* [PATCH] match.pd: Add bitwise and pattern [PR106243]
@ 2022-08-03 19:10 Sam Feifer
2022-08-03 20:44 ` Prathamesh Kulkarni
2022-08-04 7:06 ` Richard Biener
0 siblings, 2 replies; 6+ messages in thread
From: Sam Feifer @ 2022-08-03 19:10 UTC (permalink / raw)
To: GCC Patches
This patch adds a new optimization to match.pd. The pattern, -x & 1,
now gets simplified to x & 1, reducing the number of instructions
produced.
This patch also adds tests for the optimization rule.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
PR tree-optimization/106243
gcc/ChangeLog:
* match.pd (-x & 1): New simplification.
gcc/testsuite/ChangeLog:
* gcc.dg/pr106243-1.c: New test.
* gcc.dg/pr106243.c: New test.
---
gcc/match.pd | 5 ++++
gcc/testsuite/gcc.dg/pr106243-1.c | 18 +++++++++++++
gcc/testsuite/gcc.dg/pr106243.c | 43 +++++++++++++++++++++++++++++++
3 files changed, 66 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/pr106243-1.c
create mode 100644 gcc/testsuite/gcc.dg/pr106243.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 562138a8034..78b32567836 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -8061,3 +8061,8 @@ and,
(if (TYPE_UNSIGNED (TREE_TYPE (@0)))
(bit_and @0 @1)
(cond (le @0 @1) @0 (bit_and @0 @1))))))
+
+/* -x & 1 -> x & 1. */
+(simplify
+ (bit_and:c (negate @0) integer_onep@1)
+ (bit_and @0 @1))
diff --git a/gcc/testsuite/gcc.dg/pr106243-1.c b/gcc/testsuite/gcc.dg/pr106243-1.c
new file mode 100644
index 00000000000..b1dbe5cbe44
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr106243-1.c
@@ -0,0 +1,18 @@
+/* PR tree-optimization/106243 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#include "pr106243.c"
+
+int main () {
+
+ if (foo(3) != 1
+ || bar(-6) != 0
+ || baz(17) != 1
+ || qux(-128) != 0
+ || foo(127) != 1) {
+ __builtin_abort();
+ }
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr106243.c b/gcc/testsuite/gcc.dg/pr106243.c
new file mode 100644
index 00000000000..ee2706f2bf9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr106243.c
@@ -0,0 +1,43 @@
+/* PR tree-optimization/106243 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+#define vector __attribute__((vector_size(4*sizeof(int))))
+
+/* Test from PR. */
+__attribute__((noipa)) int foo (int x) {
+ return -x & 1;
+}
+
+/* Other test from PR. */
+__attribute__((noipa)) int bar (int x) {
+ return (0 - x) & 1;
+}
+
+/* Forward propogation. */
+__attribute__((noipa)) int baz (int x) {
+ x = -x;
+ return x & 1;
+}
+
+/* Commutative property. */
+__attribute__((noipa)) int qux (int x) {
+ return 1 & -x;
+}
+
+/* Vector test case. */
+__attribute__((noipa)) vector int waldo (vector int x) {
+ return -x & 1;
+}
+
+/* Should not simplify. */
+__attribute__((noipa)) int thud (int x) {
+ return -x & 2;
+}
+
+/* Should not simplify. */
+__attribute__((noipa)) int corge (int x) {
+ return -x & -1;
+}
+
+/* { dg-final {scan-tree-dump-times "-" 2 "optimized" } } */
base-commit: 388fbbd895e72669909173c3003ae65c6483a3c2
--
2.31.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] match.pd: Add bitwise and pattern [PR106243]
2022-08-03 19:10 [PATCH] match.pd: Add bitwise and pattern [PR106243] Sam Feifer
@ 2022-08-03 20:44 ` Prathamesh Kulkarni
2022-08-03 22:39 ` Jeff Law
2022-08-04 7:06 ` Richard Biener
1 sibling, 1 reply; 6+ messages in thread
From: Prathamesh Kulkarni @ 2022-08-03 20:44 UTC (permalink / raw)
To: Sam Feifer; +Cc: GCC Patches
On Thu, 4 Aug 2022 at 00:41, Sam Feifer via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This patch adds a new optimization to match.pd. The pattern, -x & 1,
> now gets simplified to x & 1, reducing the number of instructions
> produced.
