[PATCH] aarch64: Add +lse128 architectural extension command-line flag

[PATCH] aarch64: Add +lse128 architectural extension command-line flag

[Victor Do Nascimento]

Given how, at present, the choice of using LSE128 atomic instructions
by the toolchain is delegated to run-time selection in the form of
Libatomic ifuncs, responsible for querying target support, the
`+lse128' target architecture compile-time flag is absent from GCC.

This, however, contrasts with the Binutils implementation, which gates
LSE128 instructions behind the `+lse128' flag.  This can lead to
problems in GCC for certain use-cases.  One such example is in the use
of inline assembly, whereby the inability of enabling the feature in
the command-line prevents the compiler from automatically issuing the
necessary LSE128 `.arch' directive.

This patch therefore brings GCC into alignment with LLVM and Binutils
in adding support for the `+lse128' architectural extension flag.

gcc/ChangeLog:

	* config/aarch64/aarch64-option-extensions.def: Add LSE128
	AARCH64_OPT_EXTENSION, adding it as a dependency for the D128
	feature.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/lse128-flag.c: New.
	* gcc.target/aarch64/cpunative/info_23: Likewise.
	* gcc.target/aarch64/cpunative/native_cpu_23.c: Likewise.
---
 gcc/config/aarch64/aarch64-option-extensions.def      |  4 +++-
 gcc/testsuite/gcc.target/aarch64/cpunative/info_23    |  8 ++++++++
 .../gcc.target/aarch64/cpunative/native_cpu_23.c      | 11 +++++++++++
 gcc/testsuite/gcc.target/aarch64/lse128-flag.c        | 10 ++++++++++
 4 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/info_23
 create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/lse128-flag.c

diff --git a/gcc/config/aarch64/aarch64-option-extensions.def b/gcc/config/aarch64/aarch64-option-extensions.def
index 1a3b91c68cf..ac54b899a06 100644
--- a/gcc/config/aarch64/aarch64-option-extensions.def
+++ b/gcc/config/aarch64/aarch64-option-extensions.def
@@ -275,7 +275,9 @@ AARCH64_OPT_EXTENSION("mops", MOPS, (), (), (), "")
 
 AARCH64_OPT_EXTENSION("cssc", CSSC, (), (), (), "cssc")
 
-AARCH64_OPT_EXTENSION("d128", D128, (), (), (), "d128")
+AARCH64_OPT_EXTENSION("lse128", LSE128, (LSE), (), (), "lse128")
+
+AARCH64_OPT_EXTENSION("d128", D128, (LSE128), (), (), "d128")
 
 AARCH64_OPT_EXTENSION("the", THE, (), (), (), "the")
 
diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/info_23 b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
new file mode 100644
index 00000000000..d77c25d2f61
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
@@ -0,0 +1,8 @@
+processor	: 0
+BogoMIPS	: 100.00
+Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 asimddp atomics lse128
+CPU implementer	: 0xfe
+CPU architecture: 8
+CPU variant	: 0x0
+CPU part	: 0xd08
+CPU revision	: 2
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
new file mode 100644
index 00000000000..8a1e235d8ab
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
@@ -0,0 +1,11 @@
+/* { dg-do compile { target { { aarch64*-*-linux*} && native } } } */
+/* { dg-set-compiler-env-var GCC_CPUINFO "$srcdir/gcc.target/aarch64/cpunative/info_23" } */
+/* { dg-additional-options "-mcpu=native" } */
+
+int main()
+{
+  return 0;
+}
+
+/* { dg-final { scan-assembler {\.arch armv8-a\+dotprod\+crc\+crypto\+lse128} } } */
+/* Test one where lse128 is available and so should be emitted.  */
diff --git a/gcc/testsuite/gcc.target/aarch64/lse128-flag.c b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
new file mode 100644
index 00000000000..71339c3af6d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target { aarch64*-*-*} } } */
+/* { dg-additional-options "-march=armv9.4-a+lse128" } */
+
+int main()
+{
+  return 0;
+}
+
+/* { dg-final { scan-assembler {\.arch armv9\.4-a\+crc\+lse128} } } */
+/* Test a normal looking procinfo.  */
-- 
2.34.1

