Andrew Pinski <quic_apin...@quicinc.com> writes:
> Regrename can fail in some case and `insn_rr[INSN_UID (insn)].op_info`
> will be null. The FMA steering code was not expecting the failure to happen.
> This started to happen after early RA was added but it has been a latent bug
> before that.
>
> Build and tested for aarch64-linux-gnu.
>
> PR target/120119
>
> gcc/ChangeLog:
>
> * config/aarch64/cortex-a57-fma-steering.cc
> (func_fma_steering::analyze):
> Skip if renaming fails.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/torture/pr120119-1.C: New test.
OK, thanks.
Richard
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/config/aarch64/cortex-a57-fma-steering.cc | 5 +++++
> gcc/testsuite/g++.dg/torture/pr120119-1.C | 15 +++++++++++++++
> 2 files changed, 20 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/torture/pr120119-1.C
>
> diff --git a/gcc/config/aarch64/cortex-a57-fma-steering.cc
> b/gcc/config/aarch64/cortex-a57-fma-steering.cc
> index fd6da66d855..f7675bed13d 100644
> --- a/gcc/config/aarch64/cortex-a57-fma-steering.cc
> +++ b/gcc/config/aarch64/cortex-a57-fma-steering.cc
> @@ -948,6 +948,11 @@ func_fma_steering::analyze ()
>
> /* Search the chain where this instruction is (one of) the root. */
> dest_op_info = insn_rr[INSN_UID (insn)].op_info;
> +
> + /* Register rename could fail. */
> + if (!dest_op_info)
> + continue;
> +
> dest_regno = REGNO (SET_DEST (PATTERN (insn)));
> for (i = 0; i < dest_op_info->n_chains; i++)
> {
> diff --git a/gcc/testsuite/g++.dg/torture/pr120119-1.C
> b/gcc/testsuite/g++.dg/torture/pr120119-1.C
> new file mode 100644
> index 00000000000..1206feb310b
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/torture/pr120119-1.C
> @@ -0,0 +1,15 @@
> +// { dg-do compile }
> +// { dg-additional-options "-mcpu=cortex-a57" { target aarch64*-*-* } }
> +
> +// PR target/120119
> +
> +struct a {
> + float operator()(int b, int c) { return d[c * 4 + b]; }
> + float *d;
> +};
> +float e(float *);
> +auto f(a b) {
> + float g[]{b(1, 1), b(2, 1), b(3, 1), b(1, 2), b(2, 2), b(3, 2), b(1, 3),
> + b(2, 3), b(3, 3), b(3, 2), b(1, 3), b(2, 3), b(3, 3)};
> + return b.d[0] * e(g);
> +}
