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| author | Nadav Rotem <nrotem@apple.com> | 2013-01-03 01:56:33 +0000 |
|---|---|---|
| committer | Nadav Rotem <nrotem@apple.com> | 2013-01-03 01:56:33 +0000 |
| commit | 7ea18a763bb784c12fab2190876731f42eeb98c6 (patch) | |
| tree | f15a479d451f6445fd4d033c9cfcffad3df5c148 /llvm/docs/Vectorizers.rst | |
| parent | 04949fa99810054766741ffb4a186b7014557a54 (diff) | |
| download | bcm5719-llvm-7ea18a763bb784c12fab2190876731f42eeb98c6.tar.gz bcm5719-llvm-7ea18a763bb784c12fab2190876731f42eeb98c6.zip | |
Reformat the rst text.
llvm-svn: 171449
Diffstat (limited to 'llvm/docs/Vectorizers.rst')
| -rw-r--r-- | llvm/docs/Vectorizers.rst | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/llvm/docs/Vectorizers.rst b/llvm/docs/Vectorizers.rst index b4c5458953b..d679ca49540 100644 --- a/llvm/docs/Vectorizers.rst +++ b/llvm/docs/Vectorizers.rst @@ -208,15 +208,14 @@ Partial unrolling during vectorization ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Modern processors feature multiple execution units, and only programs that contain a -high degree of parallelism can fully utilize the entire width of the machine. - +high degree of parallelism can fully utilize the entire width of the machine. The Loop Vectorizer increases the instruction level parallelism (ILP) by performing partial-unrolling of loops. In the example below the entire array is accumulated into the variable 'sum'. -This is inefficient because only a single 'adder' can be used by the processor. +This is inefficient because only a single execution port can be used by the processor. By unrolling the code the Loop Vectorizer allows two or more execution ports -to be used. +to be used simultaneously. .. code-block:: c++ |
