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| author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-04-11 23:21:07 +0000 |
|---|---|---|
| committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-04-11 23:21:07 +0000 |
| commit | 23a6033104c5f3fde8fe3b359d25e57a728613aa (patch) | |
| tree | 6bb3011585150294e6983d58a6789da4f25fcccb /docs/BranchWeightMetadata.rst | |
| parent | 670060dddfa6c538039744a431a41f7cf7a842b3 (diff) | |
| download | llvm-23a6033104c5f3fde8fe3b359d25e57a728613aa.tar.gz llvm-23a6033104c5f3fde8fe3b359d25e57a728613aa.tar.bz2 llvm-23a6033104c5f3fde8fe3b359d25e57a728613aa.tar.xz | |
blockfreq: Document BlockFrequencyInfo terminology
Documents terminology used in the forthcoming rewrite of
BlockFrequencyInfo.
<rdar://problem/14292693>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206086 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/BranchWeightMetadata.rst')
| -rw-r--r-- | docs/BranchWeightMetadata.rst | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/docs/BranchWeightMetadata.rst b/docs/BranchWeightMetadata.rst index 71ecd34c82..aff7923d18 100644 --- a/docs/BranchWeightMetadata.rst +++ b/docs/BranchWeightMetadata.rst @@ -8,10 +8,11 @@ LLVM Branch Weight Metadata Introduction ============ -Branch Weight Metadata represents branch weights as its likeliness to be -taken. Metadata is assigned to the ``TerminatorInst`` as a ``MDNode`` of the -``MD_prof`` kind. The first operator is always a ``MDString`` node with the -string "branch_weights". Number of operators depends on the terminator type. +Branch Weight Metadata represents branch weights as its likeliness to be taken +(see :doc:`BlockFrequencyTerminology`). Metadata is assigned to the +``TerminatorInst`` as a ``MDNode`` of the ``MD_prof`` kind. The first operator +is always a ``MDString`` node with the string "branch_weights". Number of +operators depends on the terminator type. Branch weights might be fetch from the profiling file, or generated based on `__builtin_expect`_ instruction. |