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Diffstat (limited to 'docs/ReleaseNotes.rst')
| -rw-r--r-- | docs/ReleaseNotes.rst | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index e764bbb7f0..9716360a78 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -56,8 +56,12 @@ Improvements to Clang's diagnostics Non-comprehensive list of changes in this release ------------------------------------------------- -- ... - +- For X86 target, -march=skylake-avx512, -march=icelake-client, + -march=icelake-server, -march=cascadelake, -march=cooperlake will default to + not using 512-bit zmm registers in vectorized code unless 512-bit intrinsics + are used in the source code. 512-bit operations are known to cause the CPUs + to run at a lower frequency which can impact performance. This behavior can be + changed by passing -mprefer-vector-width=512 on the command line. New Compiler Flags ------------------ |