MATCH: Simplify `(A ==/!= B) &/| (((cast)A) CMP C)`

This patch adds support to the pattern for `(A == B) &/| (A CMP C)`
where the second A could be casted to a different type.
Some were handled correctly if using seperate `if` statements
but not if combined with BIT_AND/BIT_IOR.
In the case of pr111456-1.c, the testcase would pass if
`--param=logical-op-non-short-circuit=0` was used but now
can be optimized always.

OK? Bootstrapped and tested on x86_64-linux-gnu.

	PR tree-optimization/106164
	PR tree-optimization/111456

gcc/ChangeLog:

	* match.pd (`(A ==/!= B) & (A CMP C)`):
	Support an optional cast on the second A.
	(`(A ==/!= B) | (A CMP C)`): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/cmpbit-6.c: New test.
	* gcc.dg/tree-ssa/cmpbit-7.c: New test.
	* gcc.dg/tree-ssa/pr111456-1.c: New test.
---
 gcc/match.pd                               | 76 +++++++++++++---------
 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c   | 22 +++++++
 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c   | 28 ++++++++
 gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c | 43 ++++++++++++
 4 files changed, 139 insertions(+), 30 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c

On Thu, Sep 21, 2023 at 4:43 AM Andrew Pinski <apinski@marvell.com> wrote:
>
> This patch adds support to the pattern for `(A == B) &/| (A CMP C)`
> where the second A could be casted to a different type.
> Some were handled correctly if using seperate `if` statements
> but not if combined with BIT_AND/BIT_IOR.
> In the case of pr111456-1.c, the testcase would pass if
> `--param=logical-op-non-short-circuit=0` was used but now
> can be optimized always.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu.

OK.

