From ebb6eae1a92ca8be1f661c6da5cd0cd6a94dcd07 Mon Sep 17 00:00:00 2001
From: Bert Tenjy <bert.tenjy@gmail.com>
Date: Wed, 6 Mar 2019 21:52:48 +0000
Subject: [PATCH v10 1/12] PPC64: Add libmvec SIMD double-precision cosine
function.
[BZ #24205]
This is the 1st of 12 patches that will implement libmvec for PPC64 using
VSX hardware capabilities.
Implements double-precision cosine using VSX vector capability. Algorithm for
cosine is from x86_64 [commit #2193311288] adapted to PPC64.
Name-mangling exactly duplicates SSE ISA of the x86_64 ABI. The details are at
<https://sourceware.org/glibc/wiki/
libmvec?action=AttachFile&do=view&target=VectorABI.txt>
The patch has been tested on PPC64/POWER8 Little Endian and Big Endian. It is
tested using the framework created for libmvec on x86_64 which runs tests on
issuing 'make check'. Tests of the new vector cosine function all pass.
Library libmvec is built by default. To disable building it, pass flag
--disable-mathvec to the configure script.
A runtime check prevents vector tests running on systems lacking VSX hardware.
File vec_finite_alias.c is empty. Its existence ensures that libmvec_nonshared.a
is created. Otherwise, linking during testing of a newly-installed glibc fails.
Glibc built with this patch was installed using the procedure outlined at
<https://sourceware.org/glibc/wiki/Testing/Builds>. Compiling against the new
library created a test executable which computes cosines using the vector
version of the function. The results are at most 2-ulps away from the scalar
cosine. That is expected and indicated in the comments describing the
algorithm - as obtained from x86_64 commit #2193311288.
---
ChangeLog | 21 +++++
NEWS | 12 +++
sysdeps/powerpc/bits/math-vector.h | 41 +++++++++
sysdeps/powerpc/fpu/libm-test-ulps | 3 +
sysdeps/powerpc/powerpc64/fpu/Makefile | 7 ++
sysdeps/powerpc/powerpc64/fpu/Versions | 5 ++
sysdeps/powerpc/powerpc64/fpu/configure | 6 ++
sysdeps/powerpc/powerpc64/fpu/configure.ac | 6 ++
.../powerpc/powerpc64/fpu/math-tests-arch.h | 34 +++++++
.../powerpc/powerpc64/fpu/multiarch/Makefile | 17 ++++
.../multiarch/test-double-vlen2-wrappers.c | 24 +++++
.../powerpc64/fpu/multiarch/vec_d_cos2_vsx.c | 88 +++++++++++++++++++
.../powerpc64/fpu/multiarch/vec_d_trig_data.h | 60 +++++++++++++
.../powerpc/powerpc64/fpu/vec_finite_alias.c | 17 ++++
.../linux/powerpc/powerpc64/libmvec.abilist | 1 +
15 files changed, 342 insertions(+)
create mode 100644 sysdeps/powerpc/bits/math-vector.h
create mode 100644 sysdeps/powerpc/powerpc64/fpu/Makefile
create mode 100644 sysdeps/powerpc/powerpc64/fpu/Versions
create mode 100644 sysdeps/powerpc/powerpc64/fpu/configure
create mode 100644 sysdeps/powerpc/powerpc64/fpu/configure.ac
create mode 100644 sysdeps/powerpc/powerpc64/fpu/math-tests-arch.h
create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c
create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_cos2_vsx.c
create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h
create mode 100644 sysdeps/powerpc/powerpc64/fpu/vec_finite_alias.c
create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist
@@ -1,3 +1,24 @@
+2019-04-03 Bert Tenjy <bert.tenjy@gmail.com>
+
+ [BZ #24205]
+ * NEWS: Updated to note new SIMD vector cosine function.
+ * sysdeps/powerpc/bits/math-vector.h: New file.
+ * sysdeps/powerpc/fpu/libm-test-ulps (cos_vlen2): Regenerated.
