|  | // 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. | 
|  |  | 
|  | // Optimizations TODO: | 
|  | // * Use SLTI and SLTIU for comparisons to constants, instead of SLT/SLTU with constants in registers | 
|  | // * Use the zero register instead of moving 0 into a register. | 
|  | // * Add rules to avoid generating a temp bool value for (If (SLT[U] ...) ...). | 
|  | // * Optimize left and right shift by simplifying SLTIU, Neg, and ADD for constants. | 
|  | // * Arrange for non-trivial Zero and Move lowerings to use aligned loads and stores. | 
|  | // * Eliminate zero immediate shifts, adds, etc. | 
|  | // * Avoid using Neq32 for writeBarrier.enabled checks. | 
|  |  | 
|  | // Lowering arithmetic | 
|  | (Add64 ...) => (ADD ...) | 
|  | (AddPtr ...) => (ADD ...) | 
|  | (Add32 ...) => (ADD ...) | 
|  | (Add16 ...) => (ADD ...) | 
|  | (Add8 ...) => (ADD ...) | 
|  | (Add32F ...) => (FADDS ...) | 
|  | (Add64F ...) => (FADDD ...) | 
|  |  | 
|  | (Sub64 ...) => (SUB ...) | 
|  | (SubPtr ...) => (SUB ...) | 
|  | (Sub32 ...) => (SUB ...) | 
|  | (Sub16 ...) => (SUB ...) | 
|  | (Sub8 ...) => (SUB ...) | 
|  | (Sub32F ...) => (FSUBS ...) | 
|  | (Sub64F ...) => (FSUBD ...) | 
|  |  | 
|  | (Mul64 ...) => (MUL  ...) | 
|  | (Mul32 ...) => (MULW ...) | 
|  | (Mul16 x y) => (MULW (SignExt16to32 x) (SignExt16to32 y)) | 
|  | (Mul8 x y)  => (MULW (SignExt8to32 x)  (SignExt8to32 y)) | 
|  | (Mul32F ...) => (FMULS ...) | 
|  | (Mul64F ...) => (FMULD ...) | 
|  |  | 
|  | (Div32F ...) => (FDIVS ...) | 
|  | (Div64F ...) => (FDIVD ...) | 
|  |  | 
|  | (Div64 x y [false])  => (DIV x y) | 
|  | (Div64u ...) => (DIVU ...) | 
|  | (Div32 x y [false])  => (DIVW x y) | 
|  | (Div32u ...) => (DIVUW ...) | 
|  | (Div16 x y [false])  => (DIVW  (SignExt16to32 x) (SignExt16to32 y)) | 
|  | (Div16u x y) => (DIVUW (ZeroExt16to32 x) (ZeroExt16to32 y)) | 
|  | (Div8 x y)   => (DIVW  (SignExt8to32 x)  (SignExt8to32 y)) | 
|  | (Div8u x y)  => (DIVUW (ZeroExt8to32 x)  (ZeroExt8to32 y)) | 
|  |  | 
|  | (Hmul64 ...)  => (MULH  ...) | 
|  | (Hmul64u ...) => (MULHU ...) | 
|  | (Hmul32 x y)  => (SRAI [32] (MUL  (SignExt32to64 x) (SignExt32to64 y))) | 
|  | (Hmul32u x y) => (SRLI [32] (MUL  (ZeroExt32to64 x) (ZeroExt32to64 y))) | 
|  |  | 
|  | // (x + y) / 2 => (x / 2) + (y / 2) + (x & y & 1) | 
|  | (Avg64u <t> x y) => (ADD (ADD <t> (SRLI <t> [1] x) (SRLI <t> [1] y)) (ANDI <t> [1] (AND <t> x y))) | 
|  |  | 
|  | (Mod64 x y [false])  => (REM x y) | 
|  | (Mod64u ...) => (REMU  ...) | 
|  | (Mod32 x y [false])  => (REMW x y) | 
|  | (Mod32u ...) => (REMUW ...) | 
|  | (Mod16 x y [false])  => (REMW  (SignExt16to32 x) (SignExt16to32 y)) | 
|  | (Mod16u x y) => (REMUW (ZeroExt16to32 x) (ZeroExt16to32 y)) | 
|  | (Mod8 x y)   => (REMW  (SignExt8to32  x) (SignExt8to32  y)) | 
|  | (Mod8u x y)  => (REMUW (ZeroExt8to32  x) (ZeroExt8to32  y)) | 
|  |  | 
|  | (And64 ...) => (AND ...) | 
|  | (And32 ...) => (AND ...) | 
|  | (And16 ...) => (AND ...) | 
|  | (And8  ...) => (AND ...) | 
|  |  | 
|  | (Or64 ...) => (OR ...) | 
|  | (Or32 ...) => (OR ...) | 
|  | (Or16 ...) => (OR ...) | 
|  | (Or8  ...) => (OR ...) | 
|  |  | 
|  | (Xor64 ...) => (XOR ...) | 
|  | (Xor32 ...) => (XOR ...) | 
|  | (Xor16 ...) => (XOR ...) | 
|  | (Xor8  ...) => (XOR ...) | 
|  |  | 
|  | (Neg64  ...) => (NEG ...) | 
|  | (Neg32  ...) => (NEG ...) | 
|  | (Neg16  ...) => (NEG ...) | 
|  | (Neg8   ...) => (NEG ...) | 
|  | (Neg32F ...) => (FNEGS ...) | 
|  | (Neg64F ...) => (FNEGD ...) | 
|  |  | 
|  | (Com64 ...) => (NOT ...) | 
|  | (Com32 ...) => (NOT ...) | 
|  | (Com16 ...) => (NOT ...) | 
|  | (Com8  ...) => (NOT ...) | 
|  |  | 
|  | (Sqrt ...) => (FSQRTD ...) | 
|  |  | 
|  | // Sign and zero extension. | 
|  |  | 
|  | (SignExt8to16  ...) => (MOVBreg ...) | 
|  | (SignExt8to32  ...) => (MOVBreg ...) | 
|  | (SignExt8to64  ...) => (MOVBreg ...) | 
|  | (SignExt16to32 ...) => (MOVHreg ...) | 
|  | (SignExt16to64 ...) => (MOVHreg ...) | 
|  | (SignExt32to64 ...) => (MOVWreg ...) | 
|  |  | 
|  | (ZeroExt8to16  ...) => (MOVBUreg ...) | 
|  | (ZeroExt8to32  ...) => (MOVBUreg ...) | 
|  | (ZeroExt8to64  ...) => (MOVBUreg ...) | 
|  | (ZeroExt16to32 ...) => (MOVHUreg ...) | 
|  | (ZeroExt16to64 ...) => (MOVHUreg ...) | 
|  | (ZeroExt32to64 ...) => (MOVWUreg ...) | 
|  |  | 
|  | (Cvt32to32F ...) => (FCVTSW ...) | 
|  | (Cvt32to64F ...) => (FCVTDW ...) | 
|  | (Cvt64to32F ...) => (FCVTSL ...) | 
|  | (Cvt64to64F ...) => (FCVTDL ...) | 
|  |  | 
|  | (Cvt32Fto32 ...) => (FCVTWS ...) | 
