Re: [mips] Return correct value from TARGET_SCHED_REORDER2 (PR rtl-optimization/37360)

[Andrey Belevantsev <abel at ispras dot ru>]

On 21.10.2010 4:30, Jie Zhang wrote:
> On 10/21/2010 04:44 AM, Richard Sandiford wrote:
> > Jie Zhang<jie@codesourcery.com> writes:
> > > Currently TARGET_SCHED_REORDER2 returns mips_issue_rate (), which will
> > > reset can_issue_more to the issue_rate after scheduling each
> > > instruction. See haifa-sched.c:sched_block for the details. Because of
> > > this, issue_rate is not honored when scheduling. This caused PR
> > > rtl-optimization/37360 since the issue_rate is set to a value smaller
> > > than the number of instructions that scheduler DFA can issue in one
> > > cycle for mips sb1.
> >
> > The haifa-sched.c part looks good to me, but I can't approve it.
> > Thanks for tracking down the underlying problem.
> Andrey and scheduler maintainers?
I'm all for the patch, life is easier for the scheduler when nobody lies. 
I cannot approve it though.  As I wrote earlier, we just need to be on the 
lookout for possible fallout on other targets which may have the same 
problem.

For an extra caution, I have tried all tests from 45352 with all flag 
combinations and -fschedule-insns[2] instead of -fselective-scheduling[2], 
and they work fine.  This is with both your other haifa-sched.c patch and 
this one applied.

Andrey