+ * sysdeps/powerpc/powerpc64/fpu/Makefile: New file.
+ * sysdeps/powerpc/powerpc64/fpu/Versions: Likewise.
+ * sysdeps/powerpc/powerpc64/fpu/configure: Generated.
+ * sysdeps/powerpc/powerpc64/fpu/configure.ac: New file.
+ * sysdeps/powerpc/powerpc64/fpu/math-tests-arch.h: New file.
+ * sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile (libmvec-sysdep_routines)
+ (CFLAGS-vec_d_cos2_vsx.c, libmvec-tests, double-vlen2-funcs)
+ (double-vlen2-arch-ext-cflags): Added build of VSX vector cos function
+ and its tests.
+ * sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c: New file.
+ * sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_cos2_vsx.c: Likewise.
+ * sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h: Likewise.
+ * sysdeps/powerpc/powerpc64/fpu/vec_finite_alias.c: Likewise.
+ * sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist: Likewise.
+
2019-02-26 Joseph Myers <joseph@codesourcery.com>
* sysdeps/arm/sysdep.h (#if condition): Break lines before rather
@@ -4,11 +4,23 @@ See the end for copying conditions.
Please send GNU C library bug reports via <https://sourceware.org/bugzilla/>
using `glibc' in the "product" field.
+
Version 2.30
Major new features:
+* Start of implementing vector math library libmvec on PPC64/POWER8.
+ The double-precision cosine now has a vector version.
+ GCC support for auto-vectorization of functions on PPC64 is not yet
+ available. Until that is done, the new vector math functions are
+ inaccessible to applications.
+ Library libmvec is built by default for PPC64. Disable its creation by
+ passing flag --disable-mathvec to configure.
+ The library ABI specification is x86_64 Vector Function ABI.
+ More information on libmvec including a link to the ABI document is at:
+ <https://sourceware.org/glibc/wiki/libmvec>
+
* The dynamic linker accepts the --preload argument to preload shared
objects, in addition to the LD_PRELOAD environment variable.
new file mode 100644
@@ -0,0 +1,41 @@
+/* Platform-specific SIMD declarations of math functions.
+ Copyright (C) 2019 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/>. */
+
+#ifndef _MATH_H
+# error "Never include <bits/math-vector.h> directly;\
+ include <math.h> instead."
+#endif
+
+/* Get default empty definitions for simd declarations. */
+#include <bits/libm-simd-decl-stubs.h>
+
+#if defined __PPC64__ && defined __FAST_MATH__
+# if defined _OPENMP && _OPENMP >= 201307
+/* OpenMP case. */
+# define __DECL_SIMD_PPC64 _Pragma ("omp declare simd notinbranch")
+# elif __GNUC_PREREQ (6,0)
+/* W/o OpenMP use GCC 6.* __attribute__ ((__simd__)). */
+# define __DECL_SIMD_PPC64 __attribute__ ((__simd__ ("notinbranch")))
+# endif
+
+# ifdef __DECL_SIMD_PPC64
+# undef __DECL_SIMD_cos
+# define __DECL_SIMD_cos __DECL_SIMD_PPC64
+
+# endif
+#endif
@@ -1311,6 +1311,9 @@ ifloat128: 2
ildouble: 5
ldouble: 5
+Function: "cos_vlen2":
+double: 2
+
Function: "cosh":
double: 1
float: 1
new file mode 100644
@@ -0,0 +1,7 @@
+ifeq ($(subdir),mathvec)
+libmvec-support += vec_finite_alias
+
+CFLAGS-vec_finite_alias.c += -mvsx
+
+libmvec-static-only-routines = vec_finite_alias
+endif
new file mode 100644
@@ -0,0 +1,5 @@
+libmvec {
+ GLIBC_2.30 {
+ _ZGVbN2v_cos;
+ }
+}
new file mode 100644
@@ -0,0 +1,6 @@
+# This file is generated from configure.ac by Autoconf. DO NOT EDIT!
