On Fri, 2017-12-01 at 18:46 +0100, Richard Biener wrote:
> On December 1, 2017 6:22:21 PM GMT+01:00, Will Schmidt
> <will_schm...@vnet.ibm.com> wrote:
> >Hi,
> >Add support for folding of vec_msum in GIMPLE.
> >
> >This uses the DOT_PROD_EXPR gimple op, which is sensitive to type
> >mismatches:
> > error: type mismatch in dot product reduction
> > __vector signed int
> > __vector signed char
> > __vector unsigned char
> > D.2798 = DOT_PROD_EXPR <vsc2, vuc3, vsi2>;
> >So for those cases with a signed/unsigned mismatch in the arguments,
> >this
> >converts those arguments to their signed type.
> >
> >This also adds a define_expand for sdot_prodv16qi. This is based on a
> >similar
> >existing entry.
> >
> >Testing coverage is handled by the existing
> >gcc.target/powerpc/fold-vec-msum*.c tests.
> >
> >Sniff-tests have passed on P8. full regtests currently running on
> >other assorted
> >power systems.
> >OK for trunk with successful results?
>
> Note DOT_PROD_EXPR is only useful when the result is reduced to a scalar
> later and the reduction order is irrelevant.
>
> This is because GIMPLE doesn't specify whether the reduction reduces odd/even
> or high/low lanes of the argument vectors. Does vec_msum specify that?
Not that I see, but there may be an implied intent here that just isn't
obvious to me. I'll defer to ... someone. :-)
> That said, it exists as a 'hack' for the vectorizer and isn't otherwise
> useful for GIMPLE.
OK. With that in mind, should I just try to split this out into
separate multiply and add steps?
Thanks,
-Will
>
>
> Richard.
>
> >Thanks
> >-Will
> >
> >[gcc]
> >
> >2017-12-01 Will Schmidt <will_schm...@vnet.ibm.com>
> >
> > * config/rs6000/altivec.md (sdot_prodv16qi): New.
> > * config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Add support for
> > gimple-folding of vec_msum.
> > (builtin_function_type): Add entries for VMSUMU[BH]M and VMSUMMBM.
> >
> >diff --git a/gcc/config/rs6000/altivec.md
> >b/gcc/config/rs6000/altivec.md
> >index 7122f99..fa9e121 100644
> >--- a/gcc/config/rs6000/altivec.md
> >+++ b/gcc/config/rs6000/altivec.md
> >@@ -3349,11 +3349,26 @@
> > (match_operand:V8HI 2 "register_operand" "v")]
> > UNSPEC_VMSUMSHM)))]
> > "TARGET_ALTIVEC"
> > "
> > {
> >- emit_insn (gen_altivec_vmsumshm (operands[0], operands[1],
> >operands[2], operands[3]));
> >+ emit_insn (gen_altivec_vmsumshm (operands[0], operands[1],
> >+ operands[2], operands[3]));
> >+ DONE;
> >+}")
> >+
> >+(define_expand "sdot_prodv16qi"
> >+ [(set (match_operand:V4SI 0 "register_operand" "=v")
> >+ (plus:V4SI (match_operand:V4SI 3 "register_operand" "v")
> >+ (unspec:V4SI [(match_operand:V16QI 1
> >"register_operand" "v")
> >+ (match_operand:V16QI 2
> >"register_operand" "v")]
> >+ UNSPEC_VMSUMM)))]
> >+ "TARGET_ALTIVEC"
> >+ "
> >+{
> >+ emit_insn (gen_altivec_vmsummbm (operands[0], operands[1],
> >+ operands[2], operands[3]));
> > DONE;
> > }")
> >
> > (define_expand "widen_usum<mode>3"
> > [(set (match_operand:V4SI 0 "register_operand" "=v")
> >diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> >index 551d9c4..552fcdd 100644
> >--- a/gcc/config/rs6000/rs6000.c
> >+++ b/gcc/config/rs6000/rs6000.c
> >@@ -16614,10 +16614,40 @@ rs6000_gimple_fold_builtin
> >(gimple_stmt_iterator *gsi)
> > case VSX_BUILTIN_CMPLE_2DI:
> > case VSX_BUILTIN_CMPLE_U2DI:
> > fold_compare_helper (gsi, LE_EXPR, stmt);
> > return true;
> >
> >+ /* vec_msum. */
> >+ case ALTIVEC_BUILTIN_VMSUMUHM:
> >+ case ALTIVEC_BUILTIN_VMSUMSHM:
> >+ case ALTIVEC_BUILTIN_VMSUMUBM:
> >+ case ALTIVEC_BUILTIN_VMSUMMBM:
> >+ {
> >+ arg0 = gimple_call_arg (stmt, 0);
> >+ arg1 = gimple_call_arg (stmt, 1);
> >+ tree arg2 = gimple_call_arg (stmt, 2);
> >+ lhs = gimple_call_lhs (stmt);
> >+ if ( TREE_TYPE (arg0) == TREE_TYPE (arg1))
> >+ g = gimple_build_assign (lhs, DOT_PROD_EXPR, arg0, arg1, arg2);
> >+ else
> >+ {
> >+ // For the case where we have a mix of signed/unsigned
> >+ // arguments, convert both multiply args to their signed type.
> >+ gimple_seq stmts = NULL;
> >+ location_t loc = gimple_location (stmt);
> >+ tree new_arg_type = signed_type_for (TREE_TYPE (arg0));
> >+ tree signed_arg0 = gimple_convert (&stmts, loc, new_arg_type,
> >arg0);
> >+ tree signed_arg1 = gimple_convert (&stmts, loc, new_arg_type,
> >arg1);
> >+ gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
> >+ g = gimple_build_assign (lhs, DOT_PROD_EXPR,
> >+ signed_arg0, signed_arg1, arg2);
> >+ }
> >+ gimple_set_location (g, gimple_location (stmt));
> >+ gsi_replace (gsi, g, true);
> >+ return true;
> >+ }
> >+
> > default:
> > if (TARGET_DEBUG_BUILTIN)
> > fprintf (stderr, "gimple builtin intrinsic not matched:%d %s %s\n",
> > fn_code, fn_name1, fn_name2);
> > break;
> >@@ -18080,16 +18110,23 @@ builtin_function_type (machine_mode mode_ret,
> >machine_mode mode_arg0,
> > case CRYPTO_BUILTIN_VPERMXOR_V8HI:
> > case CRYPTO_BUILTIN_VPERMXOR_V16QI:
> > case CRYPTO_BUILTIN_VSHASIGMAW:
> > case CRYPTO_BUILTIN_VSHASIGMAD:
> > case CRYPTO_BUILTIN_VSHASIGMA:
> >+ case ALTIVEC_BUILTIN_VMSUMUHM:
> >+ case ALTIVEC_BUILTIN_VMSUMUBM:
> > h.uns_p[0] = 1;
> > h.uns_p[1] = 1;
> > h.uns_p[2] = 1;
> > h.uns_p[3] = 1;
> > break;
> >
> >+ /* The second parm to this vec_msum variant is unsigned. */
> >+ case ALTIVEC_BUILTIN_VMSUMMBM:
> >+ h.uns_p[2] = 1;
> >+ break;
> >+
> > /* signed permute functions with unsigned char mask. */
> > case ALTIVEC_BUILTIN_VPERM_16QI:
> > case ALTIVEC_BUILTIN_VPERM_8HI:
> > case ALTIVEC_BUILTIN_VPERM_4SI:
> > case ALTIVEC_BUILTIN_VPERM_4SF:
>
