[PATCH] tree-optimization/103356 Add missing (~a) == b folding for _Bool

[PATCH] tree-optimization/103356 Add missing (~a) == b folding for _Bool

[apinski]

From: Andrew Pinski <apinski@marvell.com>

The following makes sure to fold (~a) ==  b to a ^ b for truth
values.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

Thanks,
Andrew Pinski

	PR 103356

gcc/ChangeLog:

	* match.pd: ((~a) == b -> a ^ b): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr103356-1.c: New test.
---
 gcc/match.pd                      | 7 +++++++
 gcc/testsuite/gcc.dg/pr103356-1.c | 9 +++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr103356-1.c

diff --git a/gcc/match.pd b/gcc/match.pd
index a4d1386fd9f..67a0a682f31 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1999,6 +1999,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       && TYPE_PRECISION (TREE_TYPE (@0)) == 1)
   (convert (eq @0 @1))))
 
+/* (~a) == b is a ^ b for truth valued a and b.  */
+(simplify
+ (eq:c (bit_not:s truth_valued_p@0) truth_valued_p@1)
+ (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+      && TYPE_PRECISION (TREE_TYPE (@0)) == 1)
+  (convert (bit_xor @0 @1))))
+
 /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
 (simplify
  (bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2))
diff --git a/gcc/testsuite/gcc.dg/pr103356-1.c b/gcc/testsuite/gcc.dg/pr103356-1.c
new file mode 100644
index 00000000000..61d0b81da22
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103356-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-forwprop1" } */
+
+_Bool foo (_Bool a, _Bool b)
+{
+  return a == (!b);
+}
+
+/* { dg-final { scan-tree-dump "\[ab\]_\[0-9\]+\\(D\\) \\\^ \[ba\]_\[0-9\]+\\(D\\)" "forwprop1" } } */
-- 
2.17.1

Re: [PATCH] tree-optimization/103356 Add missing (~a) == b folding for _Bool

[Richard Biener]

> Am 26.11.2022 um 17:42 schrieb apinski--- via Gcc-patches <gcc-patches@gcc.gnu.org>:
> 
> From: Andrew Pinski <apinski@marvell.com>
> 
> The following makes sure to fold (~a) ==  b to a ^ b for truth
> values.
> 
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

Ok.

Richard 

> Thanks,
> Andrew Pinski
> 
>    PR 103356
> 
> gcc/ChangeLog:
> 
>    * match.pd: ((~a) == b -> a ^ b): New pattern.
> 
> gcc/testsuite/ChangeLog:
> 
>    * gcc.dg/pr103356-1.c: New test.
> ---
> gcc/match.pd                      | 7 +++++++
> gcc/testsuite/gcc.dg/pr103356-1.c | 9 +++++++++
> 2 files changed, 16 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/pr103356-1.c
> 
> diff --git a/gcc/match.pd b/gcc/match.pd
> index a4d1386fd9f..67a0a682f31 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -1999,6 +1999,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>       && TYPE_PRECISION (TREE_TYPE (@0)) == 1)
>   (convert (eq @0 @1))))
> 
> +/* (~a) == b is a ^ b for truth valued a and b.  */
> +(simplify
> + (eq:c (bit_not:s truth_valued_p@0) truth_valued_p@1)
> + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
> +      && TYPE_PRECISION (TREE_TYPE (@0)) == 1)
> +  (convert (bit_xor @0 @1))))
> +
> /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
> (simplify
>  (bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2))
> diff --git a/gcc/testsuite/gcc.dg/pr103356-1.c b/gcc/testsuite/gcc.dg/pr103356-1.c
> new file mode 100644
> index 00000000000..61d0b81da22
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr103356-1.c
> @@ -0,0 +1,9 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-forwprop1" } */
> +
> +_Bool foo (_Bool a, _Bool b)
> +{
> +  return a == (!b);
> +}
> +
> +/* { dg-final { scan-tree-dump "\[ab\]_\[0-9\]+\\(D\\) \\\^ \[ba\]_\[0-9\]+\\(D\\)" "forwprop1" } } */
> -- 
> 2.17.1
>