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| author | Mark Heffernan <meheff@google.com> | 2015-02-24 01:14:35 +0000 |
|---|---|---|
| committer | Mark Heffernan <meheff@google.com> | 2015-02-24 01:14:35 +0000 |
| commit | f97d11be8f5dd768db055930e95ba45a5d24045d (patch) | |
| tree | d21400313cdd385ac6ea9986468630087242be9d | |
| parent | 1b9e3b8f5b352de349a7173cecc2d84579fa44dd (diff) | |
Add release notes about the unroll pragmas.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_36@230294 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | docs/ReleaseNotes.rst | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index de3e4a625e..bd06133580 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -84,7 +84,17 @@ To reliably test if C++ exceptions are enabled, use ``__EXCEPTIONS && __has_feat New Pragmas in Clang ----------------------- -Clang now supports the ... +Clang now supports the `#pragma unroll` and `#pragma nounroll` directives to +specify loop unrolling optimization hints. Placed just prior to the desired +loop, `#pragma unroll` directs the loop unroller to attempt to fully unroll the +loop. The pragma may also be specified with a positive integer parameter +indicating the desired unroll count: `#pragma unroll _value_`. The unroll count +parameter can be optionally enclosed in parentheses. The directive `#pragma +nounroll` indicates that the loop should not be unrolled. These unrolling hints +may also be expressed using the `#pragma clang loop` directive. See the Clang +`language extensions +<http://clang.llvm.org/docs/LanguageExtensions.html#extensions-for-loop-hint-optimizations>`_ +for details. Windows Support --------------- |