https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|Add cmpmemM pattern for |[9/10/11 Regression] Add
|-minline-all-stringops |cmpmemM pattern for
| |-minline-all-stringops
Target Milestone|--- |11.0
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2020-05-19
--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
We used to expand memcmp to "repz cmpsb" via cmpstrnsi. It was changed
by
commit 9b0f6f5e511ca512e4faeabc81d2fd3abad9b02f
Author: Nick Clifton <ni...@redhat.com>
Date: Fri Aug 12 16:26:11 2011 +0000
builtins.c (expand_builtin_memcmp): Do not use cmpstrnsi pattern.
* builtins.c (expand_builtin_memcmp): Do not use cmpstrnsi
pattern.
* doc/md.texi (cmpstrn): Note that the comparison stops if both
fetched bytes are zero.
(cmpstr): Likewise.
(cmpmem): Note that the comparison does not stop if both of the
fetched bytes are zero.
