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[Bug c/56143] Incorrect code generation with -O0 in x86_64
- From: "pcpa at mandriva dot com.br" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 30 Jan 2013 02:19:09 +0000
- Subject: [Bug c/56143] Incorrect code generation with -O0 in x86_64
- Auto-submitted: auto-generated
- References: <bug-56143-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56143
--- Comment #3 from Paulo CÃsar Pereira de Andrade <pcpa at mandriva dot com.br> 2013-01-30 02:19:09 UTC ---
(In reply to comment #1)
> *_jit->pc.ui++ = i0 - (_jit->pc.w + 4);
>
> You have a sequence point issue. This is like doing:
> *i++ = i0 - (i + 4);
Thanks for the comments.
I understand and thought that was the case, but opened the bug
report because that code did work on systems with gcc 4.1 up
to 4.7.2, and -Wsequence-point does not tell anything, but I
agree that triggering the condition to tell the warning is not
easy due to the union usage for type punning.