[LLVMdev] PassManagerBuilder::LibraryInfo has no effect?

[Shea Levy]

I figured out the issue and posted a patch [1] to the commits ml.

Cheers,
Shea

[1] http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140203/204401.html

On Mon, Feb 03, 2014 at 11:14:26PM -0500, Shea Levy wrote:
> Hi all,
> 
> I'm using a library (the llvm-general haskell library, if it matters)
> that uses the PassManagerBuilder interface to build a PassManger given
> an optimization level, etc. I've extended this to make it possible to
> set the PassManagerBuilder's LibraryInfo member, and as a test I created
> a TargetLibraryInfo where LibFunc::malloc was set to "GC_malloc_atomic"
> (the allocator for boehm-gc). I've verified that, just before building
> the PassManager, pmb->LibraryInfo->getName(LibFunc::malloc) does indeed
> return "GC_malloc", yet when I use the PassManager on a module with a
> call to GC_malloc whose return value isn't used the call is not
> optimized away, while it is when I replace that GC_malloc call with a
> call to malloc. Am I misunderstanding the point of LibraryInfo here, or
> is something not working correctly? I am using llvm-3.4.
> 
> Thanks,
> Shea Levy