On Fri, Aug 14, 2020 at 10:22 AM Hongtao Liu <crazy...@gmail.com> wrote:
>
> Hi:
> First, since avx512 masks involve both vector isa and general part,
> so i add both maintainers to the maillist.
>
> I'm doing this in 4 steps:
> 1 - Add cost model for operation of mask registers.
> 2 - Introduce new cover class INT_MASK_REGS, this will enable direct
> move between gpr and mask registers in pass_reload by consideration of
> cost model, this is similar as INT_SSE_REGS.
> 3 - Tune cost model.
> 4 - Enable operator or/xor/and/andn/not for mask register. kxnor is
> not enabled since there's no corresponding instruction for general
> registers, 64bit mask op is not enabled for 32bit target.
> kadd/kshift/ktest are not merged into general versionsadd/ashl/test
> since i think it would be odd to use mask register for those
> operations.
>
> Bootstrap is ok, regression test is ok for i386/x86-64 result.
> There's some improvement for performance of SPEC2017 tested on SKL,
> i observe there're many spills from integer to mask registers instead
> of memory which is the reason for the improvement.
+ if (MASK_CLASS_P (regclass))
+ {
+ int index;
+ switch (GET_MODE_SIZE (mode))
+ {
+ case 1:
+ index = 0;
+ break;
+ case 2:
+ index = 1;
+ break;
+ default:
+ index = 3;
Max index = 2!
+ break;
+ }
+
+ if (in == 2)
+ return MAX (ix86_cost->hard_register.mask_load[index],
+ ix86_cost->hard_register.mask_store[index]);
+ return in ? ix86_cost->hard_register.mask_load[2]
+ : ix86_cost->hard_register.mask_store[2];
+ }
Are DImode loads and stores assumed to cost the same as SImode? A
comment would be nice here.
Uros.