Re: [PATCH] aarch64: Add +lse128 architectural extension command-line flag

[Christophe Lyon]

On Fri, 15 Mar 2024 at 12:15, Victor Do Nascimento
<victor.donascimento@arm.com> wrote:
>
> Given how, at present, the choice of using LSE128 atomic instructions
> by the toolchain is delegated to run-time selection in the form of
> Libatomic ifuncs, responsible for querying target support, the
> `+lse128' target architecture compile-time flag is absent from GCC.
>
> This, however, contrasts with the Binutils implementation, which gates
> LSE128 instructions behind the `+lse128' flag.  This can lead to
> problems in GCC for certain use-cases.  One such example is in the use
> of inline assembly, whereby the inability of enabling the feature in
> the command-line prevents the compiler from automatically issuing the
> necessary LSE128 `.arch' directive.
>
> This patch therefore brings GCC into alignment with LLVM and Binutils
> in adding support for the `+lse128' architectural extension flag.
>
> gcc/ChangeLog:
>
>         * config/aarch64/aarch64-option-extensions.def: Add LSE128
>         AARCH64_OPT_EXTENSION, adding it as a dependency for the D128
>         feature.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/aarch64/lse128-flag.c: New.
>         * gcc.target/aarch64/cpunative/info_23: Likewise.
>         * gcc.target/aarch64/cpunative/native_cpu_23.c: Likewise.
> ---
>  gcc/config/aarch64/aarch64-option-extensions.def      |  4 +++-
>  gcc/testsuite/gcc.target/aarch64/cpunative/info_23    |  8 ++++++++
>  .../gcc.target/aarch64/cpunative/native_cpu_23.c      | 11 +++++++++++
>  gcc/testsuite/gcc.target/aarch64/lse128-flag.c        | 10 ++++++++++
>  4 files changed, 32 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/info_23
>  create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
>  create mode 100644 gcc/testsuite/gcc.target/aarch64/lse128-flag.c
>
> diff --git a/gcc/config/aarch64/aarch64-option-extensions.def b/gcc/config/aarch64/aarch64-option-extensions.def
> index 1a3b91c68cf..ac54b899a06 100644
> --- a/gcc/config/aarch64/aarch64-option-extensions.def
> +++ b/gcc/config/aarch64/aarch64-option-extensions.def
> @@ -275,7 +275,9 @@ AARCH64_OPT_EXTENSION("mops", MOPS, (), (), (), "")
>
>  AARCH64_OPT_EXTENSION("cssc", CSSC, (), (), (), "cssc")
>
> -AARCH64_OPT_EXTENSION("d128", D128, (), (), (), "d128")
> +AARCH64_OPT_EXTENSION("lse128", LSE128, (LSE), (), (), "lse128")
> +
> +AARCH64_OPT_EXTENSION("d128", D128, (LSE128), (), (), "d128")
>
FWIW, looks good to me, I noticed that now we'll also have the
dependency of d128 on lse128, although d128 didn't have the (implicit)
dependency on lse before.