|  | (Cvt32Fto64 ...) => (FCVTLS ...) | 
|  | (Cvt64Fto32 ...) => (FCVTWD ...) | 
|  | (Cvt64Fto64 ...) => (FCVTLD ...) | 
|  |  | 
|  | (Cvt32Fto64F ...) => (FCVTDS ...) | 
|  | (Cvt64Fto32F ...) => (FCVTSD ...) | 
|  |  | 
|  | (CvtBoolToUint8 ...) => (Copy ...) | 
|  |  | 
|  | (Round32F ...) => (Copy ...) | 
|  | (Round64F ...) => (Copy ...) | 
|  |  | 
|  | // From genericOps.go: | 
|  | // "0 if arg0 == 0, -1 if arg0 > 0, undef if arg0<0" | 
|  | // | 
|  | // Like other arches, we compute ~((x-1) >> 63), with arithmetic right shift. | 
|  | // For positive x, bit 63 of x-1 is always 0, so the result is -1. | 
|  | // For zero x, bit 63 of x-1 is 1, so the result is 0. | 
|  | // | 
|  | (Slicemask <t> x) => (NOT (SRAI <t> [63] (ADDI <t> [-1] x))) | 
|  |  | 
|  | // Truncations | 
|  | // We ignore the unused high parts of registers, so truncates are just copies. | 
|  | (Trunc16to8  ...) => (Copy ...) | 
|  | (Trunc32to8  ...) => (Copy ...) | 
|  | (Trunc32to16 ...) => (Copy ...) | 
|  | (Trunc64to8  ...) => (Copy ...) | 
|  | (Trunc64to16 ...) => (Copy ...) | 
|  | (Trunc64to32 ...) => (Copy ...) | 
|  |  | 
|  | // Shifts | 
|  |  | 
|  | // SLL only considers the bottom 6 bits of y. If y > 64, the result should | 
|  | // always be 0. | 
|  | // | 
|  | // Breaking down the operation: | 
|  | // | 
|  | // (SLL x y) generates x << (y & 63). | 
|  | // | 
|  | // If y < 64, this is the value we want. Otherwise, we want zero. | 
|  | // | 
|  | // So, we AND with -1 * uint64(y < 64), which is 0xfffff... if y < 64 and 0 otherwise. | 
|  | (Lsh8x8   <t> x y) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Lsh8x16  <t> x y) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Lsh8x32  <t> x y) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Lsh8x64  <t> x y) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] y))) | 
|  | (Lsh16x8  <t> x y) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Lsh16x16 <t> x y) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Lsh16x32 <t> x y) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Lsh16x64 <t> x y) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] y))) | 
|  | (Lsh32x8  <t> x y) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Lsh32x16 <t> x y) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Lsh32x32 <t> x y) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Lsh32x64 <t> x y) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] y))) | 
|  | (Lsh64x8  <t> x y) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Lsh64x16 <t> x y) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Lsh64x32 <t> x y) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Lsh64x64 <t> x y) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] y))) | 
|  |  | 
|  | // SRL only considers the bottom 6 bits of y. If y > 64, the result should | 
|  | // always be 0. See Lsh above for a detailed description. | 
|  | (Rsh8Ux8   <t> x y) => (AND (SRL <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Rsh8Ux16  <t> x y) => (AND (SRL <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Rsh8Ux32  <t> x y) => (AND (SRL <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Rsh8Ux64  <t> x y) => (AND (SRL <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] y))) | 
|  | (Rsh16Ux8  <t> x y) => (AND (SRL <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Rsh16Ux16 <t> x y) => (AND (SRL <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Rsh16Ux32 <t> x y) => (AND (SRL <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Rsh16Ux64 <t> x y) => (AND (SRL <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] y))) | 
|  | (Rsh32Ux8  <t> x y) => (AND (SRL <t> (ZeroExt32to64 x) y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Rsh32Ux16 <t> x y) => (AND (SRL <t> (ZeroExt32to64 x) y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Rsh32Ux32 <t> x y) => (AND (SRL <t> (ZeroExt32to64 x) y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Rsh32Ux64 <t> x y) => (AND (SRL <t> (ZeroExt32to64 x) y) (Neg32 <t> (SLTIU <t> [64] y))) | 
|  | (Rsh64Ux8  <t> x y) => (AND (SRL <t> x                 y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt8to64  y)))) | 
|  | (Rsh64Ux16 <t> x y) => (AND (SRL <t> x                 y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt16to64 y)))) | 
|  | (Rsh64Ux32 <t> x y) => (AND (SRL <t> x                 y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt32to64 y)))) | 
|  | (Rsh64Ux64 <t> x y) => (AND (SRL <t> x                 y) (Neg64 <t> (SLTIU <t> [64] y))) | 
