> maybe check that return_copy_pat is a SET instead?
You mean something like this? I tried this but I am not sure single_set is good
enough here, because it should be "narrow" than GET_RTX_LENGTH.
+ && single_set (return_copy)
Pan
-----Original Message-----
From: Richard Biener <richard.guent...@gmail.com>
Sent: Monday, August 7, 2023 9:14 PM
To: Li, Pan2 <pan2...@intel.com>
Cc: gcc-patches@gcc.gnu.org; juzhe.zh...@rivai.ai; kito.ch...@sifive.com; Wang,
Yanzhang <yanzhang.w...@intel.com>; jeffreya...@gmail.com
Subject: Re: [PATCH v1] Mode-Switching: Fix SET_SRC ICE when only one operand
On Mon, Aug 7, 2023 at 2:30 PM Pan Li via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> From: Pan Li <pan2...@intel.com>
>
> In same cases, like gcc/testsuite/gcc.dg/pr78148.c in RISC-V, there will
> be only 1 operand when SET_SRC in create_pre_exit. For example as below.
>
> (insn 13 9 14 2 (clobber (reg/i:TI 10 a0))
> "gcc/testsuite/gcc.dg/pr78148.c":24:1 -1
> (expr_list:REG_UNUSED (reg/i:TI 10 a0)
> (nil)))
>
> Unfortunately, SET_SRC requires at least 2 operands and then Segment
> Fault here. This patch would like to fix this ICE by adding operand
> length check before SET_SRC.
>
> Signed-off-by: Pan Li <pan2...@intel.com>
>
> gcc/ChangeLog:
>
> * mode-switching.cc (create_pre_exit): Add operand length check.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/riscv/mode-switch-ice-1.c: New test.
> ---
> gcc/mode-switching.cc | 2 ++
> .../gcc.target/riscv/mode-switch-ice-1.c | 22 +++++++++++++++++++
> 2 files changed, 24 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/riscv/mode-switch-ice-1.c
>
> diff --git a/gcc/mode-switching.cc b/gcc/mode-switching.cc
> index 64ae2bc29c3..cbf03c02159 100644
> --- a/gcc/mode-switching.cc
> +++ b/gcc/mode-switching.cc
> @@ -411,6 +411,8 @@ create_pre_exit (int n_entities, int *entity_map, const
> int *num_modes)
> conflict with address reloads. */
> if (copy_start >= ret_start
> && copy_start + copy_num <= ret_end
> + && GET_RTX_LENGTH (GET_CODE (return_copy_pat)) >=
> 2
> + /* SET_SRC requires at least 2 operands. */
maybe check that return_copy_pat is a SET instead?
> && OBJECT_P (SET_SRC (return_copy_pat)))
> forced_late_switch = true;
> break;
> diff --git a/gcc/testsuite/gcc.target/riscv/mode-switch-ice-1.c
> b/gcc/testsuite/gcc.target/riscv/mode-switch-ice-1.c
> new file mode 100644
> index 00000000000..1b34a471904
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/mode-switch-ice-1.c
> @@ -0,0 +1,22 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +struct A { char e, f; };
> +
> +struct B
> +{
> + int g;
> + struct A h[4];
> +};
> +
> +extern void bar (int, int);
> +
> +struct B foo (void)
> +{
> + bar (2, 1);
> +}
> +
> +void baz ()
> +{
> + foo ();
> +}
> --
> 2.34.1
>
