On Mon, Jun 18, 2018 at 5:04 PM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> When following the definitions of SSA names, some recognisers
> already cope with statements that have been replaced by patterns.
> This patch makes that happen automatically for users of
> type_conversion_p and vect_get_internal_def. It also adds
> a vect_look_through_pattern helper that can be used directly.
>
> The reason for doing this is that the main patch for PR85694
> makes over_widening handle more general cases. These over-widened
> patterns can still be useful when matching later statements;
> e.g. an overwidened MULT_EXPR could be the input to a DOT_PROD_EXPR.
>
> The patch doesn't do anything with the STMT_VINFO_IN_PATTERN_P checks
> in vect_recog_over_widening_pattern or vect_recog_widen_shift_pattern
> since later patches rewrite them anyway.
>
> Doing this fixed an XFAIL in vect-reduc-dot-u16b.c.
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Hmm. It seems to me that *def_stmt for vect_is_simple_use should
eventually be the pattern def given the vectype overload takes the
vectype from the pattern def already but oddly enough the
DEF_TYPE is taken from the non-pattern stmt.
I wonder which callers look at def_stmt at all (and how...)
I guess swapping the def_stmt and dt arguments and adding yet another
overload to remove all unused &def_stmt args might this easier to review...
So - I'm suggesting to change vect_is_simple_use.
Otherwise it somehow looks inconsistent.
Anyhow, I can of course reconsider.
Thanks,
Richard.
> Richard
>
>
> 2018-06-18 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * tree-vectorizer.h (vect_look_through_pattern): New function.
> * tree-vect-patterns.c (vect_get_internal_def): Use it.
> (type_conversion_p): Likewise.
> (vect_recog_rotate_pattern): Likewise.
> (vect_recog_dot_prod_pattern): Check directly for a WIDEN_MULT_EXPR.
> (vect_recog_vector_vector_shift_pattern): Don't check
> STMT_VINFO_IN_PATTERN_P.
>
> gcc/testsuite/
> * gcc.dg/vect/vect-reduc-dot-u16b.c: Remove xfail and update the
> test for vectorization along the lines described in the comment.
>
> Index: gcc/tree-vectorizer.h
> ===================================================================
> --- gcc/tree-vectorizer.h 2018-06-18 15:43:52.951038712 +0100
> +++ gcc/tree-vectorizer.h 2018-06-18 15:44:05.522927566 +0100
> @@ -1422,6 +1422,19 @@ vect_get_scalar_dr_size (struct data_ref
> return tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr))));
> }
>
> +/* STMT is a statement that we're thinking about vectorizing.
> + If it has been replaced by a pattern statement, return that
> + pattern statement, otherwise return STMT itself. */
> +
> +inline gimple *
> +vect_look_through_pattern (gimple *stmt)
> +{
> + stmt_vec_info vinfo = vinfo_for_stmt (stmt);
> + if (STMT_VINFO_IN_PATTERN_P (vinfo))
> + stmt = STMT_VINFO_RELATED_STMT (vinfo);
> + return stmt;
> +}
> +
> /* Source location */
> extern source_location vect_location;
>
> Index: gcc/tree-vect-patterns.c
> ===================================================================
> --- gcc/tree-vect-patterns.c 2018-06-18 15:43:52.951038712 +0100
> +++ gcc/tree-vect-patterns.c 2018-06-18 15:44:05.522927566 +0100
> @@ -164,7 +164,7 @@ vect_get_internal_def (vec_info *vinfo,
> || dt != vect_internal_def)
> return NULL;
>
> - return vinfo_for_stmt (def_stmt);
> + return vinfo_for_stmt (vect_look_through_pattern (def_stmt));
> }
>
> /* Check whether NAME, an ssa-name used in USE_STMT,
> @@ -195,12 +195,7 @@ type_conversion_p (tree name, gimple *us
> return false;
>
> if (dt == vect_internal_def)
> - {
> - stmt_vec_info def_vinfo = vinfo_for_stmt (*def_stmt);
> - if (STMT_VINFO_IN_PATTERN_P (def_vinfo))
> - return false;
> - }
> -
> + *def_stmt = vect_look_through_pattern (*def_stmt);
> if (!is_gimple_assign (*def_stmt))
> return false;
>
