On Thu, Aug 3, 2023 at 6:41 PM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This changes gimple_bitwise_inverted_equal_p to use a 2 different match
> patterns
> to try to match bit_not wrapped with a possible nop_convert and a comparison
> also wrapped with a possible nop_convert. This is to avoid being recursive.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
OK.
Thanks,
Richard.
> gcc/ChangeLog:
>
> PR tree-optimization/110874
> * gimple-match-head.cc (gimple_bit_not_with_nop): New declaration.
> (gimple_maybe_cmp): Likewise.
> (gimple_bitwise_inverted_equal_p): Rewrite to use
> gimple_bit_not_with_nop
> and gimple_maybe_cmp instead of being recursive.
> * match.pd (bit_not_with_nop): New match pattern.
> (maybe_cmp): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/110874
> * gcc.c-torture/compile/pr110874-a.c: New test.
> ---
> gcc/gimple-match-head.cc | 87 ++++++++++---------
> gcc/match.pd | 17 ++++
> .../gcc.c-torture/compile/pr110874-a.c | 17 ++++
> 3 files changed, 79 insertions(+), 42 deletions(-)
> create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr110874-a.c
>
> diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc
> index b1e96304d7c..a097a494c39 100644
> --- a/gcc/gimple-match-head.cc
> +++ b/gcc/gimple-match-head.cc
> @@ -270,6 +270,10 @@ gimple_bitwise_equal_p (tree expr1, tree expr2, tree
> (*valueize) (tree))
> #define bitwise_inverted_equal_p(expr1, expr2) \
> gimple_bitwise_inverted_equal_p (expr1, expr2, valueize)
>
> +
> +bool gimple_bit_not_with_nop (tree, tree *, tree (*) (tree));
> +bool gimple_maybe_cmp (tree, tree *, tree (*) (tree));
> +
> /* Helper function for bitwise_equal_p macro. */
>
> static inline bool
> @@ -285,52 +289,51 @@ gimple_bitwise_inverted_equal_p (tree expr1, tree
> expr2, tree (*valueize) (tree)
> return false;
>
> tree other;
> - if (gimple_nop_convert (expr1, &other, valueize)
> - && gimple_bitwise_inverted_equal_p (other, expr2, valueize))
> - return true;
> -
> - if (gimple_nop_convert (expr2, &other, valueize)
> - && gimple_bitwise_inverted_equal_p (expr1, other, valueize))
> - return true;
> -
> - if (TREE_CODE (expr1) != SSA_NAME
> - || TREE_CODE (expr2) != SSA_NAME)
> - return false;
> -
> - gimple *d1 = get_def (valueize, expr1);
> - gassign *a1 = safe_dyn_cast <gassign *> (d1);
> - gimple *d2 = get_def (valueize, expr2);
> - gassign *a2 = safe_dyn_cast <gassign *> (d2);
> - if (a1
> - && gimple_assign_rhs_code (a1) == BIT_NOT_EXPR
> - && gimple_bitwise_equal_p (do_valueize (valueize,
> - gimple_assign_rhs1 (a1)),
> - expr2, valueize))
> + /* Try if EXPR1 was defined as ~EXPR2. */
> + if (gimple_bit_not_with_nop (expr1, &other, valueize))
> + {
> + if (operand_equal_p (other, expr2, 0))
> return true;
> - if (a2
> - && gimple_assign_rhs_code (a2) == BIT_NOT_EXPR
> - && gimple_bitwise_equal_p (expr1,
> - do_valueize (valueize,
> - gimple_assign_rhs1 (a2)),
> - valueize))
> + tree expr4;
> + if (gimple_nop_convert (expr2, &expr4, valueize)
> + && operand_equal_p (other, expr4, 0))
> return true;
> -
> - if (a1 && a2
> - && TREE_CODE_CLASS (gimple_assign_rhs_code (a1)) == tcc_comparison
> - && TREE_CODE_CLASS (gimple_assign_rhs_code (a2)) == tcc_comparison)
> + }
> + /* Try if EXPR2 was defined as ~EXPR1. */
> + if (gimple_bit_not_with_nop (expr2, &other, valueize))
> {
> - tree op10 = do_valueize (valueize, gimple_assign_rhs1 (a1));
