Re: [PATCH] [vect] Add vect_recog_cond_expr_convert_pattern.

[Richard Biener <richard.guenther@gmail.com>]

On Thu, Feb 10, 2022 at 7:59 AM liuhongt <hongtao.liu@intel.com> wrote:
>
> >But in principle @2 or @3 could safely differ in sign, you'd then need to ensure
> >to insert sign conversions to @2/@3 to the signedness of @4/@5.
> Changed.
> >you are not testing for this anywhere?
> It's tested in vect_recog_cond_expr_convert_pattern, I've move it to match.pd
>
> >Btw, matching up the comments with the types is somewhat difficult,
> >maybe using TYPE_AB, TYPE_CD, TYPE_E instead of 1,2,3 will
> >make that easier ;)
> Changed.
> >I think the precision check should be part of the match.pd pattern.  You
> >do not check that the comparison operands are integral - I think float
> >comparisons would be OK in principle but the precision check will not
> >work there.
> Restricted to integeral type.
>
> Here's updated patch.
>
> gcc/ChangeLog:
>
>         PR target/103771
>         * match.pd (cond_expr_convert_p): New match.
>         * tree-vect-patterns.cc (gimple_cond_expr_convert_p): Declare.
>         (vect_recog_cond_expr_convert_pattern): New.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/i386/pr103771-2.c: New test.
>         * gcc.target/i386/pr103771-3.c: New test.
> ---
>  gcc/match.pd                               | 14 ++++
>  gcc/testsuite/gcc.target/i386/pr103771-2.c |  8 ++
>  gcc/testsuite/gcc.target/i386/pr103771-3.c | 21 +++++
>  gcc/tree-vect-patterns.cc                  | 96 ++++++++++++++++++++++
>  4 files changed, 139 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr103771-2.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr103771-3.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 7bbb80172fc..7386ee518a1 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -7683,3 +7683,17 @@ and,
>     to the number of trailing zeroes.  */
>  (match (ctz_table_index @1 @2 @3)
>    (rshift (mult (bit_and:c (negate @1) @1) INTEGER_CST@2) INTEGER_CST@3))
> +
> +(match (cond_expr_convert_p @0 @2 @3 @6)
> + (cond (simple_comparison@6 @0 @1) (convert@4 @2) (convert@5 @3))
> +  (if (INTEGRAL_TYPE_P (type)
> +       && INTEGRAL_TYPE_P (TREE_TYPE (@2))
> +       && INTEGRAL_TYPE_P (TREE_TYPE (@0))
> +       && INTEGRAL_TYPE_P (TREE_TYPE (@3))
> +       && TYPE_PRECISION (type) != TYPE_PRECISION (TREE_TYPE (@0))
> +       && TYPE_PRECISION (TREE_TYPE (@0))
> +         == TYPE_PRECISION (TREE_TYPE (@2))
> +       && TYPE_PRECISION (TREE_TYPE (@0))
> +         == TYPE_PRECISION (TREE_TYPE (@3))
> +       && single_use (@4)
> +       && single_use (@5))))
> diff --git a/gcc/testsuite/gcc.target/i386/pr103771-2.c b/gcc/testsuite/gcc.target/i386/pr103771-2.c
> new file mode 100644
> index 00000000000..962a3a74ecf
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr103771-2.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=cascadelake -O3" } */
> +/* { dg-final { scan-assembler-not "kunpck" } } */
> +/* { dg-final { scan-assembler-not "kand" } } */
> +/* { dg-final { scan-assembler-not "kor" } } */
> +/* { dg-final { scan-assembler-not "kshift" } } */
> +
> +#include "pr103771.c"
> diff --git a/gcc/testsuite/gcc.target/i386/pr103771-3.c b/gcc/testsuite/gcc.target/i386/pr103771-3.c
> new file mode 100644
> index 00000000000..ef379b23b12
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr103771-3.c
> @@ -0,0 +1,21 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=cascadelake -O3" } */
> +/* { dg-final { scan-assembler-not "kunpck" } } */
> +/* { dg-final { scan-assembler-not "kand" } } */
> +/* { dg-final { scan-assembler-not "kor" } } */
> +/* { dg-final { scan-assembler-not "kshift" } } */
> +
> +typedef unsigned char uint8_t;
> +
> +static uint8_t x264_clip_uint8 (int x, unsigned int y)
> +{
> +  return x & (~255) ? (-x) >> 31 : y;
> +}
> +
> +void
> +mc_weight (uint8_t* __restrict dst, uint8_t* __restrict src,
> +          int i_width,int i_scale, unsigned int* __restrict y)
> +{
> +  for(int x = 0; x < i_width; x++)
> +    dst[x] = x264_clip_uint8 (src[x] * i_scale, y[x]);
> +}
> diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
> index 2baf974627e..aa54bc8bf8b 100644
> --- a/gcc/tree-vect-patterns.cc
> +++ b/gcc/tree-vect-patterns.cc
> @@ -924,6 +924,101 @@ vect_reassociating_reduction_p (vec_info *vinfo,
>    return true;
>  }
>
> +/* match.pd function to match
> +   (cond (cmp@3 a b) (convert@1 c) (convert@2 d))
> +   with conditions:
> +   1) @1, @2, c, d, a, b are all integral type.
> +   2) There's single_use for both @1 and @2.
> +   3) a, c and d have same precision.
> +   4) c and @1 have different precision.
> +
> +   record a and c and d and @3.  */
> +
> +extern bool gimple_cond_expr_convert_p (tree, tree*, tree (*)(tree));
> +
> +/* Function vect_recog_cond_expr_convert
> +
> +   Try to find the following pattern:
> +
> +   TYPE_AB A,B;
> +   TYPE_CD C,D;
> +   TYPE_E E;
> +   TYPE_E op_true = (TYPE_E) A;
> +   TYPE_E op_false = (TYPE_E) B;
> +
> +   E = C cmp D ? op_true : op_false;
> +
> +   where
> +   TYPE_PRECISION (TYPE_E) != TYPE_PRECISION (TYPE_CD);
> +   TYPE_PRECISION (TYPE_AB) == TYPE_PRECISION (TYPE_CD);
> +   single_use of op_true and op_false.
> +   TYPE_AB could differ in sign.
> +
> +   Input:
> +
> +   * STMT_VINFO: The stmt from which the pattern search begins.
> +   here it starts with E = c cmp D ? op_true : op_false;
> +
> +   Output:
> +
> +   TYPE1 E' = C cmp D ? A : B;
> +   TYPE3 E = (TYPE3) E';
> +
> +   There may extra nop_convert for A or B to handle different signness.
> +
> +   * TYPE_OUT: The vector type of the output of this pattern.
> +
> +   * Return value: A new stmt that will be used to replace the sequence of
> +   stmts that constitute the pattern. In this case it will be:
> +   E = (TYPE3)E';
> +   E' = C cmp D ? A : B; is recorded in pattern definition statements;  */
> +
> +static gimple *
> +vect_recog_cond_expr_convert_pattern (vec_info *vinfo,
> +                                     stmt_vec_info stmt_vinfo, tree *type_out)
> +{
> +  gassign *last_stmt = dyn_cast <gassign *> (stmt_vinfo->stmt);
> +  tree lhs, match[4], temp, type, new_lhs, op2;
> +  gimple *cond_stmt;
> +  gimple *pattern_stmt;
> +
> +  if (!last_stmt)
> +    return NULL;
> +
> +  lhs = gimple_assign_lhs (last_stmt);
> +
> +  /* Find E = C cmp D ? (TYPE3) A ? (TYPE3) B;
> +     TYPE_PRECISION (A) == TYPE_PRECISION (C).  */
> +  if (!gimple_cond_expr_convert_p (lhs, &match[0], NULL))
> +    return NULL;
> +
> +  vect_pattern_detected ("vect_recog_cond_expr_convert_pattern", last_stmt);
> +
> +  op2 = match[2];
> +  type = TREE_TYPE (match[1]);
> +  if (TYPE_SIGN (type) != TYPE_SIGN (TREE_TYPE (match[2])))
> +    {
> +      op2 = vect_recog_temp_ssa_var (type, NULL);
> +      gimple* nop_stmt = gimple_build_assign (op2, CONVERT_EXPR, match[2]);

