3 Commits

Author SHA1 Message Date
Sanjoy Das
59287c36a0 [IndVars] Eliminate op.with.overflow when possible (re-apply)
Summary:
If we can prove that an op.with.overflow intrinsic does not overflow, we
can get rid of the intrinsic, and replace it with non-wrapping
arithmetic.

This was first checked in at r265913 but reverted in r265950 because it
exposed some issues around how SCEV handled post-inc add recurrences.
Those issues have now been fixed.

Reviewers: atrick, regehr

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18685

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271153 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-29 00:36:25 +00:00
Sanjoy Das
5e07ce6898 This reverts commit r265913 and r265912
See PR27315

r265913: "[IndVars] Eliminate op.with.overflow when possible"

r265912: "[SCEV] See through op.with.overflow intrinsics"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265950 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-11 15:26:18 +00:00
Sanjoy Das
0a4c40265b [IndVars] Eliminate op.with.overflow when possible
Summary:
If we can prove that an op.with.overflow intrinsic does not overflow, we
can get rid of the intrinsic, and replace it with non-wrapping
arithmetic.

Reviewers: atrick, regehr

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18685

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265913 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-10 22:50:31 +00:00