> - tree op20 = do_valueize (valueize, gimple_assign_rhs1 (a2));
> - if (!operand_equal_p (op10, op20))
> - return false;
> - tree op11 = do_valueize (valueize, gimple_assign_rhs2 (a1));
> - tree op21 = do_valueize (valueize, gimple_assign_rhs2 (a2));
> - if (!operand_equal_p (op11, op21))
> - return false;
> - if (invert_tree_comparison (gimple_assign_rhs_code (a1),
> - HONOR_NANS (op10))
> - == gimple_assign_rhs_code (a2))
> + if (operand_equal_p (other, expr1, 0))
> + return true;
> + tree expr3;
> + if (gimple_nop_convert (expr1, &expr3, valueize)
> + && operand_equal_p (other, expr3, 0))
> return true;
> }
> +
> + /* If neither are defined by BIT_NOT, try to see if
> + both are defined by comparisons and see if they are
> + complementary (inversion) of each other. */
> + tree newexpr1, newexpr2;
> + if (!gimple_maybe_cmp (expr1, &newexpr1, valueize))
> + return false;
> + if (!gimple_maybe_cmp (expr2, &newexpr2, valueize))
> + return false;
> +
> + gimple *d1 = get_def (valueize, newexpr1);
> + gassign *a1 = dyn_cast <gassign *> (d1);
> + gimple *d2 = get_def (valueize, newexpr2);
> + gassign *a2 = dyn_cast <gassign *> (d2);
> + tree op10 = do_valueize (valueize, gimple_assign_rhs1 (a1));
> + tree op20 = do_valueize (valueize, gimple_assign_rhs1 (a2));
> + if (!operand_equal_p (op10, op20))
> + return false;
> + tree op11 = do_valueize (valueize, gimple_assign_rhs2 (a1));
> + tree op21 = do_valueize (valueize, gimple_assign_rhs2 (a2));
> + if (!operand_equal_p (op11, op21))
> + return false;
> + if (invert_tree_comparison (gimple_assign_rhs_code (a1),
> + HONOR_NANS (op10))
> + == gimple_assign_rhs_code (a2))
> + return true;
> return false;
> }
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 53e622bf28f..50dd653c778 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -155,6 +155,23 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> TYPE_VECTOR_SUBPARTS (TREE_TYPE (@0)))
> && tree_nop_conversion_p (TREE_TYPE (type), TREE_TYPE (TREE_TYPE
> (@0))))))
>
> +#if GIMPLE
> +/* These are used by gimple_bitwise_inverted_equal_p to simplify
> + detection of BIT_NOT and comparisons. */
> +(match (bit_not_with_nop @0)
> + (bit_not @0))
> +(match (bit_not_with_nop @0)
> + (convert (bit_not @0))
> + (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))))
> +(for cmp (tcc_comparison)
> + (match (maybe_cmp @0)
> + (cmp@0 @1 @2))
> + (match (maybe_cmp @0)
> + (convert (cmp@0 @1 @2))
> + (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))))
> +)
> +#endif
> +
> /* Transform likes of (char) ABS_EXPR <(int) x> into (char) ABSU_EXPR <x>
> ABSU_EXPR returns unsigned absolute value of the operand and the operand
> of the ABSU_EXPR will have the corresponding signed type. */
> diff --git a/gcc/testsuite/gcc.c-torture/compile/pr110874-a.c
> b/gcc/testsuite/gcc.c-torture/compile/pr110874-a.c
> new file mode 100644
> index 00000000000..b314410a892
> --- /dev/null
> +++ b/gcc/testsuite/gcc.c-torture/compile/pr110874-a.c
> @@ -0,0 +1,17 @@
> +struct S1 {
> + unsigned f0;
> +};
> +static int g_161;
> +void func_109(unsigned g_227, unsigned t) {
> + struct S1 l_178;
> + int l_160 = 0x1FAE99D5L;
> + int *l_230[] = {&l_160};
> + if (l_160) {
> + for (l_178.f0 = -7; l_178.f0;) {
> + ++g_227;
> + break;
> + }
> + (g_161) = g_227;
> + }
> + (g_161) &= t;
> +}
> --
> 2.31.1
>
