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| author | Stephen Hines <srhines@google.com> | 2014-05-29 02:49:00 -0700 |
|---|---|---|
| committer | Stephen Hines <srhines@google.com> | 2014-05-29 02:49:00 -0700 |
| commit | dce4a407a24b04eebc6a376f8e62b41aaa7b071f (patch) | |
| tree | dcebc53f2b182f145a2e659393bf9a0472cedf23 /docs/BranchWeightMetadata.rst | |
| parent | 220b921aed042f9e520c26cffd8282a94c66c3d5 (diff) | |
| download | external_llvm-dce4a407a24b04eebc6a376f8e62b41aaa7b071f.zip external_llvm-dce4a407a24b04eebc6a376f8e62b41aaa7b071f.tar.gz external_llvm-dce4a407a24b04eebc6a376f8e62b41aaa7b071f.tar.bz2 | |
Update LLVM for 3.5 rebase (r209712).
Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
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 71ecd34..aff7923 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. |