Hi!
On Wed, Jul 01, 2020 at 06:20:23PM -0400, Michael Meissner wrote:
> This patch adds support for the IEEE 128-bit floating point minimum, maximum,
> and compare instructions generating a mask. These instructions were added in
> ISA 3.1 (i.e. power10).
> (emit_fp_cmove_with_mask_xxsel): Update comment.
Your patch does not touch this function?
> + /* See if we can use the ISA 3.1 min/max/compare instructions for IEEE
> + 128-bit floating point. At present, don't worry about doing conditional
> + moves with different types for the comparison and movement (unlike
> SF/DF,
> + where you can do a conditional test between double and use float as the
> + if/then parts. */
Two spaces after a full stop.
> +;; IEEE 128-bit min/max
> +(define_insn "s<minmax><mode>3"
> + [(set (match_operand:IEEE128 0 "altivec_register_operand" "=v")
> + (fp_minmax:IEEE128
> + (match_operand:IEEE128 1 "altivec_register_operand" "v")
> + (match_operand:IEEE128 2 "altivec_register_operand" "v")))]
> + "TARGET_FLOAT128_HW && TARGET_POWER10 && FLOAT128_IEEE_P (<MODE>mode)"
> + "xs<minmax>cqp %0,%1,%2"
> + [(set_attr "type" "fp")
> + (set_attr "size" "128")])
As with the SF/DF min/max, this is undefined if either operand is a NaN,
or if both are zero (or underdefined). Because of that, the "c" version
of the instructions can be used here. But it isn't obviously clear how
this works with the builtins :-(
> +(define_insn_and_split "*mov<mode>cc_hardware"
> + [(set (match_operand:IEEE128 0 "altivec_register_operand" "=&v,v")
> + (if_then_else:IEEE128
> + (match_operator:CCFP 1 "fpmask_comparison_operator"
> + [(match_operand:IEEE128 2 "altivec_register_operand" "v,v")
> + (match_operand:IEEE128 3 "altivec_register_operand" "v,v")])
> + (match_operand:IEEE128 4 "vsx_register_operand" "wa,wa")
> + (match_operand:IEEE128 5 "vsx_register_operand" "wa,wa")))
> + (clobber (match_scratch:V2DI 6 "=0,&wa"))]
Why do you use "wa" instead of "v" here? Won't it always need "v" in the
end anyway?
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/float128-minmax-2.c
> @@ -0,0 +1,70 @@
> +/* { dg-do compile { target { powerpc*-*-* && lp64 } } } */
> +/* { dg-require-effective-target power10_ok } */
> +/* { dg-options "-mdejagnu-cpu=power10 -O2 -ffast-math" } */
> +/* { dg-final { scan-assembler-not "xscmpuqp" } } */
> +/* { dg-final { scan-assembler "xscmpeqqp" } } */
> +/* { dg-final { scan-assembler "xscmpgtqp" } } */
> +/* { dg-final { scan-assembler "xscmpgeqp" } } */
> +/* { dg-final { scan-assembler "xsmaxcqp" } } */
> +/* { dg-final { scan-assembler "xsmincqp" } } */
> +/* { dg-final { scan-assembler "xxsel" } } */
Please use \m \M.
Segher
