* [PATCH] riscv:lib: optimize memcmp with ld insn
@ 2022-08-31 13:07 Yipeng Zou
2022-08-31 13:16 ` Conor.Dooley
0 siblings, 1 reply; 5+ messages in thread
From: Yipeng Zou @ 2022-08-31 13:07 UTC (permalink / raw)
To: linux-riscv, paul.walmsley, palmer, aou, Conor.Dooley
Cc: zouyipeng, liaochang1, chris.zjh
Currently memcmp was implemented in c code(lib/string.c), which compare
memory per byte.
This patch use ld insn compare memory per word to improve. From the test
Results, this will take several times optimized.
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
---
arch/riscv/include/asm/string.h | 3 ++
arch/riscv/lib/Makefile | 1 +
arch/riscv/lib/memcmp.S | 59 +++++++++++++++++++++++++++++++++
3 files changed, 63 insertions(+)
create mode 100644 arch/riscv/lib/memcmp.S
diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
index 909049366555..3337b43d3803 100644
--- a/arch/riscv/include/asm/string.h
+++ b/arch/riscv/include/asm/string.h
@@ -18,6 +18,9 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t);
#define __HAVE_ARCH_MEMMOVE
extern asmlinkage void *memmove(void *, const void *, size_t);
extern asmlinkage void *__memmove(void *, const void *, size_t);
+#define __HAVE_ARCH_MEMCMP
+extern int memcmp(const void *, const void *, size_t);
+
/* For those files which don't want to check by kasan. */
#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
#define memcpy(dst, src, len) __memcpy(dst, src, len)
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 25d5c9664e57..70773bf0c471 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -3,6 +3,7 @@ lib-y += delay.o
lib-y += memcpy.o
lib-y += memset.o
lib-y += memmove.o
+lib-y += memcmp.o
lib-$(CONFIG_MMU) += uaccess.o
lib-$(CONFIG_64BIT) += tishift.o
diff --git a/arch/riscv/lib/memcmp.S b/arch/riscv/lib/memcmp.S
new file mode 100644
index 000000000000..83af1c433e6f
--- /dev/null
+++ b/arch/riscv/lib/memcmp.S
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2022 zouyipeng@huawei.com
+ */
+#include <linux/linkage.h>
+#include <asm-generic/export.h>
+#include <asm/asm.h>
+
+/* argrments:
+* a0: addr0
+* a1: addr1
+* a2: size
+*/
+#define addr0 a0
+#define addr1 a1
+#define limit a2
+
+#define data0 a3
+#define data1 a4
+#define tmp t3
+#define aaddr t4
+#define return a0
+
+/* load and compare */
+.macro LD_CMP op d0 d1 a0 a1 offset
+ \op \d0, 0(\a0)
+ \op \d1, 0(\a1)
+ addi \a0, \a0, \offset
+ addi \a1, \a1, \offset
+ sub tmp, \d0, \d1
+.endm
+
+ENTRY(memcmp)
+ /* test limit aligend with SZREG */
+ andi tmp, limit, SZREG - 1
+ /* load tail */
+ add aaddr, addr0, limit
+ sub aaddr, aaddr, tmp
+ add limit, addr0, limit
+
+.LloopWord:
+ sltu tmp, addr0, aaddr
+ beqz tmp, .LloopByte
+
+ LD_CMP REG_L data0 data1 addr0 addr1 SZREG
+ beqz tmp, .LloopWord
+ j .Lreturn
+
+.LloopByte:
+ sltu tmp, addr0, limit
+ beqz tmp, .Lreturn
+
+ LD_CMP lbu data0 data1 addr0 addr1 1
+ beqz tmp, .LloopByte
+.Lreturn:
+ mv return, tmp
+ ret
+END(memcmp)
+EXPORT_SYMBOL(memcmp);
--
2.17.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] riscv:lib: optimize memcmp with ld insn
2022-08-31 13:07 [PATCH] riscv:lib: optimize memcmp with ld insn Yipeng Zou
@ 2022-08-31 13:16 ` Conor.Dooley
2022-09-01 13:53 ` Yipeng Zou
0 siblings, 1 reply; 5+ messages in thread
From: Conor.Dooley @ 2022-08-31 13:16 UTC (permalink / raw)
To: zouyipeng, linux-riscv, paul.walmsley, palmer, aou; +Cc: liaochang1, chris.zjh
On 31/08/2022 14:07, Yipeng Zou wrote:
> riscv:lib: optimize memcmp with ld insn
Minor nit: "riscv: lib:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Currently memcmp was implemented in c code(lib/string.c), which compare
> memory per byte.
