------- Comment #8 from rguenth at gcc dot gnu dot org 2008-08-17 10:20 -------
Hm, I have a patch that makes PRE phi-translation use the oracle, but still
the testcase is not optimized because for
struct Loc { int x[1]; };
int foo (int i, int b)
{
struct Loc IND;
if (b)
IND.x[0] = i;
else
IND.x[0] = i;
return IND.x[0];
}
PRE doesn't do anything either (instead this case looks like something
FRE can handle with the patch I have for PR23094).
But the patch handles
struct Loc { int x[2]; };
int foo (int i, int j, int b)
{
struct Loc IND;
if (b)
{
IND.x[0] = i;
IND.x[1] = 1;
}
else
{
IND.x[0] = j;
IND.x[1] = 0;
}
return IND.x[0];
}
I suspect that the original testcase was handled by DOM, which also lacks
support from the alias-oracle. Hmm, checking with 4.3 it doesn't do anything
for the testcase - not even the PRE opportunity for IND.x[2]. So
eventually this was something done by LIM, as the testcase was placed
inside a loop? ...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35972
