https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53805
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |pinskia at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
--- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> ---
-O2 requires -fdisable-tree-ifcombine -fdisable-tree-phiopt2
-fno-tree-dominator-opts -fdisable-tree-phiopt3 -fdisable-tree-phiopt4
-fno-tree-vrp -fno-thread-jumps -fno-tree-tail-merge to preserve the
compare(s). Preserving the outer compare is enough, but it's going to be
difficult to achieve that?
Possibly fold a > b && a < b to (a > b, false). I suppose we'd need
an alternate magic return value for combine_comparisons to indicate the
result is constant but one - combined - comparison is to be preserved.
Or split that, have a function determining the comparison combination
for preserving IEEE flags and the one we have now.
