vect: Don't pass subtype to vect_widened_op_tree where not needed [PR 110142]

["Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>]

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Hi,

This patch fixes an issue introduced by 
g:2f482a07365d9f4a94a56edd13b7f01b8f78b5a0, where a subtype was beeing 
passed to vect_widened_op_tree, when no subtype was to be used. This 
lead to an errorneous use of IFN_VEC_WIDEN_MINUS.

gcc/ChangeLog:

         * tree-vect-patterns.cc (vect_recog_widen_op_pattern): Don't 
pass subtype to
         vect_widened_op_tree and remove subtype parameter.
         (vect_recog_widen_plus_pattern): Remove subtype parameter and 
dont pass to call to
         vect_recog_widen_op_pattern.
         (vect_recog_widen_minus_pattern): Likewise.

gcc/testsuite/ChangeLog:

         * gcc.dg/vect/pr110142.c: New test.

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diff --git a/gcc/testsuite/gcc.dg/vect/pr110142.c b/gcc/testsuite/gcc.dg/vect/pr110142.c
new file mode 100644
index 0000000000000000000000000000000000000000..a88dbe400f46a33a53649298345c24c569e2f567
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr110142.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O3" } */
+void test(short *x, unsigned short *y, int n)
+{
+  for (int i = 0; i < n; i++)
+      x[i] = (y[i] - x[i]) >> 1;
+}
+
+/* { dg-final { scan-tree-dump-not "widen_minus" "vect" } } */
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index dc102c919352a0328cf86eabceb3a38c41a7e4fd..599a027f9b2feb8971c1ee017b6457bc297c86c2 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -1405,15 +1405,14 @@ static gimple *
 vect_recog_widen_op_pattern (vec_info *vinfo,
 			     stmt_vec_info last_stmt_info, tree *type_out,
 			     tree_code orig_code, code_helper wide_code,
-			     bool shift_p, const char *name,
-			     optab_subtype *subtype = NULL)
+			     bool shift_p, const char *name)
 {
   gimple *last_stmt = last_stmt_info->stmt;
 
   vect_unpromoted_value unprom[2];
   tree half_type;
   if (!vect_widened_op_tree (vinfo, last_stmt_info, orig_code, orig_code,
-			     shift_p, 2, unprom, &half_type, subtype))
+			     shift_p, 2, unprom, &half_type))
 
     return NULL;
 
@@ -1484,13 +1483,11 @@ static gimple *
 vect_recog_widen_op_pattern (vec_info *vinfo,
 			     stmt_vec_info last_stmt_info, tree *type_out,
 			     tree_code orig_code, internal_fn wide_ifn,
-			     bool shift_p, const char *name,
-			     optab_subtype *subtype = NULL)
+			     bool shift_p, const char *name)
 {
   combined_fn ifn = as_combined_fn (wide_ifn);
   return vect_recog_widen_op_pattern (vinfo, last_stmt_info, type_out,
-				      orig_code, ifn, shift_p, name,
-				      subtype);
+				      orig_code, ifn, shift_p, name);
 }
 
 
@@ -1513,11 +1510,9 @@ static gimple *
 vect_recog_widen_plus_pattern (vec_info *vinfo, stmt_vec_info last_stmt_info,
 			       tree *type_out)
 {
-  optab_subtype subtype;
   return vect_recog_widen_op_pattern (vinfo, last_stmt_info, type_out,
 				      PLUS_EXPR, IFN_VEC_WIDEN_PLUS,
-				      false, "vect_recog_widen_plus_pattern",
-				      &subtype);
+				      false, "vect_recog_widen_plus_pattern");
 }
 
 /* Try to detect subtraction on widened inputs, converting MINUS_EXPR
@@ -1526,11 +1521,9 @@ static gimple *
 vect_recog_widen_minus_pattern (vec_info *vinfo, stmt_vec_info last_stmt_info,
 			       tree *type_out)
 {
-  optab_subtype subtype;
   return vect_recog_widen_op_pattern (vinfo, last_stmt_info, type_out,
 				      MINUS_EXPR, IFN_VEC_WIDEN_MINUS,
-				      false, "vect_recog_widen_minus_pattern",
-				      &subtype);
+				      false, "vect_recog_widen_minus_pattern");
 }
 
 /* Function vect_recog_ctz_ffs_pattern