[gcc r12-9302] rs6000: Don't ICE when compiling the __builtin_vec_xst_trunc built-in [PR109178]

[Peter Bergner]

https://gcc.gnu.org/g:19ad58ef1f09373b0f75eded8f0b12da381a1190

commit r12-9302-g19ad58ef1f09373b0f75eded8f0b12da381a1190
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Mon Mar 20 09:12:47 2023 -0500

    rs6000: Don't ICE when compiling the __builtin_vec_xst_trunc built-in [PR109178]
    
    When we expand the __builtin_vec_xst_trunc built-in, we use the wrong mode
    for the MEM operand which causes an unrecognizable insn ICE.  The solution
    is to use the correct TMODE mode.
    
    2023-03-20  Peter Bergner  <bergner@linux.ibm.com>
    
    gcc/
            PR target/109178
            * config/rs6000/rs6000-builtin.cc (stv_expand_builtin): Use tmode.
    
    gcc/testsuite/
            PR target/109178
            * gcc.target/powerpc/pr109178.c: New test.
    
    (cherry picked from commit fbd50e867e6a782c7b56c9727bf7e1e74dae4b94)

Diff:
---
 gcc/config/rs6000/rs6000-builtin.cc         |  2 +-
 gcc/testsuite/gcc.target/powerpc/pr109178.c | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/gcc/config/rs6000/rs6000-builtin.cc b/gcc/config/rs6000/rs6000-builtin.cc
index 26b486a9e5d..d34f9b7dd00 100644
--- a/gcc/config/rs6000/rs6000-builtin.cc
+++ b/gcc/config/rs6000/rs6000-builtin.cc
@@ -2962,7 +2962,7 @@ stv_expand_builtin (insn_code icode, rtx *op,
 
       rtx addr;
       if (op[1] == const0_rtx)
-	addr = gen_rtx_MEM (Pmode, op[2]);
+	addr = gen_rtx_MEM (tmode, op[2]);
       else
 	{
 	  op[1] = copy_to_mode_reg (Pmode, op[1]);
diff --git a/gcc/testsuite/gcc.target/powerpc/pr109178.c b/gcc/testsuite/gcc.target/powerpc/pr109178.c
new file mode 100644
index 00000000000..0f6e2d6b2eb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr109178.c
@@ -0,0 +1,13 @@
+/* PR target/109178 */
+/* { dg-require-effective-target int128 } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10" } */
+
+/* Verify we do not ICE on the following.  */
+
+typedef __attribute__ ((altivec (vector__))) signed __int128 v1ti_t;
+
+void
+foo (signed int *dst, v1ti_t src)
+{
+  __builtin_vec_xst_trunc(src, 0, dst);
+}