Christophe

>  AARCH64_OPT_EXTENSION("the", THE, (), (), (), "the")
>
> diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/info_23 b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
> new file mode 100644
> index 00000000000..d77c25d2f61
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
> @@ -0,0 +1,8 @@
> +processor      : 0
> +BogoMIPS       : 100.00
> +Features       : fp asimd evtstrm aes pmull sha1 sha2 crc32 asimddp atomics lse128
> +CPU implementer        : 0xfe
> +CPU architecture: 8
> +CPU variant    : 0x0
> +CPU part       : 0xd08
> +CPU revision   : 2
> \ No newline at end of file
> diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
> new file mode 100644
> index 00000000000..8a1e235d8ab
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { { aarch64*-*-linux*} && native } } } */
> +/* { dg-set-compiler-env-var GCC_CPUINFO "$srcdir/gcc.target/aarch64/cpunative/info_23" } */
> +/* { dg-additional-options "-mcpu=native" } */
> +
> +int main()
> +{
> +  return 0;
> +}
> +
> +/* { dg-final { scan-assembler {\.arch armv8-a\+dotprod\+crc\+crypto\+lse128} } } */
> +/* Test one where lse128 is available and so should be emitted.  */
> diff --git a/gcc/testsuite/gcc.target/aarch64/lse128-flag.c b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
> new file mode 100644
> index 00000000000..71339c3af6d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile { target { aarch64*-*-*} } } */
> +/* { dg-additional-options "-march=armv9.4-a+lse128" } */
> +
> +int main()
> +{
> +  return 0;
> +}
> +
> +/* { dg-final { scan-assembler {\.arch armv9\.4-a\+crc\+lse128} } } */
> +/* Test a normal looking procinfo.  */
> --
> 2.34.1
>

Re: [PATCH] aarch64: Add +lse128 architectural extension command-line flag

[Richard Sandiford]

Victor Do Nascimento <victor.donascimento@arm.com> writes:
> Given how, at present, the choice of using LSE128 atomic instructions
> by the toolchain is delegated to run-time selection in the form of
> Libatomic ifuncs, responsible for querying target support, the
> `+lse128' target architecture compile-time flag is absent from GCC.
>
> This, however, contrasts with the Binutils implementation, which gates
> LSE128 instructions behind the `+lse128' flag.  This can lead to
> problems in GCC for certain use-cases.  One such example is in the use
> of inline assembly, whereby the inability of enabling the feature in
> the command-line prevents the compiler from automatically issuing the
> necessary LSE128 `.arch' directive.
>
> This patch therefore brings GCC into alignment with LLVM and Binutils
> in adding support for the `+lse128' architectural extension flag.
>
> gcc/ChangeLog:
>
> 	* config/aarch64/aarch64-option-extensions.def: Add LSE128
> 	AARCH64_OPT_EXTENSION, adding it as a dependency for the D128
> 	feature.
>
> gcc/testsuite/ChangeLog:
>
> 	* gcc.target/aarch64/lse128-flag.c: New.
> 	* gcc.target/aarch64/cpunative/info_23: Likewise.
> 	* gcc.target/aarch64/cpunative/native_cpu_23.c: Likewise.

The new extension should be documented in doc/invoke.texi.