Hi Sam,
No comments on patch, but wondering if we can similarly add another pattern to
simplify abs(x) & 1 -> x & 1 ?
Currently we don't appear to do it on GIMPLE:
__attribute__((noipa))
int f1 (int x)
{
return __builtin_abs (x) & 1;
}
.optimized dump shows:
_1 = ABS_EXPR <x_2(D)>;
_3 = _1 & 1;
return _3;
altho combine simplifies it to x & 1 on RTL, resulting in code-gen:
f1:
and w0, w0, 1
ret
Thanks,
Prathamesh
>
> This patch also adds tests for the optimization rule.
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> PR tree-optimization/106243
>
> gcc/ChangeLog:
>
> * match.pd (-x & 1): New simplification.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/pr106243-1.c: New test.
> * gcc.dg/pr106243.c: New test.
> ---
> gcc/match.pd | 5 ++++
> gcc/testsuite/gcc.dg/pr106243-1.c | 18 +++++++++++++
> gcc/testsuite/gcc.dg/pr106243.c | 43 +++++++++++++++++++++++++++++++
> 3 files changed, 66 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/pr106243-1.c
> create mode 100644 gcc/testsuite/gcc.dg/pr106243.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 562138a8034..78b32567836 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -8061,3 +8061,8 @@ and,
> (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
> (bit_and @0 @1)
> (cond (le @0 @1) @0 (bit_and @0 @1))))))
> +
> +/* -x & 1 -> x & 1. */
> +(simplify
> + (bit_and:c (negate @0) integer_onep@1)
> + (bit_and @0 @1))
> diff --git a/gcc/testsuite/gcc.dg/pr106243-1.c b/gcc/testsuite/gcc.dg/pr106243-1.c
> new file mode 100644
> index 00000000000..b1dbe5cbe44
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr106243-1.c
> @@ -0,0 +1,18 @@
> +/* PR tree-optimization/106243 */
> +/* { dg-do run } */
> +/* { dg-options "-O2" } */
> +
> +#include "pr106243.c"
> +
> +int main () {
> +
> + if (foo(3) != 1
> + || bar(-6) != 0
> + || baz(17) != 1
> + || qux(-128) != 0
> + || foo(127) != 1) {
> + __builtin_abort();
> + }
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr106243.c b/gcc/testsuite/gcc.dg/pr106243.c
> new file mode 100644
> index 00000000000..ee2706f2bf9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr106243.c
> @@ -0,0 +1,43 @@
> +/* PR tree-optimization/106243 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +#define vector __attribute__((vector_size(4*sizeof(int))))
> +
> +/* Test from PR. */
> +__attribute__((noipa)) int foo (int x) {
> + return -x & 1;
> +}
> +
> +/* Other test from PR. */
> +__attribute__((noipa)) int bar (int x) {
> + return (0 - x) & 1;
> +}
> +
> +/* Forward propogation. */
> +__attribute__((noipa)) int baz (int x) {
> + x = -x;
> + return x & 1;
> +}
> +
> +/* Commutative property. */
> +__attribute__((noipa)) int qux (int x) {
> + return 1 & -x;
> +}
> +
> +/* Vector test case. */
> +__attribute__((noipa)) vector int waldo (vector int x) {
> + return -x & 1;
> +}
> +
> +/* Should not simplify. */
> +__attribute__((noipa)) int thud (int x) {
> + return -x & 2;
> +}
> +
> +/* Should not simplify. */
> +__attribute__((noipa)) int corge (int x) {
> + return -x & -1;
> +}
> +
> +/* { dg-final {scan-tree-dump-times "-" 2 "optimized" } } */
>
> base-commit: 388fbbd895e72669909173c3003ae65c6483a3c2
> --
> 2.31.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] match.pd: Add bitwise and pattern [PR106243]
2022-08-03 20:44 ` Prathamesh Kulkarni
@ 2022-08-03 22:39 ` Jeff Law
2022-08-04 7:08 ` Richard Biener
2022-08-04 12:34 ` Michael Matz
0 siblings, 2 replies; 6+ messages in thread
From: Jeff Law @ 2022-08-03 22:39 UTC (permalink / raw)
To: gcc-patches
On 8/3/2022 2:44 PM, Prathamesh Kulkarni via Gcc-patches wrote:
> On Thu, 4 Aug 2022 at 00:41, Sam Feifer via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>> This patch adds a new optimization to match.pd. The pattern, -x & 1,
>> now gets simplified to x & 1, reducing the number of instructions
>> produced.
