mirror of
https://gitlab.com/freepascal.org/fpc/source.git
synced 2025-10-22 13:13:25 +02:00
+ all code generator generated "mov reg1,reg2" instructions are now
attempted to be removed using the replacereg code
(-dnewoptimizations)
* small fixes to -dreplacereg code
This commit is contained in:
Jonas Maebe
parent
b15a98cfa4
commit
02381105d6
@ -189,12 +189,11 @@ Begin {CheckSequence}
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{ hp2 now containts the last instruction of the sequence }
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{ get the writestate at this point of the register in TmpState }
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TmpState := PPaiProp(hp2^.OptInfo)^.Regs[RegCounter].WState;
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{ hp3 := first instruction after the sequence }
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GetNextInstruction(hp2, hp2);
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{ now, even though reg is in RegsLoadedForRef, sometimes it's still used }
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{ afterwards. It is not if either it is not in usedregs anymore after the }
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{ sequence, or if it is loaded with a new value right after the sequence }
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If (TmpState = PPaiProp(hp2^.OptInfo)^.Regs[RegCounter].WState) And
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If GetNextInstruction(hp2, hp2) and
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(TmpState = PPaiProp(hp2^.OptInfo)^.Regs[RegCounter].WState) And
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(RegCounter in PPaiProp(hp2^.OptInfo)^.UsedRegs) Then
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{ it is still used, so remove it from RegsLoadedForRef }
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Begin
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@ -430,24 +429,6 @@ begin
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end
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end;
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function regLoadedWithNewValue(reg: tregister; hp: pai): boolean;
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{ assumes reg is a 32bit register }
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var p: paicpu;
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begin
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p := paicpu(hp);
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regLoadedWithNewValue :=
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assigned(hp) and
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((hp^.typ = ait_instruction) and
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(((p^.opcode = A_MOV) or
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(p^.opcode = A_MOVZX) or
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(p^.opcode = A_MOVSX) or
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(p^.opcode = A_LEA)) and
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(p^.oper[1].typ = top_reg) and
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(Reg32(p^.oper[1].reg) = reg)) or
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((p^.opcode = A_POP) and
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(Reg32(p^.oper[0].reg) = reg)));
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end;
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Procedure RestoreRegContentsTo(reg: TRegister; const c: TContent; p, endP: pai);
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var
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{$ifdef replaceregdebug}
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@ -526,19 +507,20 @@ end;
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function NoHardCodedRegs(p: paicpu): boolean;
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var chCount: byte;
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begin
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if (p^.opcode = A_IMUL) then
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noHardCodedRegs := p^.ops <> 1
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else
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begin
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NoHardCodedRegs := true;
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with InsProp[p^.opcode] do
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for chCount := 1 to MaxCh do
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if Ch[chCount] in ([Ch_REAX..Ch_MEDI,Ch_WMemEDI,Ch_All]-[Ch_RESP,Ch_WESP,Ch_RWESP]) then
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begin
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NoHardCodedRegs := false;
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break
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end;
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end;
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case p^.opcode of
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A_IMUL: noHardCodedRegs := p^.ops <> 1;
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else
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begin
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NoHardCodedRegs := true;
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with InsProp[p^.opcode] do
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for chCount := 1 to MaxCh do
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if Ch[chCount] in ([Ch_REAX..Ch_MEDI,Ch_WMemEDI,Ch_All]-[Ch_RESP,Ch_WESP,Ch_RWESP]) then
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begin
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NoHardCodedRegs := false;
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break
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end;
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end;
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end;
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end;
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Procedure ChangeReg(var Reg: TRegister; orgReg, newReg: TRegister);
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@ -575,7 +557,8 @@ function RegSizesOK(oldReg,newReg: TRegister; p: paicpu): boolean;
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var opCount: byte;
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begin
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RegSizesOK := true;
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if not(IsGP32reg(oldReg) and IsGP32Reg(newReg)) then
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{ if only one of them is a general purpose register ... }
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if (IsGP32reg(oldReg) xor IsGP32Reg(newReg)) then
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begin
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for opCount := 0 to 2 do
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if (p^.oper[opCount].typ = top_reg) and
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@ -690,7 +673,7 @@ begin
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end;
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function ReplaceReg(orgReg, newReg: TRegister; p: pai;
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const c: TContent): Boolean;
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const c: TContent; orgRegCanBeModified: Boolean): Boolean;
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{ Tries to replace orgreg with newreg in all instructions coming after p }
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{ until orgreg gets loaded with a new value. Returns true if successful, }
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{ false otherwise. If successful, the contents of newReg are set to c, }
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@ -709,23 +692,42 @@ begin
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begin
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tmpResult :=
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getNextInstruction(endP,endP);
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if tmpresult and not assigned(endP^.optInfo) then
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begin
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hp := new(pai_asm_comment,init(strpnew('next no optinfo')));
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hp^.next := endp;
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hp^.previous := endp^.previous;
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endp^.previous := hp;
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if assigned(hp^.previous) then
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hp^.previous^.next := hp;
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exit;