> ---
>  gcc/config/aarch64/aarch64-option-extensions.def      |  4 +++-
>  gcc/testsuite/gcc.target/aarch64/cpunative/info_23    |  8 ++++++++
>  .../gcc.target/aarch64/cpunative/native_cpu_23.c      | 11 +++++++++++
>  gcc/testsuite/gcc.target/aarch64/lse128-flag.c        | 10 ++++++++++
>  4 files changed, 32 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/info_23
>  create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
>  create mode 100644 gcc/testsuite/gcc.target/aarch64/lse128-flag.c
>
> diff --git a/gcc/config/aarch64/aarch64-option-extensions.def b/gcc/config/aarch64/aarch64-option-extensions.def
> index 1a3b91c68cf..ac54b899a06 100644
> --- a/gcc/config/aarch64/aarch64-option-extensions.def
> +++ b/gcc/config/aarch64/aarch64-option-extensions.def
> @@ -275,7 +275,9 @@ AARCH64_OPT_EXTENSION("mops", MOPS, (), (), (), "")
>  
>  AARCH64_OPT_EXTENSION("cssc", CSSC, (), (), (), "cssc")
>  
> -AARCH64_OPT_EXTENSION("d128", D128, (), (), (), "d128")
> +AARCH64_OPT_EXTENSION("lse128", LSE128, (LSE), (), (), "lse128")
> +
> +AARCH64_OPT_EXTENSION("d128", D128, (LSE128), (), (), "d128")
>  
>  AARCH64_OPT_EXTENSION("the", THE, (), (), (), "the")
>  
> diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/info_23 b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
> new file mode 100644
> index 00000000000..d77c25d2f61
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
> @@ -0,0 +1,8 @@
> +processor	: 0
> +BogoMIPS	: 100.00
> +Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 asimddp atomics lse128
> +CPU implementer	: 0xfe
> +CPU architecture: 8
> +CPU variant	: 0x0
> +CPU part	: 0xd08
> +CPU revision	: 2
> \ No newline at end of file
> diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
> new file mode 100644
> index 00000000000..8a1e235d8ab
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { { aarch64*-*-linux*} && native } } } */
> +/* { dg-set-compiler-env-var GCC_CPUINFO "$srcdir/gcc.target/aarch64/cpunative/info_23" } */
> +/* { dg-additional-options "-mcpu=native" } */
> +
> +int main()
> +{
> +  return 0;
> +}
> +
> +/* { dg-final { scan-assembler {\.arch armv8-a\+dotprod\+crc\+crypto\+lse128} } } */
> +/* Test one where lse128 is available and so should be emitted.  */
> diff --git a/gcc/testsuite/gcc.target/aarch64/lse128-flag.c b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
> new file mode 100644
> index 00000000000..71339c3af6d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile { target { aarch64*-*-*} } } */
> +/* { dg-additional-options "-march=armv9.4-a+lse128" } */
> +
> +int main()
> +{
> +  return 0;
> +}
> +
> +/* { dg-final { scan-assembler {\.arch armv9\.4-a\+crc\+lse128} } } */
> +/* Test a normal looking procinfo.  */

Not sure I understand the comment.  Is procinfo part of this test?

Looks good otherwise.

Thanks,
Richard

Re: [PATCH] aarch64: Add +lse128 architectural extension command-line flag

[Victor Do Nascimento]