+ # Local configure fragment for sysdeps/powerpc/powerpc64/fpu/.
+
+if test "$enable_mathvec" != "no" ; then
+ build_mathvec=yes
+fi
new file mode 100644
@@ -0,0 +1,6 @@
+GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
+# Local configure fragment for sysdeps/powerpc/powerpc64/fpu/.
+
+if test "$enable_mathvec" != "no" ; then
+ build_mathvec=yes
+fi
new file mode 100644
@@ -0,0 +1,34 @@
+/* Runtime architecture check for math tests. PPC64 version.
+ Copyright (C) 2014-2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#if defined REQUIRE_VSX
+
+# include "init-arch.h"
+
+# define INIT_ARCH_EXT
+# define CHECK_ARCH_EXT \
+ do \
+ { \
+ INIT_ARCH() \
+ if (!(hwcap & PPC_FEATURE_HAS_VSX )) return; \
+ } \
+ while (0)
+
+#else
+# include <sysdeps/generic/math-tests-arch.h>
+#endif
@@ -42,3 +42,20 @@ CFLAGS-e_hypotf-power7.c = -mcpu=power7
CFLAGS-s_modf-ppc64.c += -fsignaling-nans
CFLAGS-s_modff-ppc64.c += -fsignaling-nans
endif
+
+ifeq ($(subdir),mathvec)
+libmvec-sysdep_routines += vec_d_cos2_vsx
+CFLAGS-vec_d_cos2_vsx.c += -mabi=altivec -maltivec -mvsx
+endif
+
+# Variables for libmvec tests.
+ifeq ($(subdir),math)
+ifeq ($(build-mathvec),yes)
+libmvec-tests += double-vlen2
+
+double-vlen2-funcs = cos
+
+double-vlen2-arch-ext-cflags = -mabi=altivec -maltivec -mvsx -DREQUIRE_VSX
+CFLAGS-test-double-vlen2-wrappers.c += -mabi=altivec -maltivec -mvsx -DREQUIRE_VSX
+endif
+endif
new file mode 100644
@@ -0,0 +1,24 @@
+/* Wrapper part of tests for VSX ISA versions of vector math functions.
+ Copyright (C) 2019 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/>. */
+
+#include "test-double-vlen2.h"
+#include <altivec.h>
+
+#define VEC_TYPE vector double
+
+VECTOR_WRAPPER (WRAPPER_NAME (cos), _ZGVbN2v_cos)
new file mode 100644
@@ -0,0 +1,88 @@
+/* Function cos vectorized with VSX.
+ Copyright (C) 2019 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/>. */
+
+#include <math.h>
+#include "vec_d_trig_data.h"
+
+vector double
+_ZGVbN2v_cos (vector double x)
+{
+
+ /*
+ ARGUMENT RANGE REDUCTION:
+ Add Pi/2 to argument: X' = X+Pi/2. */
+ vector double x_prime = (vector double) __d_half_pi + x;
+
+ /* Get absolute argument value: X' = |X'|. */
+ vector double abs_x_prime = vec_abs (x_prime);
+
+ /* Y = X'*InvPi + RS : right shifter add. */
+ vector double y = (x_prime * __d_inv_pi) + __d_rshifter;
+
+ /* Check for large arguments path. */
+ vector bool long long large_in = vec_cmpgt (abs_x_prime, __d_rangeval);
+
+ /* N = Y - RS : right shifter sub. */
+ vector double n = y - __d_rshifter;
+
+ /* SignRes = Y<<63 : shift LSB to MSB place for result sign. */
+ vector double sign_res = (vector double) vec_sl ((vector long long) y,
+ (vector unsigned long long)
+ vec_splats (63));
+
+ /* N = N - 0.5. */
+ n = n - __d_one_half;
+
+ /* R = X - N*Pi1. */
+ vector double r = x - (n * __d_pi1_fma);
+
