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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-05-13 09:33:30 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-05-16 09:36:06 -0300 |
| commit | 9403b71ae97e3f1a91c796ddcbb4e6f044434734 (patch) | |
| tree | 7a36c6a109815737ff5700d55125042bd2d0951e /sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S | |
| parent | 7b1cfba79ee54221ffa7d7879433b7ee1728cd76 (diff) | |
| download | glibc-9403b71ae97e3f1a91c796ddcbb4e6f044434734.tar.gz glibc-9403b71ae97e3f1a91c796ddcbb4e6f044434734.tar.xz glibc-9403b71ae97e3f1a91c796ddcbb4e6f044434734.zip | |
x86_64: Remove bzero optimization
Both symbols are marked as legacy in POSIX.1-2001 and removed on
POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE
or _DEFAULT_SOURCE.
GCC also replaces bcopy with a memmove and bzero with memset on default
configuration (to actually get a bzero libc call the code requires
to omit string.h inclusion and built with -fno-builtin), so it is
highly unlikely programs are actually calling libc bzero symbol.
On a recent Linux distro (Ubuntu 22.04), there is no bzero calls
by the installed binaries.
$ cat count_bstring.sh
#!/bin/bash
files=`IFS=':';for i in $PATH; do test -d "$i" && find "$i" -maxdepth 1 -executable -type f; done`
total=0
for file in $files; do
symbols=`objdump -R $file 2>&1`
if [ $? -eq 0 ]; then
ncalls=`echo $symbols | grep -w $1 | wc -l`
((total=total+ncalls))
if [ $ncalls -gt 0 ]; then
echo "$file: $ncalls"
fi
fi
done
echo "TOTAL=$total"
$ ./count_bstring.sh bzero
TOTAL=0
Checked on x86_64-linux-gnu.
Diffstat (limited to 'sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S index 5d8fa78f05..6370021506 100644 --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S @@ -19,9 +19,6 @@ vpbroadcastb d, %VEC0; \ movq r, %rax -# define BZERO_ZERO_VEC0() \ - vpxorq %XMM0, %XMM0, %XMM0 - # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \ vpbroadcastd d, %VEC0; \ movq r, %rax |