|  |  | 
|  | // SRA only considers the bottom 6 bits of y. If y > 64, the result should | 
|  | // be either 0 or -1 based on the sign bit. | 
|  | // | 
|  | // We implement this by performing the max shift (-1) if y >= 64. | 
|  | // | 
|  | // We OR (uint64(y < 64) - 1) into y before passing it to SRA. This leaves | 
|  | // us with -1 (0xffff...) if y >= 64. | 
|  | // | 
|  | // We don't need to sign-extend the OR result, as it will be at minimum 8 bits, | 
|  | // more than the 6 bits SRA cares about. | 
|  | (Rsh8x8   <t> x y) => (SRA <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y))))) | 
|  | (Rsh8x16  <t> x y) => (SRA <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y))))) | 
|  | (Rsh8x32  <t> x y) => (SRA <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y))))) | 
|  | (Rsh8x64  <t> x y) => (SRA <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y)))) | 
|  | (Rsh16x8  <t> x y) => (SRA <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y))))) | 
|  | (Rsh16x16 <t> x y) => (SRA <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y))))) | 
|  | (Rsh16x32 <t> x y) => (SRA <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y))))) | 
|  | (Rsh16x64 <t> x y) => (SRA <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y)))) | 
|  | (Rsh32x8  <t> x y) => (SRA <t> (SignExt32to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y))))) | 
|  | (Rsh32x16 <t> x y) => (SRA <t> (SignExt32to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y))))) | 
|  | (Rsh32x32 <t> x y) => (SRA <t> (SignExt32to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y))))) | 
|  | (Rsh32x64 <t> x y) => (SRA <t> (SignExt32to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y)))) | 
|  | (Rsh64x8  <t> x y) => (SRA <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y))))) | 
|  | (Rsh64x16 <t> x y) => (SRA <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y))))) | 
|  | (Rsh64x32 <t> x y) => (SRA <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y))))) | 
|  | (Rsh64x64 <t> x y) => (SRA <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y)))) | 
|  |  | 
|  | // rotates | 
|  | (RotateLeft8 <t> x (MOVBconst [c])) => (Or8 (Lsh8x64 <t> x (MOVBconst [c&7])) (Rsh8Ux64 <t> x (MOVBconst [-c&7]))) | 
|  | (RotateLeft16 <t> x (MOVHconst [c])) => (Or16 (Lsh16x64 <t> x (MOVHconst [c&15])) (Rsh16Ux64 <t> x (MOVHconst [-c&15]))) | 
|  | (RotateLeft32 <t> x (MOVWconst [c])) => (Or32 (Lsh32x64 <t> x (MOVWconst [c&31])) (Rsh32Ux64 <t> x (MOVWconst [-c&31]))) | 
|  | (RotateLeft64 <t> x (MOVDconst [c])) => (Or64 (Lsh64x64 <t> x (MOVDconst [c&63])) (Rsh64Ux64 <t> x (MOVDconst [-c&63]))) | 
|  |  | 
|  | (Less64  ...) => (SLT  ...) | 
|  | (Less32  x y) => (SLT  (SignExt32to64 x) (SignExt32to64 y)) | 
|  | (Less16  x y) => (SLT  (SignExt16to64 x) (SignExt16to64 y)) | 
|  | (Less8   x y) => (SLT  (SignExt8to64  x) (SignExt8to64  y)) | 
|  | (Less64U ...) => (SLTU ...) | 
|  | (Less32U x y) => (SLTU (ZeroExt32to64 x) (ZeroExt32to64 y)) | 
|  | (Less16U x y) => (SLTU (ZeroExt16to64 x) (ZeroExt16to64 y)) | 
|  | (Less8U  x y) => (SLTU (ZeroExt8to64  x) (ZeroExt8to64  y)) | 
|  | (Less64F ...) => (FLTD ...) | 
|  | (Less32F ...) => (FLTS ...) | 
|  |  | 
|  | // Convert x <= y to !(y > x). | 
|  | (Leq64  x y) => (Not (Less64  y x)) | 
|  | (Leq32  x y) => (Not (Less32  y x)) | 
|  | (Leq16  x y) => (Not (Less16  y x)) | 
|  | (Leq8   x y) => (Not (Less8   y x)) | 
|  | (Leq64U x y) => (Not (Less64U y x)) | 
|  | (Leq32U x y) => (Not (Less32U y x)) | 
|  | (Leq16U x y) => (Not (Less16U y x)) | 
|  | (Leq8U  x y) => (Not (Less8U  y x)) | 
|  | (Leq64F ...) => (FLED ...) | 
|  | (Leq32F ...) => (FLES ...) | 
|  |  | 
|  | (EqPtr x y) => (SEQZ (SUB <x.Type> x y)) | 
|  | (Eq64  x y) => (SEQZ (SUB <x.Type> x y)) | 
|  | (Eq32  x y) => (SEQZ (SUBW <x.Type> x y)) | 
|  | (Eq16  x y) => (SEQZ (SUB <x.Type> (ZeroExt16to64 x) (ZeroExt16to64 y))) | 
|  | (Eq8   x y) => (SEQZ (SUB <x.Type> (ZeroExt8to64  x) (ZeroExt8to64  y))) | 
|  | (Eq64F ...) => (FEQD ...) | 
|  | (Eq32F ...) => (FEQS ...) | 
|  |  | 
|  | (NeqPtr x y) => (SNEZ (SUB <x.Type> x y)) | 
|  | (Neq64  x y) => (SNEZ (SUB <x.Type> x y)) | 
|  | (Neq32  x y) => (SNEZ (SUBW <x.Type> x y)) | 
|  | (Neq16  x y) => (SNEZ (SUB <x.Type> (ZeroExt16to64 x) (ZeroExt16to64 y))) | 
|  | (Neq8   x y) => (SNEZ (SUB <x.Type> (ZeroExt8to64  x) (ZeroExt8to64  y))) | 
|  | (Neq64F ...) => (FNED ...) | 
|  | (Neq32F ...) => (FNES ...) | 
|  |  | 