+ /* R = R - N*Pi2. */
+ r = r - (n * __d_pi2_fma);
+
+ /* R = R - N*Pi3. */
+ r = r - (n * __d_pi3_fma);
+
+ /* R2 = R*R. */
+ vector double r2 = r * r;
+
+ /* Poly = C3+R2*(C4+R2*(C5+R2*(C6+R2*C7))). */
+ vector double poly = r2 * __d_coeff7 + __d_coeff6;
+ poly = poly * r2 + __d_coeff5;
+ poly = poly * r2 + __d_coeff4;
+ poly = poly * r2 + __d_coeff3;
+
+ /* Poly = R+R*(R2*(C1+R2*(C2+R2*Poly))). */
+ poly = poly * r2 + __d_coeff2;
+ poly = poly * r2 + __d_coeff1;
+ poly = poly * r2 * r + r;
+
+ /*
+ RECONSTRUCTION:
+ Final sign setting: Res = Poly^SignRes. */
+ vector double out
+ = (vector double) ((vector long long) poly ^ (vector long long) sign_res);
+
+ if (large_in[0] != 0)
+ out[0] = cos (x[0]);
+
+ if (large_in[1] != 0)
+ out[1] = cos (x[1]);
+
+ return out;
+
+}
new file mode 100644
@@ -0,0 +1,60 @@
+/* Constants used in polynomial approximations for vectorized sin, cos,
+ and sincos functions.
+ Copyright (C) 2019 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/>. */
+
+#ifndef D_TRIG_DATA_H
+#define D_TRIG_DATA_H
+
+#include <altivec.h>
+
+/* PI/2. */
+const vector double __d_half_pi = {0x1.921fb54442d18p+0, 0x1.921fb54442d18p+0};
+
+/* Inverse PI. */
+const vector double __d_inv_pi = {0x1.45f306dc9c883p-2, 0x1.45f306dc9c883p-2};
+
+/* Right-shifter constant. */
+const vector double __d_rshifter = {0x1.8p+52, 0x1.8p+52};
+
+/* Working range threshold. */
+const vector double __d_rangeval = {0x1p+23, 0x1p+23};
+
+/* One-half. */
+const vector double __d_one_half = {0x1p-1, 0x1p-1};
+
+/* Range reduction PI-based constants if FMA available:
+ PI high part (FMA available). */
+const vector double __d_pi1_fma = {0x1.921fb54442d18p+1, 0x1.921fb54442d18p+1};
+
+/* PI mid part (FMA available). */
+const vector double __d_pi2_fma = {0x1.1a62633145c06p-53, 0x1.1a62633145c06p-53};
+
+/* PI low part (FMA available). */
+const vector double __d_pi3_fma
+= {0x1.c1cd129024e09p-106,0x1.c1cd129024e09p-106};
+
+/* Polynomial coefficients (relative error 2^(-52.115)). */
+const vector double __d_coeff7 = {-0x1.9f0d60811aac8p-41,-0x1.9f0d60811aac8p-41};
+const vector double __d_coeff6 = {0x1.60e6857a2f22p-33,0x1.60e6857a2f22p-33};
+const vector double __d_coeff5 = {-0x1.ae63546002231p-26,-0x1.ae63546002231p-26};
+const vector double __d_coeff4 = {0x1.71de38030feap-19,0x1.71de38030feap-19};
+const vector double __d_coeff3 = {-0x1.a01a019a5b86dp-13,-0x1.a01a019a5b86dp-13};
+const vector double __d_coeff2 = {0x1.111111110a4a8p-7,0x1.111111110a4a8p-7};
+const vector double __d_coeff1 = {-0x1.55555555554a7p-3,-0x1.55555555554a7p-3};
+
+#endif /* D_TRIG_DATA_H. */
new file mode 100644
@@ -0,0 +1,17 @@
+/* A temporary workaround to force creation of libmvec_nonshared.a.
+ Copyright (C) 2019 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/>. */
new file mode 100644
@@ -0,0 +1 @@
+GLIBC_2.30 _ZGVbN2v_cos F
--
2.20.1