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- Mov2Nop 5a and Mov2Nop 5b optimisations upgraded.

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J. Gareth "Curious Kit" Moreton 2024-04-18 12:39:43 +01:00 committed by FPK
parent f36fbd17b1
commit 1bc0ae3d18
1 changed files with 91 additions and 68 deletions
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159
compiler/x86/aoptx86.pas
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@ -4218,6 +4218,97 @@ unit aoptx86;
end;
end;
if taicpu(p).oper[0]^.typ = top_reg then
begin
{ oper[1] is a reference }
{ Saves on a large number of dereferences }
p_SourceReg := taicpu(p).oper[0]^.reg;
if NotFirstIteration and (cs_opt_level3 in current_settings.optimizerswitches) then
GetNextInstruction_p := GetNextInstructionUsingReg(p, hp1, p_SourceReg)
else
GetNextInstruction_p := GetNextInstruction(p, hp1);
if GetNextInstruction_p and (hp1.typ = ait_instruction) then
begin
if taicpu(p).oper[1]^.typ = top_reg then
begin
p_TargetReg := taicpu(p).oper[1]^.reg;
{ Change:
movl %reg1,%reg2
...
movl x(%reg1),%reg1 (If something other than %reg1 is written to, DeepMOVOpt would have caught it)
...
movl x(%reg2),%regX (%regX can be %reg2 or something else)
To:
movl %reg1,%reg2 (if %regX = %reg2, then remove this instruction)
...
movl x(%reg1),%reg1
...
movl %reg1,%regX
}
if MatchInstruction(hp1, A_MOV, [taicpu(p).opsize]) and
(taicpu(hp1).oper[0]^.typ = top_ref) { The other operand will be a register } and
(taicpu(hp1).oper[1]^.reg = p_SourceReg) and
RegInRef(p_SourceReg, taicpu(hp1).oper[0]^.ref^) and
not RegModifiedBetween(p_TargetReg, p, hp1) and
GetNextInstructionUsingReg(hp1, hp2, p_TargetReg) and
MatchInstruction(hp2, A_MOV, [taicpu(p).opsize]) and
(taicpu(hp2).oper[0]^.typ = top_ref) { The other operand will be a register } and
not RegModifiedBetween(p_SourceReg, hp1, hp2) then
begin
SourceRef := taicpu(hp2).oper[0]^.ref^;
if RegInRef(p_TargetReg, SourceRef) and
{ If %reg1 also appears in the second reference, then it will
not refer to the same memory block as the first reference }
not RegInRef(p_SourceReg, SourceRef) then
begin
{ Check to see if the references match if %reg2 is changed to %reg1 }
if SourceRef.base = p_TargetReg then
SourceRef.base := p_SourceReg;
if SourceRef.index = p_TargetReg then
SourceRef.index := p_SourceReg;
{ RefsEqual also checks to ensure both references are non-volatile }
if RefsEqual(taicpu(hp1).oper[0]^.ref^, SourceRef) then
begin
taicpu(hp2).loadreg(0, p_SourceReg);
DebugMsg(SPeepholeOptimization + 'Optimised register duplication and memory read (MovMovMov2MovMovMov)', p);
Result := True;
if taicpu(hp2).oper[1]^.reg = p_TargetReg then
begin
DebugMsg(SPeepholeOptimization + 'Mov2Nop 5a done', p);
RemoveCurrentP(p);
Exit;
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);
RemoveCurrentP(p);
Exit;
end;
end;
{ If we reach this point, p and hp1 weren't actually modified,
so we can do a bit more work on this pass }
end;
end;
end;
end;
end;
end;
GetNextInstruction_p:=GetNextInstruction(p, hp1);
{ All the next optimisations require a next instruction }
@ -4447,74 +4538,6 @@ unit aoptx86;
end;
{ mov x,reg1; mov y,reg1 -> mov y,reg1 is handled by the Mov2Nop 5 optimisation }
{ Change:
movl %reg1,%reg2
movl x(%reg1),%reg1 (If something other than %reg1 is written to, DeepMOVOpt would have caught it)
movl x(%reg2),%regX (%regX can be %reg2 or something else)
To:
movl %reg1,%reg2 (if %regX = %reg2, then remove this instruction)
movl x(%reg1),%reg1
movl %reg1,%regX
}
if MatchOpType(taicpu(p), top_reg, top_reg) then
begin
p_SourceReg := taicpu(p).oper[0]^.reg;
{ Remember that p_TargetReg contains taicpu(p).oper[1]^.reg }
if (taicpu(hp1).oper[0]^.typ = top_ref) { The other operand will be a register } and
(taicpu(hp1).oper[1]^.reg = p_SourceReg) and
RegInRef(p_SourceReg, taicpu(hp1).oper[0]^.ref^) and
GetNextInstruction(hp1, hp2) and
MatchInstruction(hp2, A_MOV, [taicpu(p).opsize]) and
(taicpu(hp2).oper[0]^.typ = top_ref) { The other operand will be a register } then
begin
SourceRef := taicpu(hp2).oper[0]^.ref^;
if RegInRef(p_TargetReg, SourceRef) and
{ If %reg1 also appears in the second reference, then it will
not refer to the same memory block as the first reference }
not RegInRef(p_SourceReg, SourceRef) then
begin
{ Check to see if the references match if %reg2 is changed to %reg1 }
if SourceRef.base = p_TargetReg then
SourceRef.base := p_SourceReg;
if SourceRef.index = p_TargetReg then
SourceRef.index := p_SourceReg;
{ RefsEqual also checks to ensure both references are non-volatile }
if RefsEqual(taicpu(hp1).oper[0]^.ref^, SourceRef) then
begin
taicpu(hp2).loadreg(0, p_SourceReg);
DebugMsg(SPeepholeOptimization + 'Optimised register duplication and memory read (MovMovMov2MovMovMov)', p);
Result := True;
if taicpu(hp2).oper[1]^.reg = p_TargetReg then
begin
DebugMsg(SPeepholeOptimization + 'Mov2Nop 5a done', p);
RemoveCurrentP(p, hp1);
Exit;
end
else
begin
{ Check to see if %reg2 is no longer in use }
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegs(TmpUsedRegs, tai(p.Next));
UpdateUsedRegs(TmpUsedRegs, tai(hp1.Next));
if not RegUsedAfterInstruction(p_TargetReg, hp2, TmpUsedRegs) then
begin
DebugMsg(SPeepholeOptimization + 'Mov2Nop 5b done', p);
RemoveCurrentP(p, hp1);
Exit;
end;
end;
{ If we reach this point, p and hp1 weren't actually modified,
so we can do a bit more work on this pass }
end;
end;
end;
end;
end;
{ search further than the next instruction for a mov (as long as it's not a jump) }