On Wed, Jul 30, 2025 at 2:14 AM Andrew Pinski <quic_apin...@quicinc.com> wrote:
>
> r16-2590-ga51bf9e10182cf was not the correct fix for this in the end.
> Instead a much simplier and localized fix is needed, just change the phi
> that is being worked on with the new result and arguments that is from the
> factored out operator.
> This solves the issue of not having result in the IR and causing issues that
> way.
>
> Bootstrapped and tested on x86_64-linux-gnu.
> Note this depends on reverting r16-2590-ga51bf9e10182cf.
OK.
Thanks,
Richard.
> PR tree-optimization/121236
> PR tree-optimization/121295
>
> gcc/ChangeLog:
>
> * tree-if-conv.cc (factor_out_operators): Change the phi node
> to the new result and args.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/torture/pr121236-1.c: New test.
> * gcc.dg/torture/pr121295-1.c: New test.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/testsuite/gcc.dg/torture/pr121236-1.c | 20 ++++++++++++++++++++
> gcc/testsuite/gcc.dg/torture/pr121295-1.c | 13 +++++++++++++
> gcc/tree-if-conv.cc | 7 +++++++
> 3 files changed, 40 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/torture/pr121236-1.c
> create mode 100644 gcc/testsuite/gcc.dg/torture/pr121295-1.c
>
> diff --git a/gcc/testsuite/gcc.dg/torture/pr121236-1.c
> b/gcc/testsuite/gcc.dg/torture/pr121236-1.c
> new file mode 100644
> index 00000000000..2b397e34078
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr121236-1.c
> @@ -0,0 +1,20 @@
> +/* { dg-do compile } */
> +/* PR tree-optimization/121236 */
> +
> +
> +unsigned func_26(short *p_27, int gg, int p) {
> + unsigned l_184 = 0;
> + unsigned m = 0;
> + for (int g_59 = 0; g_59 < 10; g_59++)
> + {
> + if (gg)
> + l_184--;
> + else
> + {
> + m |= l_184 |= p;
> + (l_184)--;
> + }
> + }
> + return m;
> +}
> +
> diff --git a/gcc/testsuite/gcc.dg/torture/pr121295-1.c
> b/gcc/testsuite/gcc.dg/torture/pr121295-1.c
> new file mode 100644
> index 00000000000..7825c6ee91b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr121295-1.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options " -fno-tree-copy-prop -fno-tree-pre
> -fno-code-hoisting" */
> +
> +/* PR tree-optimization/121295 */
> +
> +
> +int a, b, c;
> +int main() {
> + int *d = &a;
> + while (b)
> + b = (*d &= 10) <= 0 || (*d = c);
> + return 0;
> +}
> diff --git a/gcc/tree-if-conv.cc b/gcc/tree-if-conv.cc
> index ba25c19c50c..b7ce0720b15 100644
> --- a/gcc/tree-if-conv.cc
> +++ b/gcc/tree-if-conv.cc
> @@ -2291,6 +2291,13 @@ again:
> *arg0 = new_arg0;
> *arg1 = new_arg1;
> *res = new_res;
> +
> + /* Update the phi node too. */
> + gimple_phi_set_result (phi, new_res);
> + gimple_phi_arg (phi, 0)->def = new_arg0;
> + gimple_phi_arg (phi, 0)->def = new_arg1;
> + update_stmt (phi);
> +
> repeated = true;
> goto again;
> }
> --
> 2.43.0
>
