[gcc r17-2398] aarch64: Relax type-checking assert [PR126064]

https://gcc.gnu.org/g:9bfc05c8a91f3f89d579afa3a79cce1c0da34184

commit r17-2398-g9bfc05c8a91f3f89d579afa3a79cce1c0da34184
Author: Karl Meakin <[email protected]>
Date:   Wed Jul 1 12:16:40 2026 +0000

    aarch64: Relax type-checking assert [PR126064]
    
    Comparing `arg_type` and `TREE_TYPE (b)` by pointer address causes an
    assertion failure when one type is a `typedef` for the other (eg
    `uint32x2_t` and `__Uint32x2_t`. Fix by using a more relaxed comparison.
    
    gcc/ChangeLog:
    
            PR target/126064
            * config/aarch64/aarch64-neon-builtins-base.cc: Compare
            `arg_type` and `TREE_TYPE (b)` using `types_compatible_p` rather
            than comparing their pointer addresses.
    
    gcc/testsuite/ChangeLog:
    
            PR target/126064
            * gcc.target/aarch64/pr126064.c: New test.

Diff:
---
 gcc/config/aarch64/aarch64-neon-builtins-base.cc |  2 +-
 gcc/testsuite/gcc.target/aarch64/pr126064.c      | 28 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/gcc/config/aarch64/aarch64-neon-builtins-base.cc b/gcc/config/aarch64/aarch64-neon-builtins-base.cc
index 9e61ba7688ce..d8fae81388e5 100644
--- a/gcc/config/aarch64/aarch64-neon-builtins-base.cc
+++ b/gcc/config/aarch64/aarch64-neon-builtins-base.cc
@@ -562,7 +562,7 @@ public:
       std::swap (a, b);
 
     auto arg_type = TREE_TYPE (a);
-    gcc_assert (arg_type == TREE_TYPE (b));
+    gcc_assert (types_compatible_p (arg_type, TREE_TYPE (b)));
 
     auto tuple_type = TREE_TYPE (f.lhs);
     auto tuple = create_tmp_var (tuple_type);
diff --git a/gcc/testsuite/gcc.target/aarch64/pr126064.c b/gcc/testsuite/gcc.target/aarch64/pr126064.c
new file mode 100644
index 000000000000..9d7925887819
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr126064.c
@@ -0,0 +1,28 @@
+/* { dg-options "-std=c99" } */
+
+/* Check that `gimple_permute_pair::fold()` does not trip an assert when the LHS
+   type is `uint32x2_t` and the RHS type is `__Uint32x2_t`.  */
+
+#include <arm_neon.h>
+
+void
+repro (uint8_t *dst, uint8x8_t a, uint8x8_t b)
+{
+  uint32x2x2_t t;
+  uint32x2_t r;
+  uint8x8_t c;
+
+  r = vrev64_u32 (vreinterpret_u32_u8 (b));
+  t = vtrn_u32 (vreinterpret_u32_u8 (a), r);
+  c = vreinterpret_u8_u32 (t.val[1]);
+  t = vtrn_u32 (t.val[0], vreinterpret_u32_u8 (c));
+  t.val[1] = vrev64_u32 (t.val[1]);
+
+  vst1_u8 (dst, vreinterpret_u8_u32 (t.val[1]));
+}
+
+uint32x2_t
+minimized_repro (uint32x2_t a, uint32x2_t b)
+{
+  return vtrn_u32 (a, vrev64_u32 (b)).val[1];
+}