[Committed] s390x: Fix vec_xl/vec_xst type aliasing [PR114676]

[Andreas Krebbel <krebbel@linux.ibm.com>]

The requirements of the vec_xl/vec_xst intrinsincs wrt aliasing of the
pointer argument are not really documented.  As it turns out, users
are likely to get it wrong.  With this patch we let the pointer
argument alias everything in order to make it more robust for users.

Committed to mainline. Will be cherry-picked for stable branches as well.

gcc/ChangeLog:

	PR target/114676
	* config/s390/s390-c.cc (s390_expand_overloaded_builtin): Use a
	MEM_REF with an addend of type ptr_type_node.

gcc/testsuite/ChangeLog:

	PR target/114676
	* gcc.target/s390/zvector/pr114676.c: New test.

Suggested-by: Jakub Jelinek <jakub@redhat.com>
---
 gcc/config/s390/s390-c.cc                     | 16 +++++++++-------
 .../gcc.target/s390/zvector/pr114676.c        | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/s390/zvector/pr114676.c

diff --git a/gcc/config/s390/s390-c.cc b/gcc/config/s390/s390-c.cc
index 8d3d1a467a8..1bb6e810766 100644
--- a/gcc/config/s390/s390-c.cc
+++ b/gcc/config/s390/s390-c.cc
@@ -498,11 +498,11 @@ s390_expand_overloaded_builtin (location_t loc,
 	/* Build a vector type with the alignment of the source
 	   location in order to enable correct alignment hints to be
 	   generated for vl.  */
-	tree mem_type = build_aligned_type (return_type,
-					    TYPE_ALIGN (TREE_TYPE (TREE_TYPE ((*arglist)[1]))));
+	unsigned align = TYPE_ALIGN (TREE_TYPE (TREE_TYPE ((*arglist)[1])));
+	tree mem_type = build_aligned_type (return_type, align);
 	return build2 (MEM_REF, mem_type,
 		       fold_build_pointer_plus ((*arglist)[1], (*arglist)[0]),
-		       build_int_cst (TREE_TYPE ((*arglist)[1]), 0));
+		       build_int_cst (ptr_type_node, 0));
       }
     case S390_OVERLOADED_BUILTIN_s390_vec_xst:
     case S390_OVERLOADED_BUILTIN_s390_vec_xstd2:
@@ -511,11 +511,13 @@ s390_expand_overloaded_builtin (location_t loc,
 	/* Build a vector type with the alignment of the target
 	   location in order to enable correct alignment hints to be
 	   generated for vst.  */
-	tree mem_type = build_aligned_type (TREE_TYPE((*arglist)[0]),
-					    TYPE_ALIGN (TREE_TYPE (TREE_TYPE ((*arglist)[2]))));
+	unsigned align = TYPE_ALIGN (TREE_TYPE (TREE_TYPE ((*arglist)[2])));
+	tree mem_type = build_aligned_type (TREE_TYPE ((*arglist)[0]), align);
 	return build2 (MODIFY_EXPR, mem_type,
-		       build1 (INDIRECT_REF, mem_type,
-			       fold_build_pointer_plus ((*arglist)[2], (*arglist)[1])),
+		       build2 (MEM_REF, mem_type,
+			       fold_build_pointer_plus ((*arglist)[2],
+							(*arglist)[1]),
+			       build_int_cst (ptr_type_node, 0)),
 		       (*arglist)[0]);
       }
     case S390_OVERLOADED_BUILTIN_s390_vec_load_pair:
diff --git a/gcc/testsuite/gcc.target/s390/zvector/pr114676.c b/gcc/testsuite/gcc.target/s390/zvector/pr114676.c
new file mode 100644
index 00000000000..bdc66b2920a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/zvector/pr114676.c
@@ -0,0 +1,19 @@
+/* { dg-do run { target { s390*-*-* } } } */
+/* { dg-options "-O3 -mzarch -march=z14 -mzvector" } */
+
+#include <vecintrin.h>
+
+void __attribute__((noinline)) foo (int *mem)
+{
+  vec_xst ((vector float){ 1.0f, 2.0f, 3.0f, 4.0f }, 0, (float*)mem);
+}
+
+int
+main ()
+{
+  int m[4] = { 0 };
+  foo (m);
+  if (m[3] == 0)
+    __builtin_abort ();
+  return 0;
+}
-- 
2.44.0