[llvm] r245169 - [X86] Widen the 'AND' mask if doing so shrinks the encoding size

[Tobias Grosser via llvm-commits]

On 08/16/2015 06:52 AM, David Majnemer via llvm-commits wrote:
> Author: majnemer
> Date: Sat Aug 15 23:52:11 2015
> New Revision: 245169
>
> URL: http://llvm.org/viewvc/llvm-project?rev=245169&view=rev
> Log:
> [X86] Widen the 'AND' mask if doing so shrinks the encoding size
>
> We can set additional bits in a mask given that we know the other
> operand of an AND already has some bits set to zero.  This can be more
> efficient if doing so allows us to use an instruction which implicitly
> sign extends the immediate.
>
> This fixes PR24085.
>

This change seems to have broken an LNT builder:

http://lab.llvm.org:8011/builders/perf-x86_64-penryn-O3/builds/6117

FAIL: siod.execution_time

Best,
Tobias