|  | // Loads | 
|  | (Load <t> ptr mem) &&  t.IsBoolean()                  => (MOVBUload ptr mem) | 
|  | (Load <t> ptr mem) && ( is8BitInt(t) &&  isSigned(t)) => (MOVBload  ptr mem) | 
|  | (Load <t> ptr mem) && ( is8BitInt(t) && !isSigned(t)) => (MOVBUload ptr mem) | 
|  | (Load <t> ptr mem) && (is16BitInt(t) &&  isSigned(t)) => (MOVHload  ptr mem) | 
|  | (Load <t> ptr mem) && (is16BitInt(t) && !isSigned(t)) => (MOVHUload ptr mem) | 
|  | (Load <t> ptr mem) && (is32BitInt(t) &&  isSigned(t)) => (MOVWload  ptr mem) | 
|  | (Load <t> ptr mem) && (is32BitInt(t) && !isSigned(t)) => (MOVWUload ptr mem) | 
|  | (Load <t> ptr mem) && (is64BitInt(t) || isPtr(t))     => (MOVDload  ptr mem) | 
|  | (Load <t> ptr mem) &&  is32BitFloat(t)                => (FMOVWload ptr mem) | 
|  | (Load <t> ptr mem) &&  is64BitFloat(t)                => (FMOVDload 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() == 8 && !is64BitFloat(val.Type) => (MOVDstore ptr val mem) | 
|  | (Store {t} ptr val mem) && t.Size() == 4 &&  is32BitFloat(val.Type) => (FMOVWstore ptr val mem) | 
|  | (Store {t} ptr val mem) && t.Size() == 8 &&  is64BitFloat(val.Type) => (FMOVDstore ptr val mem) | 
|  |  | 
|  | // We need to fold MOVaddr into the LD/MOVDstore ops so that the live variable analysis | 
|  | // knows what variables are being read/written by the ops. | 
|  | (MOVBUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVBUload [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  | (MOVBload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVBload  [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  | (MOVHUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVHUload [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  | (MOVHload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVHload  [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  | (MOVWUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVWUload [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  | (MOVWload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVWload  [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  | (MOVDload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVDload  [off1+off2] {mergeSym(sym1,sym2)} base mem) | 
|  |  | 
|  | (MOVBstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVBstore [off1+off2] {mergeSym(sym1,sym2)} base val mem) | 
|  | (MOVHstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVHstore [off1+off2] {mergeSym(sym1,sym2)} base val mem) | 
|  | (MOVWstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVWstore [off1+off2] {mergeSym(sym1,sym2)} base val mem) | 
|  | (MOVDstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) => | 
|  | (MOVDstore [off1+off2] {mergeSym(sym1,sym2)} base val mem) | 
|  | (MOVBstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) => | 
|  | (MOVBstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) | 
|  | (MOVHstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) => | 
|  | (MOVHstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) | 
|  | (MOVWstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) => | 
|  | (MOVWstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) | 
|  | (MOVDstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) => | 
|  | (MOVDstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem) | 
|  |  | 
|  | (MOVBUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVBUload [off1+int32(off2)] {sym} base mem) | 
|  | (MOVBload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVBload  [off1+int32(off2)] {sym} base mem) | 
|  | (MOVHUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVHUload [off1+int32(off2)] {sym} base mem) | 
|  | (MOVHload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVHload  [off1+int32(off2)] {sym} base mem) | 
|  | (MOVWUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVWUload [off1+int32(off2)] {sym} base mem) | 
|  | (MOVWload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVWload  [off1+int32(off2)] {sym} base mem) | 
|  | (MOVDload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVDload  [off1+int32(off2)] {sym} base mem) | 
|  |  | 
|  | (MOVBstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVBstore [off1+int32(off2)] {sym} base val mem) | 
|  | (MOVHstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVHstore [off1+int32(off2)] {sym} base val mem) | 
|  | (MOVWstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVWstore [off1+int32(off2)] {sym} base val mem) | 
