re PR tree-optimization/65930 (Reduction with sign-change not handled)

2019-10-23  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/65930
	* tree-vect-loop.c (check_reduction_path): Allow conversions
	that only change the sign.
	(vectorizable_reduction): Relax latch def stmts we handle further.

	* gcc.dg/vect/vect-reduc-2char-big-array.c: Adjust.
	* gcc.dg/vect/vect-reduc-2char.c: Likewise.
	* gcc.dg/vect/vect-reduc-2short.c: Likewise.
	* gcc.dg/vect/vect-reduc-dot-s8b.c: Likewise.
	* gcc.dg/vect/vect-reduc-pattern-2c.c: Likewise.

From-SVN: r277322

gcc/ChangeLog

+2019-10-23  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/65930
+	* tree-vect-loop.c (check_reduction_path): Allow conversions
+	that only change the sign.
+	(vectorizable_reduction): Relax latch def stmts we handle further.
+
 2019-10-23  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/90231

gcc/testsuite/ChangeLog

+2019-10-23  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/65930
+	* gcc.dg/vect/vect-reduc-2char-big-array.c: Adjust.
+	* gcc.dg/vect/vect-reduc-2char.c: Likewise.
+	* gcc.dg/vect/vect-reduc-2short.c: Likewise.
+	* gcc.dg/vect/vect-reduc-dot-s8b.c: Likewise.
+	* gcc.dg/vect/vect-reduc-pattern-2c.c: Likewise.
+
 2019-10-23  Jakub Jelinek  <jakub@redhat.com>
 
 	* g++.dg/cpp2a/constexpr-dtor3.C: Expect in 'constexpr' expansion of

gcc/testsuite/gcc.dg/vect/vect-reduc-2char-big-array.c

@@ -62,4 +62,4 @@ int main (void)
   return 0;
 }
 
-/* { dg-final { scan-tree-dump-times "vectorized 3 loops" 1 "vect" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 3 loops" 1 "vect" } } */

gcc/testsuite/gcc.dg/vect/vect-reduc-2char.c

@@ -46,4 +46,4 @@ int main (void)
   return 0;
 }
 
-/* { dg-final { scan-tree-dump-times "vectorized 3 loops" 1 "vect" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 3 loops" 1 "vect" } } */

gcc/testsuite/gcc.dg/vect/vect-reduc-2short.c

@@ -45,4 +45,4 @@ int main (void)
   return 0;
 }
 
-/* { dg-final { scan-tree-dump-times "vectorized 3 loops" 1 "vect" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 3 loops" 1 "vect" } } */

gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s8b.c

@@ -12,12 +12,6 @@ signed char Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
 
 /* char->short->short dot product.
    The dot-product pattern should be detected.
-   The reduction is currently not vectorized becaus of the signed->unsigned->signed
-   casts, since this patch:
-
-     2005-12-26  Kazu Hirata  <kazu@codesourcery.com>
-                                                                                                
-        PR tree-optimization/25125
 
    When the dot-product is detected, the loop should be vectorized on vect_sdot_qi 
    targets (targets that support dot-product of signed char).  
@@ -60,5 +54,5 @@ int main (void)
 /* { dg-final { scan-tree-dump-times "vect_recog_dot_prod_pattern: detected" 1 "vect" { xfail *-*-* } } } */
 /* { dg-final { scan-tree-dump-times "vect_recog_widen_mult_pattern: detected" 1 "vect" } } */
 
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
 

gcc/testsuite/gcc.dg/vect/vect-reduc-pattern-2c.c

@@ -21,6 +21,8 @@ foo ()
      2005-12-26  Kazu Hirata  <kazu@codesourcery.com>
                                                                                 
         PR tree-optimization/25125
+
+     but we still handle the reduction.
    */
 
   for (i = 0; i < N; i++)
@@ -43,5 +45,4 @@ main (void)
 }
 
 /* { dg-final { scan-tree-dump-times "vect_recog_widen_sum_pattern: detected" 1 "vect" { xfail *-*-* } } } */
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { xfail *-*-* } } } */
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 0 "vect" { target { ! vect_widen_sum_qi_to_hi } } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */

gcc/tree-vect-loop.c

@@ -2695,7 +2695,11 @@ pop:
 	  if (gimple_assign_rhs2 (use_stmt) == op)
 	    neg = ! neg;
 	}
-      if (*code == ERROR_MARK)
+      if (CONVERT_EXPR_CODE_P (use_code)
+	  && tree_nop_conversion_p (TREE_TYPE (gimple_assign_lhs (use_stmt)),
+				    TREE_TYPE (gimple_assign_rhs1 (use_stmt))))
+	;
+      else if (*code == ERROR_MARK)
 	*code = use_code;
       else if (use_code != *code)
 	{
@@ -5692,19 +5696,6 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
         which is defined by the loop-header-phi.  */
 
   gassign *stmt = as_a <gassign *> (stmt_info->stmt);
-  switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
-    {
-    case GIMPLE_BINARY_RHS:
-    case GIMPLE_TERNARY_RHS:
-      break;
-
-    case GIMPLE_UNARY_RHS:
-    case GIMPLE_SINGLE_RHS:
-      return false;
-
-    default:
-      gcc_unreachable ();
-    }
   enum tree_code code = gimple_assign_rhs_code (stmt);
   int op_type = TREE_CODE_LENGTH (code);