[Bug tree-optimization/59387] [4.9 Regression] wrong code (hangs) at -Os on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59387

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Unfortunately it triggers (sccp no longer optimizes) on quite a few testcases:

gcc.c-torture/execute/pr58277-1.c
gcc.c-torture/execute/pr58831.c
gcc.c-torture/execute/pr59387.c
gcc.dg/pr58010.c
gcc.dg/torture/pr55481.c
gcc.dg/torture/pr56366.c
gcc.dg/torture/pr59058.c
gcc.dg/torture/pr59245.c
gcc.dg/tree-ssa/loop-32.c
gcc.dg/tree-ssa/loop-33.c
gcc.dg/tree-ssa/loop-35.c
gcc.dg/tree-ssa/scev-6.c

(the first test only for -m64, all the rest both -m32 and -m64, the last even
FAILs because of that).  Couldn't we just transform that somehow into an
unsigned type computation instead in that case, at least for simple cases?