diff mbox series

bpf: Forces __buildin_memcmp not to generate a call upto 1024 bytes.

Message ID 20231113223723.11760-1-cupertino.miranda@oracle.com
State New
Headers show
Series bpf: Forces __buildin_memcmp not to generate a call upto 1024 bytes. | expand

Commit Message

Cupertino Miranda Nov. 13, 2023, 10:37 p.m. UTC 
This patch forces __builtin_memcmp calls upto data sizes of 1024 to
become inline in caller.
This is a requirement by BPF and it mimics the default behaviour of the
clang BPF implementation.

gcc/ChangeLog:
	* config/bpf/bpf.cc (bpf_use_by_pieces_infrastructure_p): Added
	function to bypass default behaviour.
	* config/bpf/bpf.h (COMPARE_MAX_PIECES): Defined to 1024 bytes.
---
 gcc/config/bpf/bpf.cc | 16 ++++++++++++++++
 gcc/config/bpf/bpf.h  |  5 +++++
 2 files changed, 21 insertions(+)

Comments

Jose E. Marchesi Nov. 24, 2023, 4:54 p.m. UTC | #1 
Hi Cuper.

Sorry, I missed this patch last week.
This is OK.

Thanks!

> This patch forces __builtin_memcmp calls upto data sizes of 1024 to
> become inline in caller.
> This is a requirement by BPF and it mimics the default behaviour of the
> clang BPF implementation.
>
> gcc/ChangeLog:
> 	* config/bpf/bpf.cc (bpf_use_by_pieces_infrastructure_p): Added
> 	function to bypass default behaviour.
> 	* config/bpf/bpf.h (COMPARE_MAX_PIECES): Defined to 1024 bytes.
> ---
>  gcc/config/bpf/bpf.cc | 16 ++++++++++++++++
>  gcc/config/bpf/bpf.h  |  5 +++++
>  2 files changed, 21 insertions(+)
>
> diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
> index a0956a069729..764a3e487cb6 100644
> --- a/gcc/config/bpf/bpf.cc
> +++ b/gcc/config/bpf/bpf.cc
> @@ -1115,6 +1115,22 @@ bpf_small_register_classes_for_mode_p (machine_mode mode)
>  #define TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P \
>    bpf_small_register_classes_for_mode_p
>  
> +static bool
> +bpf_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
> +				    unsigned int align ATTRIBUTE_UNUSED,
> +				    enum by_pieces_operation op,
> +				    bool speed_p)
> +{
> +  if (op != COMPARE_BY_PIECES)
> +    return default_use_by_pieces_infrastructure_p (size, align, op, speed_p);
> +
> +  return size <= COMPARE_MAX_PIECES;
> +}
> +
> +#undef TARGET_USE_BY_PIECES_INFRASTRUCTURE_P
> +#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
> +  bpf_use_by_pieces_infrastructure_p
> +
>  /* Finally, build the GCC target.  */
>  
>  struct gcc_target targetm = TARGET_INITIALIZER;
> diff --git a/gcc/config/bpf/bpf.h b/gcc/config/bpf/bpf.h
> index 82702aa7b6ba..1f177ec4c4ef 100644
> --- a/gcc/config/bpf/bpf.h
> +++ b/gcc/config/bpf/bpf.h
> @@ -489,6 +489,11 @@ enum reg_class
>     locations.  */
>  #define MOVE_MAX 8
>  
> +/* Allow upto 1024 bytes moves to occur using by_pieces
> +   infrastructure.  This mimics clang behaviour when using
> +   __builtin_memcmp.  */
> +#define COMPARE_MAX_PIECES 1024
> +
>  /* An alias for the machine mode for pointers.  */
>  #define Pmode DImode
Cupertino Miranda Nov. 28, 2023, 12:46 p.m. UTC | #2 
Thanks! Committed !

Jose E. Marchesi writes:

> Hi Cuper.
>
> Sorry, I missed this patch last week.
> This is OK.
>
> Thanks!
>
>> This patch forces __builtin_memcmp calls upto data sizes of 1024 to
>> become inline in caller.
>> This is a requirement by BPF and it mimics the default behaviour of the
>> clang BPF implementation.
>>
>> gcc/ChangeLog:
>> 	* config/bpf/bpf.cc (bpf_use_by_pieces_infrastructure_p): Added
>> 	function to bypass default behaviour.
>> 	* config/bpf/bpf.h (COMPARE_MAX_PIECES): Defined to 1024 bytes.
>> ---
>>  gcc/config/bpf/bpf.cc | 16 ++++++++++++++++
>>  gcc/config/bpf/bpf.h  |  5 +++++
>>  2 files changed, 21 insertions(+)
>>
>> diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
>> index a0956a069729..764a3e487cb6 100644
>> --- a/gcc/config/bpf/bpf.cc
>> +++ b/gcc/config/bpf/bpf.cc
>> @@ -1115,6 +1115,22 @@ bpf_small_register_classes_for_mode_p (machine_mode mode)
>>  #define TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P \
>>    bpf_small_register_classes_for_mode_p
>>
>> +static bool
>> +bpf_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
>> +				    unsigned int align ATTRIBUTE_UNUSED,
>> +				    enum by_pieces_operation op,
>> +				    bool speed_p)
>> +{
>> +  if (op != COMPARE_BY_PIECES)
>> +    return default_use_by_pieces_infrastructure_p (size, align, op, speed_p);
>> +
>> +  return size <= COMPARE_MAX_PIECES;
>> +}
>> +
>> +#undef TARGET_USE_BY_PIECES_INFRASTRUCTURE_P
>> +#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
>> +  bpf_use_by_pieces_infrastructure_p
>> +
>>  /* Finally, build the GCC target.  */
>>
>>  struct gcc_target targetm = TARGET_INITIALIZER;
>> diff --git a/gcc/config/bpf/bpf.h b/gcc/config/bpf/bpf.h
>> index 82702aa7b6ba..1f177ec4c4ef 100644
>> --- a/gcc/config/bpf/bpf.h
>> +++ b/gcc/config/bpf/bpf.h
>> @@ -489,6 +489,11 @@ enum reg_class
>>     locations.  */
>>  #define MOVE_MAX 8
>>
>> +/* Allow upto 1024 bytes moves to occur using by_pieces
>> +   infrastructure.  This mimics clang behaviour when using
>> +   __builtin_memcmp.  */
>> +#define COMPARE_MAX_PIECES 1024
>> +
>>  /* An alias for the machine mode for pointers.  */
>>  #define Pmode DImode
Cupertino Miranda Nov. 28, 2023, 12:54 p.m. UTC | #3 
Thanks! Committed!

