* [PATCH v2] match.pd: rewrite select to branchless expression
@ 2022-11-11 2:28 Michael Collison
2022-11-11 7:44 ` Prathamesh Kulkarni
2022-11-18 12:57 ` Richard Biener
0 siblings, 2 replies; 7+ messages in thread
From: Michael Collison @ 2022-11-11 2:28 UTC (permalink / raw)
To: gcc-patches; +Cc: Richard Biener
This patches transforms ((x & 0x1) == 0) ? y : z <op> y -into
(-(typeof(y))(x & 0x1) & z) <op> y, where op is a '^' or a '|'. It also
transforms (cond (and (x , 0x1) != 0), (z op y), y ) into (-(and (x ,
0x1)) & z ) op y.
Matching this patterns allows GCC to generate branchless code for one of
the functions in coremark.
Bootstrapped and tested on x86 and RISC-V. Okay?
Michael.
2022-11-10 Michael Collison <collison@rivosinc.com>
* match.pd ((x & 0x1) == 0) ? y : z <op> y
-> (-(typeof(y))(x & 0x1) & z) <op> y.
2022-11-10 Michael Collison <collison@rivosinc.com>
* gcc.dg/tree-ssa/branchless-cond.c: New test.
---
Changes in v2:
- Rewrite comment to use C syntax
- Guard against 1-bit types
- Simplify pattern by using zero_one_valued_p
gcc/match.pd | 24 +++++++++++++++++
.../gcc.dg/tree-ssa/branchless-cond.c | 26 +++++++++++++++++++
2 files changed, 50 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 194ba8f5188..258531e9046 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3486,6 +3486,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1)
(max @2 @1))
+/* ((x & 0x1) == 0) ? y : z <op> y -> (-(typeof(y))(x & 0x1) & z) <op> y */
+(for op (bit_xor bit_ior)
+ (simplify
+ (cond (eq zero_one_valued_p@0
+ integer_zerop)
+ @1
+ (op:c @2 @1))
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_PRECISION (type) > 1
+ && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
+ (op (bit_and (negate (convert:type @0)) @2) @1))))
+
+/* ((x & 0x1) == 0) ? z <op> y : y -> (-(typeof(y))(x & 0x1) & z) <op> y */
+(for op (bit_xor bit_ior)
+ (simplify
+ (cond (ne zero_one_valued_p@0
+ integer_zerop)
+ (op:c @2 @1)
+ @1)
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_PRECISION (type) > 1
+ && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
+ (op (bit_and (negate (convert:type @0)) @2) @1))))
+
/* Simplifications of shift and rotates. */
(for rotate (lrotate rrotate)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
new file mode 100644
index 00000000000..68087ae6568
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+int f1(unsigned int x, unsigned int y, unsigned int z)
+{
+ return ((x & 1) == 0) ? y : z ^ y;
+}
+
+int f2(unsigned int x, unsigned int y, unsigned int z)
+{
+ return ((x & 1) != 0) ? z ^ y : y;
+}
+
+int f3(unsigned int x, unsigned int y, unsigned int z)
+{
+ return ((x & 1) == 0) ? y : z | y;
+}
+
+int f4(unsigned int x, unsigned int y, unsigned int z)
+{
+ return ((x & 1) != 0) ? z | y : y;
+}
+
+/* { dg-final { scan-tree-dump-times " -" 4 "optimized" } } */
+/* { dg-final { scan-tree-dump-times " & " 8 "optimized" } } */
+/* { dg-final { scan-tree-dump-not "if" "optimized" } } */
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] match.pd: rewrite select to branchless expression
2022-11-11 2:28 [PATCH v2] match.pd: rewrite select to branchless expression Michael Collison
@ 2022-11-11 7:44 ` Prathamesh Kulkarni
2022-11-11 13:00 ` Michael Collison
2022-11-18 12:57 ` Richard Biener
1 sibling, 1 reply; 7+ messages in thread
From: Prathamesh Kulkarni @ 2022-11-11 7:44 UTC (permalink / raw)
To: Michael Collison; +Cc: gcc-patches, Richard Biener
On Fri, 11 Nov 2022 at 07:58, Michael Collison <collison@rivosinc.com> wrote:
>
> This patches transforms ((x & 0x1) == 0) ? y : z <op> y -into
> (-(typeof(y))(x & 0x1) & z) <op> y, where op is a '^' or a '|'. It also
> transforms (cond (and (x , 0x1) != 0), (z op y), y ) into (-(and (x ,
> 0x1)) & z ) op y.