> Hi Sam,
> No comments on patch, but wondering if we can similarly add another pattern to
> simplify abs(x) & 1 -> x & 1 ?
> Currently we don't appear to do it on GIMPLE:
>
> __attribute__((noipa))
> int f1 (int x)
> {
> return __builtin_abs (x) & 1;
> }
>
> .optimized dump shows:
> _1 = ABS_EXPR <x_2(D)>;
> _3 = _1 & 1;
> return _3;
>
> altho combine simplifies it to x & 1 on RTL, resulting in code-gen:
> f1:
> and w0, w0, 1
> ret
Doesn't the abs(x) & mask simplify to x & mask for any mask where the
sign bit of x is off -- including cases where mask isn't necessarily a
compile-time constant, but we have range data which allows us to know
that x's sign bit is off in mask.
jeff
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] match.pd: Add bitwise and pattern [PR106243]
2022-08-03 22:39 ` Jeff Law
@ 2022-08-04 7:08 ` Richard Biener
2022-08-04 12:34 ` Michael Matz
1 sibling, 0 replies; 6+ messages in thread
From: Richard Biener @ 2022-08-04 7:08 UTC (permalink / raw)
To: Jeff Law; +Cc: GCC Patches
On Thu, Aug 4, 2022 at 12:40 AM Jeff Law via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
>
>
> On 8/3/2022 2:44 PM, Prathamesh Kulkarni via Gcc-patches wrote:
> > On Thu, 4 Aug 2022 at 00:41, Sam Feifer via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> >> This patch adds a new optimization to match.pd. The pattern, -x & 1,
> >> now gets simplified to x & 1, reducing the number of instructions
> >> produced.
> > Hi Sam,
> > No comments on patch, but wondering if we can similarly add another pattern to
> > simplify abs(x) & 1 -> x & 1 ?
> > Currently we don't appear to do it on GIMPLE:
> >
> > __attribute__((noipa))
> > int f1 (int x)
> > {
> > return __builtin_abs (x) & 1;
> > }
> >
> > .optimized dump shows:
> > _1 = ABS_EXPR <x_2(D)>;
> > _3 = _1 & 1;
> > return _3;
> >
> > altho combine simplifies it to x & 1 on RTL, resulting in code-gen:
> > f1:
> > and w0, w0, 1
> > ret
> Doesn't the abs(x) & mask simplify to x & mask for any mask where the
> sign bit of x is off -- including cases where mask isn't necessarily a
> compile-time constant, but we have range data which allows us to know
> that x's sign bit is off in mask.
You can use tree_expr_nonnegative_p but then that does simplify
abs(x) to x already. But sure, handling abs() like negate sounds it
should work.
Richard,
> jeff
>
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] match.pd: Add bitwise and pattern [PR106243]
2022-08-03 22:39 ` Jeff Law
2022-08-04 7:08 ` Richard Biener
@ 2022-08-04 12:34 ` Michael Matz
1 sibling, 0 replies; 6+ messages in thread
From: Michael Matz @ 2022-08-04 12:34 UTC (permalink / raw)
To: Jeff Law; +Cc: gcc-patches
Hello,
On Wed, 3 Aug 2022, Jeff Law via Gcc-patches wrote:
> > .optimized dump shows:
> > _1 = ABS_EXPR <x_2(D)>;
> > _3 = _1 & 1;
> > return _3;
> >
> > altho combine simplifies it to x & 1 on RTL, resulting in code-gen:
> > f1:
> > and w0, w0, 1
> > ret
> Doesn't the abs(x) & mask simplify to x & mask for any mask where the sign bit
> of x is off
No. Only the lowest bit remains the same between x and -x, all others
might or might not be inverted (first counter example: x=-3, mask=3).