>
> This patch use ld insn compare memory per word to improve. From the test
> Results, this will take several times optimized.
Hey Yipeng,
Could you share some more information about the tests you did?
The test results showing the % improvement would be nice :)
Thanks,
Conor.
>
> Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
> ---
> arch/riscv/include/asm/string.h | 3 ++
> arch/riscv/lib/Makefile | 1 +
> arch/riscv/lib/memcmp.S | 59 +++++++++++++++++++++++++++++++++
> 3 files changed, 63 insertions(+)
> create mode 100644 arch/riscv/lib/memcmp.S
>
> diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
> index 909049366555..3337b43d3803 100644
> --- a/arch/riscv/include/asm/string.h
> +++ b/arch/riscv/include/asm/string.h
> @@ -18,6 +18,9 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t);
> #define __HAVE_ARCH_MEMMOVE
> extern asmlinkage void *memmove(void *, const void *, size_t);
> extern asmlinkage void *__memmove(void *, const void *, size_t);
> +#define __HAVE_ARCH_MEMCMP
> +extern int memcmp(const void *, const void *, size_t);
> +
> /* For those files which don't want to check by kasan. */
> #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
> #define memcpy(dst, src, len) __memcpy(dst, src, len)
> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
> index 25d5c9664e57..70773bf0c471 100644
> --- a/arch/riscv/lib/Makefile
> +++ b/arch/riscv/lib/Makefile
> @@ -3,6 +3,7 @@ lib-y += delay.o
> lib-y += memcpy.o
> lib-y += memset.o
> lib-y += memmove.o
> +lib-y += memcmp.o
> lib-$(CONFIG_MMU) += uaccess.o
> lib-$(CONFIG_64BIT) += tishift.o
>
> diff --git a/arch/riscv/lib/memcmp.S b/arch/riscv/lib/memcmp.S
> new file mode 100644
> index 000000000000..83af1c433e6f
> --- /dev/null
> +++ b/arch/riscv/lib/memcmp.S
> @@ -0,0 +1,59 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2022 zouyipeng@huawei.com
> + */
> +#include <linux/linkage.h>
> +#include <asm-generic/export.h>
> +#include <asm/asm.h>
> +
> +/* argrments:
> +* a0: addr0
> +* a1: addr1
> +* a2: size
> +*/
> +#define addr0 a0
> +#define addr1 a1
> +#define limit a2
> +
> +#define data0 a3
> +#define data1 a4
> +#define tmp t3
> +#define aaddr t4
> +#define return a0
> +
> +/* load and compare */
> +.macro LD_CMP op d0 d1 a0 a1 offset
> + \op \d0, 0(\a0)
> + \op \d1, 0(\a1)
> + addi \a0, \a0, \offset
> + addi \a1, \a1, \offset
> + sub tmp, \d0, \d1
> +.endm
> +
> +ENTRY(memcmp)
> + /* test limit aligend with SZREG */
> + andi tmp, limit, SZREG - 1
> + /* load tail */
> + add aaddr, addr0, limit
> + sub aaddr, aaddr, tmp
> + add limit, addr0, limit
> +
> +.LloopWord:
> + sltu tmp, addr0, aaddr
> + beqz tmp, .LloopByte
> +
> + LD_CMP REG_L data0 data1 addr0 addr1 SZREG
> + beqz tmp, .LloopWord
> + j .Lreturn
> +
> +.LloopByte:
> + sltu tmp, addr0, limit
> + beqz tmp, .Lreturn
> +
> + LD_CMP lbu data0 data1 addr0 addr1 1
> + beqz tmp, .LloopByte
> +.Lreturn:
> + mv return, tmp
> + ret
> +END(memcmp)
> +EXPORT_SYMBOL(memcmp);
> --
> 2.17.1
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] riscv:lib: optimize memcmp with ld insn
2022-08-31 13:16 ` Conor.Dooley
@ 2022-09-01 13:53 ` Yipeng Zou
2022-09-01 15:40 ` Conor.Dooley
0 siblings, 1 reply; 5+ messages in thread
From: Yipeng Zou @ 2022-09-01 13:53 UTC (permalink / raw)
To: Conor.Dooley, linux-riscv, paul.walmsley, palmer, aou
Cc: liaochang1, chris.zjh
在 2022/8/31 21:16, Conor.Dooley@microchip.com 写道:
> On 31/08/2022 14:07, Yipeng Zou wrote:
>> riscv:lib: optimize memcmp with ld insn
> Minor nit: "riscv: lib:
ok
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> Currently memcmp was implemented in c code(lib/string.c), which compare
>> memory per byte.