>
> Matching this patterns allows GCC to generate branchless code for one of
> the functions in coremark.
>
> Bootstrapped and tested on x86 and RISC-V. Okay?
>
> Michael.
>
> 2022-11-10 Michael Collison <collison@rivosinc.com>
>
> * match.pd ((x & 0x1) == 0) ? y : z <op> y
> -> (-(typeof(y))(x & 0x1) & z) <op> y.
>
> 2022-11-10 Michael Collison <collison@rivosinc.com>
>
> * gcc.dg/tree-ssa/branchless-cond.c: New test.
>
> ---
>
> Changes in v2:
>
> - Rewrite comment to use C syntax
>
> - Guard against 1-bit types
>
> - Simplify pattern by using zero_one_valued_p
>
> gcc/match.pd | 24 +++++++++++++++++
> .../gcc.dg/tree-ssa/branchless-cond.c | 26 +++++++++++++++++++
> 2 files changed, 50 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 194ba8f5188..258531e9046 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3486,6 +3486,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1)
> (max @2 @1))
>
> +/* ((x & 0x1) == 0) ? y : z <op> y -> (-(typeof(y))(x & 0x1) & z) <op> y */
> +(for op (bit_xor bit_ior)
> + (simplify
> + (cond (eq zero_one_valued_p@0
> + integer_zerop)
> + @1
> + (op:c @2 @1))
> + (if (INTEGRAL_TYPE_P (type)
> + && TYPE_PRECISION (type) > 1
> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
> + (op (bit_and (negate (convert:type @0)) @2) @1))))
> +
> +/* ((x & 0x1) == 0) ? z <op> y : y -> (-(typeof(y))(x & 0x1) & z) <op> y */
> +(for op (bit_xor bit_ior)
> + (simplify
> + (cond (ne zero_one_valued_p@0
> + integer_zerop)
> + (op:c @2 @1)
> + @1)
> + (if (INTEGRAL_TYPE_P (type)
> + && TYPE_PRECISION (type) > 1
> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
> + (op (bit_and (negate (convert:type @0)) @2) @1))))
> +
> /* Simplifications of shift and rotates. */
>
> (for rotate (lrotate rrotate)
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> new file mode 100644
> index 00000000000..68087ae6568
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +int f1(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) == 0) ? y : z ^ y;
> +}
> +
> +int f2(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) != 0) ? z ^ y : y;
> +}
> +
> +int f3(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) == 0) ? y : z | y;
> +}
> +
> +int f4(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) != 0) ? z | y : y;
> +}
Sorry to nitpick -- Since the pattern gates on INTEGRAL_TYPE_P, would
it be a good idea
to have these tests for other integral types too besides int like
{char, short, long} ?
Thanks,
Prathamesh
> +
> +/* { dg-final { scan-tree-dump-times " -" 4 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times " & " 8 "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] match.pd: rewrite select to branchless expression
2022-11-11 7:44 ` Prathamesh Kulkarni
@ 2022-11-11 13:00 ` Michael Collison
2022-11-17 14:34 ` Jeff Law
0 siblings, 1 reply; 7+ messages in thread
From: Michael Collison @ 2022-11-11 13:00 UTC (permalink / raw)
To: Prathamesh Kulkarni; +Cc: gcc-patches, Richard Biener
Hi Prathamesh,
It is my understanding that INTEGRAL_TYPE_P applies to the other integer
types you mentioned (chart, short, long). In fact the test function that
motivated this match has a mixture of char and short and does not
restrict matching.
On 11/11/22 02:44, Prathamesh Kulkarni wrote:
> On Fri, 11 Nov 2022 at 07:58, Michael Collison <collison@rivosinc.com> wrote:
>> This patches transforms ((x & 0x1) == 0) ? y : z <op> y -into
>> (-(typeof(y))(x & 0x1) & z) <op> y, where op is a '^' or a '|'. It also
>> transforms (cond (and (x , 0x1) != 0), (z op y), y ) into (-(and (x ,
>> 0x1)) & z ) op y.
>>
>> Matching this patterns allows GCC to generate branchless code for one of
>> the functions in coremark.
>>
>> Bootstrapped and tested on x86 and RISC-V. Okay?
>>
>> Michael.
>>
>> 2022-11-10 Michael Collison <collison@rivosinc.com>
>>
>> * match.pd ((x & 0x1) == 0) ? y : z <op> y
>> -> (-(typeof(y))(x & 0x1) & z) <op> y.
