[llvm-commits] [llvm] r143214 - in /llvm/trunk: lib/Analysis/InstructionSimplify.cpp test/Transforms/InstSimplify/compare.ll

[Eli Friedman]

On Fri, Oct 28, 2011 at 4:56 PM, Eli Friedman <eli.friedman at gmail.com> wrote:
> On Fri, Oct 28, 2011 at 12:01 PM, Duncan Sands <baldrick at free.fr> wrote:
>> Author: baldrick
>> Date: Fri Oct 28 14:01:20 2011
>> New Revision: 143214
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=143214&view=rev
>> Log:
>> The expression icmp eq (select (icmp eq x, 0), 1, x), 0 folds to false.
>> Spotted by my super-optimizer in 186.crafty and 450.soplex.  We really
>> need a proper infrastructure for handling generalizations of this kind
>> of thing (which occur a lot), however this case is so simple that I decided
>> to go ahead and implement it directly.
>
> This appears to be causing a miscompile on
> MultiSource/Benchmarks/mediabench/gsm/toast, among other things.

Reverted in r143265.

-Eli