PPC64: Adds SIMD sine function for POWER8.
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  • PPC64: Adds SIMD sine function for POWER8.
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Commit Message

GT March 4, 2019, 9:03 p.m. UTC
This adds the vector sine function for PPC64/POWER8 VSX.

Testing with 'make check' passes all tests of the double-precision
sine function. The maximum error is 2-ulps, and is expected of the
algorithm which guarantees less than 4-ulps in error.

Tested on both PPC64 Little and Big Endian.

Comments

Joseph Myers March 6, 2019, 9:10 p.m. UTC | #1
On Mon, 4 Mar 2019, GT wrote:

> This adds the vector sine function for PPC64/POWER8 VSX.

As this is presumably relative to previous patches not on glibc master, it 
should be something like patch 3/N, so a patch name starting 0001- is 
unhelpful.  Could you number your patches to reflect their positions in 
the patch series?

Patch
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From 78e18edc25ab733e6e25c3c21adb077a7dba2557 Mon Sep 17 00:00:00 2001
From: Bert Tenjy <bert.tenjy@gmail.com>
Date: Mon, 4 Mar 2019 20:45:51 +0000
Subject: [PATCH] PPC64: Adds SIMD sine function for POWER8.

[BZ #24206]

Implements double-precision vector sine function. The polynomial
sine-approximating algorithm is adapted for PPC64 from x86_64 [commit #4b9c2b707b].

The patch has been tested on PPC64/POWER8 Little Endian and Big Endian.
Testing uses the framework created for libmvec on x86_64 which runs tests on
issuing 'make check'. Tests of the new vector sine function all pass.
---
 ChangeLog                                     |  18 ++++
 NEWS                                          |   1 +
 sysdeps/powerpc/bits/math-vector.h            |   2 +
 sysdeps/powerpc/fpu/libm-test-ulps            |   3 +
 sysdeps/powerpc/powerpc64/fpu/Versions        |   2 +-
 .../powerpc/powerpc64/fpu/multiarch/Makefile  |   6 +-
 .../multiarch/test-double-vlen2-wrappers.c    |   1 +
 .../powerpc64/fpu/multiarch/vec_d_sin2_vsx.c  | 101 ++++++++++++++++++
 .../powerpc64/fpu/multiarch/vec_d_trig_data.h |  44 +++++---
 .../linux/powerpc/powerpc64/libmvec.abilist   |   1 +
 10 files changed, 160 insertions(+), 19 deletions(-)
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_sin2_vsx.c

diff --git a/ChangeLog b/ChangeLog
index 0fe27f52fb..75b3d2978f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,21 @@ 
+2019-03-04    <bert.tenjy@gmail.com>
+
+	[BZ #24206]
+
+	* NEWS: Note the addition of PPC64 vector sine.
+	* sysdeps/powerpc/bits/math-vector.h: Added sine SIMD declaration.
+	* sysdeps/powerpc/fpu/libm-test-ulps: Regenerated.
+	* sysdeps/powerpc/powerpc64/fpu/Versions: Added sine entry.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile: (libmvec-sysdep_routines)
+	(CFLAGS-vec_s_cosf4_vsx.c, libmvec-tests, double-vlen2-funcs)
+	(double-vlen2-arch-ext-cflags): Added build of VSX SIMD sine function
+	and its tests.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c: Added sine entry.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_sin2_vsx.c: New file.
+	* sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h: Added constants used in
+	computing vector sine.
+	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist: SIMD sine added.
+
 2019-03-03    <bert.tenjy@gmail.com>
 
 	[BZ #24205]
diff --git a/NEWS b/NEWS
index 42b5aca08b..bbb86dfd41 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,7 @@  using `glibc' in the "product" field.
   The following functions now have vector versions:
   - cos (double-precision cosine)
   - cosf (single-precision cosine)
+  - sin (double-precision sine)
 
   GCC support for auto-vectorization of functions on PPC64 is not yet
   available. Until that is done, the new vector math functions are
diff --git a/sysdeps/powerpc/bits/math-vector.h b/sysdeps/powerpc/bits/math-vector.h
index bb4834c0a7..0327f204a9 100644
--- a/sysdeps/powerpc/bits/math-vector.h
+++ b/sysdeps/powerpc/bits/math-vector.h
@@ -38,6 +38,8 @@ 
 #  define __DECL_SIMD_cos __DECL_SIMD_PPC64
 #  undef __DECL_SIMD_cosf
 #  define __DECL_SIMD_cosf __DECL_SIMD_PPC64
+#  undef __DECL_SIMD_sin
+#  define __DECL_SIMD_sin __DECL_SIMD_PPC64
 
 # endif
 #endif
diff --git a/sysdeps/powerpc/fpu/libm-test-ulps b/sysdeps/powerpc/fpu/libm-test-ulps
index 3bd9e67096..e72452e757 100644
--- a/sysdeps/powerpc/fpu/libm-test-ulps
+++ b/sysdeps/powerpc/fpu/libm-test-ulps
@@ -2570,6 +2570,9 @@  ifloat128: 3
 ildouble: 5
 ldouble: 5
 
