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Replace load with cheaper move instr for stack loads on Arm64 (Followup of #83458) #83886

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Merged
BruceForstall merged 1 commit into from
Mar 24, 2023
Merged

Replace load with cheaper move instr for stack loads on Arm64 (Followup of #83458) #83886

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7 changes: 3 additions & 4 deletions src/coreclr/jit/emitarm64.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -16369,7 +16369,7 @@ emitter::RegisterOrder emitter::IsOptimizableLdrStrWithPair(
// instruction into a cheaper "mov" instruction.
//
// Examples: ldr w1, [x20, #0x10]
// ldr w2, [x20, #0x10] => mov w1, w2
// ldr w2, [x20, #0x10] => mov w2, w1
//
// Arguments:
// ins - The instruction code
Expand Down Expand Up @@ -16398,7 +16398,7 @@ bool emitter::IsOptimizableLdrToMov(
}

regNumber prevReg1 = emitLastIns->idReg1();
regNumber prevReg2 = emitLastIns->idReg2();
regNumber prevReg2 = encodingZRtoSP(emitLastIns->idReg2());
insFormat lastInsFmt = emitLastIns->idInsFmt();
emitAttr prevSize = emitLastIns->idOpSize();
ssize_t prevImm = emitGetInsSC(emitLastIns);
Expand All @@ -16418,8 +16418,7 @@ bool emitter::IsOptimizableLdrToMov(

if (!isGeneralRegister(reg1) || !isGeneralRegister(prevReg1))
{
// Either register 1 or previous register 1 is not a general register
// or the zero register, so we cannot optimise.
// We cannot optimise when register 1 or previous register 1 is a general register.
return false;
}

Expand Down