[glibc] x86: ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST expect no transactions
Noah Goldstein
nwg@sourceware.org
Tue Jun 7 20:45:07 GMT 2022
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c28db9cb29a7d6cf3ce08fd8445e6b7dea03f35b
commit c28db9cb29a7d6cf3ce08fd8445e6b7dea03f35b
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Fri Jun 3 18:52:37 2022 -0500
x86: ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST expect no transactions
Give fall-through path to `vzeroupper` and taken-path to `vzeroall`.
Generally even on machines with RTM the expectation is the
string-library functions will not be called in transactions.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Diff:
---
sysdeps/x86_64/sysdep.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/sysdeps/x86_64/sysdep.h b/sysdeps/x86_64/sysdep.h
index 4f512d5566..7f5defa4ec 100644
--- a/sysdeps/x86_64/sysdep.h
+++ b/sysdeps/x86_64/sysdep.h
@@ -99,11 +99,11 @@ lose: \
to avoid RTM abort triggered by VZEROUPPER inside transactionally. */
#define ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST \
xtest; \
- jz 1f; \
- vzeroall; \
+ jnz 1f; \
+ vzeroupper; \
ret; \
1: \
- vzeroupper; \
+ vzeroall; \
ret
/* Can be used to replace vzeroupper that is not directly before a
More information about the Glibc-cvs
mailing list