powerpc: Add multiarch sqrtf128 for ppc64le

Message ID 1526532912-1716-1-git-send-email-raji@linux.vnet.ibm.com
State New
Headers show
Series
  • powerpc: Add multiarch sqrtf128 for ppc64le
Related show

Commit Message

Rajalakshmi Srinivasaraghavan May 17, 2018, 4:55 a.m.
This patch creates ifunc for sqrtf128() to make use of new xssqrtqp
instruction for POWER9 when --enable-multi-arch and --with-cpu=power8
options are used on power9 system.  This is achieved by explicitly
adding -mcpu=power9 flag for sqrtf128-power9.

2018-05-17  Rajalakshmi Srinivasaraghavan  <raji@linux.vnet.ibm.com>

	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile: New file to
	add w_sqrtf128-power9 and w_sqrtf128-ppc64le to libm-sysdep_routines.
	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c:
	New file.
	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c: Likewise.
	* sysdeps/powerpc/powerpc64/le/power9/fpu/e_sqrtf128.c: Remove file
	as __ieee754_sqrtf128() for power9 is present already in
	sysdeps/powerpc/fpu/math_private.h.
---
 .../powerpc/powerpc64/le/fpu/multiarch/Makefile    |  6 ++++
 .../multiarch/w_sqrtf128-power9.c}                 | 21 ++++++------
 .../le/fpu/multiarch/w_sqrtf128-ppc64le.c          | 37 ++++++++++++++++++++++
 .../powerpc64/le/fpu/multiarch/w_sqrtf128.c        | 31 ++++++++++++++++++
 4 files changed, 85 insertions(+), 10 deletions(-)
 create mode 100644 sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile
 rename sysdeps/powerpc/powerpc64/le/{power9/fpu/e_sqrtf128.c => fpu/multiarch/w_sqrtf128-power9.c} (81%)
 create mode 100644 sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c
 create mode 100644 sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c

Comments

Gabriel F. T. Gomes May 29, 2018, 3:37 p.m. | #1
On Thu, 17 May 2018, Rajalakshmi Srinivasaraghavan wrote:

>This patch creates ifunc for sqrtf128() to make use of new xssqrtqp
>instruction for POWER9 when --enable-multi-arch and --with-cpu=power8
>options are used on power9 system.  This is achieved by explicitly
>adding -mcpu=power9 flag for sqrtf128-power9.
>
>2018-05-17  Rajalakshmi Srinivasaraghavan  <raji@linux.vnet.ibm.com>
>
>	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile: New file to
>	add w_sqrtf128-power9 and w_sqrtf128-ppc64le to libm-sysdep_routines.
>	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c:
>	New file.
>	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c:
>	Likewise.
>	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c: Likewise.

This part looks good to me.

>	* sysdeps/powerpc/powerpc64/le/power9/fpu/e_sqrtf128.c: Remove file
>	as __ieee754_sqrtf128() for power9 is present already in
>	sysdeps/powerpc/fpu/math_private.h.

This doesn't.

The function provided by e_sqrtf128.c (__sqrtf128_finite) is export by
GLIBC and accessible by users when they are building their code with
-ffast-math.  When building glibc with --with-cpu=power8, removing this
file would be OK.  However, when building glibc with --with-cpu=power9,
__sqrtf128_finite will use software emulation when it could use xssqrtqp.
Since math_private.h is not installed, it will not work for glibc users.

You patch is OK without this removal.

>+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c
> (...)
>+#include <math-type-macros-float128.h>
> (...)
>+#undef __USE_WRAPPER_TEMPLATE
>+#define __USE_WRAPPER_TEMPLATE 1

Do you actually need this?  What behaviour are you trying to override?
The float128 implementation always uses the wrapper templates.

>+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c
> (...)
>+#include <math-type-macros-float128.h>
> (...)
>+#undef __USE_WRAPPER_TEMPLATE
>+#define __USE_WRAPPER_TEMPLATE 1

Likewise.

>+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c
> (...)
>+libc_ifunc (__sqrtf128,
>+	    (hwcap2 & PPC_FEATURE2_ARCH_3_00)
>+	    ? __sqrtf128_power9
>+	    : __sqrtf128_ppc64le);
>+declare_mgen_alias (__sqrt, sqrt)

OK.
Rajalakshmi Srinivasaraghavan May 30, 2018, 4:05 p.m. | #2
On 05/29/2018 09:07 PM, Gabriel F. T. Gomes wrote:
> On Thu, 17 May 2018, Rajalakshmi Srinivasaraghavan wrote:
> 
>> This patch creates ifunc for sqrtf128() to make use of new xssqrtqp
>> instruction for POWER9 when --enable-multi-arch and --with-cpu=power8
>> options are used on power9 system.  This is achieved by explicitly
>> adding -mcpu=power9 flag for sqrtf128-power9.
>>
>> 2018-05-17  Rajalakshmi Srinivasaraghavan  <raji@linux.vnet.ibm.com>
>>
>> 	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile: New file to
>> 	add w_sqrtf128-power9 and w_sqrtf128-ppc64le to libm-sysdep_routines.
>> 	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c:
>> 	New file.
>> 	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c:
>> 	Likewise.
>> 	* sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c: Likewise.
> 
> This part looks good to me.

