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+ x86: LeaLea2Lea optimization

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git-svn-id: trunk@43177 -
This commit is contained in:
florian 2019-10-12 21:51:14 +00:00
parent fb91899457
commit 00c2fd4005
1 changed files with 42 additions and 0 deletions
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42
compiler/x86/aoptx86.pas
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@ -39,6 +39,7 @@ unit aoptx86;
function RegLoadedWithNewValue(reg : tregister; hp : tai) : boolean; override;
function InstructionLoadsFromReg(const reg : TRegister; const hp : tai) : boolean; override;
function RegReadByInstruction(reg : TRegister; hp : tai) : boolean;
function GetNextInstructionUsingReg(Current: tai; out Next: tai; reg: TRegister): Boolean;
protected
{ checks whether loading a new value in reg1 overwrites the entirety of reg2 }
function Reg1WriteOverwritesReg2Entirely(reg1, reg2: tregister): boolean;
@ -274,6 +275,19 @@ unit aoptx86;
end;
function TX86AsmOptimizer.GetNextInstructionUsingReg(Current: tai; out Next: tai; reg: TRegister): Boolean;
begin
Next:=Current;
repeat
Result:=GetNextInstruction(Next,Next);
until not (Result) or
not(cs_opt_level3 in current_settings.optimizerswitches) or
(Next.typ<>ait_instruction) or
RegInInstruction(reg,Next) or
is_calljmp(taicpu(Next).opcode);
end;
function TX86AsmOptimizer.InstructionLoadsFromReg(const reg: TRegister;const hp: tai): boolean;
begin
Result:=RegReadByInstruction(reg,hp);
@ -2181,6 +2195,34 @@ unit aoptx86;
result:=true;
end;
end;
{ changes
lea offset1(regX), reg1
lea offset2(reg1), reg1
to
lea offset1+offset2(regX), reg1 }
if GetNextInstructionUsingReg(p,hp1,taicpu(p).oper[1]^.reg) and
MatchInstruction(hp1,A_LEA,[S_L]) and
MatchOperand(taicpu(p).oper[1]^,taicpu(hp1).oper[1]^) and
(taicpu(hp1).oper[0]^.ref^.base=taicpu(p).oper[1]^.reg) and
(taicpu(p).oper[0]^.ref^.index=NR_NO) and
(taicpu(p).oper[0]^.ref^.relsymbol=nil) and
(taicpu(p).oper[0]^.ref^.scalefactor in [0,1]) and
(taicpu(p).oper[0]^.ref^.segment=NR_NO) and
(taicpu(p).oper[0]^.ref^.symbol=nil) and
(taicpu(p).oper[0]^.ref^.index=taicpu(hp1).oper[0]^.ref^.index) and
(taicpu(p).oper[0]^.ref^.relsymbol=taicpu(hp1).oper[0]^.ref^.relsymbol) and
(taicpu(p).oper[0]^.ref^.scalefactor=taicpu(hp1).oper[0]^.ref^.scalefactor) and
(taicpu(p).oper[0]^.ref^.segment=taicpu(hp1).oper[0]^.ref^.segment) and
(taicpu(p).oper[0]^.ref^.symbol=taicpu(hp1).oper[0]^.ref^.symbol) then
begin
DebugMsg(SPeepholeOptimization + 'LeaLea2Lea done',p);
inc(taicpu(hp1).oper[0]^.ref^.offset,taicpu(p).oper[0]^.ref^.offset);
taicpu(hp1).oper[0]^.ref^.base:=taicpu(p).oper[0]^.ref^.base;
asml.Remove(p);
p.Free;
p:=hp1;
result:=true;
end;
end;