* [PATCH] MATCH: Move `(X & ~Y) | (~X & Y)` over to use bitwise_inverted_equal_p
@ 2023-08-25 16:21 Andrew Pinski
2023-08-28 7:04 ` Richard Biener
0 siblings, 1 reply; 2+ messages in thread
From: Andrew Pinski @ 2023-08-25 16:21 UTC (permalink / raw)
To: gcc-patches; +Cc: Andrew Pinski
This moves the pattern `(X & ~Y) | (~X & Y)` to use bitwise_inverted_equal_p
so we can simplify earlier the case where X and Y are defined by comparisons.
We were able to optimize to (!X)^(!Y) in the end due to the pattern added in
r14-3110-g7fb65f102851248bafa0815 and the older pattern r13-4620-g4d9db4bdd458 .
But folding it earlier is better.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
Note pr87009.c now gets `return x ^ s; in one case where the test had been expecting
`return s ^ x;` both are valid and would be expectly the same; just we now chose a slightly
different order of simplification which causes the order of the operands to be different.
gcc/ChangeLog:
* match.pd (`(X & ~Y) | (~X & Y)`): Use bitwise_inverted_equal_p
instead of specifically checking for ~X.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/cmpbit-3.c: New test.
* gcc.dg/pr87009.c: Update test.
---
gcc/match.pd | 13 +++++-----
gcc/testsuite/gcc.dg/pr87009.c | 2 +-
gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c | 33 ++++++++++++++++++++++++
3 files changed, 41 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 70884bd48eb..e41403664d0 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1228,12 +1228,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* Simplify (X & ~Y) |^+ (~X & Y) -> X ^ Y. */
(for op (bit_ior bit_xor plus)
(simplify
- (op (bit_and:c @0 (bit_not @1)) (bit_and:c (bit_not @0) @1))
- (bit_xor @0 @1))
- (simplify
- (op:c (bit_and @0 INTEGER_CST@2) (bit_and (bit_not @0) INTEGER_CST@1))
- (if (~wi::to_wide (@2) == wi::to_wide (@1))
- (bit_xor @0 @1))))
+ (op (bit_and:c @0 @2) (bit_and:c @3 @1))
+ (with { bool wascmp0, wascmp1; }
+ (if (bitwise_inverted_equal_p (@2, @1, wascmp0)
+ && bitwise_inverted_equal_p (@0, @3, wascmp1)
+ && ((!wascmp0 && !wascmp1)
+ || element_precision (type) == 1))
+ (bit_xor @0 @1)))))
/* PR53979: Transform ((a ^ b) | a) -> (a | b) */
(simplify
diff --git a/gcc/testsuite/gcc.dg/pr87009.c b/gcc/testsuite/gcc.dg/pr87009.c
index eb8a4ecd920..6f0341d17cc 100644
--- a/gcc/testsuite/gcc.dg/pr87009.c
+++ b/gcc/testsuite/gcc.dg/pr87009.c
@@ -1,6 +1,6 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-original" } */
-/* { dg-final { scan-tree-dump-times "return s \\^ x;" 4 "original" } } */
+/* { dg-final { scan-tree-dump-times "return s \\^ x;|return x \\^ s;" 4 "original" } } */
int f1 (int x, int s)
{
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c
new file mode 100644
index 00000000000..936c0934a10
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized-raw -fdump-tree-dse1-raw -fdump-tree-forwprop1" } */
+
+_Bool f(int a, int b)
+{
+ _Bool X = a==1, Y = b == 2;
+return (X & !Y) | (!X & Y);
+}
+
+
+_Bool f1(int a, int b)
+{
+ _Bool X = a==1, Y = b == 2;
+ _Bool c = (X & !Y);
+ _Bool d = (!X & Y);
+ return c | d;
+}
+
+/* Both of these should be optimized to (a==1) ^ (b==2) or (a != 1) ^ (b != 2) */
+/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */
+/* { dg-final { scan-tree-dump-not "gimple_phi " "optimized" } } */
+/* { dg-final { scan-tree-dump-times "ne_expr|eq_expr, " 4 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 2 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "gimple_assign " 6 "optimized" } } */
+
+/* Both of these should be optimized early in the pipeline after forwprop1 */
+/* { dg-final { scan-tree-dump-times "ne_expr|eq_expr, " 4 "forwprop1" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 2 "forwprop1" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "gimple_assign " 6 "forwprop1" { xfail *-*-* } } } */
+/* Note forwprop1 does not remove all unused statements sometimes so test dse1 also. */
+/* { dg-final { scan-tree-dump-times "ne_expr|eq_expr, " 4 "dse1" } } */
+/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 2 "dse1" } } */
+/* { dg-final { scan-tree-dump-times "gimple_assign " 6 "dse1" } } */
--
2.31.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] MATCH: Move `(X & ~Y) | (~X & Y)` over to use bitwise_inverted_equal_p
2023-08-25 16:21 [PATCH] MATCH: Move `(X & ~Y) | (~X & Y)` over to use bitwise_inverted_equal_p Andrew Pinski
@ 2023-08-28 7:04 ` Richard Biener
0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2023-08-28 7:04 UTC (permalink / raw)
To: Andrew Pinski; +Cc: gcc-patches
On Fri, Aug 25, 2023 at 6:22 PM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This moves the pattern `(X & ~Y) | (~X & Y)` to use bitwise_inverted_equal_p
> so we can simplify earlier the case where X and Y are defined by comparisons.