Thanks for the review.

> 
>> 	* sysdeps/powerpc/powerpc64/le/power9/fpu/e_sqrtf128.c: Remove file
>> 	as __ieee754_sqrtf128() for power9 is present already in
>> 	sysdeps/powerpc/fpu/math_private.h.
> 
> This doesn't.
> 
> The function provided by e_sqrtf128.c (__sqrtf128_finite) is export by
> GLIBC and accessible by users when they are building their code with
> -ffast-math.  When building glibc with --with-cpu=power8, removing this
> file would be OK.  However, when building glibc with --with-cpu=power9,
> __sqrtf128_finite will use software emulation when it could use xssqrtqp.
> Since math_private.h is not installed, it will not work for glibc users.
> 
> You patch is OK without this removal.

Good catch. Ack.

> 
>> +++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c
>> (...)
>> +#include <math-type-macros-float128.h>
>> (...)
>> +#undef __USE_WRAPPER_TEMPLATE
>> +#define __USE_WRAPPER_TEMPLATE 1
> 
> Do you actually need this?  What behaviour are you trying to override?
> The float128 implementation always uses the wrapper templates.

Yes. This is not needed.

> 
>> +++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c
>> (...)
>> +#include <math-type-macros-float128.h>
>> (...)
>> +#undef __USE_WRAPPER_TEMPLATE
>> +#define __USE_WRAPPER_TEMPLATE 1
> 
> Likewise.
> 
>> +++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c
>> (...)
>> +libc_ifunc (__sqrtf128,
>> +	    (hwcap2 & PPC_FEATURE2_ARCH_3_00)
>> +	    ? __sqrtf128_power9
>> +	    : __sqrtf128_ppc64le);
>> +declare_mgen_alias (__sqrt, sqrt)
> 
> OK.

Pushed as 2c93fce76a8e672abfdf7771c97be9ea49b7222b.

> 
>

Patch

diff --git a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile
new file mode 100644
index 0000000000..a32f3d8b81
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/Makefile
@@ -0,0 +1,6 @@ 
+ifeq ($(subdir),math)
+libm-sysdep_routines += w_sqrtf128-power9 w_sqrtf128-ppc64le
+
+CFLAGS-w_sqrtf128-ppc64le.c += -mfloat128
+CFLAGS-w_sqrtf128-power9.c += -mfloat128 -mcpu=power9
+endif
diff --git a/sysdeps/powerpc/powerpc64/le/power9/fpu/e_sqrtf128.c b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c
similarity index 81%
rename from sysdeps/powerpc/powerpc64/le/power9/fpu/e_sqrtf128.c
rename to sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c
index 76ab451dbb..0629060754 100644
--- a/sysdeps/powerpc/powerpc64/le/power9/fpu/e_sqrtf128.c
+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-power9.c
@@ -1,6 +1,5 @@ 
 /* POWER9 sqrt for _Float128
-   Return sqrt(a)
-   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   Copyright (C) 2018 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -26,11 +25,13 @@ 
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-__float128
-__ieee754_sqrtf128 (__float128 a)
-{
-  __float128 z;
-  asm ("xssqrtqp %0,%1" : "=v" (z) : "v" (a));
-  return z;
-}
-strong_alias (__ieee754_sqrtf128, __sqrtf128_finite)
+#include <math-type-macros-float128.h>
+
+#define __sqrtf128 __sqrtf128_power9
+
+#undef __USE_WRAPPER_TEMPLATE
+#define __USE_WRAPPER_TEMPLATE 1
+#undef declare_mgen_alias
+#define declare_mgen_alias(a, b)
+
+#include <w_sqrt_template.c>
diff --git a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c
new file mode 100644
index 0000000000..313ef8ba9a
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128-ppc64le.c
@@ -0,0 +1,37 @@ 
+/* PPC64LE sqrt for _Float128
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file into
+   combinations with other programs, and to distribute those
+   combinations without any restriction coming from the use of this
+   file.  (The Lesser General Public License restrictions do apply in
+   other respects; for example, they cover modification of the file,
+   and distribution when not linked into a combine executable.)
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math-type-macros-float128.h>
+
+#define __sqrtf128 __sqrtf128_ppc64le
+
+#undef __USE_WRAPPER_TEMPLATE
+#define __USE_WRAPPER_TEMPLATE 1
+#undef declare_mgen_alias
+#define declare_mgen_alias(a, b)
+
+#include <w_sqrt_template.c>
diff --git a/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c
new file mode 100644
index 0000000000..a44bf4f5cc
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/le/fpu/multiarch/w_sqrtf128.c
@@ -0,0 +1,31 @@ 
+/* Multiple versions of __sqrtf128.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include "init-arch.h"
+#include <math-type-macros-float128.h>
+
+extern __typeof (__sqrtf128) __sqrtf128_ppc64le attribute_hidden;
+extern __typeof (__sqrtf128) __sqrtf128_power9 attribute_hidden;
+
+libc_ifunc (__sqrtf128,
+	    (hwcap2 & PPC_FEATURE2_ARCH_3_00)
+	    ? __sqrtf128_power9
+	    : __sqrtf128_ppc64le);
+declare_mgen_alias (__sqrt, sqrt)