|  | (MOVDstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) => | 
|  | (MOVDstore [off1+int32(off2)] {sym} base val mem) | 
|  | (MOVBstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVBstorezero [off1+int32(off2)] {sym} ptr mem) | 
|  | (MOVHstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVHstorezero [off1+int32(off2)] {sym} ptr mem) | 
|  | (MOVWstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVWstorezero [off1+int32(off2)] {sym} ptr mem) | 
|  | (MOVDstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVDstorezero [off1+int32(off2)] {sym} ptr mem) | 
|  |  | 
|  | // Similarly, fold ADDI into MOVaddr to avoid confusing live variable analysis | 
|  | // with OffPtr -> ADDI. | 
|  | (ADDI [c] (MOVaddr [d] {s} x)) && is32Bit(c+int64(d)) => (MOVaddr [int32(c)+d] {s} x) | 
|  |  | 
|  | // Small zeroing | 
|  | (Zero [0] _ mem) => mem | 
|  | (Zero [1] ptr mem) => (MOVBstore ptr (MOVBconst [0]) mem) | 
|  | (Zero [2] {t} ptr mem) && t.Alignment()%2 == 0 => | 
|  | (MOVHstore ptr (MOVHconst [0]) mem) | 
|  | (Zero [2] ptr mem) => | 
|  | (MOVBstore [1] ptr (MOVBconst [0]) | 
|  | (MOVBstore ptr (MOVBconst [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 (MOVHconst [0]) | 
|  | (MOVHstore ptr (MOVHconst [0]) mem)) | 
|  | (Zero [4] ptr mem) => | 
|  | (MOVBstore [3] ptr (MOVBconst [0]) | 
|  | (MOVBstore [2] ptr (MOVBconst [0]) | 
|  | (MOVBstore [1] ptr (MOVBconst [0]) | 
|  | (MOVBstore ptr (MOVBconst [0]) mem)))) | 
|  | (Zero [8] {t} ptr mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore ptr (MOVDconst [0]) mem) | 
|  | (Zero [8] {t} ptr mem) && t.Alignment()%4 == 0 => | 
|  | (MOVWstore [4] ptr (MOVWconst [0]) | 
|  | (MOVWstore ptr (MOVWconst [0]) mem)) | 
|  | (Zero [8] {t} ptr mem) && t.Alignment()%2 == 0 => | 
|  | (MOVHstore [6] ptr (MOVHconst [0]) | 
|  | (MOVHstore [4] ptr (MOVHconst [0]) | 
|  | (MOVHstore [2] ptr (MOVHconst [0]) | 
|  | (MOVHstore ptr (MOVHconst [0]) mem)))) | 
|  |  | 
|  | (Zero [3] ptr mem) => | 
|  | (MOVBstore [2] ptr (MOVBconst [0]) | 
|  | (MOVBstore [1] ptr (MOVBconst [0]) | 
|  | (MOVBstore ptr (MOVBconst [0]) mem))) | 
|  | (Zero [6] {t} ptr mem) && t.Alignment()%2 == 0 => | 
|  | (MOVHstore [4] ptr (MOVHconst [0]) | 
|  | (MOVHstore [2] ptr (MOVHconst [0]) | 
|  | (MOVHstore ptr (MOVHconst [0]) mem))) | 
|  | (Zero [12] {t} ptr mem) && t.Alignment()%4 == 0 => | 
|  | (MOVWstore [8] ptr (MOVWconst [0]) | 
|  | (MOVWstore [4] ptr (MOVWconst [0]) | 
|  | (MOVWstore ptr (MOVWconst [0]) mem))) | 
|  | (Zero [16] {t} ptr mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore [8] ptr (MOVDconst [0]) | 
|  | (MOVDstore ptr (MOVDconst [0]) mem)) | 
|  | (Zero [24] {t} ptr mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore [16] ptr (MOVDconst [0]) | 
|  | (MOVDstore [8] ptr (MOVDconst [0]) | 
|  | (MOVDstore ptr (MOVDconst [0]) mem))) | 
|  | (Zero [32] {t} ptr mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore [24] ptr (MOVDconst [0]) | 
|  | (MOVDstore [16] ptr (MOVDconst [0]) | 
|  | (MOVDstore [8] ptr (MOVDconst [0]) | 
|  | (MOVDstore ptr (MOVDconst [0]) mem)))) | 
|  |  | 
|  | // Medium 8-aligned zeroing uses a Duff's device | 
|  | // 8 and 128 are magic constants, see runtime/mkduff.go | 
|  | (Zero [s] {t} ptr mem) | 
|  | && s%8 == 0 && s <= 8*128 | 
|  | && t.Alignment()%8 == 0 && !config.noDuffDevice => | 
|  | (DUFFZERO [8 * (128 - s/8)] ptr mem) | 
|  |  | 
|  | // Generic zeroing uses a loop | 
|  | (Zero [s] {t} ptr mem) => | 
|  | (LoweredZero [t.Alignment()] | 
|  | ptr | 
|  | (ADD <ptr.Type> ptr (MOVDconst [s-moveSize(t.Alignment(), config)])) | 
|  | mem) | 
|  |  | 
|  | (Convert ...) => (MOVconvert ...) | 
|  |  | 
|  | // Checks | 
|  | (IsNonNil p) => (NeqPtr (MOVDconst [0]) p) | 
|  | (IsInBounds ...) => (Less64U ...) | 
|  | (IsSliceInBounds ...) => (Leq64U ...) | 
|  |  | 
|  | // Trivial lowering | 
|  | (NilCheck ...) => (LoweredNilCheck ...) | 
|  | (GetClosurePtr ...) => (LoweredGetClosurePtr ...) | 
|  | (GetCallerSP ...) => (LoweredGetCallerSP ...) | 
|  | (GetCallerPC ...) => (LoweredGetCallerPC ...) | 
|  |  | 
|  | // 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) | 
|  |  | 
|  | // Small moves | 
|  | (Move [0] _ _ mem) => mem | 
|  | (Move [1] dst src mem) => (MOVBstore dst (MOVBload src mem) mem) | 
|  | (Move [2] {t} dst src mem) && t.Alignment()%2 == 0 => | 
|  | (MOVHstore dst (MOVHload src mem) mem) | 
|  | (Move [2] dst src mem) => | 
|  | (MOVBstore [1] dst (MOVBload [1] src mem) | 
