[Bug tree-optimization/78725] [7 Regression] wrong code at -O3 on x86_64-linux-gnu (in both 32-bit and 64-bit modes)

matz at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Mon Dec 12 15:33:00 GMT 2016


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78725

--- Comment #5 from Michael Matz <matz at gcc dot gnu.org> ---
(In reply to Michael Matz from comment #4)
> Thanks for the second testcase as well.  It's not quite the same
> miscompilation
> (the induction vars don't overflow), but a related one (the value of d
> considered in the conditional statement is the final one after the d-loop
> finishes, not the value at the use itself).  Fixed with v2 of the patch,
> at https://gcc.gnu.org/ml/gcc-patches/2016-12/msg01035.html .

(Btw: nice testcases, I assume they are generated somehow by a code generator
that knows a bit about semantics?)


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