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| author | Mark Heffernan <meheff@google.com> | 2015-07-13 18:26:27 +0000 |
|---|---|---|
| committer | Mark Heffernan <meheff@google.com> | 2015-07-13 18:26:27 +0000 |
| commit | 8a9e01d606ce9954fcdc431ce3be3f7ae2411f38 (patch) | |
| tree | 1873024adb9d5c60325334fadb180f3b06a2fe79 /lib/Transforms | |
| parent | 8f5464d3abfc9cbadbb39b80825efed0d3b4a694 (diff) | |
| download | llvm-8a9e01d606ce9954fcdc431ce3be3f7ae2411f38.tar.gz | |
Enable runtime unrolling with unroll pragma metadata
Enable runtime unrolling for loops with unroll count metadata ("#pragma unroll N")
and a runtime trip count. Also, do not unroll loops with unroll full metadata if the
loop has a runtime loop count. Previously, such loops would be unrolled with a
very large threshold (pragma-unroll-threshold) if runtime unrolled happened to be
enabled resulting in a very large (and likely unwise) unroll factor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242047 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/LoopUnrollPass.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/LoopUnrollPass.cpp b/lib/Transforms/Scalar/LoopUnrollPass.cpp index 9e7558d9c45f..d78db6c369b3 100644 --- a/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -840,8 +840,10 @@ bool LoopUnroll::runOnLoop(Loop *L, LPPassManager &LPM) { // Reduce count based on the type of unrolling and the threshold values. unsigned OriginalCount = Count; - bool AllowRuntime = UserRuntime ? CurrentRuntime : UP.Runtime; - if (HasRuntimeUnrollDisablePragma(L)) { + bool AllowRuntime = + (PragmaCount > 0) || (UserRuntime ? CurrentRuntime : UP.Runtime); + // Don't unroll a runtime trip count loop with unroll full pragma. + if (HasRuntimeUnrollDisablePragma(L) || PragmaFullUnroll) { AllowRuntime = false; } if (Unrolling == Partial) { |