[Polly] Run-time alias check construction hangs

tobiasgrosser commented 10 years ago


Bugzilla Link	21166
Resolution	FIXED
Resolved on	Jan 18, 2016 17:01
Version	unspecified
OS	Linux
Attachments	Test case
CC	@jdoerfert

Extended Description

Running

alias polly-opt='opt -load LLVMPolly.so'

polly-opt -polly-code-generator=isl test-case.ll

causes a time out for me.

My first investigations point to:

commit 61337345c7fbc77f04a816d5ca45631a013132f9 Author: Johannes Doerfert doerfert@cs.uni-saarland.de Date: Wed Oct 1 12:42:37 2014 +0000

[RTC] Use the domain to split alias groups.

  We use a parametric abstraction of the domain to split alias groups
  if accesses cannot be executed under the same parameter evaluation.

  The two test cases check that we can remove alias groups if the
  pointers which might alias are never accessed under the same parameter
  evaluation and that the minimal/maximal accesses are not global but
  with regards to the parameter evaluation.

Differential Revision: http://reviews.llvm.org/D5436

tlattner commented 8 years ago

Move to Polly Product.

jdoerfert commented 10 years ago

Fixed in r219131.

jdoerfert commented 10 years ago

When you dump the SCoP before we build alias groups you see:

   Stmt_for_body9
        Domain :=
            { Stmt_for_body9[i0, i1] : 1 = 0 };

and that's why the splitting procedure doesn't converge.

Fix: http://reviews.llvm.org/D5623

llvm / llvm-project

[Polly] Run-time alias check construction hangs #21540

Extended Description