>>
>> 2022-11-10 Michael Collison <collison@rivosinc.com>
>>
>> * gcc.dg/tree-ssa/branchless-cond.c: New test.
>>
>> ---
>>
>> Changes in v2:
>>
>> - Rewrite comment to use C syntax
>>
>> - Guard against 1-bit types
>>
>> - Simplify pattern by using zero_one_valued_p
>>
>> gcc/match.pd | 24 +++++++++++++++++
>> .../gcc.dg/tree-ssa/branchless-cond.c | 26 +++++++++++++++++++
>> 2 files changed, 50 insertions(+)
>> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>>
>> diff --git a/gcc/match.pd b/gcc/match.pd
>> index 194ba8f5188..258531e9046 100644
>> --- a/gcc/match.pd
>> +++ b/gcc/match.pd
>> @@ -3486,6 +3486,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>> (cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1)
>> (max @2 @1))
>>
>> +/* ((x & 0x1) == 0) ? y : z <op> y -> (-(typeof(y))(x & 0x1) & z) <op> y */
>> +(for op (bit_xor bit_ior)
>> + (simplify
>> + (cond (eq zero_one_valued_p@0
>> + integer_zerop)
>> + @1
>> + (op:c @2 @1))
>> + (if (INTEGRAL_TYPE_P (type)
>> + && TYPE_PRECISION (type) > 1
>> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
>> + (op (bit_and (negate (convert:type @0)) @2) @1))))
>> +
>> +/* ((x & 0x1) == 0) ? z <op> y : y -> (-(typeof(y))(x & 0x1) & z) <op> y */
>> +(for op (bit_xor bit_ior)
>> + (simplify
>> + (cond (ne zero_one_valued_p@0
>> + integer_zerop)
>> + (op:c @2 @1)
>> + @1)
>> + (if (INTEGRAL_TYPE_P (type)
>> + && TYPE_PRECISION (type) > 1
>> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
>> + (op (bit_and (negate (convert:type @0)) @2) @1))))
>> +
>> /* Simplifications of shift and rotates. */
>>
>> (for rotate (lrotate rrotate)
>> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>> new file mode 100644
>> index 00000000000..68087ae6568
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>> @@ -0,0 +1,26 @@
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2 -fdump-tree-optimized" } */
>> +
>> +int f1(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) == 0) ? y : z ^ y;
>> +}
>> +
>> +int f2(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) != 0) ? z ^ y : y;
>> +}
>> +
>> +int f3(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) == 0) ? y : z | y;
>> +}
>> +
>> +int f4(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) != 0) ? z | y : y;
>> +}
> Sorry to nitpick -- Since the pattern gates on INTEGRAL_TYPE_P, would
> it be a good idea
> to have these tests for other integral types too besides int like
> {char, short, long} ?
>
> Thanks,
> Prathamesh
>> +
>> +/* { dg-final { scan-tree-dump-times " -" 4 "optimized" } } */
>> +/* { dg-final { scan-tree-dump-times " & " 8 "optimized" } } */
>> +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */
>> --
>> 2.34.1
>>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] match.pd: rewrite select to branchless expression
2022-11-11 13:00 ` Michael Collison
@ 2022-11-17 14:34 ` Jeff Law
0 siblings, 0 replies; 7+ messages in thread
From: Jeff Law @ 2022-11-17 14:34 UTC (permalink / raw)
To: Michael Collison, Prathamesh Kulkarni; +Cc: gcc-patches, Richard Biener
On 11/11/22 06:00, Michael Collison wrote:
> Hi Prathamesh,
>
> It is my understanding that INTEGRAL_TYPE_P applies to the other
> integer types you mentioned (chart, short, long). In fact the test
> function that motivated this match has a mixture of char and short and
> does not restrict matching.
What I think Prathamesh is asking is whether or not we want to have
tests with different types. It's less about correctness I think and
more about ensuring that the testsuite covers those tests in case they
regress in the future.
jeff
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] match.pd: rewrite select to branchless expression
2022-11-11 2:28 [PATCH v2] match.pd: rewrite select to branchless expression Michael Collison
2022-11-11 7:44 ` Prathamesh Kulkarni
@ 2022-11-18 12:57 ` Richard Biener
2022-12-01 18:57 ` Michael Collison
1 sibling, 1 reply; 7+ messages in thread
From: Richard Biener @ 2022-11-18 12:57 UTC (permalink / raw)
To: Michael Collison; +Cc: gcc-patches
On Fri, Nov 11, 2022 at 3:28 AM Michael Collison <collison@rivosinc.com> wrote:
>
> This patches transforms ((x & 0x1) == 0) ? y : z <op> y -into
> (-(typeof(y))(x & 0x1) & z) <op> y, where op is a '^' or a '|'. It also
> transforms (cond (and (x , 0x1) != 0), (z op y), y ) into (-(and (x ,
> 0x1)) & z ) op y.
