[PATCH] [msan] Run more optimization after MemorySanitizer pass

[John McCall]

On Jan 30, 2013, at 6:38 AM, Evgeniy Stepanov <eugenis at google.com> wrote:
>  Here, the best I can say without writing a page-long essay with examples. Sorry, it's not much.
> 
>  MSan instrumentation is driven by the original code. We essentially take every incoming instruction and emit another instruction (or ten) next to it, operating on the shadow values (but sometimes on the real values, too). Two programs in one, essentially. There can be any kinds of redundancies in the second one, so we just run whatever is normally run at -O2, and then exclude some passes that do not help much with benchmarks.

The comment looks good, and what you've written above makes sense to go in
the commit message.  Go ahead.

John.