[Bug tree-optimization/49234] [4.6/4.7/4.8 Regression] -Wstrict-overflow gives obviously unwarranted warning

[aldyh at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49234

--- Comment #18 from Aldy Hernandez <aldyh at gcc dot gnu.org> 2013-03-06 16:11:22 UTC ---
Created attachment 29599
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29599
do not set overflow on [+-]INF

This is Richi's suggestion from comment 10.  The problem is that it obviously
causes the VRP strict overflow warnings to fail:

$ make check-gcc RUNTESTFLAGS=dg.exp=*strict*
FAIL: gcc.dg/Wstrict-overflow-12.c correct warning (test for warnings, line 13)
FAIL: gcc.dg/Wstrict-overflow-13.c correct warning (test for warnings, line 14)
FAIL: gcc.dg/Wstrict-overflow-14.c  (test for warnings, line 13)
FAIL: gcc.dg/Wstrict-overflow-15.c  (test for warnings, line 13)
FAIL: gcc.dg/Wstrict-overflow-21.c correct warning (test for warnings, line 8)
FAIL: gcc.dg/no-strict-overflow-6.c scan-tree-dump optimized "return bits"
FAIL: c-c++-common/restrict-1.c  -Wc++-compat  (test for excess errors)

If y'all are willing to work with this patch and XFAIL these tests, I'm more
than happy to test and commit this patch, otherwise I may have to drop this for
now, as I am not volunteering to fix VRP for SSA cycles as suggested.  I am
switching gears from 4.8 bugfixing into other duties shortly...

Let me know...