On Fri, Jun 9, 2023 at 3:48 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> So for the attached testcase, we assumed that zero_one_valued_p would
> be the value [0,1] but currently zero_one_valued_p matches also
> signed 1 bit integers.
> This changes that not to match that and fixes the 2 new testcases at
> all optimization levels.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
OK.
> Note the GCC 13 patch will be slightly different due to the changes
> made to zero_one_valued_p.
>
> PR tree-optimization/110165
> PR tree-optimization/110166
>
> gcc/ChangeLog:
>
> * match.pd (zero_one_valued_p): Don't accept
> signed 1-bit integers.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.c-torture/execute/pr110165-1.c: New test.
> * gcc.c-torture/execute/pr110166-1.c: New test.
> ---
> gcc/match.pd | 13 ++++++--
> .../gcc.c-torture/execute/pr110165-1.c | 28 ++++++++++++++++
> .../gcc.c-torture/execute/pr110166-1.c | 33 +++++++++++++++++++
> 3 files changed, 71 insertions(+), 3 deletions(-)
> create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr110165-1.c
> create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr110166-1.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 4ad037d641a..9a6bc2e9348 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -1984,12 +1984,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> @0)
>
> /* zero_one_valued_p will match when a value is known to be either
> - 0 or 1 including constants 0 or 1. */
> + 0 or 1 including constants 0 or 1.
> + Signed 1-bits includes -1 so they cannot match here. */
> (match zero_one_valued_p
> @0
> - (if (INTEGRAL_TYPE_P (type) && wi::leu_p (tree_nonzero_bits (@0), 1))))
> + (if (INTEGRAL_TYPE_P (type)
> + && (TYPE_UNSIGNED (type)
> + || TYPE_PRECISION (type) > 1)
> + && wi::leu_p (tree_nonzero_bits (@0), 1))))
> (match zero_one_valued_p
> - truth_valued_p@0)
> + truth_valued_p@0
> + (if (INTEGRAL_TYPE_P (type)
> + && (TYPE_UNSIGNED (type)
> + || TYPE_PRECISION (type) > 1))))
>
> /* Transform { 0 or 1 } * { 0 or 1 } into { 0 or 1 } & { 0 or 1 }. */
> (simplify
> diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110165-1.c
> b/gcc/testsuite/gcc.c-torture/execute/pr110165-1.c
> new file mode 100644
> index 00000000000..9521a19428e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.c-torture/execute/pr110165-1.c
> @@ -0,0 +1,28 @@
> +struct s
> +{
> + int t : 1;
> +};
> +
> +int f(struct s t, int a, int b) __attribute__((noinline));
> +int f(struct s t, int a, int b)
> +{
> + int bd = t.t;
> + if (bd) a|=b;
> + return a;
> +}
> +
> +int main(void)
> +{
> + struct s t;
> + for(int i = -1;i <= 1; i++)
> + {
> + int a = 0x10;
> + int b = 0x0f;
> + int c = a | b;
> + struct s t = {i};
> + int r = f(t, a, b);
> + int exp = (i != 0) ? a | b : a;
> + if (exp != r)
> + __builtin_abort();
> + }
> +}
> diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110166-1.c
> b/gcc/testsuite/gcc.c-torture/execute/pr110166-1.c
> new file mode 100644
> index 00000000000..f999d47fe69
> --- /dev/null
> +++ b/gcc/testsuite/gcc.c-torture/execute/pr110166-1.c
> @@ -0,0 +1,33 @@
> +struct s
> +{
> + int t : 1;
> + int t1 : 1;
> +};
> +
> +int f(struct s t) __attribute__((noinline));
> +int f(struct s t)
> +{
> + int c = t.t;
> + int d = t.t1;
> + if (c > d)
> + t.t = d;
> + else
> + t.t = c;
> + return t.t;
> +}
> +
> +int main(void)
> +{
> + struct s t;
> + for(int i = -1;i <= 0; i++)
> + {
> + for(int j = -1;j <= 0; j++)
> + {
> + struct s t = {i, j};
> + int r = f(t);
> + int exp = i < j ? i : j;
> + if (exp != r)
> + __builtin_abort();
> + }
> + }
> +}
> --
> 2.31.1
>
