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JIT64: optimize carry calculations further

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Keep carry flags in the x86 flags register if used in the next instruction.
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Fiora committed 2014-09-13 13:48:20 -07:00
1 parent bea2504a51
commit 45d84605a9
8 files changed
+109 -42
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Source/Core/Core/PowerPC/PPCAnalyst.cpp
+6
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@@ -460,7 +460,13 @@ void PPCAnalyzer::SetInstructionStats(CodeBlock *block, CodeOp *code, GekkoOPInf
code->wantsCA = (opinfo->flags & FL_READ_CA) ? true : false;
code->outputCA = (opinfo->flags & FL_SET_CA) ? true : false;
// We're going to try to avoid storing carry in XER if we can avoid it -- keep it in the x86 carry flag!
// If the instruction reads CA but doesn't write it, we still need to store CA in XER; we can't
// leave it in flags.
code->wantsCAInFlags = code->wantsCA && code->outputCA && code->inst.SUBOP10 != 512;
// mfspr/mtspr can affect/use XER, so be super careful here
// we need to note specifically that mfspr needs CA in XER, not in the x86 carry flag
if (code->inst.OPCD == 31 && code->inst.SUBOP10 == 339) // mfspr
code->wantsCA = ((code->inst.SPRU << 5) | (code->inst.SPRL & 0x1F)) == SPR_XER;
if (code->inst.OPCD == 31 && code->inst.SUBOP10 == 467) // mtspr