>
> Matching this patterns allows GCC to generate branchless code for one of
> the functions in coremark.
>
> Bootstrapped and tested on x86 and RISC-V. Okay?
OK.
Thanks,
Richard.
> Michael.
>
> 2022-11-10 Michael Collison <collison@rivosinc.com>
>
> * match.pd ((x & 0x1) == 0) ? y : z <op> y
> -> (-(typeof(y))(x & 0x1) & z) <op> y.
>
> 2022-11-10 Michael Collison <collison@rivosinc.com>
>
> * gcc.dg/tree-ssa/branchless-cond.c: New test.
>
> ---
>
> Changes in v2:
>
> - Rewrite comment to use C syntax
>
> - Guard against 1-bit types
>
> - Simplify pattern by using zero_one_valued_p
>
> gcc/match.pd | 24 +++++++++++++++++
> .../gcc.dg/tree-ssa/branchless-cond.c | 26 +++++++++++++++++++
> 2 files changed, 50 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 194ba8f5188..258531e9046 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3486,6 +3486,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1)
> (max @2 @1))
>
> +/* ((x & 0x1) == 0) ? y : z <op> y -> (-(typeof(y))(x & 0x1) & z) <op> y */
> +(for op (bit_xor bit_ior)
> + (simplify
> + (cond (eq zero_one_valued_p@0
> + integer_zerop)
> + @1
> + (op:c @2 @1))
> + (if (INTEGRAL_TYPE_P (type)
> + && TYPE_PRECISION (type) > 1
> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
> + (op (bit_and (negate (convert:type @0)) @2) @1))))
> +
> +/* ((x & 0x1) == 0) ? z <op> y : y -> (-(typeof(y))(x & 0x1) & z) <op> y */
> +(for op (bit_xor bit_ior)
> + (simplify
> + (cond (ne zero_one_valued_p@0
> + integer_zerop)
> + (op:c @2 @1)
> + @1)
> + (if (INTEGRAL_TYPE_P (type)
> + && TYPE_PRECISION (type) > 1
> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
> + (op (bit_and (negate (convert:type @0)) @2) @1))))
> +
> /* Simplifications of shift and rotates. */
>
> (for rotate (lrotate rrotate)
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> new file mode 100644
> index 00000000000..68087ae6568
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +int f1(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) == 0) ? y : z ^ y;
> +}
> +
> +int f2(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) != 0) ? z ^ y : y;
> +}
> +
> +int f3(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) == 0) ? y : z | y;
> +}
> +
> +int f4(unsigned int x, unsigned int y, unsigned int z)
> +{
> + return ((x & 1) != 0) ? z | y : y;
> +}
> +
> +/* { dg-final { scan-tree-dump-times " -" 4 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times " & " 8 "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] match.pd: rewrite select to branchless expression
2022-11-18 12:57 ` Richard Biener
@ 2022-12-01 18:57 ` Michael Collison
2022-12-02 8:22 ` Richard Biener
0 siblings, 1 reply; 7+ messages in thread
From: Michael Collison @ 2022-12-01 18:57 UTC (permalink / raw)
To: Richard Biener; +Cc: gcc-patches
Richard,
Can you submit this patch for me while I sort out git write access?
On 11/18/22 07:57, Richard Biener wrote:
> On Fri, Nov 11, 2022 at 3:28 AM Michael Collison <collison@rivosinc.com> wrote:
>> This patches transforms ((x & 0x1) == 0) ? y : z <op> y -into
>> (-(typeof(y))(x & 0x1) & z) <op> y, where op is a '^' or a '|'. It also
>> transforms (cond (and (x , 0x1) != 0), (z op y), y ) into (-(and (x ,
>> 0x1)) & z ) op y.
>>
>> Matching this patterns allows GCC to generate branchless code for one of
>> the functions in coremark.
>>
>> Bootstrapped and tested on x86 and RISC-V. Okay?
> OK.
>
> Thanks,
> Richard.
