[gcc r12-8740] rs6000: Don't ICE when we disassemble an MMA variable [PR101322]

[Peter Bergner]

https://gcc.gnu.org/g:2d4f60f206cf1100b7484d708f6c913762618676

commit r12-8740-g2d4f60f206cf1100b7484d708f6c913762618676
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Wed Aug 31 21:14:36 2022 -0500

    rs6000: Don't ICE when we disassemble an MMA variable [PR101322]
    
    When we expand an MMA disassemble built-in with C++ using a pointer that
    is cast to a valid MMA type, the type isn't passed down to the expand
    machinery and we end up using the base type of the pointer which leads to
    an ICE.  This patch enforces we always use the correct MMA type regardless
    of the pointer type being used.
    
    2022-08-31  Peter Bergner  <bergner@linux.ibm.com>
    
    gcc/
            PR target/101322
            * config/rs6000/rs6000-builtin.cc (rs6000_gimple_fold_mma_builtin):
            Enforce the use of a valid MMA pointer type.
    
    gcc/testsuite/
            PR target/101322
            * g++.target/powerpc/pr101322.C: New test.
    
    (cherry picked from commit 2985049049f12b0aa3366ca244d387820385b9e8)

Diff:
---
 gcc/config/rs6000/rs6000-builtin.cc         |  7 ++++++-
 gcc/testsuite/g++.target/powerpc/pr101322.C | 17 +++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/gcc/config/rs6000/rs6000-builtin.cc b/gcc/config/rs6000/rs6000-builtin.cc
index e925ba9fad9..15370e45e65 100644
--- a/gcc/config/rs6000/rs6000-builtin.cc
+++ b/gcc/config/rs6000/rs6000-builtin.cc
@@ -1121,7 +1121,12 @@ rs6000_gimple_fold_mma_builtin (gimple_stmt_iterator *gsi,
       unsigned nvec = (fncode == RS6000_BIF_DISASSEMBLE_ACC) ? 4 : 2;
       tree dst_ptr = gimple_call_arg (stmt, 0);
       tree src_ptr = gimple_call_arg (stmt, 1);
-      tree src_type = TREE_TYPE (src_ptr);
+      tree src_type = (fncode == RS6000_BIF_DISASSEMBLE_ACC)
+		      ? build_pointer_type (vector_quad_type_node)
+		      : build_pointer_type (vector_pair_type_node);
+      if (TREE_TYPE (src_ptr) != src_type)
+	src_ptr = build1 (NOP_EXPR, src_type, src_ptr);
+
       tree src = create_tmp_reg_or_ssa_name (TREE_TYPE (src_type));
       gimplify_assign (src, build_simple_mem_ref (src_ptr), &new_seq);
 
diff --git a/gcc/testsuite/g++.target/powerpc/pr101322.C b/gcc/testsuite/g++.target/powerpc/pr101322.C
new file mode 100644
index 00000000000..43eaf3afcd4
--- /dev/null
+++ b/gcc/testsuite/g++.target/powerpc/pr101322.C
@@ -0,0 +1,17 @@
+/* PR target/101322 */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10" } */
+
+/* Verify we don't ICE on the following test cases.  */
+
+void
+foo (char *resp, char *vpp)
+{
+  __builtin_vsx_disassemble_pair (resp, (__vector_pair *) vpp);
+}
+
+void
+bar (char *resp, char *vpp)
+{
+  __builtin_mma_disassemble_acc (resp, (__vector_quad *)vpp);
+}