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* x86: Registers are now allocated properly during a FuncMov2Func

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optimisation
This commit is contained in:
J. Gareth "Curious Kit" Moreton 2023-02-02 08:37:18 +00:00 committed by FPK
parent 18eec3055e
commit 3cae3e7e48
1 changed files with 22 additions and 5 deletions
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27
compiler/x86/aoptx86.pas
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@ -2902,7 +2902,7 @@ unit aoptx86;
function TX86AsmOptimizer.FuncMov2Func(var p: tai; const hp1: tai): Boolean;
var
hp2: tai;
hp2, hp_regalloc: tai;
p_SourceReg, p_TargetReg: TRegister;
begin
@ -2962,15 +2962,32 @@ unit aoptx86;
else
begin
DebugMsg(SPeepholeOptimization + 'Removed MOV and changed destination on previous instruction to optimise register usage (FuncMov2Func)', p);
taicpu(hp2).oper[taicpu(hp2).ops-1]^.reg := p_TargetReg;
{ if %reg2 (p_SourceReg) is allocated before func., remove it completely }
hp_regalloc := FindRegAllocBackward(p_SourceReg, hp2);
if Assigned(hp_regalloc) then
begin
Asml.Remove(hp_regalloc);
if Assigned(FindRegDealloc(p_SourceReg, p)) then
begin
ExcludeRegFromUsedRegs(p_SourceReg, UsedRegs);
hp_regalloc.Free;
end
else
{ If the register is not explicitly deallocated, it's
being reused, so move the allocation to after func. }
AsmL.InsertAfter(hp_regalloc, hp2);
end;
if not RegInInstruction(p_TargetReg, hp2) then
begin
{ Since we're allocating from an earlier point, we
need to remove the register from the tracking }
ExcludeRegFromUsedRegs(p_TargetReg, TmpUsedRegs);
TransferUsedRegs(TmpUsedRegs);
AllocRegBetween(p_TargetReg, hp2, p, TmpUsedRegs);
end;
{ Actually make the changes }
taicpu(hp2).oper[taicpu(hp2).ops-1]^.reg := p_TargetReg;
RemoveCurrentp(p, hp1);
{ If the Func was another MOV instruction, we might get