>>
>> This patch use ld insn compare memory per word to improve. From the test
>> Results, this will take several times optimized.
> Hey Yipeng,
> Could you share some more information about the tests you did?
> The test results showing the % improvement would be nice :)
> Thanks,
> Conor.
Ofcourse, But My board was not ready, So i just test this patch on qemu
RV64 & RV32 .
Alloc 8,4,1KB buffer to compare, each loop 10k times.
Size(B)
8k
4k
1k
Min(ns)
40800
26500
15600
Min(ns)
16100
14200
12400
Size(B)
8k
4k
1k
AVG(ns)
46316
32302
17965
AVG(ns)
21281
16446
14316
>> Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
>> ---
>> arch/riscv/include/asm/string.h | 3 ++
>> arch/riscv/lib/Makefile | 1 +
>> arch/riscv/lib/memcmp.S | 59 +++++++++++++++++++++++++++++++++
>> 3 files changed, 63 insertions(+)
>> create mode 100644 arch/riscv/lib/memcmp.S
>>
>> diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
>> index 909049366555..3337b43d3803 100644
>> --- a/arch/riscv/include/asm/string.h
>> +++ b/arch/riscv/include/asm/string.h
>> @@ -18,6 +18,9 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t);
>> #define __HAVE_ARCH_MEMMOVE
>> extern asmlinkage void *memmove(void *, const void *, size_t);
>> extern asmlinkage void *__memmove(void *, const void *, size_t);
>> +#define __HAVE_ARCH_MEMCMP
>> +extern int memcmp(const void *, const void *, size_t);
>> +
>> /* For those files which don't want to check by kasan. */
>> #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>> #define memcpy(dst, src, len) __memcpy(dst, src, len)
>> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
>> index 25d5c9664e57..70773bf0c471 100644
>> --- a/arch/riscv/lib/Makefile
>> +++ b/arch/riscv/lib/Makefile
>> @@ -3,6 +3,7 @@ lib-y += delay.o
>> lib-y += memcpy.o
>> lib-y += memset.o
>> lib-y += memmove.o
>> +lib-y += memcmp.o
>> lib-$(CONFIG_MMU) += uaccess.o
>> lib-$(CONFIG_64BIT) += tishift.o
>>
>> diff --git a/arch/riscv/lib/memcmp.S b/arch/riscv/lib/memcmp.S
>> new file mode 100644
>> index 000000000000..83af1c433e6f
>> --- /dev/null
>> +++ b/arch/riscv/lib/memcmp.S
>> @@ -0,0 +1,59 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (C) 2022 zouyipeng@huawei.com
>> + */
>> +#include <linux/linkage.h>
>> +#include <asm-generic/export.h>
>> +#include <asm/asm.h>
>> +
>> +/* argrments:
>> +* a0: addr0
>> +* a1: addr1
>> +* a2: size
>> +*/
>> +#define addr0 a0
>> +#define addr1 a1
>> +#define limit a2
>> +
>> +#define data0 a3
>> +#define data1 a4
>> +#define tmp t3
>> +#define aaddr t4
>> +#define return a0
>> +
>> +/* load and compare */
>> +.macro LD_CMP op d0 d1 a0 a1 offset
>> + \op \d0, 0(\a0)
>> + \op \d1, 0(\a1)
>> + addi \a0, \a0, \offset
>> + addi \a1, \a1, \offset
>> + sub tmp, \d0, \d1
>> +.endm
>> +
>> +ENTRY(memcmp)
>> + /* test limit aligend with SZREG */
>> + andi tmp, limit, SZREG - 1
>> + /* load tail */
>> + add aaddr, addr0, limit
>> + sub aaddr, aaddr, tmp
>> + add limit, addr0, limit
>> +
>> +.LloopWord:
>> + sltu tmp, addr0, aaddr
>> + beqz tmp, .LloopByte
>> +
>> + LD_CMP REG_L data0 data1 addr0 addr1 SZREG
>> + beqz tmp, .LloopWord
>> + j .Lreturn
>> +
>> +.LloopByte:
>> + sltu tmp, addr0, limit
>> + beqz tmp, .Lreturn
>> +
>> + LD_CMP lbu data0 data1 addr0 addr1 1
>> + beqz tmp, .LloopByte
