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[Bug c/46619] gcc thinks line of code can be removed.
- From: "eskil at obsession dot se" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 23 Nov 2010 17:56:03 +0000
- Subject: [Bug c/46619] gcc thinks line of code can be removed.
- Auto-submitted: auto-generated
- References: <bug-46619-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46619
--- Comment #3 from Eskil Steenberg <eskil at obsession dot se> 2010-11-23 17:55:56 UTC ---
(In reply to comment #2)
> Do you have a run-time testcase?
There is a test you can run in v_prime.c , it should fail to set the high bit
and therefor should not ever find a prime. Testing that something is broken by
finding that some thing doesn't do some thing is kind of hard, so I would
rather recommend looking at just the assembly code and try to figure out why it
thinks that the specific line can be removed. (the obvious one to me is that it
thinks that uv is signed and therefor can never go as high as 0x80000000).
Cheers
E