[RFC] AArch64: use movz/movk instead of literal pools in start.S
Commit Message
On 2017/9/14 16:35, Szabolcs Nagy wrote:
> On 14/09/17 04:21, Boshi Wang wrote:
>> On 2017/9/11 17:11, Szabolcs Nagy wrote:
>>> On 07/09/17 08:33, wangboshi wrote:
>>>> 2017-09-07 Wang Boshi <wangboshi@huawei.com>
>>>>
>>>> * sysdeps/aarch64/start.S: Use MOVL instead of literal pools.
>>>> * sysdeps/aarch64/sysdep.h (MOVL): Add MOVL macro.
>>>>
>>> thanks, the patch looks good to me (except for a nit below),
>>> do you have copyright assignment?
>>> do you have commit rights to the glibc repo?
>> I have read requirements of copyright assignment. I don't have that.
>>
>> I don't have commit rights, too.
>>
>> So how can I contribute the change? Could you give me some suggestions?
>>
> i think your change is just below the legally-significant limit
> https://www.gnu.org/prep/maintain/maintain.html#Legally-Significant
> so i can commit it for you.
>
> but getting your employer to sort it out with the fsf would be better,
> in case you run into further issues that need glibc fixes.
>
That's great. I have a few doubt. Could you add my name into the patch?
The new patch is here below.
Thank you, Nagy.
Comments
On 15/09/17 02:16, Boshi Wang wrote:
> On 2017/9/14 16:35, Szabolcs Nagy wrote:
>> On 14/09/17 04:21, Boshi Wang wrote:
>>> On 2017/9/11 17:11, Szabolcs Nagy wrote:
>>>> On 07/09/17 08:33, wangboshi wrote:
>>>>> 2017-09-07 Wang Boshi <wangboshi@huawei.com>
>>>>>
>>>>> * sysdeps/aarch64/start.S: Use MOVL instead of literal pools.
>>>>> * sysdeps/aarch64/sysdep.h (MOVL): Add MOVL macro.
>>>>>
>>>> thanks, the patch looks good to me (except for a nit below),
>>>> do you have copyright assignment?
>>>> do you have commit rights to the glibc repo?
>>> I have read requirements of copyright assignment. I don't have that.
>>>
>>> I don't have commit rights, too.
>>>
>>> So how can I contribute the change? Could you give me some suggestions?
>>>
>> i think your change is just below the legally-significant limit
>> https://www.gnu.org/prep/maintain/maintain.html#Legally-Significant
>> so i can commit it for you.
>>
>> but getting your employer to sort it out with the fsf would be better,
>> in case you run into further issues that need glibc fixes.
>>
> That's great. I have a few doubt. Could you add my name into the patch?
> The new patch is here below.
>
committed.
@@ -71,9 +71,9 @@ _start:
ldr PTR_REG (4), [x4, #:got_lo12:__libc_csu_fini]
#else
/* Set up the other arguments in registers */
- ldr PTR_REG (0), =main
- ldr PTR_REG (3), =__libc_csu_init
- ldr PTR_REG (4), =__libc_csu_fini
+ MOVL(0, main)
+ MOVL(3, __libc_csu_init)
+ MOVL(4, __libc_csu_fini)
#endif
/* __libc_start_main (main, argc, argv, init, fini, rtld_fini,
@@ -137,6 +137,20 @@
ldr PTR_REG (T), [x##T, #:got_lo12:EXPR]; \
OP PTR_REG (R), [x##T];
+/* Load an immediate into R.
+ Note R is a register number and not a register name. */
+#ifdef __LP64__
+# define MOVL(R, NAME) \
+ movz PTR_REG(R), #:abs_g3:NAME; \
+ movk PTR_REG(R), #:abs_g2_nc:NAME; \
+ movk PTR_REG(R), #:abs_g1_nc:NAME; \
+ movk PTR_REG(R), #:abs_g0_nc:NAME;
+#else
+# define MOVL(R, NAME) \
+ movz PTR_REG(R), #:abs_g1:NAME; \
+ movk PTR_REG(R), #:abs_g0_nc:NAME;
+#endif
+
/* Since C identifiers are not normally prefixed with an underscore
on this system, the asm identifier `syscall_error' intrudes on the
C name space. Make sure we use an innocuous name. */