|  | (MOVBstore dst (MOVBload 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 (MOVHload [2] src mem) | 
|  | (MOVHstore dst (MOVHload src mem) mem)) | 
|  | (Move [4] dst src mem) => | 
|  | (MOVBstore [3] dst (MOVBload [3] src mem) | 
|  | (MOVBstore [2] dst (MOVBload [2] src mem) | 
|  | (MOVBstore [1] dst (MOVBload [1] src mem) | 
|  | (MOVBstore dst (MOVBload src mem) mem)))) | 
|  | (Move [8] {t} dst src mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore dst (MOVDload 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 [3] dst src mem) => | 
|  | (MOVBstore [2] dst (MOVBload [2] src mem) | 
|  | (MOVBstore [1] dst (MOVBload [1] src mem) | 
|  | (MOVBstore dst (MOVBload 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()%8 == 0 => | 
|  | (MOVDstore [8] dst (MOVDload [8] src mem) | 
|  | (MOVDstore dst (MOVDload src mem) mem)) | 
|  | (Move [24] {t} dst src mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore [16] dst (MOVDload [16] src mem) | 
|  | (MOVDstore [8] dst (MOVDload [8] src mem) | 
|  | (MOVDstore dst (MOVDload src mem) mem))) | 
|  | (Move [32] {t} dst src mem) && t.Alignment()%8 == 0 => | 
|  | (MOVDstore [24] dst (MOVDload [24] src mem) | 
|  | (MOVDstore [16] dst (MOVDload [16] src mem) | 
|  | (MOVDstore [8] dst (MOVDload [8] src mem) | 
|  | (MOVDstore dst (MOVDload src mem) mem)))) | 
|  |  | 
|  | // Medium 8-aligned move uses a Duff's device | 
|  | // 16 and 128 are magic constants, see runtime/mkduff.go | 
|  | (Move [s] {t} dst src mem) | 
|  | && s%8 == 0 && s <= 8*128 && t.Alignment()%8 == 0 | 
|  | && !config.noDuffDevice && logLargeCopy(v, s) => | 
|  | (DUFFCOPY [16 * (128 - s/8)] dst src mem) | 
|  |  | 
|  | // Generic move uses a loop | 
|  | (Move [s] {t} dst src mem) && (s <= 16 || logLargeCopy(v, s)) => | 
|  | (LoweredMove [t.Alignment()] | 
|  | dst | 
|  | src | 
|  | (ADDI <src.Type> [s-moveSize(t.Alignment(), config)] src) | 
|  | mem) | 
|  |  | 
|  | // Boolean ops; 0=false, 1=true | 
|  | (AndB ...) => (AND ...) | 
|  | (OrB  ...) => (OR  ...) | 
|  | (EqB  x y) => (SEQZ (XOR <typ.Bool> x y)) | 
|  | (NeqB ...) => (XOR ...) | 
|  | (Not  ...) => (SEQZ ...) | 
|  |  | 
|  | // Lowering pointer arithmetic | 
|  | // TODO: Special handling for SP offsets, like ARM | 
|  | (OffPtr [off] ptr:(SP)) && is32Bit(off) => (MOVaddr [int32(off)] ptr) | 
|  | (OffPtr [off] ptr) && is32Bit(off) => (ADDI [off] ptr) | 
|  | (OffPtr [off] ptr) => (ADD (MOVDconst [off]) ptr) | 
|  |  | 
|  | // TODO(jsing): Check if we actually need MOV{B,H,W}const as most platforms | 
|  | // use a single MOVDconst op. | 
|  | (Const8 ...) => (MOVBconst ...) | 
|  | (Const16 ...) => (MOVHconst ...) | 
|  | (Const32 ...) => (MOVWconst ...) | 
|  | (Const64 ...) => (MOVDconst ...) | 
|  | (Const32F [val]) => (FMVSX (MOVWconst [int32(math.Float32bits(val))])) | 
|  | (Const64F [val]) => (FMVDX (MOVDconst [int64(math.Float64bits(val))])) | 
|  | (ConstNil) => (MOVDconst [0]) | 
|  | (ConstBool [val]) => (MOVBconst [int8(b2i(val))]) | 
|  |  | 
|  | // Convert 64 bit immediate to two 32 bit immediates, combine with add and shift. | 
|  | // The lower 32 bit immediate will be treated as signed, | 
|  | // so if it is negative, adjust for the borrow by incrementing the top half. | 
|  | // We don't have to worry about overflow from the increment, | 
|  | // because if the top half is all 1s, and int32(c) is negative, | 
|  | // then the overall constant fits in an int32. | 
|  | (MOVDconst <t> [c]) && !is32Bit(c) && int32(c) <  0 => (ADD (SLLI <t> [32] (MOVDconst [c>>32+1])) (MOVDconst [int64(int32(c))])) | 
|  | (MOVDconst <t> [c]) && !is32Bit(c) && int32(c) >= 0 => (ADD (SLLI <t> [32] (MOVDconst [c>>32+0])) (MOVDconst [int64(int32(c))])) | 
|  |  | 
|  | (Addr {sym} base) => (MOVaddr {sym} [0] base) | 
|  | (LocalAddr {sym} base _) => (MOVaddr {sym} base) | 
|  |  | 
|  | // Calls | 
|  | (StaticCall  ...) => (CALLstatic  ...) | 
|  | (ClosureCall ...) => (CALLclosure ...) | 
|  | (InterCall   ...) => (CALLinter   ...) | 
|  |  | 
|  | // Atomic Intrinsics | 
|  | (AtomicLoad8   ...) => (LoweredAtomicLoad8  ...) | 
|  | (AtomicLoad32  ...) => (LoweredAtomicLoad32 ...) | 
|  | (AtomicLoad64  ...) => (LoweredAtomicLoad64 ...) | 
|  | (AtomicLoadPtr ...) => (LoweredAtomicLoad64 ...) | 
|  |  | 
|  | (AtomicStore8       ...) => (LoweredAtomicStore8  ...) | 
|  | (AtomicStore32      ...) => (LoweredAtomicStore32 ...) | 
|  | (AtomicStore64      ...) => (LoweredAtomicStore64 ...) | 
|  | (AtomicStorePtrNoWB ...) => (LoweredAtomicStore64 ...) | 
