[gcc r12-3034] rs6000: Fix ICE expanding lxvp and stxvp gimple built-ins [PR101849]

[Peter Bergner <bergner@gcc.gnu.org>]

https://gcc.gnu.org/g:b0963c4379becafaebd8e52b0b42698ff151c293

commit r12-3034-gb0963c4379becafaebd8e52b0b42698ff151c293
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Thu Aug 19 17:33:29 2021 -0500

    rs6000: Fix ICE expanding lxvp and stxvp gimple built-ins [PR101849]
    
    PR101849 shows we ICE on a test case when we pass a non __vector_pair *
    pointer to the __builtin_vsx_lxvp and __builtin_vsx_stxvp built-ins
    that is cast to __vector_pair *.  The problem is that when we expand
    the built-in, the cast has already been removed from gimple and we are
    only given the base pointer.  The solution used here (which fixes the ICE)
    is to catch this case and convert the pointer to a __vector_pair * pointer
    when expanding the built-in.
    
    2021-08-19  Peter Bergner  <bergner@linux.ibm.com>
    
    gcc/
            PR target/101849
            * config/rs6000/rs6000-call.c (rs6000_gimple_fold_mma_builtin): Cast
            pointer to __vector_pair *.
    
    gcc/testsuite/
            PR target/101849
            * gcc.target/powerpc/pr101849.c: New test.

Diff:
---
 gcc/config/rs6000/rs6000-call.c             |  6 ++++++
 gcc/testsuite/gcc.target/powerpc/pr101849.c | 22 ++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index 8b16d65e684..3c3108a1c87 100644
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -11919,6 +11919,9 @@ rs6000_gimple_fold_mma_builtin (gimple_stmt_iterator *gsi)
       tree offset = gimple_call_arg (stmt, 0);
       tree ptr = gimple_call_arg (stmt, 1);
       tree lhs = gimple_call_lhs (stmt);
+      if (TREE_TYPE (TREE_TYPE (ptr)) != vector_pair_type_node)
+	ptr = build1 (VIEW_CONVERT_EXPR,
+		      build_pointer_type (vector_pair_type_node), ptr);
       tree mem = build_simple_mem_ref (build2 (POINTER_PLUS_EXPR,
 					       TREE_TYPE (ptr), ptr, offset));
       gimplify_assign (lhs, mem, &new_seq);
@@ -11932,6 +11935,9 @@ rs6000_gimple_fold_mma_builtin (gimple_stmt_iterator *gsi)
       tree src = gimple_call_arg (stmt, 0);
       tree offset = gimple_call_arg (stmt, 1);
       tree ptr = gimple_call_arg (stmt, 2);
+      if (TREE_TYPE (TREE_TYPE (ptr)) != vector_pair_type_node)
+	ptr = build1 (VIEW_CONVERT_EXPR,
+		      build_pointer_type (vector_pair_type_node), ptr);
       tree mem = build_simple_mem_ref (build2 (POINTER_PLUS_EXPR,
 					       TREE_TYPE (ptr), ptr, offset));
       gimplify_assign (mem, src, &new_seq);
diff --git a/gcc/testsuite/gcc.target/powerpc/pr101849.c b/gcc/testsuite/gcc.target/powerpc/pr101849.c
new file mode 100644
index 00000000000..823fbfe9647
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr101849.c
@@ -0,0 +1,22 @@
+/* PR target/101849 */
+/* { dg-do compile } */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10" } */
+
+/* Verify we do not ICE on the tests below.  */
+
+void
+foo (__vector_pair *dst, double *x, long offset)
+{
+  dst[0] = __builtin_vsx_lxvp (0, (__vector_pair *)(void *)x);
+  dst[1] = __builtin_vsx_lxvp (32, (__vector_pair *)(void *)x);
+  dst[2] = __builtin_vsx_lxvp (offset, (__vector_pair *)(void *)x);
+}
+
+void
+bar (__vector_pair *src, double *x, long offset)
+{
+  __builtin_vsx_stxvp (src[0], 0, (__vector_pair *)(void *)x);
+  __builtin_vsx_stxvp (src[1], 32, (__vector_pair *)(void *)x);
+  __builtin_vsx_stxvp (src[2], offset, (__vector_pair *)(void *)x);
+}