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* x86: Fixed bug in "MovMovMov2MovMovMov" optimisation where a register wasn't properly tracked

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J. Gareth "Curious Kit" Moreton 2025-02-24 05:04:15 +00:00 committed by J. Gareth "Kit" Moreton
parent 79b240ec81
commit 4648f967bd
1 changed files with 7 additions and 5 deletions
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12
compiler/x86/aoptx86.pas
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@ -4369,6 +4369,13 @@ unit aoptx86;
begin
taicpu(hp2).loadreg(0, p_SourceReg);
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegsBetween(TmpUsedRegs, tai(p.Next), hp1);
{ Make sure the register is allocated between these instructions
even though it doesn't change value, since it may cause
optimisations on a later pass to behave incorrectly. (Fixes #41155) }
AllocRegBetween(p_SourceReg, hp1, hp2, TmpUsedRegs);
DebugMsg(SPeepholeOptimization + 'Optimised register duplication and memory read (MovMovMov2MovMovMov)', p);
Result := True;
if taicpu(hp2).oper[1]^.reg = p_TargetReg then
@ -4379,11 +4386,6 @@ unit aoptx86;
end
else
begin
{ Check to see if %reg2 is no longer in use }
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegsBetween(TmpUsedRegs, tai(p.Next), hp1);
UpdateUsedRegsBetween(TmpUsedRegs, tai(hp1.Next), hp2);
if not RegUsedAfterInstruction(p_TargetReg, hp2, TmpUsedRegs) then
begin
DebugMsg(SPeepholeOptimization + 'Mov2Nop 5b done', p);