[PATCH] [vect] Add vect_recog_cond_expr_convert_pattern.

[liuhongt <hongtao.liu@intel.com>]

The pattern converts (cond (cmp a b) (convert c) (convert d))
to (convert (cond (cmp a b) c d)) when
1) types_match (c, d)
2) single_use for (convert c) and (convert d)
3) TYPE_PRECISION (TREE_TYPE (c)) == TYPE_PRECISION (TREE_TYPE (a))
4) INTEGERAL_TYPE_P (TREE_TYPE (c))

The pattern can save packing of mask and data(partial for data, 2 vs
1).

Bootstrapped and regtested for x86_64-pc-linux-gnu{-m32,}
and x86_64-pc-linux-gnu{-m32\ -march=native,\ -march=native} on CLX.
Ok for trunk?

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/match.pd                               |  8 +++
 gcc/testsuite/gcc.target/i386/pr103771-2.c |  8 +++
 gcc/tree-vect-patterns.cc                  | 83 ++++++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr103771-2.c

diff --git a/gcc/match.pd b/gcc/match.pd
index c68eed70a26..5808c4561ee 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -7647,3 +7647,11 @@ 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 (types_match (TREE_TYPE (@2), TREE_TYPE (@3))
+       && INTEGRAL_TYPE_P (type)
+       && INTEGRAL_TYPE_P (TREE_TYPE (@2))
+       && 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/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index bea04992160..cbdfa96789c 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -924,6 +924,88 @@ 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) there's single_use for both @1 and @2.
+   2) c and d have same type.
+   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:
+
+   TYPE1 A, B;
+   TYPE2 C,D;
+   TYPE3 E;
+   TYPE3 op_true = (TYPE3)A;
+   TYPE4 op_false = (TYPE3)B;
+
+   E = C cmp D ? op_true : op_false;
+
+   where
+   TYPE_PRECISION (TYPE1) != TYPE_PRECISION (TYPE3);
+   TYPE_PRECISION (TYPE1) == TYPE_PRECISION (TYPE2);
+   single_use of op_true and op_false.
+
+   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';
+
+   * 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;
+  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)
+      || (TYPE_PRECISION (TREE_TYPE (match[0]))
+	  != TYPE_PRECISION (TREE_TYPE (match[1]))))
+    return NULL;
+
+  vect_pattern_detected ("vect_recog_cond_expr_convert_pattern", last_stmt);
+
+  type = TREE_TYPE (match[1]);
+  temp = vect_recog_temp_ssa_var (type, NULL);
+  cond_stmt = gimple_build_assign (temp, build3 (COND_EXPR, type, match[3],
+						 match[1], match[2]));
+  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);
+  *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 +5574,7 @@ 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