh32x32 x (MOVWconst [c&31])) (Rsh32Ux32 x (MOVWconst [-c&31]))) (RotateLeft64 x (MOVWconst [c])) => (Or64 (Lsh64x32 x (MOVWconst [c&63])) (Rsh64Ux32 x (MOVWconst [-c&63]))) // unary ops (Neg(32|16|8) ...) => (NEG ...) (Neg(32|64)F ...) => (NEG(F|D) ...) (Com(32|16|8) x) => (NORconst [0] x) (Sqrt ...) => (SQRTD ...) (Sqrt32 ...) => (SQRTF ...) // TODO: optimize this case? (Ctz32NonZero ...) => (Ctz32 ...) // count trailing zero // 32 - CLZ(x&-x - 1) (Ctz32 x) => (SUB (MOVWconst [32]) (CLZ (SUBconst [1] (AND x (NEG x))))) // bit length (BitLen32 x) => (SUB (MOVWconst [32]) (CLZ x)) // boolean ops -- booleans are represented with 0=false, 1=true (AndB ...) => (AND ...) (OrB ...) => (OR ...) (EqB x y) => (XORconst [1] (XOR x y)) (NeqB ...) => (XOR ...) (Not x) => (XORconst [1] x) // constants (Const(32|16|8) [val]) => (MOVWconst [int32(val)]) (Const(32|64)F ...) => (MOV(F|D)const ...) (ConstNil) => (MOVWconst [0]) (ConstBool [t]) => (MOVWconst [b2i32(t)]) // truncations // Because we ignore high parts of registers, truncates are just copies. (Trunc16to8 ...) => (Copy ...) (Trunc32to8 ...) => (Copy ...) (Trunc32to16 ...) => (Copy ...) // Zero-/Sign-extensions (ZeroExt8to16 ...) => (MOVBUreg ...) (ZeroExt8to32 ...) => (MOVBUreg ...) (ZeroExt16to32 ...) => (MOVHUreg ...) (SignExt8to16 ...) => (MOVBreg ...) (SignExt8to32 ...) => (MOVBreg ...) (SignExt16to32 ...) => (MOVHreg ...) (Signmask x) => (SRAconst x [31]) (Zeromask x) => (NEG (SGTU x (MOVWconst [0]))) (Slicemask x) => (SRAconst (NEG x) [31]) // float-int conversion (Cvt32to(32|64)F ...) => (MOVW(F|D) ...) (Cvt(32|64)Fto32 ...) => (TRUNC(F|D)W ...) (Cvt32Fto64F ...) => (MOVFD ...) (Cvt64Fto32F ...) => (MOVDF ...) (CvtBoolToUint8 ...) => (Copy ...) (Round(32|64)F ...) => (Copy ...) // comparisons (Eq8 x y) => (SGTUconst [1] (XOR (ZeroExt8to32 x) (ZeroExt8to32 y))) (Eq16 x y) => (SGTUconst [1] (XOR (ZeroExt16to32 x) (ZeroExt16to32 y))) (Eq32 x y) => (SGTUconst [1] (XOR x y)) (EqPtr x y) => (SGTUconst [1] (XOR x y)) (Eq(32|64)F x y) => (FPFlagTrue (CMPEQ(F|D) x y)) (Neq8 x y) => (SGTU (XOR (ZeroExt8to32 x) (ZeroExt8to32 y)) (MOVWconst [0])) (Neq16 x y) => (SGTU (XOR (ZeroExt16to32 x) (ZeroExt16to32 y)) (MOVWconst [0])) (Neq32 x y) => (SGTU (XOR x y) (MOVWconst [0])) (NeqPtr x y) => (SGTU (XOR x y) (MOVWconst [0])) (Neq(32|64)F x y) => (FPFlagFalse (CMPEQ(F|D) x y)) (Less8 x y) => (SGT (SignExt8to32 y) (SignExt8to32 x)) (Less16 x y) => (SGT (SignExt16to32 y) (SignExt16to32 x)) (Less32 x y) => (SGT y x) (Less(32|64)F x y) => (FPFlagTrue (CMPGT(F|D) y x)) // reverse operands to work around NaN (Less8U x y) => (SGTU (ZeroExt8to32 y) (ZeroExt8to32 x)) (Less16U x y) => (SGTU (ZeroExt16to32 y) (ZeroExt16to32 x)) (Less32U x y) => (SGTU y x) (Leq8 x y) => (XORconst [1] (SGT (SignExt8to32 x) (SignExt8to32 y))) (Leq16 x y) => (XORconst [1] (SGT (SignExt16to32 x) (SignExt16to32 y))) (Leq32 x y) => (XORconst [1] (SGT x y)) (Leq(32|64)F x y) => (FPFlagTrue (CMPGE(F|D) y x)) // reverse operands to work around NaN (Leq8U x y) => (XORconst [1] (SGTU (ZeroExt8to32 x) (ZeroExt8to32 y))) (Leq16U x y) => (XORconst [1] (SGTU (ZeroExt16to32 x) (ZeroExt16to32 y))) (Leq32U x y) => (XORconst [1] (SGTU x y)) (OffPtr [off] ptr:(SP)) => (MOVWaddr [int32(off)] ptr) (OffPtr [off] ptr) => (ADDconst [int32(off)] ptr) (Addr {sym} base) => (MOVWaddr {sym} base) (LocalAddr {sym} base _) => (MOVWaddr {sym} base) // loads (Load ptr mem) && t.IsBoolean() => (MOVBUload ptr mem) (Load ptr mem) && (is8BitInt(t) && isSigned(t)) => (MOVBload ptr mem) (Load ptr mem) && (is8BitInt(t) && !isSigned(t)) => (MOVBUload ptr mem) (Load ptr mem) && (is16BitInt(t) && isSigned(t)) => (MOVHload ptr mem) (Load ptr mem) && (is16BitInt(t) && !isSigned(t)) => (MOVHUload ptr mem) (Load ptr mem) && (is32BitInt(t) || isPtr(t)) => (MOVWload ptr mem) (Load ptr mem) && is32BitFloat(t) => (MOVFload ptr mem) (Load ptr mem) && is64BitFloat(t) => (MOVDload ptr mem) // stores (Store {t} ptr val mem) && t.Size() == 1 => (MOVBstore ptr val mem) (Store {t} ptr val mem) && t.Size() == 2 => (MOVHstore ptr val mem) (Store {t} ptr val mem) && t.Size() == 4 && !is32BitFloat(val.Type) => (MOVWstore ptr val mem) (Store {t} ptr val mem) && t.Size() == 4 && is32BitFloat(val.Type) => (MOVFstore ptr val mem) (Store {t} ptr val mem) && t.Size() == 8 && is64BitFloat(val.Type) => (MOVDstore ptr val mem) // zero instructions (Zero [0] _ mem) => mem (Zero [1] ptr mem) => (MOVBstore ptr (MOVWconst [0]) mem) (Zero [2] {t} ptr mem) && t.Alignment()%2 == 0 => (MOVHstore ptr (MOVWconst [0]) mem) (Zero [2] ptr mem) => (MOVBstore [1] ptr (MOVWconst [0]) (MOVBstore [0] ptr (MOVWconst [0]) mem)) (Zero [4] {t} ptr mem) && t.Alignment()%4 == 0 => (MOVWstore ptr (MOVWconst [0]) mem) (Zero [4] {t} ptr mem) && t.Alignment()%2 == 0 => (MOVHstore [2] ptr (MOVWconst [0]) (MOVHstore [0] ptr (MOVWconst [0]) mem)) (Zero [4] ptr mem) => (MOVBstore [3] ptr (MOVWconst [0]) (MOVBstore [2] ptr (MOVWconst [0]) (MOVBstore [1] ptr (MOVWconst [0]) (MOVBstore [0] ptr (MOVWconst [0]) mem)))) (Zero [3] ptr mem) => (MOVBstore [2] ptr (MOVWconst [0]) (MOVBstore [1] ptr (MOVWconst [0]) (MOVBstore [0] ptr (MOVWconst [0]) mem))) (Zero [6] {t} ptr mem) && t.Alignment()%2 == 0 => (MOVHstore [4] ptr (MOVWconst [0]) (MOVHstore [2] ptr (MOVWconst [0]) (MOVHstore [0] ptr (MOVWconst [0]) mem))) (Zero [8] {t} ptr mem) && t.Alignment()%4 == 0 => (MOVWstore [4] ptr (MOVWconst [0]) (MOVWstore [0] ptr (MOVWconst [0]) mem)) (Zero [12] {t} ptr mem) && t.Alignment()%4 == 0 => (MOVWstore [8] ptr (MOVWconst [0]) (MOVWstore [4] ptr (MOVWconst [0]) (MOVWstore [0] ptr (MOVWconst [0]) mem))) (Zero [16] {t} ptr mem) && t.Alignment()%4 == 0 => (MOVWstore [12] ptr (MOVWconst [0]) (MOVWstore [8] ptr (MOVWconst [0]) (MOVWstore [4] ptr (MOVWconst [0]) (MOVWstore [0] ptr (MOVWconst [0]) mem)))) // large or unaligned zeroing uses a loop (Zero [s] {t} ptr mem) && (s > 16 || t.Alignment()%4 != 0) => (LoweredZero [int32(t.Alignment())] ptr (ADDconst ptr [int32(s-moveSize(t.Alignment(), config))]) mem) // moves (Move [0] _ _ mem) => mem (Move [1] dst src mem) => (MOVBstore dst (MOVBUload src mem) mem) (Move [2] {t} dst src mem) && t.Alignment()%2 == 0 => (MOVHstore dst (MOVHUload src mem) mem) (Move [2] dst src mem) => (MOVBstore [1] dst (MOVBUload [1] src mem) (MOVBstore dst (MOVBUload src mem) mem)) (Move [4] {t} dst src mem) && t.Alignment()%4 == 0 => (MOVWstore dst (MOVWload src mem) mem) (Move [4] {t} dst src mem) && t.Alignment()%2 == 0 => (MOVHstore [2] dst (MOVHUload [2] src mem) (MOVHstore dst (MOVHUload src mem) mem)) (Move [4] dst src mem) => (MOVBstore [3] dst (MOVBUload [3] src mem) (MOVBstore [2] dst (MOVBUload [2] src mem) (MOVBstore [1] dst (MOVBUload [1] src mem) (MOVBstore dst (MOVBUload src mem) mem)))) (Move [3] dst src mem) => (MOVBstore [2] dst (MOVBUload [2] src mem) (MOVBstore [1] dst (MOVBUload [1] src mem) (MOVBstore dst (MOVBUload src mem) mem))) (Move [8] {t} dst src mem) && t.Alignment()%4 == 0 => (MOVWstore [4] dst (MOVWload [4] src mem) (MOVWstore dst (MOVWload src mem) mem)) (Move [8] {t} dst src mem) && t.Alignment()%2 == 0 => (MOVHstore [6] dst (MOVHload [6] src mem) (MOVHstore [4] dst (MOVHload [4] src mem) (MOVHstore [2] dst (MOVHload [2] src mem) (MOVHstore dst (MOVHload src mem) mem)))) (Move [6] {t} dst src mem) && t.Alignment()%2 == 0 => (MOVHstore [4] dst (MOVHload [4] src mem) (MOVHstore [2] dst (MOVHload [2] src mem) (MOVHstore dst (MOVHload src mem) mem))) (Move [12] {t} dst src mem) && t.Alignment()%4 == 0 => (MOVWstore [8] dst (MOVWload [8] src mem) (MOVWstore [4] dst (MOVWload [4] src mem) (MOVWstore dst (MOVWload src mem) mem))) (Move [16] {t} dst src mem) && t.Alignment()%4 == 0 => (MOVWstore [12] dst (MOVWload [12] src mem) (MOVWstore [8] dst (MOVWload [8] src mem) (MOVWstore [4] dst (MOVWload [4] src mem) (MOVWstore dst (MOVWload src mem) mem)))) // large or unaligned move uses a loop (Move [s] {t} dst src mem) && (s > 16 && logLargeCopy(v, s) || t.Alignment()%4 != 0) => (LoweredMove [int32(t.Alignment())] dst src (ADDconst src [int32(s-moveSize(t.Alignment(), config))]) mem) // calls (StaticCall ...) => (CALLstatic ...) (ClosureCall ...) => (CALLclosure ...) (InterCall ...) => (CALLinter ...) (TailCall ...) => (CALLtail ...) // atomic intrinsics (AtomicLoad(8|32) ...) => (LoweredAtomicLoad(8|32) ...) (AtomicLoadPtr ...) => (LoweredAtomicLoad32 ...) (AtomicStore(8|32) ...) => (LoweredAtomicStore(8|32) ...) (AtomicStorePtrNoWB ...) => (LoweredAtomicStore32 ...) (AtomicExchange32 ...) => (LoweredAtomicExchange ...) (AtomicAdd32 ...) => (LoweredAtomicAdd ...) (AtomicCompareAndSwap32 ...) => (LoweredAtomicCas ...) // AtomicOr8(ptr,val) => LoweredAtomicOr(ptr&^3,uint32(val) << ((ptr & 3) * 8)) (AtomicOr8 ptr val mem) && !config.BigEndian => (LoweredAtomicOr (AND (MOVWconst [^3]) ptr) (SLL (ZeroExt8to32 val) (SLLconst [3] (ANDconst [3] ptr))) mem) // AtomicAnd8(ptr,val) => LoweredAtomicAnd(ptr&^3,(uint32(val) << ((ptr & 3) * 8)) | ^(uint32(0xFF) << ((ptr & 3) * 8)))) (AtomicAnd8 ptr val mem) && !config.BigEndian => (LoweredAtomicAnd (AND (MOVWconst [^3]) ptr) (OR (SLL (ZeroExt8to32 val) (SLLconst [3] (ANDconst [3] ptr))) (NORconst [0] (SLL (MOVWconst [0xff]) (SLLconst [3] (ANDconst [3] ptr))))) mem) // AtomicOr8(ptr,val) => LoweredAtomicOr(ptr&^3,uint32(val) << (((ptr^3) & 3) * 8)) (AtomicOr8 ptr val mem) && config.BigEndian => (LoweredAtomicOr (AND (MOVWconst [^3]) ptr) (SLL (ZeroExt8to32 val) (SLLconst [3] (ANDconst [3] (XORconst [3] ptr)))) mem) // AtomicAnd8(ptr,val) => LoweredAtomicAnd(ptr&^3,(uint32(val) << (((ptr^3) & 3) * 8)) | ^(uint32(0xFF) << (((ptr^3) & 3) * 8)))) (AtomicAnd8 ptr val mem) && config.BigEndian => (LoweredAtomicAnd (AND (MOVWconst [^3]) ptr) (OR (SLL (ZeroExt8to32 val) (SLLconst [3] (ANDconst [3] (XORconst [3] ptr)))) (NORconst [0] (SLL (MOVWconst [0xff]) (SLLconst [3] (ANDconst [3] (XORconst [3] ptr)))))) mem) (AtomicAnd32 ...) => (LoweredAtomicAnd ...) (AtomicOr32 ...) => (LoweredAtomicOr ...) // checks (NilCheck ...) => (LoweredNilCheck ...) (IsNonNil