On Sun, Sep 22, 2024 at 12:50 PM <pan2...@intel.com> wrote:
>
> From: Pan Li <pan2...@intel.com>
>
> This patch would like to fix one ICE when try to match the binary
> phi for below cfg. We check the first edge of the Phi block comes
> from b0, instead of check the only one edge of b1 comes from the
> b0 too. Thus, it will result in some code to be recog as .SAT_SUB
> but it is not, and finally result the verify_ssa failure.
>
> +------+
> | b0: |
> | def | +-----+
> | ... | | b1: |
> | cond |------>| def |
> +------+ | ... |
> | +-----+
> | |
> | |
> v |
> +-----+ |
> | b2: | |
> | Phi |<----------+
> +-----+
>
> The below test suites are passed for this patch.
> * The rv64gcv fully regression test.
> * The x86 bootstrap test.
> * The x86 fully regression test.
OK.
Thanks,
Richard.
> PR target/116795
>
> gcc/ChangeLog:
>
> * gimple-match-head.cc (match_cond_with_binary_phi): Fix the
> incorrect cfg check as b0->b1 in above example.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/torture/pr116795-1.c: New test.
>
> Signed-off-by: Pan Li <pan2...@intel.com>
> ---
> gcc/gimple-match-head.cc | 2 +-
> gcc/testsuite/gcc.dg/torture/pr116795-1.c | 14 ++++++++++++++
> 2 files changed, 15 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/gcc.dg/torture/pr116795-1.c
>
> diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc
> index b63b66e9485..b5d4a71ddc5 100644
> --- a/gcc/gimple-match-head.cc
> +++ b/gcc/gimple-match-head.cc
> @@ -402,7 +402,7 @@ match_cond_with_binary_phi (gphi *phi, tree *true_arg,
> tree *false_arg)
> if (EDGE_COUNT (pred_b0->succs) == 2
> && EDGE_COUNT (pred_b1->succs) == 1
> && EDGE_COUNT (pred_b1->preds) == 1
> - && pred_b0 == EDGE_PRED (gimple_bb (phi), 0)->src)
> + && pred_b0 == EDGE_PRED (pred_b1, 0)->src)
> /*
> * +------+
> * | b0: |
> diff --git a/gcc/testsuite/gcc.dg/torture/pr116795-1.c
> b/gcc/testsuite/gcc.dg/torture/pr116795-1.c
> new file mode 100644
> index 00000000000..629bdf4bacd
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr116795-1.c
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O3" } */
> +
> +volatile int a, b;
> +int c;
> +int main() {
> + unsigned e = 0;
> + for (; e < 2; e++) {
> + a && b;
> + if (c)
> + e = -(c ^ e);
> + }
> + return 0;
> +}
> --
> 2.43.0
>
