> -----Original Message-----
> From: Christophe Lyon <[email protected]>
> Sent: Thursday, May 6, 2021 10:23 AM
> To: Tamar Christina <[email protected]>
> Cc: gcc Patches <[email protected]>; nd <[email protected]>
> Subject: Re: [PATCH 3/4][AArch32]: Add support for sign differing dot-
> product usdot for NEON.
>
> On Wed, 5 May 2021 at 19:39, Tamar Christina via Gcc-patches <gcc-
> [email protected]> wrote:
> >
> > Hi All,
> >
> > This adds optabs implementing usdot_prod.
> >
> > The following testcase:
> >
> > #define N 480
> > #define SIGNEDNESS_1 unsigned
> > #define SIGNEDNESS_2 signed
> > #define SIGNEDNESS_3 signed
> > #define SIGNEDNESS_4 unsigned
> >
> > SIGNEDNESS_1 int __attribute__ ((noipa)) f (SIGNEDNESS_1 int res,
> > SIGNEDNESS_3 char *restrict a,
> > SIGNEDNESS_4 char *restrict b)
> > {
> > for (__INTPTR_TYPE__ i = 0; i < N; ++i)
> > {
> > int av = a[i];
> > int bv = b[i];
> > SIGNEDNESS_2 short mult = av * bv;
> > res += mult;
> > }
> > return res;
> > }
> >
> > Generates
> >
> > f:
> > vmov.i32 q8, #0 @ v4si
> > add r3, r2, #480
> > .L2:
> > vld1.8 {q10}, [r2]!
> > vld1.8 {q9}, [r1]!
> > vusdot.s8 q8, q9, q10
> > cmp r3, r2
> > bne .L2
> > vadd.i32 d16, d16, d17
> > vpadd.i32 d16, d16, d16
> > vmov.32 r3, d16[0]
> > add r0, r0, r3
> > bx lr
> >
> > instead of
> >
> > f:
> > vmov.i32 q8, #0 @ v4si
> > add r3, r2, #480
> > .L2:
> > vld1.8 {q9}, [r2]!
> > vld1.8 {q11}, [r1]!
> > cmp r3, r2
> > vmull.s8 q10, d18, d22
> > vmull.s8 q9, d19, d23
> > vaddw.s16 q8, q8, d20
> > vaddw.s16 q8, q8, d21
> > vaddw.s16 q8, q8, d18
> > vaddw.s16 q8, q8, d19
> > bne .L2
> > vadd.i32 d16, d16, d17
> > vpadd.i32 d16, d16, d16
> > vmov.32 r3, d16[0]
> > add r0, r0, r3
> > bx lr
> >
> > For NEON. I couldn't figure out if the MVE instruction vmlaldav.s16
> > could be used to emulate this. Because it would require additional
> > widening to work I left MVE out of this patch set but perhaps someone
> should take a look.
> >
> > Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> I guess you mean arm-linux-gnueabihf ?
>
Oops, yeah, automatic pilot..
> >
> > Ok for master?
> >
> > Thanks,
> > Tamar
> >
> > gcc/ChangeLog:
> >
> > * config/arm/neon.md (usdot_prod<vsi2qi>): New.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * gcc.target/arm/simd/vusdot-autovec.c: New test.
> >
> > --- inline copy of patch --
> > diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md index
> >
> fec2cc91d24b6eff7b6fc8fdd54f39b3d646c468..23ad411178db77c5d19bee7452
> bc
> > 1070331c1aa0 100644
> > --- a/gcc/config/arm/neon.md
> > +++ b/gcc/config/arm/neon.md
> > @@ -3075,6 +3075,24 @@ (define_expand "<sup>dot_prod<vsi2qi>"
> > DONE;
> > })
> >
> > +;; Auto-vectorizer pattern for usdot
> > +(define_expand "usdot_prod<vsi2qi>"
> > + [(set (match_operand:VCVTI 0 "register_operand")
> > + (plus:VCVTI (unspec:VCVTI [(match_operand:<VSI2QI> 1
> > + "register_operand")
> > + (match_operand:<VSI2QI> 2
> > + "register_operand")]
> > + UNSPEC_DOT_US)
> > + (match_operand:VCVTI 3 "register_operand")))]
> > + "TARGET_I8MM"
> > +{
> > + emit_insn (
> > + gen_neon_usdot<vsi2qi> (operands[3], operands[3], operands[1],
> > + operands[2]));
> > + emit_insn (gen_rtx_SET (operands[0], operands[3]));
> > + DONE;
> > +})
> > +
> > (define_expand "neon_copysignf<mode>"
> > [(match_operand:VCVTF 0 "register_operand")
> > (match_operand:VCVTF 1 "register_operand") diff --git
> > a/gcc/testsuite/gcc.target/arm/simd/vusdot-autovec.c
> > b/gcc/testsuite/gcc.target/arm/simd/vusdot-autovec.c
> > new file mode 100644
> > index
> >
> 0000000000000000000000000000000000000000..7cc56f68817d77d6950df0ab37
> 2d
> > 6fbaad6b3813
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/arm/simd/vusdot-autovec.c
> > @@ -0,0 +1,38 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-O3 -march=armv8.2-a+i8mm" } */
> > +
> > +#define N 480
> > +#define SIGNEDNESS_1 unsigned
> > +#define SIGNEDNESS_2 signed
> > +#define SIGNEDNESS_3 signed
> > +#define SIGNEDNESS_4 unsigned
> > +
> > +SIGNEDNESS_1 int __attribute__ ((noipa)) f (SIGNEDNESS_1 int res,
> > +SIGNEDNESS_3 char *restrict a,
> > + SIGNEDNESS_4 char *restrict b)
> > +{
> > + for (__INTPTR_TYPE__ i = 0; i < N; ++i)
> > + {
> > + int av = a[i];
> > + int bv = b[i];
> > + SIGNEDNESS_2 short mult = av * bv;
> > + res += mult;
> > + }
> > + return res;
> > +}
> > +
> > +SIGNEDNESS_1 int __attribute__ ((noipa)) g (SIGNEDNESS_1 int res,
> > +SIGNEDNESS_3 char *restrict b,
> > + SIGNEDNESS_4 char *restrict a)
> > +{
> > + for (__INTPTR_TYPE__ i = 0; i < N; ++i)
> > + {
> > + int av = a[i];
> > + int bv = b[i];
> > + SIGNEDNESS_2 short mult = av * bv;
> > + res += mult;
> > + }
> > + return res;
> > +}
> > +
> > +/* { dg-final { scan-assembler-times {vusdot.s8} 2 { target {
> > +arm-*-*-gnueabihf } } } } */
> >
> >
> > --
