Merging r183060:

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r183060 | atrick | 2013-05-31 16:34:46 -0700 (Fri, 31 May 2013) | 11 lines

Prevent loop-unroll from making assumptions about undefined behavior.

Fixes rdar:14036816, PR16130.

There is an opportunity to compute precise trip counts for 'or'
expressions and multi-exit loops.
rdar:14038809: Optimize trip count computation for multi-exit loops.

To do this we need to record the fact that ExitLimit assumes NSW. When
it does not we can safely assume that the loop trip count is the
minimum ExitLimt across all subexpressions and loop exits.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_33@183246 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2013-06-04 19:58:28 +00:00
parent 4e7df86628
commit 97f870366b

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