> We were able to optimize to (!X)^(!Y) in the end due to the pattern added in
> r14-3110-g7fb65f102851248bafa0815 and the older pattern r13-4620-g4d9db4bdd458 .
> But folding it earlier is better.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
OK.
> Note pr87009.c now gets `return x ^ s; in one case where the test had been expecting
> `return s ^ x;` both are valid and would be expectly the same; just we now chose a slightly
> different order of simplification which causes the order of the operands to be different.
>
> gcc/ChangeLog:
>
> * match.pd (`(X & ~Y) | (~X & Y)`): Use bitwise_inverted_equal_p
> instead of specifically checking for ~X.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/tree-ssa/cmpbit-3.c: New test.
> * gcc.dg/pr87009.c: Update test.
> ---
> gcc/match.pd | 13 +++++-----
> gcc/testsuite/gcc.dg/pr87009.c | 2 +-
> gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c | 33 ++++++++++++++++++++++++
> 3 files changed, 41 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 70884bd48eb..e41403664d0 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -1228,12 +1228,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> /* Simplify (X & ~Y) |^+ (~X & Y) -> X ^ Y. */
> (for op (bit_ior bit_xor plus)
> (simplify
> - (op (bit_and:c @0 (bit_not @1)) (bit_and:c (bit_not @0) @1))
> - (bit_xor @0 @1))
> - (simplify
> - (op:c (bit_and @0 INTEGER_CST@2) (bit_and (bit_not @0) INTEGER_CST@1))
> - (if (~wi::to_wide (@2) == wi::to_wide (@1))
> - (bit_xor @0 @1))))
> + (op (bit_and:c @0 @2) (bit_and:c @3 @1))
> + (with { bool wascmp0, wascmp1; }
> + (if (bitwise_inverted_equal_p (@2, @1, wascmp0)
> + && bitwise_inverted_equal_p (@0, @3, wascmp1)
> + && ((!wascmp0 && !wascmp1)
> + || element_precision (type) == 1))
> + (bit_xor @0 @1)))))
>
> /* PR53979: Transform ((a ^ b) | a) -> (a | b) */
> (simplify
> diff --git a/gcc/testsuite/gcc.dg/pr87009.c b/gcc/testsuite/gcc.dg/pr87009.c
> index eb8a4ecd920..6f0341d17cc 100644
> --- a/gcc/testsuite/gcc.dg/pr87009.c
> +++ b/gcc/testsuite/gcc.dg/pr87009.c
> @@ -1,6 +1,6 @@
> /* { dg-do compile } */
> /* { dg-options "-O -fdump-tree-original" } */
> -/* { dg-final { scan-tree-dump-times "return s \\^ x;" 4 "original" } } */
> +/* { dg-final { scan-tree-dump-times "return s \\^ x;|return x \\^ s;" 4 "original" } } */
>
> int f1 (int x, int s)
> {
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c
> new file mode 100644
> index 00000000000..936c0934a10
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-3.c
> @@ -0,0 +1,33 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized-raw -fdump-tree-dse1-raw -fdump-tree-forwprop1" } */
> +
> +_Bool f(int a, int b)
> +{
> + _Bool X = a==1, Y = b == 2;
> +return (X & !Y) | (!X & Y);
> +}
> +
> +
> +_Bool f1(int a, int b)
> +{
> + _Bool X = a==1, Y = b == 2;
> + _Bool c = (X & !Y);
> + _Bool d = (!X & Y);
> + return c | d;
> +}
> +
> +/* Both of these should be optimized to (a==1) ^ (b==2) or (a != 1) ^ (b != 2) */
> +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "gimple_phi " "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "ne_expr|eq_expr, " 4 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 2 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "gimple_assign " 6 "optimized" } } */
> +
> +/* Both of these should be optimized early in the pipeline after forwprop1 */
> +/* { dg-final { scan-tree-dump-times "ne_expr|eq_expr, " 4 "forwprop1" { xfail *-*-* } } } */
> +/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 2 "forwprop1" { xfail *-*-* } } } */
> +/* { dg-final { scan-tree-dump-times "gimple_assign " 6 "forwprop1" { xfail *-*-* } } } */
> +/* Note forwprop1 does not remove all unused statements sometimes so test dse1 also. */
> +/* { dg-final { scan-tree-dump-times "ne_expr|eq_expr, " 4 "dse1" } } */
> +/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 2 "dse1" } } */
> +/* { dg-final { scan-tree-dump-times "gimple_assign " 6 "dse1" } } */
> --
> 2.31.1
>
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2023-08-28 7:04 ` Richard Biener
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