On 3/26/24 12:26, Richard Sandiford wrote:
> Victor Do Nascimento <victor.donascimento@arm.com> writes:
>> Given how, at present, the choice of using LSE128 atomic instructions
>> by the toolchain is delegated to run-time selection in the form of
>> Libatomic ifuncs, responsible for querying target support, the
>> `+lse128' target architecture compile-time flag is absent from GCC.
>>
>> This, however, contrasts with the Binutils implementation, which gates
>> LSE128 instructions behind the `+lse128' flag.  This can lead to
>> problems in GCC for certain use-cases.  One such example is in the use
>> of inline assembly, whereby the inability of enabling the feature in
>> the command-line prevents the compiler from automatically issuing the
>> necessary LSE128 `.arch' directive.
>>
>> This patch therefore brings GCC into alignment with LLVM and Binutils
>> in adding support for the `+lse128' architectural extension flag.
>>
>> gcc/ChangeLog:
>>
>> 	* config/aarch64/aarch64-option-extensions.def: Add LSE128
>> 	AARCH64_OPT_EXTENSION, adding it as a dependency for the D128
>> 	feature.
>>
>> gcc/testsuite/ChangeLog:
>>
>> 	* gcc.target/aarch64/lse128-flag.c: New.
>> 	* gcc.target/aarch64/cpunative/info_23: Likewise.
>> 	* gcc.target/aarch64/cpunative/native_cpu_23.c: Likewise.
> 
> The new extension should be documented in doc/invoke.texi.
> 
>> ---
>>   gcc/config/aarch64/aarch64-option-extensions.def      |  4 +++-
>>   gcc/testsuite/gcc.target/aarch64/cpunative/info_23    |  8 ++++++++
>>   .../gcc.target/aarch64/cpunative/native_cpu_23.c      | 11 +++++++++++
>>   gcc/testsuite/gcc.target/aarch64/lse128-flag.c        | 10 ++++++++++
>>   4 files changed, 32 insertions(+), 1 deletion(-)
>>   create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/info_23
>>   create mode 100644 gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
>>   create mode 100644 gcc/testsuite/gcc.target/aarch64/lse128-flag.c
>>
>> diff --git a/gcc/config/aarch64/aarch64-option-extensions.def b/gcc/config/aarch64/aarch64-option-extensions.def
>> index 1a3b91c68cf..ac54b899a06 100644
>> --- a/gcc/config/aarch64/aarch64-option-extensions.def
>> +++ b/gcc/config/aarch64/aarch64-option-extensions.def
>> @@ -275,7 +275,9 @@ AARCH64_OPT_EXTENSION("mops", MOPS, (), (), (), "")
>>   
>>   AARCH64_OPT_EXTENSION("cssc", CSSC, (), (), (), "cssc")
>>   
>> -AARCH64_OPT_EXTENSION("d128", D128, (), (), (), "d128")
>> +AARCH64_OPT_EXTENSION("lse128", LSE128, (LSE), (), (), "lse128")
>> +
>> +AARCH64_OPT_EXTENSION("d128", D128, (LSE128), (), (), "d128")
>>   
>>   AARCH64_OPT_EXTENSION("the", THE, (), (), (), "the")
>>   
>> diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/info_23 b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
>> new file mode 100644
>> index 00000000000..d77c25d2f61
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/aarch64/cpunative/info_23
>> @@ -0,0 +1,8 @@
>> +processor	: 0
>> +BogoMIPS	: 100.00
>> +Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 asimddp atomics lse128
>> +CPU implementer	: 0xfe
>> +CPU architecture: 8
>> +CPU variant	: 0x0
>> +CPU part	: 0xd08
>> +CPU revision	: 2
>> \ No newline at end of file
>> diff --git a/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
>> new file mode 100644
>> index 00000000000..8a1e235d8ab
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/aarch64/cpunative/native_cpu_23.c
>> @@ -0,0 +1,11 @@
>> +/* { dg-do compile { target { { aarch64*-*-linux*} && native } } } */
>> +/* { dg-set-compiler-env-var GCC_CPUINFO "$srcdir/gcc.target/aarch64/cpunative/info_23" } */
>> +/* { dg-additional-options "-mcpu=native" } */
>> +
>> +int main()
>> +{
>> +  return 0;
>> +}
>> +
>> +/* { dg-final { scan-assembler {\.arch armv8-a\+dotprod\+crc\+crypto\+lse128} } } */
>> +/* Test one where lse128 is available and so should be emitted.  */
>> diff --git a/gcc/testsuite/gcc.target/aarch64/lse128-flag.c b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
>> new file mode 100644
>> index 00000000000..71339c3af6d
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/aarch64/lse128-flag.c
>> @@ -0,0 +1,10 @@
>> +/* { dg-do compile { target { aarch64*-*-*} } } */
>> +/* { dg-additional-options "-march=armv9.4-a+lse128" } */
>> +
>> +int main()
>> +{
>> +  return 0;
>> +}
>> +
>> +/* { dg-final { scan-assembler {\.arch armv9\.4-a\+crc\+lse128} } } */
>> +/* Test a normal looking procinfo.  */
> 
> Not sure I understand the comment.  Is procinfo part of this test?

Thank you for catching this, Richard.  This was originally a 
procinfo-reliant test which ended up being redesigned without reference 
to procinfo and this remained.  I've now dropped it from the patch.

Cheers!

> Looks good otherwise.
> 
> Thanks,
> Richard

Re: [PATCH] aarch64: Add +lse128 architectural extension command-line flag

[Andreas Schwab]

On Mär 15 2024, Victor Do Nascimento wrote:

> \ No newline at end of file

Please fix that.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."