ptr) => (SGTU ptr (MOVWconst [0])) (IsInBounds idx len) => (SGTU len idx) (IsSliceInBounds idx len) => (XORconst [1] (SGTU idx len)) // pseudo-ops (GetClosurePtr ...) => (LoweredGetClosurePtr ...) (GetCallerSP ...) => (LoweredGetCallerSP ...) (GetCallerPC ...) => (LoweredGetCallerPC ...) (If cond yes no) => (NE cond yes no) // Write barrier. (WB ...) => (LoweredWB ...) (PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem) (PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem) (PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem) (PanicExtend [kind] hi lo y mem) && boundsABI(kind) == 0 => (LoweredPanicExtendA [kind] hi lo y mem) (PanicExtend [kind] hi lo y mem) && boundsABI(kind) == 1 => (LoweredPanicExtendB [kind] hi lo y mem) (PanicExtend [kind] hi lo y mem) && boundsABI(kind) == 2 => (LoweredPanicExtendC [kind] hi lo y mem) // Optimizations // Absorb boolean tests into block (NE (FPFlagTrue cmp) yes no) => (FPT cmp yes no) (NE (FPFlagFalse cmp) yes no) => (FPF cmp yes no) (EQ (FPFlagTrue cmp) yes no) => (FPF cmp yes no) (EQ (FPFlagFalse cmp) yes no) => (FPT cmp yes no) (NE (XORconst [1] cmp:(SGT _ _)) yes no) => (EQ cmp yes no) (NE (XORconst [1] cmp:(SGTU _ _)) yes no) => (EQ cmp yes no) (NE (XORconst [1] cmp:(SGTconst _)) yes no) => (EQ cmp yes no) (NE (XORconst [1] cmp:(SGTUconst _)) yes no) => (EQ cmp yes no) (NE (XORconst [1] cmp:(SGTzero _)) yes no) => (EQ cmp yes no) (NE (XORconst [1] cmp:(SGTUzero _)) yes no) => (EQ cmp yes no) (EQ (XORconst [1] cmp:(SGT _ _)) yes no) => (NE cmp yes no) (EQ (XORconst [1] cmp:(SGTU _ _)) yes no) => (NE cmp yes no) (EQ (XORconst [1] cmp:(SGTconst _)) yes no) => (NE cmp yes no) (EQ (XORconst [1] cmp:(SGTUconst _)) yes no) => (NE cmp yes no) (EQ (XORconst [1] cmp:(SGTzero _)) yes no) => (NE cmp yes no) (EQ (XORconst [1] cmp:(SGTUzero _)) yes no) => (NE cmp yes no) (NE (SGTUconst [1] x) yes no) => (EQ x yes no) (EQ (SGTUconst [1] x) yes no) => (NE x yes no) (NE (SGTUzero x) yes no) => (NE x yes no) (EQ (SGTUzero x) yes no) => (EQ x yes no) (NE (SGTconst [0] x) yes no) => (LTZ x yes no) (EQ (SGTconst [0] x) yes no) => (GEZ x yes no) (NE (SGTzero x) yes no) => (GTZ x yes no) (EQ (SGTzero x) yes no) => (LEZ x yes no) // fold offset into address (ADDconst [off1] (MOVWaddr [off2] {sym} ptr)) => (MOVWaddr [off1+off2] {sym} ptr) // fold address into load/store (MOVBload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVBload [off1+off2] {sym} ptr mem) (MOVBUload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVBUload [off1+off2] {sym} ptr mem) (MOVHload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVHload [off1+off2] {sym} ptr mem) (MOVHUload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVHUload [off1+off2] {sym} ptr mem) (MOVWload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVWload [off1+off2] {sym} ptr mem) (MOVFload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVFload [off1+off2] {sym} ptr mem) (MOVDload [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVDload [off1+off2] {sym} ptr mem) (MOVBstore [off1] {sym} x:(ADDconst [off2] ptr) val mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVBstore [off1+off2] {sym} ptr val mem) (MOVHstore [off1] {sym} x:(ADDconst [off2] ptr) val mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVHstore [off1+off2] {sym} ptr val mem) (MOVWstore [off1] {sym} x:(ADDconst [off2] ptr) val mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVWstore [off1+off2] {sym} ptr val mem) (MOVFstore [off1] {sym} x:(ADDconst [off2] ptr) val mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVFstore [off1+off2] {sym} ptr val mem) (MOVDstore [off1] {sym} x:(ADDconst [off2] ptr) val mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVDstore [off1+off2] {sym} ptr val mem) (MOVBstorezero [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVBstorezero [off1+off2] {sym} ptr mem) (MOVHstorezero [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVHstorezero [off1+off2] {sym} ptr mem) (MOVWstorezero [off1] {sym} x:(ADDconst [off2] ptr) mem) && (is16Bit(int64(off1+off2)) || x.Uses == 1) => (MOVWstorezero [off1+off2] {sym} ptr mem) (MOVBload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVBload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVBUload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVBUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVHload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVHload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVHUload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVHUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVWload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVWload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVFload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVFload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVDload [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVDload [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVBstore [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) val mem) && canMergeSym(sym1,sym2) => (MOVBstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem) (MOVHstore [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) val mem) && canMergeSym(sym1,sym2) => (MOVHstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem) (MOVWstore [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) val mem) && canMergeSym(sym1,sym2) => (MOVWstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem) (MOVFstore [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) val mem) && canMergeSym(sym1,sym2) => (MOVFstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem) (MOVDstore [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) val mem) && canMergeSym(sym1,sym2) => (MOVDstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem) (MOVBstorezero [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVBstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVHstorezero [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVHstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) (MOVWstorezero [off1] {sym1} (MOVWaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) => (MOVWstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) // replace load from same location as preceding store with zero/sign extension (or copy in case of full width) (MOVBload [off] {sym} ptr (MOVBstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVBreg x) (MOVBUload [off] {sym} ptr (MOVBstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVBUreg x) (MOVHload [off] {sym} ptr (MOVHstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVHreg x) (MOVHUload [off] {sym} ptr (MOVHstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVHUreg