[gcc r12-8361] Fix internal error with vectorization on SPARC

[Eric Botcazou <ebotcazou@gcc.gnu.org>]

https://gcc.gnu.org/g:b931d0cfd33fec6ffc259b1be5c832144b4e7bea

commit r12-8361-gb931d0cfd33fec6ffc259b1be5c832144b4e7bea
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Tue May 10 09:33:16 2022 +0200

    Fix internal error with vectorization on SPARC
    
    This is a regression present since the 10.x series, but the underlying issue
    has been there since the TARGET_VEC_PERM_CONST hook was implemented, in the
    form of an ICE when expanding a constant VEC_PERM_EXPR in V4QI, while the
    back-end only supports V8QI constant VEC_PERM_EXPRs.
    
    gcc/
            PR target/105292
            * config/sparc/sparc.cc (sparc_vectorize_vec_perm_const): Return
            true only for 8-byte vector modes.
    
    gcc/testsuite/
            * gcc.target/sparc/20220510-1.c: New test.

Diff:
---
 gcc/config/sparc/sparc.cc                   |  4 ++--
 gcc/testsuite/gcc.target/sparc/20220510-1.c | 31 +++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/gcc/config/sparc/sparc.cc b/gcc/config/sparc/sparc.cc
index 467a9f171d2..aca925befe1 100644
--- a/gcc/config/sparc/sparc.cc
+++ b/gcc/config/sparc/sparc.cc
@@ -13041,9 +13041,9 @@ sparc_vectorize_vec_perm_const (machine_mode vmode, rtx target, rtx op0,
   if (!TARGET_VIS2)
     return false;
 
-  /* All permutes are supported.  */
+  /* All 8-byte permutes are supported.  */
   if (!target)
-    return true;
+    return GET_MODE_SIZE (vmode) == 8;
 
   /* Force target-independent code to convert constant permutations on other
      modes down to V8QI.  Rely on this to avoid the complexity of the byte
diff --git a/gcc/testsuite/gcc.target/sparc/20220510-1.c b/gcc/testsuite/gcc.target/sparc/20220510-1.c
new file mode 100644
index 00000000000..f321cab8482
--- /dev/null
+++ b/gcc/testsuite/gcc.target/sparc/20220510-1.c
@@ -0,0 +1,31 @@
+/* PR target/105292 */
+/* Reported by Koakuma <koachan+gccbugs@protonmail.com> */
+
+/* { dg-do compile } */
+/* { dg-options "-O3 -mvis2" } */
+
+extern void get_vbytes_v2 (unsigned);
+
+typedef struct {
+  unsigned ctt_info;
+  unsigned ctt_size;
+} ctf_type_t;
+
+typedef struct {
+  unsigned short cts_offset;
+  unsigned short cts_bits;
+} ctf_slice_t;
+
+void flip_types_len (ctf_type_t *t, int bsx1, int bsx2)
+{
+  const int kind = t->ctt_info;
+
+  get_vbytes_v2 (t->ctt_size);
+
+  if (kind == 4)
+    {
+      ctf_slice_t *s = (ctf_slice_t *)t;
+      s->cts_offset = __builtin_bswap16(bsx1);
+      s->cts_bits   = __builtin_bswap16(bsx2);
+    }
+}