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| author | Ayal Zaks <ayal.zaks@intel.com> | 2017-05-23 07:08:02 +0000 |
|---|---|---|
| committer | Ayal Zaks <ayal.zaks@intel.com> | 2017-05-23 07:08:02 +0000 |
| commit | 589e1d9610d1eed8e06c9424c4726a504d43391c (patch) | |
| tree | 6a93025d7d662eb14a3e2bb2b382c709119eb782 /llvm/docs/Vectorizers.rst | |
| parent | 53fc355e7d4c3a6cef1d8ebdc5d7b35e61e7f9db (diff) | |
| download | bcm5719-llvm-589e1d9610d1eed8e06c9424c4726a504d43391c.tar.gz bcm5719-llvm-589e1d9610d1eed8e06c9424c4726a504d43391c.zip | |
[LV] Report multiple reasons for not vectorizing under allowExtraAnalysis
The default behavior of -Rpass-analysis=loop-vectorizer is to report only the
first reason encountered for not vectorizing, if one is found, at which time the
vectorizer aborts its handling of the loop. This patch allows multiple reasons
for not vectorizing to be identified and reported, at the potential expense of
additional compile-time, under allowExtraAnalysis which can currently be turned
on by Clang's -fsave-optimization-record and opt's -pass-remarks-missed.
Removed from LoopVectorizationLegality::canVectorize() the redundant checking
and reporting if we CantComputeNumberOfIterations, as LAI::canAnalyzeLoop() also
does that. This redundancy is caught by a lit test once multiple reasons are
reported.
Patch initially developed by Dror Barak.
Differential Revision: https://reviews.llvm.org/D33396
llvm-svn: 303613
Diffstat (limited to 'llvm/docs/Vectorizers.rst')
| -rw-r--r-- | llvm/docs/Vectorizers.rst | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/llvm/docs/Vectorizers.rst b/llvm/docs/Vectorizers.rst index 65c19aa2bc0..a909d458c31 100644 --- a/llvm/docs/Vectorizers.rst +++ b/llvm/docs/Vectorizers.rst @@ -99,7 +99,9 @@ Optimization remarks are enabled using: indicates if vectorization was specified. ``-Rpass-analysis=loop-vectorize`` identifies the statements that caused -vectorization to fail. +vectorization to fail. If in addition ``-fsave-optimization-record`` is +provided, multiple causes of vectorization failure may be listed (this behavior +might change in the future). Consider the following loop: |