>         PR tree-optimization/106164
>         PR tree-optimization/111456
>
> gcc/ChangeLog:
>
>         * match.pd (`(A ==/!= B) & (A CMP C)`):
>         Support an optional cast on the second A.
>         (`(A ==/!= B) | (A CMP C)`): Likewise.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.dg/tree-ssa/cmpbit-6.c: New test.
>         * gcc.dg/tree-ssa/cmpbit-7.c: New test.
>         * gcc.dg/tree-ssa/pr111456-1.c: New test.
> ---
>  gcc/match.pd                               | 76 +++++++++++++---------
>  gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c   | 22 +++++++
>  gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c   | 28 ++++++++
>  gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c | 43 ++++++++++++
>  4 files changed, 139 insertions(+), 30 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index a37af05f873..0bf91bde486 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -2973,7 +2973,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>         && TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1)))
>    (gt @0 (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))
>
> -/* Convert (X == CST1) && (X OP2 CST2) to a known value
> +/* Convert (X == CST1) && ((other)X OP2 CST2) to a known value
>     based on CST1 OP2 CST2.  Similarly for (X != CST1).  */
>  /* Convert (X == Y) && (X OP2 Y) to a known value if X is an integral type.
>     Similarly for (X != Y).  */
> @@ -2981,26 +2981,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>  (for code1 (eq ne)
>   (for code2 (eq ne lt gt le ge)
>    (simplify
> -   (bit_and:c (code1@3 @0 @1) (code2@4 @0 @2))
> +   (bit_and:c (code1:c@3 @0 @1) (code2:c@4 (convert?@c0 @0) @2))
>     (if ((TREE_CODE (@1) == INTEGER_CST
>          && TREE_CODE (@2) == INTEGER_CST)
>         || ((INTEGRAL_TYPE_P (TREE_TYPE (@1))
>              || POINTER_TYPE_P (TREE_TYPE (@1)))
> -           && operand_equal_p (@1, @2)))
> +           && bitwise_equal_p (@1, @2)))
>      (with
>       {
>        bool one_before = false;
>        bool one_after = false;
>        int cmp = 0;
> +      bool allbits = true;
>        if (TREE_CODE (@1) == INTEGER_CST
>           && TREE_CODE (@2) == INTEGER_CST)
>         {
> -         cmp = tree_int_cst_compare (@1, @2);
> +         allbits = TYPE_PRECISION (TREE_TYPE (@1)) <= TYPE_PRECISION (TREE_TYPE (@2));
> +         auto t1 = wi::to_wide (fold_convert (TREE_TYPE (@2), @1));
> +         auto t2 = wi::to_wide (@2);
> +         cmp = wi::cmp (t1, t2, TYPE_SIGN (TREE_TYPE (@2)));
>           if (cmp < 0
> -             && wi::to_wide (@1) == wi::to_wide (@2) - 1)
> +             && t1 == t2 - 1)
>             one_before = true;
>           if (cmp > 0
> -             && wi::to_wide (@1) == wi::to_wide (@2) + 1)
> +             && t1 == t2 + 1)
>             one_after = true;
>         }
>        bool val;
> @@ -3018,25 +3022,29 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>       (switch
>        (if (code1 == EQ_EXPR && val) @3)
>        (if (code1 == EQ_EXPR && !val) { constant_boolean_node (false, type); })
> -      (if (code1 == NE_EXPR && !val) @4)
> +      (if (code1 == NE_EXPR && !val && allbits) @4)
>        (if (code1 == NE_EXPR
>             && code2 == GE_EXPR
> -          && cmp == 0)
> -       (gt @0 @1))
> +          && cmp == 0
> +          && allbits)
> +       (gt @c0 (convert @1)))
>        (if (code1 == NE_EXPR
>             && code2 == LE_EXPR
> -          && cmp == 0)
> -       (lt @0 @1))
> +          && cmp == 0
> +          && allbits)
> +       (lt @c0 (convert @1)))
>        /* (a != (b+1)) & (a > b) -> a > (b+1) */
>        (if (code1 == NE_EXPR
>             && code2 == GT_EXPR
> -          && one_after)
> -       (gt @0 @1))
> +          && one_after
> +          && allbits)
> +       (gt @c0 (convert @1)))
>        /* (a != (b-1)) & (a < b) -> a < (b-1) */
>        (if (code1 == NE_EXPR
>             && code2 == LT_EXPR
> -          && one_before)
> -       (lt @0 @1))
> +          && one_before
> +          && allbits)
> +       (lt @c0 (convert @1)))
>       )
>      )
>     )
> @@ -3100,26 +3108,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>  (for code1 (eq ne)
>   (for code2 (eq ne lt gt le ge)
>    (simplify
> -   (bit_ior:c (code1@3 @0 @1) (code2@4 @0 @2))
> +   (bit_ior:c (code1:c@3 @0 @1) (code2:c@4 (convert?@c0 @0) @2))
>     (if ((TREE_CODE (@1) == INTEGER_CST
>          && TREE_CODE (@2) == INTEGER_CST)
>         || ((INTEGRAL_TYPE_P (TREE_TYPE (@1))
>             || POINTER_TYPE_P (TREE_TYPE (@1)))
> -           && operand_equal_p (@1, @2)))
> +           && bitwise_equal_p (@1, @2)))
>      (with
>       {
>        bool one_before = false;
>        bool one_after = false;
>        int cmp = 0;
> +      bool allbits = true;
>        if (TREE_CODE (@1) == INTEGER_CST
>           && TREE_CODE (@2) == INTEGER_CST)
>         {
> -         cmp = tree_int_cst_compare (@1, @2);
