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* remove unneeded movs

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git-svn-id: trunk@21885 -
This commit is contained in:
florian 2012-07-11 20:58:52 +00:00
parent d6066ed51a
commit 701a5d76bb
1 changed files with 47 additions and 23 deletions
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70
compiler/arm/aoptcpu.pas
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@ -505,33 +505,57 @@ Implementation
hp1.free;
end;
{
This changes the very common
mov r0, #0
str r0, [...]
mov r0, #0
str r0, [...]
and removes all superfluous mov instructions
{
optimize
mov rX, yyyy
....
}
if (taicpu(p).ops = 2) and
(taicpu(p).oper[1]^.typ = top_const) and
GetNextInstruction(p,hp1) then
begin
while MatchInstruction(hp1, A_STR, [taicpu(p).condition], []) and
MatchOperand(taicpu(p).oper[0]^, taicpu(hp1).oper[0]^) and
GetNextInstruction(hp1, hp2) and
MatchInstruction(hp2, A_MOV, [taicpu(p).condition], [PF_None]) and
(taicpu(hp2).ops = 2) and
MatchOperand(taicpu(hp2).oper[0]^, taicpu(p).oper[0]^) and
MatchOperand(taicpu(hp2).oper[1]^, taicpu(p).oper[1]^) do
begin
asml.insertbefore(tai_comment.Create(strpnew('Peephole MovStrMov done')), hp2);
GetNextInstruction(hp2,hp1);
asml.remove(hp2);
hp2.free;
if not assigned(hp1) then break;
end;
{
This changes the very common
mov r0, #0
str r0, [...]
mov r0, #0
str r0, [...]
and removes all superfluous mov instructions
}
if (taicpu(p).oper[1]^.typ = top_const) and
(taicpu(hp1).opcode=A_STR) then
while MatchInstruction(hp1, A_STR, [taicpu(p).condition], []) and
MatchOperand(taicpu(p).oper[0]^, taicpu(hp1).oper[0]^) and
GetNextInstruction(hp1, hp2) and
MatchInstruction(hp2, A_MOV, [taicpu(p).condition], [PF_None]) and
(taicpu(hp2).ops = 2) and
MatchOperand(taicpu(hp2).oper[0]^, taicpu(p).oper[0]^) and
MatchOperand(taicpu(hp2).oper[1]^, taicpu(p).oper[1]^) do
begin
asml.insertbefore(tai_comment.Create(strpnew('Peephole MovStrMov done')), hp2);
GetNextInstruction(hp2,hp1);
asml.remove(hp2);
hp2.free;
if not assigned(hp1) then break;
end
{
This removes the first mov from
mov rX,...
mov rX,...
}
else if taicpu(hp1).opcode=A_MOV then
while MatchInstruction(hp1, A_MOV, [taicpu(p).condition], [taicpu(p).oppostfix]) and
(taicpu(hp1).ops = 2) and
MatchOperand(taicpu(p).oper[0]^, taicpu(hp1).oper[0]^) do
begin
asml.insertbefore(tai_comment.Create(strpnew('Peephole MovMov done')), p);
asml.remove(p);
p.free;
p:=hp1;
GetNextInstruction(hp1,hp1);
if not assigned(hp1) then
break;
end;
end;
{
change