[gcc r14-6116] tree-optimization/112818 - re-instantiate vector type size check for bswap

[Richard Biener]

https://gcc.gnu.org/g:80d67d8f682a6050a3bf4dcfa18a83f321986f2a

commit r14-6116-g80d67d8f682a6050a3bf4dcfa18a83f321986f2a
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Dec 4 12:50:36 2023 +0100

    tree-optimization/112818 - re-instantiate vector type size check for bswap
    
    For __builtin_bswap vectorization we still require an equal vector
    type size.  Re-instantiate that check.
    
            PR tree-optimization/112818
            * tree-vect-stmts.cc (vectorizable_bswap): Check input and
            output vector types have the same size.
    
            * gcc.dg/vect/pr112818.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/vect/pr112818.c | 34 ++++++++++++++++++++++++++++++++++
 gcc/tree-vect-stmts.cc               |  9 +++++++++
 2 files changed, 43 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/vect/pr112818.c b/gcc/testsuite/gcc.dg/vect/pr112818.c
new file mode 100644
index 00000000000..61a30a576b7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr112818.c
@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+
+extern char tag_data[];
+struct pppoe_tag {
+    unsigned short tag_type;
+    unsigned short tag_len;
+};
+
+char code;
+int *add_tag_pack;
+void *add_tag_data;
+short e;
+long c, d;
+
+static int add_tag(int type, int len) {
+    short a, b;
+    struct pppoe_tag *tag = (struct pppoe_tag *)add_tag_pack;
+    if (e + len || len < 0)
+      return 1;
+    b = __builtin_bswap16(type);
+    tag->tag_type = b;
+    a = __builtin_bswap16(len);
+    tag->tag_len = a;
+    if (add_tag_data)
+      __builtin___memcpy_chk(tag_data, add_tag_data, len, c);
+    return 0;
+}
+void pppoe_serv_read() {
+    switch (code)
+  case 9: {
+	      add_tag(2, d);
+	      add_tag(0, 2);
+	  }
+}
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 067abac3917..390c8472fd6 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -2976,6 +2976,15 @@ vectorizable_bswap (vec_info *vinfo,
 
   gcc_assert (ncopies >= 1);
 
+  if (TYPE_SIZE (vectype_in) != TYPE_SIZE (vectype))
+    {
+      if (dump_enabled_p ())
+	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			 "mismatched vector sizes %T and %T\n",
+			 vectype_in, vectype);
+      return false;
+    }
+
   tree char_vectype = get_same_sized_vectype (char_type_node, vectype_in);
   if (! char_vectype)
     return false;