[PATCH, ira] Ignore some conflict cost

Marek Polacek polacek@redhat.com
Wed Sep 17 09:29:00 GMT 2014


On Wed, Sep 17, 2014 at 05:18:27PM +0800, Zhenqiang Chen wrote:
> Hi,
> 
> When assign_hard_reg, we always check_hard_reg_p, which has code
> 
> if (! TEST_HARD_REG_BIT (profitable_regs, hard_regno))
>   return false;
> 
> i.e. If a hard_regno is not in profitable_regs, we can not allocate it to
> the ira_allocno_t A.
> 
> So the conflict on a hard_regno, which does not belong to the
> profitable_regs, can be ignored. Please refer
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63210 for the detail of the
> test case.
> 
> Bootstrap and no make check regression on X86-64 and ARM Chromebook.
> NO spec2k performance regression on X86-64 and ARM Chromebook.
> CSiBE code size is 0.01% better for ARM Cortex-M0.

Note that your MUA malformed the patch, so it can't be easily applied.

	Marek



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