* [PATCH] x86-64: Replace movzx with movzbl
@ 2021-11-02 20:44 Fangrui Song
2021-11-02 21:14 ` H.J. Lu
0 siblings, 1 reply; 4+ messages in thread
From: Fangrui Song @ 2021-11-02 20:44 UTC (permalink / raw)
To: libc-alpha, H.J. Lu
Clang cannot assemble movzx in the AT&T dialect mode.
../sysdeps/x86_64/strcmp.S:2232:16: error: invalid operand for instruction
movzx (%rsi), %ecx
^~~~
Change movzx to movzbl, which follows the AT&T dialect and is used
elsewhere in the file.
---
sysdeps/x86_64/strcmp.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sysdeps/x86_64/strcmp.S b/sysdeps/x86_64/strcmp.S
index c7cbe4042a..bfe83abede 100644
--- a/sysdeps/x86_64/strcmp.S
+++ b/sysdeps/x86_64/strcmp.S
@@ -2229,8 +2229,8 @@ LABEL(strcmp_exitz):
.p2align 4
LABEL(Byte0):
- movzx (%rsi), %ecx
- movzx (%rdi), %eax
+ movzbl (%rsi), %ecx
+ movzbl (%rdi), %eax
#if defined USE_AS_STRCASECMP_L || defined USE_AS_STRNCASECMP_L
leaq _nl_C_LC_CTYPE_tolower+128*4(%rip), %rdx
--
2.33.1.1089.g2158813163f-goog
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] x86-64: Replace movzx with movzbl
2021-11-02 20:44 [PATCH] x86-64: Replace movzx with movzbl Fangrui Song
@ 2021-11-02 21:14 ` H.J. Lu
2021-11-03 1:15 ` Fangrui Song
0 siblings, 1 reply; 4+ messages in thread
From: H.J. Lu @ 2021-11-02 21:14 UTC (permalink / raw)
To: Fangrui Song; +Cc: GNU C Library
On Tue, Nov 2, 2021 at 1:45 PM Fangrui Song <maskray@google.com> wrote:
>
> Clang cannot assemble movzx in the AT&T dialect mode.
>
> ../sysdeps/x86_64/strcmp.S:2232:16: error: invalid operand for instruction
> movzx (%rsi), %ecx
> ^~~~
>
> Change movzx to movzbl, which follows the AT&T dialect and is used
> elsewhere in the file.
> ---
> sysdeps/x86_64/strcmp.S | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/sysdeps/x86_64/strcmp.S b/sysdeps/x86_64/strcmp.S
> index c7cbe4042a..bfe83abede 100644
> --- a/sysdeps/x86_64/strcmp.S
> +++ b/sysdeps/x86_64/strcmp.S
> @@ -2229,8 +2229,8 @@ LABEL(strcmp_exitz):
>
> .p2align 4
> LABEL(Byte0):
> - movzx (%rsi), %ecx
> - movzx (%rdi), %eax
> + movzbl (%rsi), %ecx
> + movzbl (%rdi), %eax
>
> #if defined USE_AS_STRCASECMP_L || defined USE_AS_STRNCASECMP_L
> leaq _nl_C_LC_CTYPE_tolower+128*4(%rip), %rdx
> --
> 2.33.1.1089.g2158813163f-goog
>
LGTM.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Thanks.
--
H.J.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] x86-64: Replace movzx with movzbl
2021-11-02 21:14 ` H.J. Lu
@ 2021-11-03 1:15 ` Fangrui Song
2022-04-23 1:36 ` Sunil Pandey
0 siblings, 1 reply; 4+ messages in thread
From: Fangrui Song @ 2021-11-03 1:15 UTC (permalink / raw)
To: H.J. Lu; +Cc: GNU C Library
On 2021-11-02, H.J. Lu wrote:
>On Tue, Nov 2, 2021 at 1:45 PM Fangrui Song <maskray@google.com> wrote:
>>
>> Clang cannot assemble movzx in the AT&T dialect mode.