Please use NOP_EXPR here ...

> +      append_pattern_def_seq (vinfo, stmt_vinfo, nop_stmt,
> +                             get_vectype_for_scalar_type (vinfo, type));
> +    }
> +
> +  temp = vect_recog_temp_ssa_var (type, NULL);
> +  cond_stmt = gimple_build_assign (temp, build3 (COND_EXPR, type, match[3],
> +                                                match[1], op2));
> +  append_pattern_def_seq (vinfo, stmt_vinfo, cond_stmt,
> +                         get_vectype_for_scalar_type (vinfo, type));
> +  new_lhs = vect_recog_temp_ssa_var (TREE_TYPE (lhs), NULL);
> +  pattern_stmt = gimple_build_assign (new_lhs, CONVERT_EXPR, temp);

... and here.  OK with that change.

Thanks,
Richard.

> +  *type_out = STMT_VINFO_VECTYPE (stmt_vinfo);
> +
> +  if (dump_enabled_p ())
> +    dump_printf_loc (MSG_NOTE, vect_location,
> +                    "created pattern stmt: %G", pattern_stmt);
> +  return pattern_stmt;
> +}
> +
>  /* Function vect_recog_dot_prod_pattern
>
>     Try to find the following pattern:
> @@ -5492,6 +5587,7 @@ static vect_recog_func vect_vect_recog_func_ptrs[] = {
>    /* Must come after over_widening, which narrows the shift as much as
>       possible beforehand.  */
>    { vect_recog_average_pattern, "average" },
> +  { vect_recog_cond_expr_convert_pattern, "cond_expr_convert" },
>    { vect_recog_mulhs_pattern, "mult_high" },
>    { vect_recog_cast_forwprop_pattern, "cast_forwprop" },
>    { vect_recog_widen_mult_pattern, "widen_mult" },
> --
> 2.18.1
>