[gcc r14-10087] s390x: Fix vec_xl/vec_xst type aliasing [PR114676]

[gcc r14-10087] s390x: Fix vec_xl/vec_xst type aliasing [PR114676]

[Andreas Krebbel]

https://gcc.gnu.org/g:42189f21b22c43ac8ab46edf5f6a7b4d99bc86a5

commit r14-10087-g42189f21b22c43ac8ab46edf5f6a7b4d99bc86a5
Author: Andreas Krebbel <krebbel@linux.ibm.com>
Date:   Tue Apr 23 10:05:46 2024 +0200

    s390x: Fix vec_xl/vec_xst type aliasing [PR114676]
    
    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.
    
    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>

Diff:
---
 gcc/config/s390/s390-c.cc                        | 16 +++++++++-------
 gcc/testsuite/gcc.target/s390/zvector/pr114676.c | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+), 7 deletions(-)

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;
+}