On Sun, Aug 25, 2024 at 10:28 PM Andrew Pinski <quic_apin...@quicinc.com> wrote:
>
> When expanding popcount used for equal to 1 (or rather
> __builtin_stdc_has_single_bit),
> the wrong mode was bsing used for the mode of the store flags. We were using
> the mode
> of the argument to popcount but since popcount's return value is always int,
> the mode
> of the expansion here should have been the mode of the return type rater than
> the argument.
>
> Built and tested on aarch64-linux-gnu with no regressions.
> Also bootstrapped and tested on x86_64-linux-gnu.
OK.
Richard.
> PR middle-end/116480
>
> gcc/ChangeLog:
>
> * internal-fn.cc (expand_POPCOUNT): Use the correct mode
> for store flags.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/torture/pr116480-1.c: New test.
> * gcc.dg/torture/pr116480-2.c: New test.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/internal-fn.cc | 3 ++-
> gcc/testsuite/gcc.dg/torture/pr116480-1.c | 8 ++++++++
> gcc/testsuite/gcc.dg/torture/pr116480-2.c | 8 ++++++++
> 3 files changed, 18 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/gcc.dg/torture/pr116480-1.c
> create mode 100644 gcc/testsuite/gcc.dg/torture/pr116480-2.c
>
> diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
> index a96e61e527c..89da13b38ce 100644
> --- a/gcc/internal-fn.cc
> +++ b/gcc/internal-fn.cc
> @@ -5311,6 +5311,7 @@ expand_POPCOUNT (internal_fn fn, gcall *stmt)
> bool nonzero_arg = integer_zerop (gimple_call_arg (stmt, 1));
> tree type = TREE_TYPE (arg);
> machine_mode mode = TYPE_MODE (type);
> + machine_mode lhsmode = TYPE_MODE (TREE_TYPE (lhs));
> do_pending_stack_adjust ();
> start_sequence ();
> expand_unary_optab_fn (fn, stmt, popcount_optab);
> @@ -5318,7 +5319,7 @@ expand_POPCOUNT (internal_fn fn, gcall *stmt)
> end_sequence ();
> start_sequence ();
> rtx plhs = expand_normal (lhs);
> - rtx pcmp = emit_store_flag (NULL_RTX, EQ, plhs, const1_rtx, mode, 0, 0);
> + rtx pcmp = emit_store_flag (NULL_RTX, EQ, plhs, const1_rtx, lhsmode, 0, 0);
> if (pcmp == NULL_RTX)
> {
> fail:
> diff --git a/gcc/testsuite/gcc.dg/torture/pr116480-1.c
> b/gcc/testsuite/gcc.dg/torture/pr116480-1.c
> new file mode 100644
> index 00000000000..15a5727941c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr116480-1.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile { target int128 } } */
> +
> +int
> +foo(unsigned __int128 b)
> +{
> + return __builtin_popcountg(b) == 1;
> +}
> +
> diff --git a/gcc/testsuite/gcc.dg/torture/pr116480-2.c
> b/gcc/testsuite/gcc.dg/torture/pr116480-2.c
> new file mode 100644
> index 00000000000..7bf690283b4
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr116480-2.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile { target bitint } } */
> +
> +int
> +foo(unsigned _BitInt(127) b)
> +{
> + return __builtin_popcountg(b) == 1;
> +}
> +
> --
> 2.43.0
>
