S390: Increase function alignment to 16 bytes.
Commit Message
Hi,
this patch sets the default function alignment to 16 bytes in order to
get rid of some unwanted performance effects.
Please see also GCC commit "S/390: Set default function
alignment to 16."
Bye,
Stefan
ChangeLog:
* sysdeps/s390/s390-64/sysdep.h(ENTRY): Use alignment of 16byte.
* sysdeps/s390/s390-32/sysdep.h: Likewise.
Comments
* Stefan Liebler:
> commit 3ca7542058593c6870ca10d0eed801ccc4326a4c
> Author: Stefan Liebler <stli@linux.ibm.com>
> Date: Wed Feb 20 09:02:56 2019 +0100
>
> S390: Increase function alignment to 16 bytes.
>
> Set the default function alignment to 16 bytes in order to
> get rid of some unwanted performance effects.
>
> Please see also GCC commit "S/390: Set default function
> alignment to 16."
>
> ChangeLog:
>
> * sysdeps/s390/s390-64/sysdep.h(ENTRY): Use alignment of
> 16byte.
“16 bytes”? Maybe also reference Subversion revision (rXXX) in the
commit message if it's already committed to GCC.
The actual change looks fine to me (though I can't comment on the
performance implications 8-).
Thanks,
Florian
On 3/1/19 4:47 PM, Florian Weimer wrote:
> * Stefan Liebler:
>
>> commit 3ca7542058593c6870ca10d0eed801ccc4326a4c
>> Author: Stefan Liebler <stli@linux.ibm.com>
>> Date: Wed Feb 20 09:02:56 2019 +0100
>>
>> S390: Increase function alignment to 16 bytes.
>>
>> Set the default function alignment to 16 bytes in order to
>> get rid of some unwanted performance effects.
>>
>> Please see also GCC commit "S/390: Set default function
>> alignment to 16."
>>
>> ChangeLog:
>>
>> * sysdeps/s390/s390-64/sysdep.h(ENTRY): Use alignment of
>> 16byte.
>
> “16 bytes”? Maybe also reference Subversion revision (rXXX) in the
> commit message if it's already committed to GCC.
>
> The actual change looks fine to me (though I can't comment on the
> performance implications 8-).
>
> Thanks,
> Florian
>
Committed with the additional information of the gcc commit:
Subversion revision 262817
Thanks,
Stefan
commit 3ca7542058593c6870ca10d0eed801ccc4326a4c
Author: Stefan Liebler <stli@linux.ibm.com>
Date: Wed Feb 20 09:02:56 2019 +0100
S390: Increase function alignment to 16 bytes.
Set the default function alignment to 16 bytes in order to
get rid of some unwanted performance effects.
Please see also GCC commit "S/390: Set default function
alignment to 16."
ChangeLog:
* sysdeps/s390/s390-64/sysdep.h(ENTRY): Use alignment of 16byte.
* sysdeps/s390/s390-32/sysdep.h: Likewise.
@@ -32,7 +32,7 @@
#define ENTRY(name) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),@function; \
- .align ALIGNARG(2); \
+ .align ALIGNARG(4); \
C_LABEL(name) \
cfi_startproc; \
CALL_MCOUNT
@@ -32,7 +32,7 @@
#define ENTRY(name) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),@function; \
- .align ALIGNARG(2); \
+ .align ALIGNARG(4); \
C_LABEL(name) \
cfi_startproc; \
CALL_MCOUNT