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* CSE now updates the RegAlloc's

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This commit is contained in:
Jonas Maebe 1999-10-01 13:51:40 +00:00
parent ca15c4c4fb
commit 6ca2b6e276
1 changed files with 81 additions and 48 deletions
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47
compiler/csopt386.pas
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@ -208,6 +208,36 @@ Begin {CheckSequence}
{$endif fpc}
End; {CheckSequence}
Procedure AllocRegBetween(AsmL: PAasmOutput; Reg: TRegister; p1, p2: Pai);
{ allocates register Reg between (and including) instructions p1 and p2 }
{ the type of p1 and p2 must not be in SkipInstr }
var hp: pai;
Begin
If not(assigned(p1)) Then
{ this happens with registers which are loaded implicitely, outside the }
{ current block (e.g. esi with self) }
exit;
Repeat
If Assigned(p1^.OptInfo) Then
Include(PPaiProp(p1^.OptInfo)^.UsedRegs,Reg);
p1 := Pai(p1^.next);
Repeat
While (p1^.typ in (SkipInstr-[ait_regalloc])) Do
p1 := Pai(p1^.next);
{ remove all allocation/deallocation info about the register in between }
If (p1^.typ = ait_regalloc) Then
If (PaiRegAlloc(p1)^.Reg = Reg) Then
Begin
hp := Pai(p1^.Next);
AsmL^.Remove(p1);
Dispose(p1, Done);
p1 := hp;
End
Else p1 := Pai(p1^.next);
Until Not(p1^.typ in SkipInstr);
Until p1 = p2;
End;
Procedure DoCSE(AsmL: PAasmOutput; First, Last: Pai);
{marks the instructions that can be removed by RemoveInstructs. They're not
removed immediately because sometimes an instruction needs to be checked in
@ -288,8 +318,6 @@ Begin
InsertLLItem(AsmL, Pai(hp2^.Previous), hp2, hp3);
{hp4 is used to get the contents of the registers before the sequence}
GetLastInstruction(hp2, hp4);
{ If some registers were different in the old and the new sequence, move }
{ the contents of those old registers to the new ones }
{$IfDef CSDebug}
For RegCounter := R_EAX To R_EDI Do
If (RegCounter in RegInfo.RegsLoadedForRef) Then
@ -299,18 +327,21 @@ Begin
InsertLLItem(AsmL, Pai(hp2^.previous), hp2, hp5);
End;
{$EndIf CSDebug}
{ If some registers were different in the old and the new sequence, move }
{ the contents of those old registers to the new ones }
For RegCounter := R_EAX To R_EDI Do
If Not(RegCounter in [R_ESP,procinfo^.framepointer]) And
(RegInfo.New2OldReg[RegCounter] <> R_NO) Then
Begin
If (RegInfo.New2OldReg[RegCounter] <> R_NO) Then
AllocRegBetween(AsmL,RegInfo.New2OldReg[RegCounter],
PPaiProp(hp4^.OptInfo)^.Regs[RegInfo.New2OldReg[RegCounter]].StartMod,hp2);
If Not(RegCounter In RegInfo.RegsLoadedForRef) And
{old reg new reg}
(RegInfo.New2OldReg[RegCounter] <> RegCounter) Then
Begin
hp3 := New(Paicpu,Op_Reg_Reg(A_MOV, S_L,
{old reg new reg}
RegInfo.New2OldReg[RegCounter], RegCounter));
hp3^.fileinfo := hp2^.fileinfo;
InsertLLItem(AsmL, Pai(hp2^.previous), hp2, hp3);
End
Else
@ -332,7 +363,6 @@ Begin
{ RegLoadedForRef, have to be changed to their contents from before the }
{ sequence. }
Begin
{load Cnt2 with the total number of instructions of this sequence}
Cnt2 := PPaiProp(hp4^.OptInfo)^.
Regs[RegInfo.New2OldReg[RegCounter]].NrOfMods;
@ -499,7 +529,10 @@ End.
{
$Log$
Revision 1.26 1999-09-30 14:43:13 jonas
Revision 1.27 1999-10-01 13:51:40 jonas
* CSE now updates the RegAlloc's
Revision 1.26 1999/09/30 14:43:13 jonas
* fixed small efficiency which caused some missed optimizations (saves 1
assembler instruction on the whole compiler/RTL source tree! :)