------- Comment #25 from rguenth at gcc dot gnu dot org 2006-02-04 13:52
-------
On the mainline now even g() regresses, probably because of the reassoc pass
rewrite. Of course on the mainline this is also "fixed" by --param
salias-max-array-elements=6, which makes load/store motion work on the tree
level.
It looks like expand only with
<L0>:;
r[0] = r[0] + r[1];
r[1] = r[1] + r[2];
r[2] = r[2] + r[3];
r[3] = r[3] + r[4];
r[4] = r[4] + r[5];
r[5] = r[5] + r[0];
ivtmp.63 = ivtmp.63 + 1;
if (ivtmp.63 != (unsigned int) n.68) goto <L0>; else goto <L2>;
produces RTL that we can optimize to
.L13:
addl %edi, %esi
incl %ebp
addl %ebx, %edi
addl %ecx, %ebx
addl %edx, %ecx
addl %eax, %edx
addl %esi, %eax
cmpl (%esp), %ebp
jne .L13
but not for (mainline)
<L0>:;
D.1544 = r[1] + r[0];
r[0] = D.1544;
r[1] = r[2] + r[1];
r[2] = r[3] + r[2];
r[3] = r[4] + r[3];
r[4] = r[5] + r[4];
r[5] = D.1544 + r[5];
n.61 = n.61 - 1;
if (n.61 != 0) goto <L0>; else goto <L2>;
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19580
