JitArm64: Improve pipelining of lmw/stmw #11344
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The calculation of each address in lmw/stmw currently has a dependency on the calculation of the previous address. By removing this dependency, the host CPU should be able to pipeline the loads/stores better. The cost we pay for this is up to one extra register and one extra MOV instruction per guest instruction, but often nothing. Making EmitBackpatchRoutine support using any register as the address register would let us get rid of the MOV, but I consider that to be too big of a task to do in one go at the same time as this.
lioncash
approved these changes
Dec 20, 2022
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The calculation of each address in lmw/stmw currently has a dependency on the calculation of the previous address. By removing this dependency, the host CPU should be able to pipeline the loads/stores better. The cost we pay for this is up to one extra register and one extra MOV instruction per guest instruction, but often nothing.
Making EmitBackpatchRoutine support using any register as the address register would let us get rid of the MOV, but I consider that to be too big of a task to do in one go at the same time as this.