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| author | Nadav Rotem <nrotem@apple.com> | 2012-10-31 03:31:07 +0000 |
|---|---|---|
| committer | Nadav Rotem <nrotem@apple.com> | 2012-10-31 03:31:07 +0000 |
| commit | 5b2c4dc5f8f70352f029d595797089821eb39b3c (patch) | |
| tree | 5ffb655cdd74ec272750c49407181271f76c5f98 /lib/Transforms/Vectorize | |
| parent | 42d43351b274603ed0ac28128498a35b8987ce15 (diff) | |
| download | llvm-5b2c4dc5f8f70352f029d595797089821eb39b3c.tar.gz llvm-5b2c4dc5f8f70352f029d595797089821eb39b3c.tar.bz2 llvm-5b2c4dc5f8f70352f029d595797089821eb39b3c.tar.xz | |
LoopVectorize: Do not vectorize loops with tiny constant trip counts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167101 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Vectorize')
| -rw-r--r-- | lib/Transforms/Vectorize/LoopVectorize.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index e82dfa2454..fd728bd616 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -1145,6 +1145,14 @@ bool LoopVectorizationLegality::canVectorize() { return false; } + // Do not loop-vectorize loops with a tiny trip count. + unsigned TC = SE->getSmallConstantTripCount(TheLoop, BB); + if (TC > 0 && TC < 16) { + DEBUG(dbgs() << "LV: Found a loop with a very small trip count. " << + "This loop is not worth vectorizing.\n"); + return false; + } + DEBUG(dbgs() << "LV: We can vectorize this loop!\n"); // Okay! We can vectorize. At this point we don't have any other mem analysis |