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+ LeaCallLeaRet2Jmp

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git-svn-id: trunk@43372 -
This commit is contained in:
florian 2019-11-02 22:37:30 +00:00
parent 6842c5784d
commit 1fc7667b3b
1 changed files with 53 additions and 0 deletions
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53
compiler/x86/aoptx86.pas
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@ -4029,6 +4029,8 @@ unit aoptx86;
function TX86AsmOptimizer.PostPeepholeOptLea(var p : tai) : Boolean;
var
hp1, hp2, hp3: tai;
begin
Result:=false;
if not (RegInUsedRegs(NR_DEFAULTFLAGS,UsedRegs)) and
@ -4051,6 +4053,57 @@ unit aoptx86;
taicpu(p).opcode:=A_ADD;
DebugMsg(SPeepholeOptimization + 'Lea2AddIndex done',p);
result:=true;
end
{ replace
leal(q) x(<stackpointer>),<stackpointer>
call procname
leal(q) -x(<stackpointer>),<stackpointer>
ret
by
jmp procname
this should never hurt except when pic is used, not sure
how to handle it then
but do it only on level 4 because it destroys stack back traces
}
else if (cs_opt_level4 in current_settings.optimizerswitches) and
MatchOpType(taicpu(p),top_ref,top_reg) and
(taicpu(p).oper[0]^.ref^.base=NR_STACK_POINTER_REG) and
(taicpu(p).oper[0]^.ref^.index=NR_NO) and
(taicpu(p).oper[0]^.ref^.symbol=nil) and
(taicpu(p).oper[0]^.ref^.relsymbol=nil) and
(taicpu(p).oper[0]^.ref^.segment=NR_NO) and
(taicpu(p).oper[1]^.reg=NR_STACK_POINTER_REG) and
GetNextInstruction(p, hp1) and
{ trick to skip label }
((hp1.typ=ait_instruction) or GetNextInstruction(hp1, hp1)) and
MatchInstruction(hp1,A_CALL,[S_NO]) and
GetNextInstruction(hp1, hp2) and
MatchInstruction(hp2,A_LEA,[taicpu(p).opsize]) and
MatchOpType(taicpu(hp2),top_ref,top_reg) and
(taicpu(hp2).oper[0]^.ref^.offset=-taicpu(p).oper[0]^.ref^.offset) and
(taicpu(hp2).oper[0]^.ref^.base=NR_STACK_POINTER_REG) and
(taicpu(hp2).oper[0]^.ref^.index=NR_NO) and
(taicpu(hp2).oper[0]^.ref^.symbol=nil) and
(taicpu(hp2).oper[0]^.ref^.relsymbol=nil) and
(taicpu(hp2).oper[0]^.ref^.segment=NR_NO) and
(taicpu(hp2).oper[1]^.reg=NR_STACK_POINTER_REG) and
GetNextInstruction(hp2, hp3) and
{ trick to skip label }
((hp3.typ=ait_instruction) or GetNextInstruction(hp3, hp3)) and
MatchInstruction(hp3,A_RET,[S_NO]) and
(taicpu(hp3).ops=0) then
begin
taicpu(hp1).opcode := A_JMP;
taicpu(hp1).is_jmp := true;
DebugMsg(SPeepholeOptimization + 'LeaCallLeaRet2Jmp done',p);
RemoveCurrentP(p);
AsmL.Remove(hp2);
hp2.free;
AsmL.Remove(hp3);
hp3.free;
Result:=true;
end;
end;