On 01/08/2018 05:32 PM, Tom de Vries wrote:
On 12/18/2017 05:57 PM, Vladimir Makarov wrote:
On 12/15/2017 06:25 AM, Tom de Vries wrote:
Proposed Solution:
The patch addresses the problem, by:
- marking the hard regs that have been used in lra_spill in
hard_regs_spilled_into
- using hard_regs_spilled_into in lra_create_live_ranges to
make sure those registers are marked in the conflict_hard_regs
of pseudos that overlap with the spill register usage
[ I've also tried an approach where I didn't use
hard_regs_spilled_into, but tried to propagate all hard regs. I
figured out that I needed to mask out eliminable_regset. Also I
needed to masked out lra_no_alloc_regs, but that could be due to
gcn-specific problems (pointers take 2 hard regs), I'm not yet sure.
Anyway, in the submitted patch I tried to avoid these problems and
went for the more minimal approach. ]
Tom, thank you for the detail explanation of the problem and solutions
you considered. It helped me a lot. Your simple solution is adequate
as the most transformations and allocation are done on the 1st LRA
subpasses iteration.
In order to get the patch accepted for trunk, I think we need:
- bootstrap and reg-test on x86_64
- build and reg-test on mips (the only primary platform that has the
spill_class hook enabled)
Any comments?
The patch looks ok to me. You can commit it after successful testing
on x86-64 and mips but I am sure there will be no problems with x86-64
as it does not use spill_class currently (actually your patch might
help to switch it on again for x86-64. spill_class was quite useful
for x86-64 performance on Intel processors).
Hi Matthew,
there's an lra optimization that is currently enabled for MIPS, and not
for any other primary or secondary target.
This (already approved) patch fixes a bug in that optimization, and
needs to be tested on MIPS.
Unfortunately, the optimization is only enabled for MIPS16, and we don't
have a current setup to test this.
Could you help us out here and test this patch for MIPS16 on trunk?
Hi Matthew,
is this something you can help us out with?
Thanks,
- Tom