Jose E. Marchesi writes:

> Hi Cuper.
>
> Sorry, I missed this patch last week.
> This is OK.
>
> Thanks!
>
>> This patch forces __builtin_memcmp calls upto data sizes of 1024 to
>> become inline in caller.
>> This is a requirement by BPF and it mimics the default behaviour of the
>> clang BPF implementation.
>>
>> gcc/ChangeLog:
>> 	* config/bpf/bpf.cc (bpf_use_by_pieces_infrastructure_p): Added
>> 	function to bypass default behaviour.
>> 	* config/bpf/bpf.h (COMPARE_MAX_PIECES): Defined to 1024 bytes.
>> ---
>>  gcc/config/bpf/bpf.cc | 16 ++++++++++++++++
>>  gcc/config/bpf/bpf.h  |  5 +++++
>>  2 files changed, 21 insertions(+)
>>
>> diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
>> index a0956a069729..764a3e487cb6 100644
>> --- a/gcc/config/bpf/bpf.cc
>> +++ b/gcc/config/bpf/bpf.cc
>> @@ -1115,6 +1115,22 @@ bpf_small_register_classes_for_mode_p (machine_mode mode)
>>  #define TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P \
>>    bpf_small_register_classes_for_mode_p
>>
>> +static bool
>> +bpf_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
>> +				    unsigned int align ATTRIBUTE_UNUSED,
>> +				    enum by_pieces_operation op,
>> +				    bool speed_p)
>> +{
>> +  if (op != COMPARE_BY_PIECES)
>> +    return default_use_by_pieces_infrastructure_p (size, align, op, speed_p);
>> +
>> +  return size <= COMPARE_MAX_PIECES;
>> +}
>> +
>> +#undef TARGET_USE_BY_PIECES_INFRASTRUCTURE_P
>> +#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
>> +  bpf_use_by_pieces_infrastructure_p
>> +
>>  /* Finally, build the GCC target.  */
>>
>>  struct gcc_target targetm = TARGET_INITIALIZER;
>> diff --git a/gcc/config/bpf/bpf.h b/gcc/config/bpf/bpf.h
>> index 82702aa7b6ba..1f177ec4c4ef 100644
>> --- a/gcc/config/bpf/bpf.h
>> +++ b/gcc/config/bpf/bpf.h
>> @@ -489,6 +489,11 @@ enum reg_class
>>     locations.  */
>>  #define MOVE_MAX 8
>>
>> +/* Allow upto 1024 bytes moves to occur using by_pieces
>> +   infrastructure.  This mimics clang behaviour when using
>> +   __builtin_memcmp.  */
>> +#define COMPARE_MAX_PIECES 1024
>> +
>>  /* An alias for the machine mode for pointers.  */
>>  #define Pmode DImode
diff mbox series

Patch

diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
index a0956a069729..764a3e487cb6 100644
--- a/gcc/config/bpf/bpf.cc
+++ b/gcc/config/bpf/bpf.cc
@@ -1115,6 +1115,22 @@  bpf_small_register_classes_for_mode_p (machine_mode mode)
 #define TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P \
   bpf_small_register_classes_for_mode_p
 
+static bool
+bpf_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
+				    unsigned int align ATTRIBUTE_UNUSED,
+				    enum by_pieces_operation op,
+				    bool speed_p)
+{
+  if (op != COMPARE_BY_PIECES)
+    return default_use_by_pieces_infrastructure_p (size, align, op, speed_p);
+
+  return size <= COMPARE_MAX_PIECES;
+}
+
+#undef TARGET_USE_BY_PIECES_INFRASTRUCTURE_P
+#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
+  bpf_use_by_pieces_infrastructure_p
+
 /* Finally, build the GCC target.  */
 
 struct gcc_target targetm = TARGET_INITIALIZER;
diff --git a/gcc/config/bpf/bpf.h b/gcc/config/bpf/bpf.h
index 82702aa7b6ba..1f177ec4c4ef 100644
--- a/gcc/config/bpf/bpf.h
+++ b/gcc/config/bpf/bpf.h
@@ -489,6 +489,11 @@  enum reg_class
    locations.  */
 #define MOVE_MAX 8
 
+/* Allow upto 1024 bytes moves to occur using by_pieces
+   infrastructure.  This mimics clang behaviour when using
+   __builtin_memcmp.  */
+#define COMPARE_MAX_PIECES 1024
+
 /* An alias for the machine mode for pointers.  */
 #define Pmode DImode