[llvm-bugs] [Bug 26734] wrong code at -O2, -O3 (NOT -Os) on x86-64-linux-gnu (in 32- and 64-bit modes)

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=26734

Matthew Simpson <mssimpso at codeaurora.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #3 from Matthew Simpson <mssimpso at codeaurora.org> ---
This should be fixed as of r262624 (test case included with the fix).

We should not have tried to vectorize this code because the incoming phi value
corresponding to the loop latch block (the previous value) is not defined
inside the loop. It's defined in the preheader. This led to the dominance
problem Michael discovered.

The fix ensures the previous value is defined inside the loop when checking for
first-order recurrences.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20160303/421f8be3/attachment.html>