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* patch by J. Gareth Moreton: Memory CMP optimisation, resolves #38907

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git-svn-id: trunk@49382 -
This commit is contained in:
florian 2021-05-19 20:29:04 +00:00
parent 12a0083c59
commit 6f482952de
1 changed files with 64 additions and 15 deletions
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79
compiler/x86/aoptx86.pas
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@ -2819,24 +2819,73 @@ unit aoptx86;
Result:=true; Result:=true;
exit; exit;
end; end;
if MatchOpType(taicpu(p),top_reg,top_ref) and if MatchInstruction(hp1,A_CMP,A_TEST,[taicpu(p).opsize]) then
MatchInstruction(hp1,A_CMP,A_TEST,[taicpu(p).opsize]) and
(taicpu(hp1).oper[1]^.typ = top_ref) and
RefsEqual(taicpu(p).oper[1]^.ref^, taicpu(hp1).oper[1]^.ref^) then
begin begin
{ change if MatchOpType(taicpu(p),top_reg,top_ref) and
mov reg1, mem1 (taicpu(hp1).oper[1]^.typ = top_ref) and
test/cmp x, mem1 RefsEqual(taicpu(p).oper[1]^.ref^, taicpu(hp1).oper[1]^.ref^) then
begin
{ change
mov reg1, mem1
test/cmp x, mem1
to to
mov reg1, mem1 mov reg1, mem1
test/cmp x, reg1 test/cmp x, reg1
} }
taicpu(hp1).loadreg(1,taicpu(p).oper[0]^.reg); taicpu(hp1).loadreg(1,taicpu(p).oper[0]^.reg);
DebugMsg(SPeepholeOptimization + 'MovTestCmp2MovTestCmp 1',hp1); DebugMsg(SPeepholeOptimization + 'MovTestCmp2MovTestCmp 1',hp1);
AllocRegBetween(taicpu(p).oper[0]^.reg,p,hp1,usedregs); AllocRegBetween(taicpu(p).oper[0]^.reg,p,hp1,usedregs);
exit; Result := True;
Exit;
end;
if MatchOpType(taicpu(p),top_ref,top_reg) and
{ The x86 assemblers have difficulty comparing values against absolute addresses }
(taicpu(p).oper[0]^.ref^.refaddr in [addr_no, addr_pic, addr_pic_no_got]) and
(taicpu(hp1).oper[0]^.typ <> top_ref) and
MatchOperand(taicpu(hp1).oper[1]^, taicpu(p).oper[1]^.reg) and
(
(
(taicpu(hp1).opcode = A_TEST)
) or (
(taicpu(hp1).opcode = A_CMP) and
{ A sanity check more than anything }
not MatchOperand(taicpu(hp1).oper[0]^, taicpu(p).oper[1]^.reg)
)
) then
begin
{ change
mov mem, %reg
cmp/test x, %reg / test %reg,%reg
(reg deallocated)
to
cmp/test x, mem / cmp 0, mem
}
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegs(TmpUsedRegs, tai(p.Next));
if not RegUsedAfterInstruction(taicpu(p).oper[1]^.reg, hp1, TmpUsedRegs) then
begin
{ Convert test %reg,%reg or test $-1,%reg to cmp $0,mem }
if (taicpu(hp1).opcode = A_TEST) and
(
MatchOperand(taicpu(hp1).oper[0]^, taicpu(p).oper[1]^.reg) or
MatchOperand(taicpu(hp1).oper[0]^, -1)
) then
begin
taicpu(hp1).opcode := A_CMP;
taicpu(hp1).loadconst(0, 0);
end;
taicpu(hp1).loadref(1, taicpu(p).oper[0]^.ref^);
DebugMsg(SPeepholeOptimization + 'MOV/CMP -> CMP (memory check)', p);
RemoveCurrentP(p, hp1);
Result := True;
Exit;
end;
end;
end; end;
if MatchInstruction(hp1,A_LEA,[S_L{$ifdef x86_64},S_Q{$endif x86_64}]) and if MatchInstruction(hp1,A_LEA,[S_L{$ifdef x86_64},S_Q{$endif x86_64}]) and