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end;
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If tmpResult and
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{ don't take into account instructions that will be removed }
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Not (PPaiProp(endP^.optInfo)^.canBeRemoved) then
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begin
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sequenceEnd :=
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noHardCodedRegs(paicpu(endP)) and
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(RegLoadedWithNewValue(newReg,paicpu(endP)) or
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(GetNextInstruction(endp,hp) and
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FindRegDealloc(newReg,hp)));
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RegLoadedWithNewValue(newReg,true,paicpu(endP)) or
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(GetNextInstruction(endp,hp) and
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FindRegDealloc(newReg,hp));
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newRegModified :=
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newRegModified or
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(not(sequenceEnd) and
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RegModifiedByInstruction(newReg,endP));
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orgRegRead := newRegModified and RegReadByInstruction(orgReg,endP);
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sequenceEnd := SequenceEnd and not(newRegModified and orgRegRead);
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sequenceEnd := SequenceEnd and
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{ since newReg will be replaced by orgReg, we can't allow that newReg }
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{ gets modified if orgReg is still read afterwards (since after }
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{ replacing, this would mean that orgReg first gets modified and then }
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{ gets read in the assumption it still contains the unmodified value) }
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not(newRegModified and orgRegRead) and
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{ since newReg will be replaced by orgReg, we can't allow that newReg }
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{ gets modified if orgRegCanBeModified = false }
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(orgRegCanBeModified or not(newRegModified));
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tmpResult :=
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not(newRegModified and orgRegRead) and
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(orgRegCanBeModified or not(newRegModified)) and
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(endP^.typ = ait_instruction) and
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not(paicpu(endP)^.is_jmp) and
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NoHardCodedRegs(paicpu(endP)) and
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@ -734,9 +736,10 @@ begin
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end;
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end;
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sequenceEnd := sequenceEnd and
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RegSizesOk(orgReg,newReg,paicpu(endP)) and
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not(newRegModified and
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(orgReg in PPaiProp(endP^.optInfo)^.usedRegs) and
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not(RegLoadedWithNewValue(orgReg,paicpu(endP))));
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not(RegLoadedWithNewValue(orgReg,true,paicpu(endP))));
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if SequenceEnd then
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begin
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@ -777,11 +780,11 @@ begin
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{ isn't used anymore }
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{ In case b, the newreg was completely replaced by oldreg, so it's contents }
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{ are unchanged compared the start of this sequence, so restore them }
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If RegLoadedWithNewValue(newReg,endP) then
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If RegLoadedWithNewValue(newReg,true,endP) then
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GetLastInstruction(endP,hp)
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else hp := endP;
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if (p <> endp) or
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not RegLoadedWithNewValue(newReg,endP) then
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not RegLoadedWithNewValue(newReg,true,endP) then
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RestoreRegContentsTo(newReg, c ,p, hp);
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{ In both case a and b, it is possible that the new register was modified }
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{ (e.g. an add/sub), so if it was replaced by oldreg in that instruction, }
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@ -956,7 +959,7 @@ Begin
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getLastInstruction(p,hp3);
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If not ReplaceReg(RegInfo.New2OldReg[RegCounter],
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regCounter,hp3,
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PPaiProp(hp4^.optInfo)^.Regs[regCounter]) then
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PPaiProp(hp4^.optInfo)^.Regs[regCounter],true) then
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begin
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{$endif replacereg}
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hp3 := New(Paicpu,Op_Reg_Reg(A_MOV, S_L,
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@ -1064,6 +1067,21 @@ Begin
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End;
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End;
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End;
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{$ifdef replacereg}
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top_Reg:
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{ try to replace the new reg with the old reg }
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if (paicpu(p)^.opcode = A_MOV) and
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getLastInstruction(p,hp4) then
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begin
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Case paicpu(p)^.oper[1].typ of
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top_Reg:
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if ReplaceReg(paicpu(p)^.oper[0].reg,
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paicpu(p)^.oper[1].reg,p,
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PPaiProp(hp4^.optInfo)^.Regs[regCounter],false) then
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PPaiProp(p^.optInfo)^.canBeRemoved := true;
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end
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end;
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{$endif replacereg}
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Top_Const:
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Begin
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Case Paicpu(p)^.oper[1].typ Of
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@ -1149,7 +1167,13 @@ End.
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{
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$Log$
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Revision 1.39 2000-01-13 13:07:05 jonas
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Revision 1.40 2000-01-22 16:10:06 jonas
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+ all code generator generated "mov reg1,reg2" instructions are now
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attempted to be removed using the replacereg code
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(-dnewoptimizations)
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* small fixes to -dreplacereg code
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Revision 1.39 2000/01/13 13:07:05 jonas
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* released -dalignreg
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* some small fixes to -dnewOptimizations helper procedures
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