On Fri, Nov 19, 2021 at 2:54 AM apinski--- via Gcc-patches
<[email protected]> wrote:
>
> From: Andrew Pinski <[email protected]>
>
> The problem is r12-5300-gf98f373dd822b35c allows phiopt to recognize more
> basic blocks
> but missed one location where the basic block does not need to be empty but
> still
> needs to have a single predecessor. This patch fixes that over sight.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
OK.
Thanks,
Richard.
> PR tree-optimization/103317
>
> gcc/ChangeLog:
>
> * tree-ssa-phiopt.c (minmax_replacement): For the non empty
> middle bb case, check to make sure it has a single predecessor.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.c-torture/compile/pr103317-1.c: New test.
> ---
> gcc/testsuite/gcc.c-torture/compile/pr103317-1.c | 13 +++++++++++++
> gcc/tree-ssa-phiopt.c | 3 +++
> 2 files changed, 16 insertions(+)
> create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr103317-1.c
>
> diff --git a/gcc/testsuite/gcc.c-torture/compile/pr103317-1.c
> b/gcc/testsuite/gcc.c-torture/compile/pr103317-1.c
> new file mode 100644
> index 00000000000..f9d145e0da9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.c-torture/compile/pr103317-1.c
> @@ -0,0 +1,13 @@
> +int a, b;
> +char c;
> +void
> +d (void)
> +{
> + char e = c;
> + if (b)
> + if (c < 16 - 11)
> + e = 16 - 11;
> + if (e > 8)
> + e = 8;
> + a = e;
> +}
> diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
> index f0431684089..1abc4ea21cc 100644
> --- a/gcc/tree-ssa-phiopt.c
> +++ b/gcc/tree-ssa-phiopt.c
> @@ -1780,6 +1780,9 @@ minmax_replacement (basic_block cond_bb, basic_block
> middle_bb,
> gimple *assign = last_and_only_stmt (middle_bb);
> tree lhs, op0, op1, bound;
>
> + if (!single_pred_p (middle_bb))
> + return false;
> +
> if (!assign
> || gimple_code (assign) != GIMPLE_ASSIGN)
> return false;
> --
> 2.17.1
>
