On 06/19/2014 09:37 AM, Tom de Vries wrote:
> On 19-06-14 05:59, Richard Henderson wrote:
>> On 06/01/2014 04:27 AM, Tom de Vries wrote:
>>> + if (TARGET_AAPCS_BASED)
>>> + {
>>> + /* For AAPCS, IP and CC can be clobbered by veneers inserted by the
>>> + linker. We need to add these to allow
>>> + arm_call_fusage_contains_non_callee_clobbers to return true. */
>>> + rtx *fusage = &CALL_INSN_FUNCTION_USAGE (insn);
>>> + clobber_reg (fusage, gen_rtx_REG (word_mode, IP_REGNUM));
>>> + clobber_reg (fusage, gen_rtx_REG (word_mode, CC_REGNUM));
>>
>> Why are you adding CC_REGNUM if fixed registers are automatically included?
>>
>
> Richard,
>
> You're right, setting a fixed register here is not required for
> fuse-caller-save to work safely.
>
> But it fits the definition of the hook
> TARGET_CALL_FUSAGE_CONTAINS_NON_CALLEE_CLOBBERS:
> ...
> Set to true if all the calls in the current function contain clobbers in
> CALL_INSN_FUNCTION_USAGE for the registers that are clobbered by the call
> rather than by the callee, and are not already set or clobbered in the call
> pattern.
> ...
>
> We can adapt the definition to not include fixed registers. I can make a patch
> for that, if you like.
I think that would be best. It'll save just a bit of memory and scanning time.
r~
