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+ optimize op ... / cmp .... when possible

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git-svn-id: trunk@22200 -
This commit is contained in:
florian 2012-08-23 08:54:47 +00:00
parent 2d653999b4
commit 2d2c66467c
1 changed files with 13 additions and 7 deletions
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20
compiler/arm/aoptcpu.pas
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@ -351,7 +351,6 @@ Implementation
case p.typ of
ait_instruction:
begin
(* optimization proved not to be safe, see tw4768.pp
{
change
<op> reg,x,y
@ -361,27 +360,34 @@ Implementation
}
{ this optimization can applied only to the currently enabled operations because
the other operations do not update all flags and FPC does not track flag usage }
if (taicpu(p).opcode in [A_ADC,A_ADD,A_SUB {A_UDIV,A_SDIV,A_MUL,A_MVN,A_MOV,A_ORR,A_EOR,A_AND}]) and
if ((taicpu(p).opcode in [A_ADC,A_ADD,A_SUB,A_MUL,A_MVN,A_MOV,A_ORR,A_EOR,A_AND]) or
{ those two values are > 255 so check separately }
(taicpu(p).opcode=A_UDIV) or
(taicpu(p).opcode=A_SDIV)
) and
(taicpu(p).oppostfix = PF_None) and
(taicpu(p).condition = C_None) and
GetNextInstruction(p, hp1) and
MatchInstruction(hp1, A_CMP, [C_None], [PF_None]) and
(taicpu(hp1).oper[1]^.typ = top_const) and
(taicpu(p).oper[0]^.reg = taicpu(hp1).oper[0]^.reg) and
(taicpu(hp1).oper[1]^.val = 0) { and
(taicpu(hp1).oper[1]^.val = 0) and
GetNextInstruction(hp1, hp2) and
(tai(hp2).typ = ait_instruction) and
// be careful here, following instructions could use other flags
// however after a jump fpc never depends on the value of flags
{ be careful here, following instructions could use other flags
however after a jump fpc never depends on the value of flags }
(taicpu(hp2).opcode = A_B) and
(taicpu(hp2).condition in [C_EQ,C_NE,C_MI,C_PL])} then
(((taicpu(p).opcode in [A_ADC,A_ADD,A_SUB]) and
(taicpu(hp2).condition in [C_EQ,C_NE,C_MI,C_PL])) or
(taicpu(hp2).condition in [C_EQ,C_NE])) and
assigned(FindRegDealloc(NR_DEFAULTFLAGS,tai(hp2.Next))) then
begin
taicpu(p).oppostfix:=PF_S;
asml.insertbefore(tai_comment.Create(strpnew('Peephole OpCmp2OpS done')), p);
asml.remove(hp1);
hp1.free;
end
else
*)
case taicpu(p).opcode of
A_STR:
begin