> +         allbits = TYPE_PRECISION (TREE_TYPE (@1)) <= TYPE_PRECISION (TREE_TYPE (@2));
> +         auto t1 = wi::to_wide (fold_convert (TREE_TYPE (@2), @1));
> +         auto t2 = wi::to_wide (@2);
> +         cmp = wi::cmp (t1, t2, TYPE_SIGN (TREE_TYPE (@2)));
>           if (cmp < 0
> -             && wi::to_wide (@1) == wi::to_wide (@2) - 1)
> +             && t1 == t2 - 1)
>             one_before = true;
>           if (cmp > 0
> -             && wi::to_wide (@1) == wi::to_wide (@2) + 1)
> +             && t1 == t2 + 1)
>             one_after = true;
>         }
>        bool val;
> @@ -3136,26 +3148,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>       }
>       (switch
>        (if (code1 == EQ_EXPR && val) @4)
> -      (if (code1 == NE_EXPR && val) { constant_boolean_node (true, type); })
> -      (if (code1 == NE_EXPR && !val) @3)
> +      (if (code1 == NE_EXPR && val && allbits) { constant_boolean_node (true, type); })
> +      (if (code1 == NE_EXPR && !val && allbits) @3)
>        (if (code1 == EQ_EXPR
>             && code2 == GT_EXPR
> -          && cmp == 0)
> -       (ge @0 @1))
> +          && cmp == 0
> +          && allbits)
> +       (ge @c0 @2))
>        (if (code1 == EQ_EXPR
>             && code2 == LT_EXPR
> -          && cmp == 0)
> -       (le @0 @1))
> +          && cmp == 0
> +          && allbits)
> +       (le @c0 @2))
>        /* (a == (b-1)) | (a >= b) -> a >= (b-1) */
>        (if (code1 == EQ_EXPR
>             && code2 == GE_EXPR
> -          && one_before)
> -       (ge @0 @1))
> +          && one_before
> +          && allbits)
> +       (ge @c0 (convert @1)))
>        /* (a == (b+1)) | (a <= b) -> a <= (b-1) */
>        (if (code1 == EQ_EXPR
>             && code2 == LE_EXPR
> -          && one_after)
> -       (le @0 @1))
> +          && one_after
> +          && allbits)
> +       (le @c0 (convert @1)))
>       )
>      )
>     )
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c
> new file mode 100644
> index 00000000000..4ec73f030bb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-6.c
> @@ -0,0 +1,22 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +/* PR tree-optimization/106164 */
> +/* PR tree-optimization/111456 */
> +
> +_Bool iu(int a)
> +{
> +  _Bool t = a == 0;
> +  unsigned t1 = a;
> +  _Bool t2 = t1 >= 3;
> +  return t & t2;
> +}
> +
> +_Bool is(int a)
> +{
> +  _Bool t = a == 0;
> +  short t1 = a;
> +  _Bool t2 = t1 >= 3;
> +  return t & t2;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "return 0" 2 "optimized" } } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c
> new file mode 100644
> index 00000000000..ee04ebbaaed
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-7.c
> @@ -0,0 +1,28 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-forwprop1" } */
> +/* PR tree-optimization/106164 */
> +/* PR tree-optimization/111456 */
> +
> +_Bool f(int a)
> +{
> +        _Bool t = a == 3;
> +        unsigned t1 = a;
> +        _Bool t2 = t1 >= 3;
> +        return t | t2;
> +}
> +
> +/* Should be able to optimize down to just `a > 2` during forwprop1 */
> +/* { dg-final { scan-tree-dump-not "a_\[0-9\]+.D. == 3" "forwprop1" } } */
> +
> +_Bool f1(int b)
> +{
> +        _Bool t = b == 3;
> +        short t1 = b;
> +        _Bool t2 = t1 >= 3;
> +        return t | t2;
> +}
> +
> +/* Should be able to optimize down to just `a > 2` during forwprop1 as `((short)a) >= 3` is
> +   true already when `a == 3`. */
> +/* { dg-final { scan-tree-dump-not "b_\[0-9\]+.D. == 3" "forwprop1" } } */
> +/* { dg-final { scan-tree-dump-times "_\[0-9\]+ > 2" 2 "forwprop1" } } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c
> new file mode 100644
> index 00000000000..8a2f730b387
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr111456-1.c
> @@ -0,0 +1,43 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +/* PR tree-optimization/111456 */
> +
> +void foo(void);
> +static int i;
> +static int *j = &i;
> +static char l;
> +static void(a)(char) {}
> +static short(b)(short c, short d) { return c - d; }
> +static short(e)(short f, int g) {
> +    return f < 0 || g < 0 || g >= 32 ? f : f >> g;
> +}
> +static short(h)(short f, int g) { return g >= 2 ?: f >> g; }
> +static char k(char m, short n) {
> +    short o;
> +    int *p = &i;
> +    if (!(((m) >= 1) && ((m) <= 1))) {
> +        __builtin_unreachable();
> +    }
> +    o = e(i, i);
> +    if (h(1, o))
> +        ;
> +    else {
> +        m = 0;
> +        for (; m >= -20; m = b(m, 9))
> +            if (a(i), n) {
> +                if (*p)
> +                    ;
> +                else
> +                    foo();
> +                ;
> +            } else
> +                return l;
> +    }
> +    return i;
> +}
> +int main() { k(0 <= 0 > *j, i); }
> +
> +
> +/* { dg-final { scan-tree-dump-not "foo " "optimized" } } */
> +/* { dg-final { scan-tree-dump "return 0;" "optimized" } } */
> +
> --
> 2.31.1
>