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+ Teach peephole optimizer the cmc/adc trick I used in int_str.

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git-svn-id: trunk@9799 -
This commit is contained in:
daniel 2008-01-19 21:47:37 +00:00
parent 5fbc947ae8
commit 459382faa8
1 changed files with 176 additions and 121 deletions
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57
compiler/i386/popt386.pas
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@ -1745,6 +1745,7 @@ var
hp3: tai;
{$endif USECMOV}
UsedRegs, TmpUsedRegs: TRegSet;
carryadd_opcode: Tasmop;
begin
p := BlockStart;
@ -1756,8 +1757,61 @@ begin
Ait_Instruction:
begin
case taicpu(p).opcode Of
{$ifdef USECMOV}
A_Jcc:
begin
{ jb @@1 cmc
inc/dec operand --> adc/sbb operand,0
@@1:
... and ...
jnb @@1
inc/dec operand --> adc/sbb operand,0
@@1: }
if GetNextInstruction(p,hp1) and (hp1.typ=ait_instruction) and
GetNextInstruction(hp1,hp2) and (hp2.typ=ait_label) and
(Tasmlabel(Taicpu(p).oper[0]^.ref^.symbol)=Tai_label(hp2).labsym) then
begin
carryadd_opcode:=A_NONE;
if Taicpu(p).condition in [C_NAE,C_B] then
begin
if Taicpu(hp1).opcode=A_INC then
carryadd_opcode:=A_ADC;
if Taicpu(hp1).opcode=A_DEC then
carryadd_opcode:=A_SBB;
if carryadd_opcode<>A_NONE then
begin
Taicpu(p).clearop(0);
Taicpu(p).ops:=0;
Taicpu(p).is_jmp:=false;
Taicpu(p).opcode:=A_CMC;
Taicpu(p).condition:=C_NONE;
Taicpu(hp1).ops:=2;
Taicpu(hp1).loadoper(1,Taicpu(hp1).oper[0]^);
Taicpu(hp1).loadconst(0,0);
Taicpu(hp1).opcode:=carryadd_opcode;
continue;
end;
end;
if Taicpu(p).condition in [C_AE,C_NB] then
begin
if Taicpu(hp1).opcode=A_INC then
carryadd_opcode:=A_ADC;
if Taicpu(hp1).opcode=A_DEC then
carryadd_opcode:=A_SBB;
if carryadd_opcode<>A_NONE then
begin
asml.remove(p);
p.free;
Taicpu(hp1).ops:=2;
Taicpu(hp1).loadoper(1,Taicpu(hp1).oper[0]^);
Taicpu(hp1).loadconst(0,0);
Taicpu(hp1).opcode:=carryadd_opcode;
continue;
end;
end;
end;
{$ifdef USECMOV}
if (current_settings.cputype>=cpu_Pentium2) then
begin
{ check for
@ -1881,6 +1935,7 @@ begin
end;
end;
{$endif USECMOV}
end;
A_FSTP,A_FISTP:
if doFpuLoadStoreOpt(asmL,p) then
continue;