middle-end/105140 - fix bogus recursion in fold_convertible_p

fold_convertible_p expects an operand and a type to convert to
but recurses with two vector component types.  Fixed by allowing
types instead of an operand as well.

2022-04-04  Richard Biener  <rguenther@suse.de>

	PR middle-end/105140
	* fold-const.cc (fold_convertible_p): Allow a TYPE_P arg.

	* gcc.dg/pr105140.c: New testcase.

diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index b647e53..fb08fa1 100644 (file)
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -2379,12 +2379,13 @@ build_zero_vector (tree type)
   return build_vector_from_val (type, t);
 }
 
-/* Returns true, if ARG is convertible to TYPE using a NOP_EXPR.  */
+/* Returns true, if ARG, an operand or a type, is convertible to TYPE
+   using a NOP_EXPR.  */
 
 bool
 fold_convertible_p (const_tree type, const_tree arg)
 {
-  tree orig = TREE_TYPE (arg);
+  const_tree orig = TYPE_P (arg) ? arg : TREE_TYPE (arg);
 
   if (type == orig)
     return true;

diff --git a/gcc/testsuite/gcc.dg/pr105140.c b/gcc/testsuite/gcc.dg/pr105140.c
new file mode 100644 (file)
index 0000000..14bff2f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr105140.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-Os -w -Wno-psabi" } */
+
+typedef char __attribute__((__vector_size__ (16 * sizeof (char)))) U;
+typedef int __attribute__((__vector_size__ (16 * sizeof (int)))) V;
+
+void bar ();
+
+bar (int i, int j, int k, V v)
+{
+}
+
+void
+foo (void)
+{
+  bar ((V){}, (V){}, (V){}, (U){});
+}