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* convert <real x>*<real x> into sqr(<real x>), it might reduces register

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pressure and/or memory accesses without a drawback

git-svn-id: trunk@18252 -
This commit is contained in:
florian 2011-08-17 16:00:16 +00:00
parent f6fbc17463
commit e796a878ca
1 changed files with 41 additions and 28 deletions
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69
compiler/nadd.pas
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@ -748,35 +748,48 @@ implementation
exit;
end;
{ the comparison is might be expensive and the nodes are usually only
equal if some previous optimizations were done so don't check
this simplification always
}
if (cs_opt_level2 in current_settings.optimizerswitches) and
is_boolean(left.resultdef) and is_boolean(right.resultdef) and
{ since the expressions might have sideeffects, we may only remove them
if short boolean evaluation is turned on }
(nf_short_bool in flags) then
begin
if left.isequal(right) then
begin
case nodetype of
andn,orn:
begin
result:=left;
left:=nil;
exit;
end;
{
xorn:
begin
result:=cordconstnode.create(0,resultdef,true);
exit;
end;
}
{ slow simplifications }
if (cs_opt_level2 in current_settings.optimizerswitches) then
begin
{ the comparison is might be expensive and the nodes are usually only
equal if some previous optimizations were done so don't check
this simplification always
}
if is_boolean(left.resultdef) and is_boolean(right.resultdef) and
{ since the expressions might have sideeffects, we may only remove them
if short boolean evaluation is turned on }
(nf_short_bool in flags) then
begin
if left.isequal(right) then
begin
case nodetype of
andn,orn:
begin
result:=left;
left:=nil;
exit;
end;
{
xorn:
begin
result:=cordconstnode.create(0,resultdef,true);
exit;
end;
}
end;
end;
end;
end;
end;
{ using sqr(x) for reals instead of x*x might reduces register pressure and/or
memory accesses while sqr(<real>) has no drawback }
if is_real(left.resultdef) and is_real(left.resultdef) and
left.isequal(right) then
begin
result:=cinlinenode.create(in_sqr_real,false,left);
left:=nil;
exit;
end;
end;
end;