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Diffstat (limited to 'docs/LangRef.rst')
| -rw-r--r-- | docs/LangRef.rst | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/docs/LangRef.rst b/docs/LangRef.rst index 72648edbcb..e07d8fe8db 100644 --- a/docs/LangRef.rst +++ b/docs/LangRef.rst @@ -2680,8 +2680,10 @@ determined automatically. '``llvm.vectorizer.width``' Metadata ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -This metadata forces the loop vectorizer to widen scalar values to a vector -width of ``N`` rather than computing the width using a cost model. +This metadata sets the target width of the vectorizer to ``N``. Without +this metadata, the vectorizer will choose a width automatically. +Regardless of this metadata, the vectorizer will only vectorize loops if +it believes it is valid to do so. The first operand is the string ``llvm.vectorizer.width`` and the second operand is an integer specifying the width. For example: |