>>
>> ../sysdeps/x86_64/strcmp.S:2232:16: error: invalid operand for instruction
>> movzx (%rsi), %ecx
>> ^~~~
>>
>> Change movzx to movzbl, which follows the AT&T dialect and is used
>> elsewhere in the file.
>> ---
>> sysdeps/x86_64/strcmp.S | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/sysdeps/x86_64/strcmp.S b/sysdeps/x86_64/strcmp.S
>> index c7cbe4042a..bfe83abede 100644
>> --- a/sysdeps/x86_64/strcmp.S
>> +++ b/sysdeps/x86_64/strcmp.S
>> @@ -2229,8 +2229,8 @@ LABEL(strcmp_exitz):
>>
>> .p2align 4
>> LABEL(Byte0):
>> - movzx (%rsi), %ecx
>> - movzx (%rdi), %eax
>> + movzbl (%rsi), %ecx
>> + movzbl (%rdi), %eax
>>
>> #if defined USE_AS_STRCASECMP_L || defined USE_AS_STRNCASECMP_L
>> leaq _nl_C_LC_CTYPE_tolower+128*4(%rip), %rdx
>> --
>> 2.33.1.1089.g2158813163f-goog
>>
>
>LGTM.
>
>Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
>
>Thanks.
Thanks for the quick review!
Just noticed that sysdeps/x86_64/multiarch/strcmp-sse42.S has a similar
pattern which needs fixing as well. I'll fix that, too.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] x86-64: Replace movzx with movzbl
2021-11-03 1:15 ` Fangrui Song
@ 2022-04-23 1:36 ` Sunil Pandey
0 siblings, 0 replies; 4+ messages in thread
From: Sunil Pandey @ 2022-04-23 1:36 UTC (permalink / raw)
To: Fangrui Song, libc-stable; +Cc: H.J. Lu, GNU C Library
On Tue, Nov 2, 2021 at 6:16 PM Fangrui Song via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> On 2021-11-02, H.J. Lu wrote:
> >On Tue, Nov 2, 2021 at 1:45 PM Fangrui Song <maskray@google.com> wrote:
> >>
> >> Clang cannot assemble movzx in the AT&T dialect mode.
> >>
> >> ../sysdeps/x86_64/strcmp.S:2232:16: error: invalid operand for instruction
> >> movzx (%rsi), %ecx
> >> ^~~~
> >>
> >> Change movzx to movzbl, which follows the AT&T dialect and is used
> >> elsewhere in the file.
> >> ---
> >> sysdeps/x86_64/strcmp.S | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/sysdeps/x86_64/strcmp.S b/sysdeps/x86_64/strcmp.S
> >> index c7cbe4042a..bfe83abede 100644
> >> --- a/sysdeps/x86_64/strcmp.S
> >> +++ b/sysdeps/x86_64/strcmp.S
> >> @@ -2229,8 +2229,8 @@ LABEL(strcmp_exitz):
> >>
> >> .p2align 4
> >> LABEL(Byte0):
> >> - movzx (%rsi), %ecx
> >> - movzx (%rdi), %eax
> >> + movzbl (%rsi), %ecx
> >> + movzbl (%rdi), %eax
> >>
> >> #if defined USE_AS_STRCASECMP_L || defined USE_AS_STRNCASECMP_L
> >> leaq _nl_C_LC_CTYPE_tolower+128*4(%rip), %rdx
> >> --
> >> 2.33.1.1089.g2158813163f-goog
> >>
> >
> >LGTM.
> >
> >Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
> >
> >Thanks.
>
> Thanks for the quick review!
>
> Just noticed that sysdeps/x86_64/multiarch/strcmp-sse42.S has a similar
> pattern which needs fixing as well. I'll fix that, too.
I would like to backport this patch to release branches.
Any comments or objections?
--Sunil
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-04-23 1:37 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-11-02 20:44 [PATCH] x86-64: Replace movzx with movzbl Fangrui Song
2021-11-02 21:14 ` H.J. Lu
2021-11-03 1:15 ` Fangrui Song
2022-04-23 1:36 ` Sunil Pandey
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