>> +.Lreturn:
>> + mv return, tmp
>> + ret
>> +END(memcmp)
>> +EXPORT_SYMBOL(memcmp);
>> --
>> 2.17.1
>>
--
Regards,
Yipeng Zou
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] riscv:lib: optimize memcmp with ld insn
2022-09-01 13:53 ` Yipeng Zou
@ 2022-09-01 15:40 ` Conor.Dooley
2022-09-02 10:32 ` Yipeng Zou
0 siblings, 1 reply; 5+ messages in thread
From: Conor.Dooley @ 2022-09-01 15:40 UTC (permalink / raw)
To: zouyipeng, linux-riscv, paul.walmsley, palmer, aou; +Cc: liaochang1, chris.zjh
On 01/09/2022 14:53, Yipeng Zou wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> 在 2022/8/31 21:16, Conor.Dooley@microchip.com 写道:
>> On 31/08/2022 14:07, Yipeng Zou wrote:
>>> riscv:lib: optimize memcmp with ld insn
>> Minor nit: "riscv: lib:
> ok
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>
>>> Currently memcmp was implemented in c code(lib/string.c), which compare
>>> memory per byte.
>>>
>>> This patch use ld insn compare memory per word to improve. From the test
>>> Results, this will take several times optimized.
>> Hey Yipeng,
>> Could you share some more information about the tests you did?
>> The test results showing the % improvement would be nice :)
>> Thanks,
>> Conor.
>
> Ofcourse, But My board was not ready, So i just test this patch on qemu
> RV64 & RV32 .
>
> Alloc 8,4,1KB buffer to compare, each loop 10k times.
I fixed that up since it was fairly unreadable..
Size(B) Min(ns) AVG(ns) //before
8k 40800 46316
4k 26500 32302
1k 15600 17965
Size(B) Min(ns) AVG(ns) //after
8k 16100 21281
4k 14200 16446
1k 12400 14316
I think putting this into the commit message would be nice.
I am no whizz on these kinds of things, but with the commit message
fixed up:
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
>>> Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
>>> ---
>>> arch/riscv/include/asm/string.h | 3 ++
>>> arch/riscv/lib/Makefile | 1 +
>>> arch/riscv/lib/memcmp.S | 59 +++++++++++++++++++++++++++++++++
>>> 3 files changed, 63 insertions(+)
>>> create mode 100644 arch/riscv/lib/memcmp.S
>>>
>>> diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
>>> index 909049366555..3337b43d3803 100644
>>> --- a/arch/riscv/include/asm/string.h
>>> +++ b/arch/riscv/include/asm/string.h
>>> @@ -18,6 +18,9 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t);
>>> #define __HAVE_ARCH_MEMMOVE
>>> extern asmlinkage void *memmove(void *, const void *, size_t);
>>> extern asmlinkage void *__memmove(void *, const void *, size_t);
>>> +#define __HAVE_ARCH_MEMCMP
>>> +extern int memcmp(const void *, const void *, size_t);
>>> +
>>> /* For those files which don't want to check by kasan. */
>>> #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>>> #define memcpy(dst, src, len) __memcpy(dst, src, len)
>>> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
>>> index 25d5c9664e57..70773bf0c471 100644
>>> --- a/arch/riscv/lib/Makefile
>>> +++ b/arch/riscv/lib/Makefile
>>> @@ -3,6 +3,7 @@ lib-y += delay.o
>>> lib-y += memcpy.o
>>> lib-y += memset.o
>>> lib-y += memmove.o
>>> +lib-y += memcmp.o
>>> lib-$(CONFIG_MMU) += uaccess.o
>>> lib-$(CONFIG_64BIT) += tishift.o
>>>
>>> diff --git a/arch/riscv/lib/memcmp.S b/arch/riscv/lib/memcmp.S
>>> new file mode 100644
>>> index 000000000000..83af1c433e6f
