[PATCH 2/4] sparc: Avoid new window for FP save/restore

Sebastian Huber sebastian.huber at embedded-brains.de
Sat May 30 14:52:44 UTC 2015


I checked it in with the jmp instruction since it is also used in other SPARC assembler files.  It seems that in general the synthetic instructions are avoided.

----- Am 29. Mai 2015 um 18:38 schrieb Gedare Bloom gedare at gwu.edu:

> On Fri, May 29, 2015 at 11:37 AM, Gedare Bloom <gedare at gwu.edu> wrote:
>> On Fri, May 29, 2015 at 10:46 AM, Sebastian Huber
>> <sebastian.huber at embedded-brains.de> wrote:
>>>
>>> ----- Gedare Bloom <gedare at gwu.edu> schrieb:
>>>> Straightforward leaf-optimization, except is there a reason to use jmp
>>>> %o7 + 8 instead of ret?
>>>
>>> Hm, the GCC generates this instruction, is this the same as "ret"?
>>>
>> Yes I think so. Probably the manual will list ret as a synthetic
>> instruction, which is usually better for readability.
>>
> Also, I think sparc has retl instruction for returning from a
> leaf-optimized function, which I think will not have the delay slot.
> Should check the sparc manual though...
> 
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