|  |  | 
|  | (AtomicAdd32 ...) => (LoweredAtomicAdd32 ...) | 
|  | (AtomicAdd64 ...) => (LoweredAtomicAdd64 ...) | 
|  |  | 
|  | (AtomicCompareAndSwap32 ...) => (LoweredAtomicCas32 ...) | 
|  | (AtomicCompareAndSwap64 ...) => (LoweredAtomicCas64 ...) | 
|  |  | 
|  | (AtomicExchange32 ...) => (LoweredAtomicExchange32 ...) | 
|  | (AtomicExchange64 ...) => (LoweredAtomicExchange64 ...) | 
|  |  | 
|  | // Conditional branches | 
|  | (If cond yes no) => (BNEZ cond yes no) | 
|  |  | 
|  | // Optimizations | 
|  |  | 
|  | // Absorb SEQZ/SNEZ into branch. | 
|  | (BEQZ (SEQZ x) yes no) => (BNEZ x yes no) | 
|  | (BEQZ (SNEZ x) yes no) => (BEQZ x yes no) | 
|  | (BNEZ (SEQZ x) yes no) => (BEQZ x yes no) | 
|  | (BNEZ (SNEZ x) yes no) => (BNEZ x yes no) | 
|  |  | 
|  | // Convert BEQZ/BNEZ into more optimal branch conditions. | 
|  | (BEQZ (SUB x y) yes no) => (BEQ x y yes no) | 
|  | (BNEZ (SUB x y) yes no) => (BNE x y yes no) | 
|  | (BEQZ (SLT x y) yes no) => (BGE x y yes no) | 
|  | (BNEZ (SLT x y) yes no) => (BLT x y yes no) | 
|  | (BEQZ (SLTU x y) yes no) => (BGEU x y yes no) | 
|  | (BNEZ (SLTU x y) yes no) => (BLTU x y yes no) | 
|  |  | 
|  | // Convert branch with zero to BEQZ/BNEZ. | 
|  | (BEQ (MOVDconst [0]) cond yes no) => (BEQZ cond yes no) | 
|  | (BEQ cond (MOVDconst [0]) yes no) => (BEQZ cond yes no) | 
|  | (BNE (MOVDconst [0]) cond yes no) => (BNEZ cond yes no) | 
|  | (BNE cond (MOVDconst [0]) yes no) => (BNEZ cond yes no) | 
|  |  | 
|  | // Store zero | 
|  | (MOVBstore [off] {sym} ptr (MOVBconst [0]) mem) => (MOVBstorezero [off] {sym} ptr mem) | 
|  | (MOVHstore [off] {sym} ptr (MOVHconst [0]) mem) => (MOVHstorezero [off] {sym} ptr mem) | 
|  | (MOVWstore [off] {sym} ptr (MOVWconst [0]) mem) => (MOVWstorezero [off] {sym} ptr mem) | 
|  | (MOVDstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVDstorezero [off] {sym} ptr mem) | 
|  |  | 
|  | // Avoid sign/zero extension for consts. | 
|  | (MOVBreg  (MOVBconst [c])) => (MOVDconst [int64(c)]) | 
|  | (MOVHreg  (MOVBconst [c])) => (MOVDconst [int64(c)]) | 
|  | (MOVHreg  (MOVHconst [c])) => (MOVDconst [int64(c)]) | 
|  | (MOVWreg  (MOVBconst [c])) => (MOVDconst [int64(c)]) | 
|  | (MOVWreg  (MOVHconst [c])) => (MOVDconst [int64(c)]) | 
|  | (MOVWreg  (MOVWconst [c])) => (MOVDconst [int64(c)]) | 
|  | (MOVBUreg (MOVBconst [c])) => (MOVDconst [int64(uint8(c))]) | 
|  | (MOVHUreg (MOVBconst [c])) => (MOVDconst [int64(uint16(c))]) | 
|  | (MOVHUreg (MOVHconst [c])) => (MOVDconst [int64(uint16(c))]) | 
|  | (MOVWUreg (MOVBconst [c])) => (MOVDconst [int64(uint32(c))]) | 
|  | (MOVWUreg (MOVHconst [c])) => (MOVDconst [int64(uint32(c))]) | 
|  | (MOVWUreg (MOVWconst [c])) => (MOVDconst [int64(uint32(c))]) | 
|  |  | 
|  | // Avoid sign/zero extension after properly typed load. | 
|  | (MOVBreg  x:(MOVBload  _ _)) => (MOVDreg x) | 
|  | (MOVHreg  x:(MOVBload  _ _)) => (MOVDreg x) | 
|  | (MOVHreg  x:(MOVBUload _ _)) => (MOVDreg x) | 
|  | (MOVHreg  x:(MOVHload  _ _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVBload  _ _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVBUload _ _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVHload  _ _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVHUload _ _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVWload  _ _)) => (MOVDreg x) | 
|  | (MOVBUreg x:(MOVBUload _ _)) => (MOVDreg x) | 
|  | (MOVHUreg x:(MOVBUload _ _)) => (MOVDreg x) | 
|  | (MOVHUreg x:(MOVHUload _ _)) => (MOVDreg x) | 
|  | (MOVWUreg x:(MOVBUload _ _)) => (MOVDreg x) | 
|  | (MOVWUreg x:(MOVHUload _ _)) => (MOVDreg x) | 
|  | (MOVWUreg x:(MOVWUload _ _)) => (MOVDreg x) | 
|  |  | 
|  | // Fold double extensions. | 
|  | (MOVBreg  x:(MOVBreg  _)) => (MOVDreg x) | 
|  | (MOVHreg  x:(MOVBreg  _)) => (MOVDreg x) | 
|  | (MOVHreg  x:(MOVBUreg _)) => (MOVDreg x) | 
|  | (MOVHreg  x:(MOVHreg  _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVBreg  _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVBUreg _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVHreg  _)) => (MOVDreg x) | 
|  | (MOVWreg  x:(MOVWreg  _)) => (MOVDreg x) | 
|  | (MOVBUreg x:(MOVBUreg _)) => (MOVDreg x) | 
|  | (MOVHUreg x:(MOVBUreg _)) => (MOVDreg x) | 
|  | (MOVHUreg x:(MOVHUreg _)) => (MOVDreg x) | 
|  | (MOVWUreg x:(MOVBUreg _)) => (MOVDreg x) | 
|  | (MOVWUreg x:(MOVHUreg _)) => (MOVDreg x) | 
|  | (MOVWUreg x:(MOVWUreg _)) => (MOVDreg x) | 
|  |  | 
|  | // Do not extend before store. | 
