diff mbox series

tree-optimization: [PR31531] Improve ~a < CST, allow a nop cast inbetween ~ and a

Message ID 1637430754-23697-1-git-send-email-apinski@marvell.com
State New
Headers show
Series tree-optimization: [PR31531] Improve ~a < CST, allow a nop cast inbetween ~ and a | expand

Commit Message

apinski--- via Gcc-patches Nov. 20, 2021, 5:52 p.m. UTC
From: Andrew Pinski <apinski@marvell.com>

This PR was orignally for the missed optimization of a few isnegative which
had been solved a long time ago (sometime before 4.4.0). I noticed there was
one missed optimization on the gimple level. There is a match.pd pattern
for ~a < CST but we miss that there could be a nop_convert between the the
comparison and the bit_not. This adds the optional option cast to the current
match.pd pattern.

OK? Bootstrapped and tested on x86_64 with no regressions.

	PR tree-optimization/31531

gcc/ChangeLog:

	* match.pd (~X op C): Allow for an optional nop convert.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr31531-1.c: New test.
---
 gcc/match.pd                              |  5 +++--
 gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c

Comments

Richard Biener Nov. 22, 2021, 11:26 a.m. UTC | #1
On Sun, Nov 21, 2021 at 3:19 PM apinski--- via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> From: Andrew Pinski <apinski@marvell.com>
>
> This PR was orignally for the missed optimization of a few isnegative which
> had been solved a long time ago (sometime before 4.4.0). I noticed there was
> one missed optimization on the gimple level. There is a match.pd pattern
> for ~a < CST but we miss that there could be a nop_convert between the the
> comparison and the bit_not. This adds the optional option cast to the current
> match.pd pattern.
>
> OK? Bootstrapped and tested on x86_64 with no regressions.
>
>         PR tree-optimization/31531
>
> gcc/ChangeLog:
>
>         * match.pd (~X op C): Allow for an optional nop convert.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.dg/tree-ssa/pr31531-1.c: New test.
> ---
>  gcc/match.pd                              |  5 +++--
>  gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c | 19 +++++++++++++++++++
>  2 files changed, 22 insertions(+), 2 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 37c5be9e5f4..ca6c9eff624 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -4729,10 +4729,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>  (for cmp (simple_comparison)
>       scmp (swapped_simple_comparison)
>   (simplify
> -  (cmp (bit_not@2 @0) CONSTANT_CLASS_P@1)
> +  (cmp (nop_convert?:s (bit_not@2 @0)) CONSTANT_CLASS_P@1)

Any specific reason you add :s to the conversion?

OK with removing it.

Thanks,
Richard.

>    (if (single_use (@2)
>         && (TREE_CODE (@1) == INTEGER_CST || TREE_CODE (@1) == VECTOR_CST))
> -   (scmp @0 (bit_not @1)))))
> +   (with { tree type1 = TREE_TYPE (@1); }
> +    (scmp (convert:type1 @0) (bit_not @1))))))
>
>  (for cmp (simple_comparison)
>   /* Fold (double)float1 CMP (double)float2 into float1 CMP float2.  */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c
> new file mode 100644
> index 00000000000..c27299151eb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c
> @@ -0,0 +1,19 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +/* PR tree-optimization/31531 */
> +
> +int f(int a)
> +{
> +  int b = ~a;
> +  return b<0;
> +}
> +
> +
> +int f1(unsigned a)
> +{
> +  int b = ~a;
> +  return b<0;
> +}
> +/* We should convert the above two functions from b <0 to ((int)a) >= 0. */
> +/* { dg-final { scan-tree-dump-times ">= 0" 2 "optimized"} } */
> +/* { dg-final { scan-tree-dump-times "~" 0 "optimized"} } */
> --
> 2.17.1
>
diff mbox series

Patch

diff --git a/gcc/match.pd b/gcc/match.pd
index 37c5be9e5f4..ca6c9eff624 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -4729,10 +4729,11 @@  DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (for cmp (simple_comparison)
      scmp (swapped_simple_comparison)
  (simplify
-  (cmp (bit_not@2 @0) CONSTANT_CLASS_P@1)
+  (cmp (nop_convert?:s (bit_not@2 @0)) CONSTANT_CLASS_P@1)
   (if (single_use (@2)
        && (TREE_CODE (@1) == INTEGER_CST || TREE_CODE (@1) == VECTOR_CST))
-   (scmp @0 (bit_not @1)))))
+   (with { tree type1 = TREE_TYPE (@1); }
+    (scmp (convert:type1 @0) (bit_not @1))))))
 
 (for cmp (simple_comparison)
  /* Fold (double)float1 CMP (double)float2 into float1 CMP float2.  */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c
new file mode 100644
index 00000000000..c27299151eb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr31531-1.c
@@ -0,0 +1,19 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* PR tree-optimization/31531 */
+
+int f(int a)
+{
+  int b = ~a;
+  return b<0;
+}
+
+
+int f1(unsigned a)
+{
+  int b = ~a;
+  return b<0;
+}
+/* We should convert the above two functions from b <0 to ((int)a) >= 0. */
+/* { dg-final { scan-tree-dump-times ">= 0" 2 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "~" 0 "optimized"} } */