>>> --- /dev/null
>>> +++ b/arch/riscv/lib/memcmp.S
>>> @@ -0,0 +1,59 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2022 zouyipeng@huawei.com
>>> + */
>>> +#include <linux/linkage.h>
>>> +#include <asm-generic/export.h>
>>> +#include <asm/asm.h>
>>> +
>>> +/* argrments:
>>> +* a0: addr0
>>> +* a1: addr1
>>> +* a2: size
>>> +*/
>>> +#define addr0 a0
>>> +#define addr1 a1
>>> +#define limit a2
>>> +
>>> +#define data0 a3
>>> +#define data1 a4
>>> +#define tmp t3
>>> +#define aaddr t4
>>> +#define return a0
>>> +
>>> +/* load and compare */
>>> +.macro LD_CMP op d0 d1 a0 a1 offset
>>> + \op \d0, 0(\a0)
>>> + \op \d1, 0(\a1)
>>> + addi \a0, \a0, \offset
>>> + addi \a1, \a1, \offset
>>> + sub tmp, \d0, \d1
>>> +.endm
>>> +
>>> +ENTRY(memcmp)
>>> + /* test limit aligend with SZREG */
>>> + andi tmp, limit, SZREG - 1
>>> + /* load tail */
>>> + add aaddr, addr0, limit
>>> + sub aaddr, aaddr, tmp
>>> + add limit, addr0, limit
>>> +
>>> +.LloopWord:
>>> + sltu tmp, addr0, aaddr
>>> + beqz tmp, .LloopByte
>>> +
>>> + LD_CMP REG_L data0 data1 addr0 addr1 SZREG
>>> + beqz tmp, .LloopWord
>>> + j .Lreturn
>>> +
>>> +.LloopByte:
>>> + sltu tmp, addr0, limit
>>> + beqz tmp, .Lreturn
>>> +
>>> + LD_CMP lbu data0 data1 addr0 addr1 1
>>> + beqz tmp, .LloopByte
>>> +.Lreturn:
>>> + mv return, tmp
>>> + ret
>>> +END(memcmp)
>>> +EXPORT_SYMBOL(memcmp);
>>> --
>>> 2.17.1
>>>
> --
> Regards,
> Yipeng Zou
>
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] riscv:lib: optimize memcmp with ld insn
2022-09-01 15:40 ` Conor.Dooley
@ 2022-09-02 10:32 ` Yipeng Zou
0 siblings, 0 replies; 5+ messages in thread
From: Yipeng Zou @ 2022-09-02 10:32 UTC (permalink / raw)
To: Conor.Dooley, linux-riscv, paul.walmsley, palmer, aou
Cc: liaochang1, chris.zjh
在 2022/9/1 23:40, Conor.Dooley@microchip.com 写道:
> On 01/09/2022 14:53, Yipeng Zou wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> 在 2022/8/31 21:16, Conor.Dooley@microchip.com 写道:
>>> On 31/08/2022 14:07, Yipeng Zou wrote:
>>>> riscv:lib: optimize memcmp with ld insn
>>> Minor nit: "riscv: lib:
>> ok
>>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>>
>>>> Currently memcmp was implemented in c code(lib/string.c), which compare
>>>> memory per byte.
>>>>
>>>> This patch use ld insn compare memory per word to improve. From the test
>>>> Results, this will take several times optimized.
>>> Hey Yipeng,
>>> Could you share some more information about the tests you did?
>>> The test results showing the % improvement would be nice :)
>>> Thanks,
>>> Conor.
>> Ofcourse, But My board was not ready, So i just test this patch on qemu
>> RV64 & RV32 .
>>
>> Alloc 8,4,1KB buffer to compare, each loop 10k times.
> I fixed that up since it was fairly unreadable..
>
> Size(B) Min(ns) AVG(ns) //before
>
> 8k 40800 46316
> 4k 26500 32302
> 1k 15600 17965
>
> Size(B) Min(ns) AVG(ns) //after
>
> 8k 16100 21281
> 4k 14200 16446
> 1k 12400 14316
Sorry, the text format is broken and thank you very much for fix that up.
>
> I think putting this into the commit message would be nice.
>
> I am no whizz on these kinds of things, but with the commit message
> fixed up:
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Will putting this in v2 and thanks again.