> @@ -384,20 +379,11 @@ vect_recog_dot_prod_pattern (vec<gimple
> /* FORNOW. Can continue analyzing the def-use chain when this stmt in a
> phi
> inside the loop (in case we are analyzing an outer-loop). */
> gassign *mult = dyn_cast <gassign *> (mult_vinfo->stmt);
> - if (!mult || gimple_assign_rhs_code (mult) != MULT_EXPR)
> + if (!mult)
> return NULL;
> - if (STMT_VINFO_IN_PATTERN_P (mult_vinfo))
> + if (gimple_assign_rhs_code (mult) == WIDEN_MULT_EXPR)
> {
> /* Has been detected as a widening multiplication? */
> -
> - mult = dyn_cast <gassign *> (STMT_VINFO_RELATED_STMT (mult_vinfo));
> - if (!mult || gimple_assign_rhs_code (mult) != WIDEN_MULT_EXPR)
> - return NULL;
> - STMT_VINFO_PATTERN_DEF_SEQ (stmt_vinfo)
> - = STMT_VINFO_PATTERN_DEF_SEQ (mult_vinfo);
> - mult_vinfo = vinfo_for_stmt (mult);
> - gcc_assert (mult_vinfo);
> - gcc_assert (STMT_VINFO_DEF_TYPE (mult_vinfo) == vect_internal_def);
> oprnd00 = gimple_assign_rhs1 (mult);
> oprnd01 = gimple_assign_rhs2 (mult);
> }
> @@ -407,6 +393,9 @@ vect_recog_dot_prod_pattern (vec<gimple
> gimple *def_stmt;
> tree oprnd0, oprnd1;
>
> + if (gimple_assign_rhs_code (mult) != MULT_EXPR)
> + return NULL;
> +
> oprnd0 = gimple_assign_rhs1 (mult);
> oprnd1 = gimple_assign_rhs2 (mult);
> if (!type_conversion_p (oprnd0, mult, true, &half_type0, &def_stmt,
> @@ -1803,6 +1792,9 @@ vect_recog_rotate_pattern (vec<gimple *>
> && dt != vect_external_def)
> return NULL;
>
> + if (dt == vect_internal_def)
> + def_stmt = vect_look_through_pattern (def_stmt);
> +
> vectype = get_vectype_for_scalar_type (type);
> if (vectype == NULL_TREE)
> return NULL;
> @@ -2051,9 +2043,7 @@ vect_recog_vector_vector_shift_pattern (
>
> tree def = NULL_TREE;
> gassign *def_stmt = dyn_cast <gassign *> (def_vinfo->stmt);
> - if (!STMT_VINFO_IN_PATTERN_P (def_vinfo)
> - && def_stmt
> - && gimple_assign_cast_p (def_stmt))
> + if (def_stmt && gimple_assign_cast_p (def_stmt))
> {
> tree rhs1 = gimple_assign_rhs1 (def_stmt);
> if (TYPE_MODE (TREE_TYPE (rhs1)) == TYPE_MODE (TREE_TYPE (oprnd0))
> Index: gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16b.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16b.c 2016-11-11
> 17:07:36.588798042 +0000
> +++ gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16b.c 2018-06-18
> 15:44:05.522927566 +0100
> @@ -10,11 +10,8 @@ #define DOT2 43680
> unsigned short X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
> unsigned short Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
>
> -/* short->int->int dot product.
> - Currently not detected as a dot-product pattern: the multiplication
> - promotes the ushorts to int, and then the product is promoted to unsigned
> - int for the addition. Which results in an int->unsigned int cast, which
> - since no bits are modified in the cast should be trivially vectorizable.
> */
> +/* ushort->int->uint dot product: the multiplication promotes the ushorts
> + to int, and then the product is converted to uint for the addition. */
> __attribute__ ((noinline)) unsigned int
> foo2(int len) {
> int i;
> @@ -47,12 +44,6 @@ int main (void)
> return 0;
> }
>
> -/* { dg-final { scan-tree-dump-times "vect_recog_dot_prod_pattern: detected"
> 1 "vect" { xfail *-*-* } } } */
> -
> -/* Once the dot-product pattern is detected, we expect
> - that loop to be vectorized on vect_udot_hi targets (targets that support
> - dot-product of unsigned shorts) and targets that support widening
> multiplication. */
> -/* The induction loop in main is vectorized. */
> -/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" { xfail
> *-*-* } } } */
> -/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target
> vect_pack_trunc } } } */
> +/* { dg-final { scan-tree-dump-times "vect_recog_dot_prod_pattern: detected"
> 1 "vect" } } */
>
> +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target
> { vect_pack_trunc || vect_udot_hi } } } } */
