On Tue, Feb 17, 2026 at 02:44:12PM -0800, Andrew Pinski wrote:
> aarch64_init_ls64_builtins_types currently creates an array with type
> uint64_t[8]
> and then sets the mode to V8DI. The problem here is if you used that array
> type before, you would get a mode of BLK.
> This causes an ICE in some cases, with the C++ front-end with -g, you would
> get "type variant differs by TYPE_MODE" and in some cases even without -g,
> "canonical types differ for identical types".
>
> The fix is to do build_distinct_type_copy of the array in
> aarch64_init_ls64_builtins_types
> before assigning the mode to that copy. We keep the same ls64 structures
> correct and
> user provided arrays are not influenced when "arm_neon.h" is included.
>
> Build and tested on aarch64-linux-gnu.
>
> PR target/124126
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64-builtins.cc
> (aarch64_init_ls64_builtins_types): Copy
> the array type before setting the mode.
>
> gcc/testsuite/ChangeLog:
>
> * c-c++-common/aarch64/pr124126-1.c: New test.
>
> Signed-off-by: Andrew Pinski <[email protected]>
> ---
> gcc/config/aarch64/aarch64-builtins.cc | 1 +
> gcc/testsuite/c-c++-common/aarch64/pr124126-1.c | 15 +++++++++++++++
> 2 files changed, 16 insertions(+)
> create mode 100644 gcc/testsuite/c-c++-common/aarch64/pr124126-1.c
>
> diff --git a/gcc/config/aarch64/aarch64-builtins.cc
> b/gcc/config/aarch64/aarch64-builtins.cc
> index 5bb873c3923..611f6dc45e0 100644
> --- a/gcc/config/aarch64/aarch64-builtins.cc
> +++ b/gcc/config/aarch64/aarch64-builtins.cc
> @@ -2321,6 +2321,7 @@ aarch64_init_ls64_builtins_types (void)
> const char *tuple_type_name = "__arm_data512_t";
> tree node_type = get_typenode_from_name (UINT64_TYPE);
> tree array_type = build_array_type_nelts (node_type, 8);
> + array_type = build_distinct_type_copy (array_type);
> SET_TYPE_MODE (array_type, V8DImode);
>
> gcc_assert (TYPE_MODE_RAW (array_type) == TYPE_MODE (array_type));
> diff --git a/gcc/testsuite/c-c++-common/aarch64/pr124126-1.c
> b/gcc/testsuite/c-c++-common/aarch64/pr124126-1.c
> new file mode 100644
> index 00000000000..ffe4fb6690b
> --- /dev/null
> +++ b/gcc/testsuite/c-c++-common/aarch64/pr124126-1.c
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-g" } */
The bug can be reproduced on older branches by adding `+ls64` to the command
line.
This patch is ok with that change (for all open branches).
Alice
> +/* PR target/124126 */
> +/* Make sure an array of uint64_t[8] works when
> + used before the inlcude of arm_acle.h. */
> +
> +typedef unsigned long uint64_t;
> +void executeSuperscalar(uint64_t (*r)[8]);
> +
> +#include "arm_acle.h"
> +
> +void initDatasetItem() {
> + uint64_t rl[8];
> + executeSuperscalar(&rl);
> +}
> --
> 2.43.0
>