>>>> Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
>>>> ---
>>>> arch/riscv/include/asm/string.h | 3 ++
>>>> arch/riscv/lib/Makefile | 1 +
>>>> arch/riscv/lib/memcmp.S | 59 +++++++++++++++++++++++++++++++++
>>>> 3 files changed, 63 insertions(+)
>>>> create mode 100644 arch/riscv/lib/memcmp.S
>>>>
>>>> diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
>>>> index 909049366555..3337b43d3803 100644
>>>> --- a/arch/riscv/include/asm/string.h
>>>> +++ b/arch/riscv/include/asm/string.h
>>>> @@ -18,6 +18,9 @@ extern asmlinkage void *__memcpy(void *, const void *, size_t);
>>>> #define __HAVE_ARCH_MEMMOVE
>>>> extern asmlinkage void *memmove(void *, const void *, size_t);
>>>> extern asmlinkage void *__memmove(void *, const void *, size_t);
>>>> +#define __HAVE_ARCH_MEMCMP
>>>> +extern int memcmp(const void *, const void *, size_t);
>>>> +
>>>> /* For those files which don't want to check by kasan. */
>>>> #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>>>> #define memcpy(dst, src, len) __memcpy(dst, src, len)
>>>> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
>>>> index 25d5c9664e57..70773bf0c471 100644
>>>> --- a/arch/riscv/lib/Makefile
>>>> +++ b/arch/riscv/lib/Makefile
>>>> @@ -3,6 +3,7 @@ lib-y += delay.o
>>>> lib-y += memcpy.o
>>>> lib-y += memset.o
>>>> lib-y += memmove.o
>>>> +lib-y += memcmp.o
>>>> lib-$(CONFIG_MMU) += uaccess.o
>>>> lib-$(CONFIG_64BIT) += tishift.o
>>>>
>>>> diff --git a/arch/riscv/lib/memcmp.S b/arch/riscv/lib/memcmp.S
>>>> new file mode 100644
>>>> index 000000000000..83af1c433e6f
>>>> --- /dev/null
>>>> +++ b/arch/riscv/lib/memcmp.S
>>>> @@ -0,0 +1,59 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>>> +/*
>>>> + * Copyright (C) 2022 zouyipeng@huawei.com
>>>> + */
>>>> +#include <linux/linkage.h>
>>>> +#include <asm-generic/export.h>
>>>> +#include <asm/asm.h>
>>>> +
>>>> +/* argrments:
>>>> +* a0: addr0
>>>> +* a1: addr1
>>>> +* a2: size
>>>> +*/
>>>> +#define addr0 a0
>>>> +#define addr1 a1
>>>> +#define limit a2
>>>> +
>>>> +#define data0 a3
>>>> +#define data1 a4
>>>> +#define tmp t3
>>>> +#define aaddr t4
>>>> +#define return a0
>>>> +
>>>> +/* load and compare */
>>>> +.macro LD_CMP op d0 d1 a0 a1 offset
>>>> + \op \d0, 0(\a0)
>>>> + \op \d1, 0(\a1)
>>>> + addi \a0, \a0, \offset
>>>> + addi \a1, \a1, \offset
>>>> + sub tmp, \d0, \d1
>>>> +.endm
>>>> +
>>>> +ENTRY(memcmp)
>>>> + /* test limit aligend with SZREG */
>>>> + andi tmp, limit, SZREG - 1
>>>> + /* load tail */
>>>> + add aaddr, addr0, limit
>>>> + sub aaddr, aaddr, tmp
>>>> + add limit, addr0, limit
>>>> +
>>>> +.LloopWord:
>>>> + sltu tmp, addr0, aaddr
>>>> + beqz tmp, .LloopByte
>>>> +
>>>> + LD_CMP REG_L data0 data1 addr0 addr1 SZREG
>>>> + beqz tmp, .LloopWord
>>>> + j .Lreturn
>>>> +
>>>> +.LloopByte:
>>>> + sltu tmp, addr0, limit
>>>> + beqz tmp, .Lreturn
>>>> +
>>>> + LD_CMP lbu data0 data1 addr0 addr1 1
>>>> + beqz tmp, .LloopByte
>>>> +.Lreturn:
>>>> + mv return, tmp
>>>> + ret
>>>> +END(memcmp)
>>>> +EXPORT_SYMBOL(memcmp);
>>>> --
>>>> 2.17.1
>>>>
>> --
>> Regards,
>> Yipeng Zou
>>
--
Regards,
Yipeng Zou
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-09-02 10:32 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-31 13:07 [PATCH] riscv:lib: optimize memcmp with ld insn Yipeng Zou
2022-08-31 13:16 ` Conor.Dooley
2022-09-01 13:53 ` Yipeng Zou
2022-09-01 15:40 ` Conor.Dooley
2022-09-02 10:32 ` Yipeng Zou
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