>
>> Michael.
>>
>> 2022-11-10 Michael Collison <collison@rivosinc.com>
>>
>> * match.pd ((x & 0x1) == 0) ? y : z <op> y
>> -> (-(typeof(y))(x & 0x1) & z) <op> y.
>>
>> 2022-11-10 Michael Collison <collison@rivosinc.com>
>>
>> * gcc.dg/tree-ssa/branchless-cond.c: New test.
>>
>> ---
>>
>> Changes in v2:
>>
>> - Rewrite comment to use C syntax
>>
>> - Guard against 1-bit types
>>
>> - Simplify pattern by using zero_one_valued_p
>>
>> gcc/match.pd | 24 +++++++++++++++++
>> .../gcc.dg/tree-ssa/branchless-cond.c | 26 +++++++++++++++++++
>> 2 files changed, 50 insertions(+)
>> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>>
>> diff --git a/gcc/match.pd b/gcc/match.pd
>> index 194ba8f5188..258531e9046 100644
>> --- a/gcc/match.pd
>> +++ b/gcc/match.pd
>> @@ -3486,6 +3486,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>> (cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1)
>> (max @2 @1))
>>
>> +/* ((x & 0x1) == 0) ? y : z <op> y -> (-(typeof(y))(x & 0x1) & z) <op> y */
>> +(for op (bit_xor bit_ior)
>> + (simplify
>> + (cond (eq zero_one_valued_p@0
>> + integer_zerop)
>> + @1
>> + (op:c @2 @1))
>> + (if (INTEGRAL_TYPE_P (type)
>> + && TYPE_PRECISION (type) > 1
>> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
>> + (op (bit_and (negate (convert:type @0)) @2) @1))))
>> +
>> +/* ((x & 0x1) == 0) ? z <op> y : y -> (-(typeof(y))(x & 0x1) & z) <op> y */
>> +(for op (bit_xor bit_ior)
>> + (simplify
>> + (cond (ne zero_one_valued_p@0
>> + integer_zerop)
>> + (op:c @2 @1)
>> + @1)
>> + (if (INTEGRAL_TYPE_P (type)
>> + && TYPE_PRECISION (type) > 1
>> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
>> + (op (bit_and (negate (convert:type @0)) @2) @1))))
>> +
>> /* Simplifications of shift and rotates. */
>>
>> (for rotate (lrotate rrotate)
>> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>> new file mode 100644
>> index 00000000000..68087ae6568
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
>> @@ -0,0 +1,26 @@
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2 -fdump-tree-optimized" } */
>> +
>> +int f1(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) == 0) ? y : z ^ y;
>> +}
>> +
>> +int f2(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) != 0) ? z ^ y : y;
>> +}
>> +
>> +int f3(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) == 0) ? y : z | y;
>> +}
>> +
>> +int f4(unsigned int x, unsigned int y, unsigned int z)
>> +{
>> + return ((x & 1) != 0) ? z | y : y;
>> +}
>> +
>> +/* { dg-final { scan-tree-dump-times " -" 4 "optimized" } } */
>> +/* { dg-final { scan-tree-dump-times " & " 8 "optimized" } } */
>> +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */
>> --
>> 2.34.1
>>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] match.pd: rewrite select to branchless expression
2022-12-01 18:57 ` Michael Collison
@ 2022-12-02 8:22 ` Richard Biener
0 siblings, 0 replies; 7+ messages in thread
From: Richard Biener @ 2022-12-02 8:22 UTC (permalink / raw)
To: Michael Collison; +Cc: gcc-patches
On Thu, Dec 1, 2022 at 7:57 PM Michael Collison <collison@rivosinc.com> wrote:
>
> Richard,
>
> Can you submit this patch for me while I sort out git write access?
Done. I had to apply the patch manually - in future please make sure
to send patches that can be applied with git am.
Thanks,
Richard.
> On 11/18/22 07:57, Richard Biener wrote:
> > On Fri, Nov 11, 2022 at 3:28 AM Michael Collison <collison@rivosinc.com> wrote:
> >> This patches transforms ((x & 0x1) == 0) ? y : z <op> y -into
> >> (-(typeof(y))(x & 0x1) & z) <op> y, where op is a '^' or a '|'. It also
> >> transforms (cond (and (x , 0x1) != 0), (z op y), y ) into (-(and (x ,
> >> 0x1)) & z ) op y.
> >>
> >> Matching this patterns allows GCC to generate branchless code for one of
> >> the functions in coremark.