|  | (MOVBstore [off] {sym} ptr (MOVBreg  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 (MOVWreg  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 (MOVHUreg x) mem) => (MOVBstore [off] {sym} ptr x mem) | 
|  | (MOVBstore [off] {sym} ptr (MOVWUreg 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 (MOVWreg  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 (MOVWUreg x) mem) => (MOVHstore [off] {sym} ptr x mem) | 
|  | (MOVWstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVWstore [off] {sym} ptr x mem) | 
|  | (MOVWstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVWstore [off] {sym} ptr x mem) | 
|  |  | 
|  | // Replace extend after load with alternate load where possible. | 
|  | (MOVBreg  <t> x:(MOVBUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBload  <t> [off] {sym} ptr mem) | 
|  | (MOVHreg  <t> x:(MOVHUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHload  <t> [off] {sym} ptr mem) | 
|  | (MOVWreg  <t> x:(MOVWUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWload  <t> [off] {sym} ptr mem) | 
|  | (MOVBUreg <t> x:(MOVBload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBUload <t> [off] {sym} ptr mem) | 
|  | (MOVHUreg <t> x:(MOVHload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHUload <t> [off] {sym} ptr mem) | 
|  | (MOVWUreg <t> x:(MOVWload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWUload <t> [off] {sym} ptr mem) | 
|  |  | 
|  | // If a register move has only 1 use, just use the same register without emitting instruction | 
|  | // MOVnop does not emit an instruction, only for ensuring the type. | 
|  | (MOVDreg x) && x.Uses == 1 => (MOVDnop x) | 
|  |  | 
|  | // Fold constant into immediate instructions where possible. | 
|  | (ADD (MOVBconst [val]) x) => (ADDI [int64(val)] x) | 
|  | (ADD (MOVHconst [val]) x) => (ADDI [int64(val)] x) | 
|  | (ADD (MOVWconst [val]) x) => (ADDI [int64(val)] x) | 
|  | (ADD (MOVDconst [val]) x) && is32Bit(val) => (ADDI [val] x) | 
|  |  | 
|  | (AND (MOVBconst [val]) x) => (ANDI [int64(val)] x) | 
|  | (AND (MOVHconst [val]) x) => (ANDI [int64(val)] x) | 
|  | (AND (MOVWconst [val]) x) => (ANDI [int64(val)] x) | 
|  | (AND (MOVDconst [val]) x) && is32Bit(val) => (ANDI [val] x) | 
|  |  | 
|  | (OR (MOVBconst [val]) x) => (ORI [int64(val)] x) | 
|  | (OR (MOVHconst [val]) x) => (ORI [int64(val)] x) | 
|  | (OR (MOVWconst [val]) x) => (ORI [int64(val)] x) | 
|  | (OR (MOVDconst [val]) x) && is32Bit(val) => (ORI [val] x) | 
|  |  | 
|  | (XOR (MOVBconst [val]) x) => (XORI [int64(val)] x) | 
|  | (XOR (MOVHconst [val]) x) => (XORI [int64(val)] x) | 
|  | (XOR (MOVWconst [val]) x) => (XORI [int64(val)] x) | 
|  | (XOR (MOVDconst [val]) x) && is32Bit(val) => (XORI [val] x) | 
|  |  | 
|  | (SLL x (MOVBconst [val])) => (SLLI [int64(val&63)] x) | 
|  | (SLL x (MOVHconst [val])) => (SLLI [int64(val&63)] x) | 
|  | (SLL x (MOVWconst [val])) => (SLLI [int64(val&63)] x) | 
|  | (SLL x (MOVDconst [val])) => (SLLI [int64(val&63)] x) | 
|  |  | 
|  | (SRL x (MOVBconst [val])) => (SRLI [int64(val&63)] x) | 
|  | (SRL x (MOVHconst [val])) => (SRLI [int64(val&63)] x) | 
|  | (SRL x (MOVWconst [val])) => (SRLI [int64(val&63)] x) | 
|  | (SRL x (MOVDconst [val])) => (SRLI [int64(val&63)] x) | 
|  |  | 
|  | (SRA x (MOVBconst [val])) => (SRAI [int64(val&63)] x) | 
|  | (SRA x (MOVHconst [val])) => (SRAI [int64(val&63)] x) | 
|  | (SRA x (MOVWconst [val])) => (SRAI [int64(val&63)] x) | 
|  | (SRA x (MOVDconst [val])) => (SRAI [int64(val&63)] x) | 
|  |  | 
|  | // Convert subtraction of a const into ADDI with negative immediate, where possible. | 
|  | (SUB x (MOVBconst [val])) => (ADDI [-int64(val)] x) | 
|  | (SUB x (MOVHconst [val])) => (ADDI [-int64(val)] x) | 
|  | (SUB x (MOVWconst [val])) && is32Bit(-int64(val)) => (ADDI [-int64(val)] x) | 
|  | (SUB x (MOVDconst [val])) && is32Bit(-val) => (ADDI [-val] x) | 
|  |  | 
|  | // Subtraction of zero. | 
|  | (SUB x (MOVBconst [0])) => x | 
|  | (SUB x (MOVHconst [0])) => x | 
|  | (SUB x (MOVWconst [0])) => x | 
|  | (SUB x (MOVDconst [0])) => x | 
|  |  | 
|  | // Subtraction of zero with sign extension. | 
|  | (SUBW x (MOVWconst [0])) => (ADDIW [0] x) | 
|  |  | 
|  | // Subtraction from zero. | 
|  | (SUB (MOVBconst [0]) x) => (NEG x) | 
|  | (SUB (MOVHconst [0]) x) => (NEG x) | 
|  | (SUB (MOVWconst [0]) x) => (NEG x) | 
|  | (SUB (MOVDconst [0]) x) => (NEG x) | 
|  |  | 
|  | // Subtraction from zero with sign extension. | 
|  | (SUBW (MOVDconst [0]) x) => (NEGW x) | 
|  |  | 
|  | // Addition of zero. | 
|  | (ADDI [0] x) => x |