x) (MOVWload [off] {sym} ptr (MOVWstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => x (MOVFload [off] {sym} ptr (MOVFstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => x (MOVDload [off] {sym} ptr (MOVDstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => x // store zero (MOVBstore [off] {sym} ptr (MOVWconst [0]) mem) => (MOVBstorezero [off] {sym} ptr mem) (MOVHstore [off] {sym} ptr (MOVWconst [0]) mem) => (MOVHstorezero [off] {sym} ptr mem) (MOVWstore [off] {sym} ptr (MOVWconst [0]) mem) => (MOVWstorezero [off] {sym} ptr mem) // don't extend after proper load (MOVBreg x:(MOVBload _ _)) => (MOVWreg x) (MOVBUreg x:(MOVBUload _ _)) => (MOVWreg x) (MOVHreg x:(MOVBload _ _)) => (MOVWreg x) (MOVHreg x:(MOVBUload _ _)) => (MOVWreg x) (MOVHreg x:(MOVHload _ _)) => (MOVWreg x) (MOVHUreg x:(MOVBUload _ _)) => (MOVWreg x) (MOVHUreg x:(MOVHUload _ _)) => (MOVWreg x) // fold double extensions (MOVBreg x:(MOVBreg _)) => (MOVWreg x) (MOVBUreg x:(MOVBUreg _)) => (MOVWreg x) (MOVHreg x:(MOVBreg _)) => (MOVWreg x) (MOVHreg x:(MOVBUreg _)) => (MOVWreg x) (MOVHreg x:(MOVHreg _)) => (MOVWreg x) (MOVHUreg x:(MOVBUreg _)) => (MOVWreg x) (MOVHUreg x:(MOVHUreg _)) => (MOVWreg x) // sign extended loads // Note: The combined instruction must end up in the same block // as the original load. If not, we end up making a value with // memory type live in two different blocks, which can lead to // multiple memory values alive simultaneously. // Make sure we don't combine these ops if the load has another use. // This prevents a single load from being split into multiple loads // which then might return different values. See test/atomicload.go. (MOVBreg x:(MOVBUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBload [off] {sym} ptr mem) (MOVBUreg x:(MOVBload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBUload [off] {sym} ptr mem) (MOVHreg x:(MOVHUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHload [off] {sym} ptr mem) (MOVHUreg x:(MOVHload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHUload [off] {sym} ptr mem) // fold extensions and ANDs together (MOVBUreg (ANDconst [c] x)) => (ANDconst [c&0xff] x) (MOVHUreg (ANDconst [c] x)) => (ANDconst [c&0xffff] x) (MOVBreg (ANDconst [c] x)) && c & 0x80 == 0 => (ANDconst [c&0x7f] x) (MOVHreg (ANDconst [c] x)) && c & 0x8000 == 0 => (ANDconst [c&0x7fff] x) // don't extend before store (MOVBstore [off] {sym} ptr (MOVBreg x) mem) => (MOVBstore [off] {sym} ptr x mem) (MOVBstore [off] {sym} ptr (MOVBUreg x) mem) => (MOVBstore [off] {sym} ptr x mem) (MOVBstore [off] {sym} ptr (MOVHreg x) mem) => (MOVBstore [off] {sym} ptr x mem) (MOVBstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVBstore [off] {sym} ptr x mem) (MOVBstore [off] {sym} ptr (MOVWreg x) mem) => (MOVBstore [off] {sym} ptr x mem) (MOVHstore [off] {sym} ptr (MOVHreg x) mem) => (MOVHstore [off] {sym} ptr x mem) (MOVHstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVHstore [off] {sym} ptr x mem) (MOVHstore [off] {sym} ptr (MOVWreg x) mem) => (MOVHstore [off] {sym} ptr x mem) (MOVWstore [off] {sym} ptr (MOVWreg x) mem) => (MOVWstore [off] {sym} ptr x mem) // if a register move has only 1 use, just use the same register without emitting instruction // MOVWnop doesn't emit instruction, only for ensuring the type. (MOVWreg x) && x.Uses == 1 => (MOVWnop x) // TODO: we should be able to get rid of MOVWnop all together. // But for now, this is enough to get rid of lots of them. (MOVWnop (MOVWconst [c])) => (MOVWconst [c]) // fold constant into arithmatic ops (ADD x (MOVWconst [c])) => (ADDconst [c] x) (SUB x (MOVWconst [c])) => (SUBconst [c] x) (AND x (MOVWconst [c])) => (ANDconst [c] x) (OR x (MOVWconst [c])) => (ORconst [c] x) (XOR x (MOVWconst [c])) => (XORconst [c] x) (NOR x (MOVWconst [c])) => (NORconst [c] x) (SLL x (MOVWconst [c])) => (SLLconst x [c&31]) (SRL x (MOVWconst [c])) => (SRLconst x [c&31]) (SRA x (MOVWconst [c])) => (SRAconst x [c&31]) (SGT (MOVWconst [c]) x) => (SGTconst [c] x) (SGTU (MOVWconst [c]) x) => (SGTUconst [c] x) (SGT x (MOVWconst [0])) => (SGTzero x) (SGTU x (MOVWconst [0])) => (SGTUzero x) // mul with constant (Select1 (MULTU (MOVWconst [0]) _ )) => (MOVWconst [0]) (Select0 (MULTU (MOVWconst [0]) _ )) => (MOVWconst [0]) (Select1 (MULTU (MOVWconst [1]) x )) => x (Select0 (MULTU (MOVWconst [1]) _ )) => (MOVWconst [0]) (Select1 (MULTU (MOVWconst [-1]) x )) => (NEG x) (Select0 (MULTU (MOVWconst [-1]) x )) => (CMOVZ (ADDconst [-1] x) (MOVWconst [0]) x) (Select1 (MULTU (MOVWconst [c]) x )) && isPowerOfTwo64(int64(uint32(c))) => (SLLconst [int32(log2uint32(int64(c)))] x) (Select0 (MULTU (MOVWconst [c]) x )) && isPowerOfTwo64(int64(uint32(c))) => (SRLconst [int32(32-log2uint32(int64(c)))] x) (MUL (MOVWconst [0]) _ ) => (MOVWconst [0]) (MUL (MOVWconst [1]) x ) => x (MUL (MOVWconst [-1]) x ) => (NEG x) (MUL (MOVWconst [c]) x ) && isPowerOfTwo64(int64(uint32(c))) => (SLLconst [int32(log2uint32(int64(c)))] x) // generic simplifications (ADD x (NEG y)) => (SUB x y) (SUB x x) => (MOVWconst [0]) (SUB (MOVWconst [0]) x) => (NEG x) (AND x x) => x (OR x x) => x (XOR x x) => (MOVWconst [0]) // miscellaneous patterns generated by dec64 (AND (SGTUconst [1] x) (SGTUconst [1] y)) => (SGTUconst [1] (OR x y)) (OR (SGTUzero x) (SGTUzero y)) => (SGTUzero (OR x y)) // remove redundant *const ops (ADDconst [0] x) => x (SUBconst [0] x) => x (ANDconst [0] _) => (MOVWconst [0]) (ANDconst [-1] x) => x (ORconst [0] x) => x (ORconst [-1] _) => (MOVWconst [-1]) (XORconst [0] x) => x (XORconst [-1] x) => (NORconst [0] x) // generic constant folding (ADDconst [c] (MOVWconst [d])) => (MOVWconst [int32(c+d)]) (ADDconst [c] (ADDconst [d] x)) => (ADDconst [c+d] x) (ADDconst [c] (SUBconst [d] x)) => (ADDconst [c-d] x) (SUBconst [c] (MOVWconst [d])) => (MOVWconst [d-c]) (SUBconst [c] (SUBconst [d] x)) => (ADDconst [-c-d] x) (SUBconst [c] (ADDconst [d] x)) => (ADDconst [-c+d] x) (SLLconst [c] (MOVWconst [d])) => (MOVWconst [d< (MOVWconst [int32(uint32(d)>>uint32(c))]) (SRAconst [c] (MOVWconst [d])) => (MOVWconst [d>>uint32(c)]) (MUL (MOVWconst [c]) (MOVWconst [d])) => (MOVWconst [c*d]) (Select1 (MULTU (MOVWconst [c]) (MOVWconst [d]))) => (MOVWconst [int32(uint32(c)*uint32(d))]) (Select0 (MULTU (MOVWconst [c]) (MOVWconst [d]))) => (MOVWconst [int32((int64(uint32(c))*int64(uint32(d)))>>32)]) (Select1 (DIV (MOVWconst [c]) (MOVWconst [d]))) && d != 0 => (MOVWconst [c/d]) (Select1 (DIVU (MOVWconst [c]) (MOVWconst [d]))) && d != 0 => (MOVWconst [int32(uint32(c)/uint32(d))]) (Select0 (DIV (MOVWconst [c]) (MOVWconst [d]))) && d != 0 => (MOVWconst [c%d]) (Select0 (DIVU (MOVWconst [c]) (MOVWconst [d]))) && d != 0 => (MOVWconst [int32(uint32(c)%uint32(d))]) (ANDconst [c] (MOVWconst [d])) => (MOVWconst [c&d]) (ANDconst [c] (ANDconst [d] x)) => (ANDconst [c&d] x) (ORconst [c] (MOVWconst [d])) => (MOVWconst [c|d]) (ORconst [c] (ORconst [d] x)) => (ORconst [c|d] x) (XORconst [c] (MOVWconst [d])) => (MOVWconst [c^d]) (XORconst [c] (XORconst [d] x)) => (XORconst [c^d] x) (NORconst [c] (MOVWconst [d])) => (MOVWconst [^(c|d)]) (NEG (MOVWconst [c])) => (MOVWconst [-c]) (MOVBreg (MOVWconst [c])) => (MOVWconst [int32(int8(c))]) (MOVBUreg (MOVWconst [c])) => (MOVWconst [int32(uint8(c))]) (MOVHreg (MOVWconst [c])) => (MOVWconst [int32(int16(c))]) (MOVHUreg (MOVWconst [c])) => (MOVWconst [int32(uint16(c))]) (MOVWreg (MOVWconst [c])) => (MOVWconst [c]) // constant comparisons (SGTconst [c] (MOVWconst [d])) && c > d => (MOVWconst [1]) (SGTconst [c] (MOVWconst [d])) && c <= d => (MOVWconst [0]) (SGTUconst [c] (MOVWconst [d])) && uint32(c) > uint32(d) => (MOVWconst [1]) (SGTUconst [c] (MOVWconst [d])) && uint32(c) <= uint32(d) => (MOVWconst [0]) (SGTzero (MOVWconst [d])) && d > 0 => (MOVWconst [1]) (SGTzero (MOVWconst [d])) && d <= 0 => (MOVWconst [0]) (SGTUzero (MOVWconst [d])) && d != 0 => (MOVWconst [1]) (SGTUzero (MOVWconst [d])) && d == 0 => (MOVWconst [0]) // other known comparisons (SGTconst [c] (MOVBreg _)) && 0x7f < c => (MOVWconst [1]) (SGTconst [c] (MOVBreg _)) && c <= -0x80 => (MOVWconst [0]) (SGTconst [c] (MOVBUreg _)) && 0xff < c => (MOVWconst [1]) (SGTconst [c] (MOVBUreg _)) && c < 0 => (MOVWconst [0]) (SGTUconst [c] (MOVBUreg _)) && 0xff < uint32(c) => (MOVWconst [1]) (SGTconst [c] (MOVHreg _)) && 0x7fff < c => (MOVWconst [1]) (SGTconst [c] (MOVHreg _)) && c <= -0x8000 => (MOVWconst [0]) (SGTconst [c] (MOVHUreg _)) && 0xffff < c => (MOVWconst [1]) (SGTconst [c] (MOVHUreg _)) && c < 0 => (MOVWconst [0]) (SGTUconst [c] (MOVHUreg _)) && 0xffff < uint32(c) => (MOVWconst [1]) (SGTconst [c] (ANDconst [m] _)) && 0 <= m && m < c => (MOVWconst [1]) (SGTUconst [c] (ANDconst [m] _)) && uint32(m) < uint32(c) => (MOVWconst [1]) (SGTconst [c] (SRLconst _ [d])) && 0 <= c && uint32(d) <= 31 && 0xffffffff>>uint32(d) < uint32(c) => (MOVWconst [1]) (SGTUconst [c] (SRLconst _ [d])) && uint32(d) <= 31 && 0xffffffff>>uint32(d) < uint32(c) => (MOVWconst [1]) // absorb constants into branches (EQ (MOVWconst [0]) yes no) => (First yes no) (EQ (MOVWconst [c]) yes no) && c != 0 => (First no yes) (NE (MOVWconst [0]) yes no) => (First no yes) (NE (MOVWconst [c]) yes no) && c != 0 => (First yes no) (LTZ (MOVWconst [c]) yes no) && c < 0 => (First yes no) (LTZ (MOVWconst [c]) yes no) && c >= 0 => (First no yes) (LEZ (MOVWconst [c]) yes no) && c <= 0 => (First yes no) (LEZ (MOVWconst [c]) yes no) && c > 0 => (First no yes) (GTZ (MOVWconst [c]) yes no) && c > 0 => (First yes no) (GTZ (MOVWconst [c]) yes no) && c <= 0 => (First no yes) (GEZ (MOVWconst [c]) yes no) && c >= 0 => (First yes no) (GEZ (MOVWconst [c]) yes no) && c < 0 => (First no yes) // conditional move (CMOVZ _ f (MOVWconst [0])) => f (CMOVZ a _ (MOVWconst [c])) && c!=0 => a (CMOVZzero _ (MOVWconst [0])) => (MOVWconst [0]) (CMOVZzero a (MOVWconst [c])) && c!=0 => a (CMOVZ a (MOVWconst [0]) c) => (CMOVZzero a c) // atomic (LoweredAtomicStore32 ptr (MOVWconst [0]) mem) => (LoweredAtomicStorezero ptr mem) (LoweredAtomicAdd ptr (MOVWconst [c]) mem) && is16Bit(int64(c)) => (LoweredAtomicAddconst [c] ptr mem)