http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46528
--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-24
21:50:55 UTC ---
The CFGs match, the spanning tree as well. Instrumenting needs to split
two edges, but that shouldn't matter and happens elsewhere as well.
But we have in .optimized (of the -fprofile-generate case)
<bb 11>:
pretmp.676_490 = (unsigned int) D.8874_415;
pretmp.677_491 = macro_39->params;
pretmp.681_496 = *.LPBX1[67];
<bb 12>:
# len_429 = PHI <len_55(12), len_44(11)>
# ivtmp.698_171 = PHI <ivtmp.698_92(12), 0(11)>
D.8871_52 = MEM[base: pretmp.677_491, index: ivtmp.698_171, step: 8, offset:
0B];
D.8872_53 = D.8871_52->ident.len;
D.8873_54 = D.8872_53 + 1;
len_55 = D.8873_54 + len_429;
# DEBUG len => len_55
# DEBUG i => D#11
# DEBUG len => len_55
# DEBUG i => D#11
ivtmp.698_92 = ivtmp.698_171 + 1;
i_64 = (unsigned int) ivtmp.698_92;
if (i_64 < pretmp.676_490)
goto <bb 12>;
else
goto <bb 13>;
<bb 13>:
D.11695_474 = pretmp.681_496 + 1;
D.11697_493 = pretmp.676_490 + 4294967295;
D.11698_127 = (long int) D.11697_493;
*.LPBX1_I_lsm.686_486 = D.11695_474 + D.11698_127;
*.LPBX1[67] = *.LPBX1_I_lsm.686_486;
which at least looks odd to me and produced by SCCP (supposedly
*.LPBX1[67] + 1 + (long)(niter - 1), so not 100% invalid).
Soooo ... for those who can reproduce it, can you try with
-fno-tree-scev-cprop?
I'll wrap my brain around that above computation tomorrow ;)