Ciao,
Michael.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] match.pd: Add bitwise and pattern [PR106243]
2022-08-03 19:10 [PATCH] match.pd: Add bitwise and pattern [PR106243] Sam Feifer
2022-08-03 20:44 ` Prathamesh Kulkarni
@ 2022-08-04 7:06 ` Richard Biener
1 sibling, 0 replies; 6+ messages in thread
From: Richard Biener @ 2022-08-04 7:06 UTC (permalink / raw)
To: Sam Feifer; +Cc: GCC Patches
On Wed, Aug 3, 2022 at 9:11 PM Sam Feifer via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This patch adds a new optimization to match.pd. The pattern, -x & 1,
> now gets simplified to x & 1, reducing the number of instructions
> produced.
>
> This patch also adds tests for the optimization rule.
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> PR tree-optimization/106243
>
> gcc/ChangeLog:
>
> * match.pd (-x & 1): New simplification.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/pr106243-1.c: New test.
> * gcc.dg/pr106243.c: New test.
> ---
> gcc/match.pd | 5 ++++
> gcc/testsuite/gcc.dg/pr106243-1.c | 18 +++++++++++++
> gcc/testsuite/gcc.dg/pr106243.c | 43 +++++++++++++++++++++++++++++++
> 3 files changed, 66 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/pr106243-1.c
> create mode 100644 gcc/testsuite/gcc.dg/pr106243.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 562138a8034..78b32567836 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -8061,3 +8061,8 @@ and,
> (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
> (bit_and @0 @1)
> (cond (le @0 @1) @0 (bit_and @0 @1))))))
> +
> +/* -x & 1 -> x & 1. */
> +(simplify
> + (bit_and:c (negate @0) integer_onep@1)
Note the bit_and doesn't need :c because constant operands are always
canonicalized second.
OK with that change.
Thanks,
Richard.
> + (bit_and @0 @1))
> diff --git a/gcc/testsuite/gcc.dg/pr106243-1.c b/gcc/testsuite/gcc.dg/pr106243-1.c
> new file mode 100644
> index 00000000000..b1dbe5cbe44
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr106243-1.c
> @@ -0,0 +1,18 @@
> +/* PR tree-optimization/106243 */
> +/* { dg-do run } */
> +/* { dg-options "-O2" } */
> +
> +#include "pr106243.c"
> +
> +int main () {
> +
> + if (foo(3) != 1
> + || bar(-6) != 0
> + || baz(17) != 1
> + || qux(-128) != 0
> + || foo(127) != 1) {
> + __builtin_abort();
> + }
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr106243.c b/gcc/testsuite/gcc.dg/pr106243.c
> new file mode 100644
> index 00000000000..ee2706f2bf9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr106243.c
> @@ -0,0 +1,43 @@
> +/* PR tree-optimization/106243 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +#define vector __attribute__((vector_size(4*sizeof(int))))
> +
> +/* Test from PR. */
> +__attribute__((noipa)) int foo (int x) {
> + return -x & 1;
> +}
> +
> +/* Other test from PR. */
> +__attribute__((noipa)) int bar (int x) {
> + return (0 - x) & 1;
> +}
> +
> +/* Forward propogation. */
> +__attribute__((noipa)) int baz (int x) {
> + x = -x;
> + return x & 1;
> +}
> +
> +/* Commutative property. */
> +__attribute__((noipa)) int qux (int x) {
> + return 1 & -x;
> +}
> +
> +/* Vector test case. */
> +__attribute__((noipa)) vector int waldo (vector int x) {
> + return -x & 1;
> +}
> +
> +/* Should not simplify. */
> +__attribute__((noipa)) int thud (int x) {
> + return -x & 2;
> +}
> +
> +/* Should not simplify. */
> +__attribute__((noipa)) int corge (int x) {
> + return -x & -1;
> +}
> +
> +/* { dg-final {scan-tree-dump-times "-" 2 "optimized" } } */
>
> base-commit: 388fbbd895e72669909173c3003ae65c6483a3c2
> --
> 2.31.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2022-08-03 19:10 [PATCH] match.pd: Add bitwise and pattern [PR106243] Sam Feifer
2022-08-03 20:44 ` Prathamesh Kulkarni
2022-08-03 22:39 ` Jeff Law
2022-08-04 7:08 ` Richard Biener
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