> >>
> >> Bootstrapped and tested on x86 and RISC-V. Okay?
> > OK.
> >
> > Thanks,
> > Richard.
> >
> >> Michael.
> >>
> >> 2022-11-10 Michael Collison <collison@rivosinc.com>
> >>
> >> * match.pd ((x & 0x1) == 0) ? y : z <op> y
> >> -> (-(typeof(y))(x & 0x1) & z) <op> y.
> >>
> >> 2022-11-10 Michael Collison <collison@rivosinc.com>
> >>
> >> * gcc.dg/tree-ssa/branchless-cond.c: New test.
> >>
> >> ---
> >>
> >> Changes in v2:
> >>
> >> - Rewrite comment to use C syntax
> >>
> >> - Guard against 1-bit types
> >>
> >> - Simplify pattern by using zero_one_valued_p
> >>
> >> gcc/match.pd | 24 +++++++++++++++++
> >> .../gcc.dg/tree-ssa/branchless-cond.c | 26 +++++++++++++++++++
> >> 2 files changed, 50 insertions(+)
> >> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> >>
> >> diff --git a/gcc/match.pd b/gcc/match.pd
> >> index 194ba8f5188..258531e9046 100644
> >> --- a/gcc/match.pd
> >> +++ b/gcc/match.pd
> >> @@ -3486,6 +3486,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> >> (cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1)
> >> (max @2 @1))
> >>
> >> +/* ((x & 0x1) == 0) ? y : z <op> y -> (-(typeof(y))(x & 0x1) & z) <op> y */
> >> +(for op (bit_xor bit_ior)
> >> + (simplify
> >> + (cond (eq zero_one_valued_p@0
> >> + integer_zerop)
> >> + @1
> >> + (op:c @2 @1))
> >> + (if (INTEGRAL_TYPE_P (type)
> >> + && TYPE_PRECISION (type) > 1
> >> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
> >> + (op (bit_and (negate (convert:type @0)) @2) @1))))
> >> +
> >> +/* ((x & 0x1) == 0) ? z <op> y : y -> (-(typeof(y))(x & 0x1) & z) <op> y */
> >> +(for op (bit_xor bit_ior)
> >> + (simplify
> >> + (cond (ne zero_one_valued_p@0
> >> + integer_zerop)
> >> + (op:c @2 @1)
> >> + @1)
> >> + (if (INTEGRAL_TYPE_P (type)
> >> + && TYPE_PRECISION (type) > 1
> >> + && (INTEGRAL_TYPE_P (TREE_TYPE (@0))))
> >> + (op (bit_and (negate (convert:type @0)) @2) @1))))
> >> +
> >> /* Simplifications of shift and rotates. */
> >>
> >> (for rotate (lrotate rrotate)
> >> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> >> new file mode 100644
> >> index 00000000000..68087ae6568
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.dg/tree-ssa/branchless-cond.c
> >> @@ -0,0 +1,26 @@
> >> +/* { dg-do compile } */
> >> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> >> +
> >> +int f1(unsigned int x, unsigned int y, unsigned int z)
> >> +{
> >> + return ((x & 1) == 0) ? y : z ^ y;
> >> +}
> >> +
> >> +int f2(unsigned int x, unsigned int y, unsigned int z)
> >> +{
> >> + return ((x & 1) != 0) ? z ^ y : y;
> >> +}
> >> +
> >> +int f3(unsigned int x, unsigned int y, unsigned int z)
> >> +{
> >> + return ((x & 1) == 0) ? y : z | y;
> >> +}
> >> +
> >> +int f4(unsigned int x, unsigned int y, unsigned int z)
> >> +{
> >> + return ((x & 1) != 0) ? z | y : y;
> >> +}
> >> +
> >> +/* { dg-final { scan-tree-dump-times " -" 4 "optimized" } } */
> >> +/* { dg-final { scan-tree-dump-times " & " 8 "optimized" } } */
> >> +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */
> >> --
> >> 2.34.1
> >>
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-12-02 8:23 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-11 2:28 [PATCH v2] match.pd: rewrite select to branchless expression Michael Collison
2022-11-11 7:44 ` Prathamesh Kulkarni
2022-11-11 13:00 ` Michael Collison
2022-11-17 14:34 ` Jeff Law
2022-11-18 12:57 ` Richard Biener
2022-12-01 18:57 ` Michael Collison
2022-12-02 8:22 ` Richard Biener
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