+Function: "sin_vlen2":
+double: 2
+
 Function: "sincos":
 double: 1
 float: 1
diff --git a/sysdeps/powerpc/powerpc64/fpu/Versions b/sysdeps/powerpc/powerpc64/fpu/Versions
index bdd4b657c4..4852a2791f 100644
--- a/sysdeps/powerpc/powerpc64/fpu/Versions
+++ b/sysdeps/powerpc/powerpc64/fpu/Versions
@@ -1,5 +1,5 @@ 
 libmvec {
   GLIBC_2.30 {
-    _ZGVbN2v_cos; _ZGVbN4v_cosf;
+    _ZGVbN2v_cos; _ZGVbN4v_cosf; _ZGVbN2v_sin;
   }
 }
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
index 5f70c7659f..20a3721854 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
@@ -44,9 +44,11 @@  CFLAGS-s_modff-ppc64.c += -fsignaling-nans
 endif
 
 ifeq ($(subdir),mathvec)
-libmvec-sysdep_routines += vec_d_cos2_vsx vec_s_cosf4_vsx
+libmvec-sysdep_routines += vec_d_cos2_vsx vec_s_cosf4_vsx \
+			   vec_d_sin2_vsx
 CFLAGS-vec_d_cos2_vsx.c += -mvsx
 CFLAGS-vec_s_cosf4_vsx.c += -mvsx
+CFLAGS-vec_d_sin2_vsx.c += -mvsx
 endif
 
 # Variables for libmvec tests.
@@ -54,7 +56,7 @@  ifeq ($(subdir),math)
 ifeq ($(build-mathvec),yes)
 libmvec-tests += double-vlen2 float-vlen4
 
-double-vlen2-funcs = cos
+double-vlen2-funcs = cos sin
 float-vlen4-funcs = cos
 
 double-vlen2-arch-ext-cflags = -mvsx -DREQUIRE_VSX
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c
index 17e2cc0724..10a1ec281b 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c
@@ -22,3 +22,4 @@ 
 #define VEC_TYPE vector double
 
 VECTOR_WRAPPER (WRAPPER_NAME (cos), _ZGVbN2v_cos)
+VECTOR_WRAPPER (WRAPPER_NAME (sin), _ZGVbN2v_sin)
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_sin2_vsx.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_sin2_vsx.c
new file mode 100644
index 0000000000..d6c1e25673
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_sin2_vsx.c
@@ -0,0 +1,101 @@ 
+/* Function sin 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"
+
+/* ALGORITHM DESCRIPTION:
+
+      ( low accuracy ( < 4ulp ) or enhanced performance
+      ( half of correct mantissa ) implementation )
+
+     Argument representation:
+     arg = N*Pi + R
+
+     Result calculation:
+     sin(arg) = sin(N*Pi + R) = (-1)^N * sin(R)
+     sin(R) is approximated by corresponding polynomial.  */
+
+vector double
+_ZGVbN2v_sin (vector double x)
+{
+
+  /* ARGUMENT RANGE REDUCTION: X' = |X|.  */
+  vector double abs_x_prime = vec_abs (x);
+
+  /* Y = X'*InvPi + RS : right shifter add.  */
+  vector double y = (abs_x_prime * __d_inv_pi) + __d_rshifter;
+
+  /* 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));
+
+  /* Check for large arguments path.  */
+  vector bool long long large_in = vec_cmpgt (abs_x_prime, __d_rangeval);
+
+  /* R = X' - N*Pi1.  */
+  vector double r = abs_x_prime - (n * __d_pi1_fma);
+
+  /* R = R - N*Pi2.  */
+  r = r - (n * __d_pi2_fma);
+
+  /* R = R - N*Pi3.  */
+  r = r - (n * __d_pi3_fma);
+
+  /* POLYNOMIAL APPROXIMATION: R2 = R*R.  */
+  vector double r2 = r * r;
+
+  /* R = R^SignRes : update sign of reduced argument.  */
+  vector double r_sign
+      = (vector double) ((vector long long) r ^ (vector long long) sign_res);
+
+  /* Poly = C3+R2*(C4+R2*(C5+R2*(C6+R2*C7))).  */
+  vector double poly = r2 * __d_coeff7_sin + __d_coeff6_sin;
+  poly = poly * r2 + __d_coeff5_sin;
+  poly = poly * r2 + __d_coeff4_sin;
+  poly = poly * r2 + __d_coeff3_sin;
+
+  /* Poly = R2*(C1+R2*(C2+R2*Poly)).  */
+  poly = poly * r2 + __d_coeff2_sin;
+  poly = poly * r2 + __d_coeff1_sin;
+  poly = poly * r2;
+
+  /* Poly = Poly*R + R.  */
+  poly = poly * r_sign + r_sign;
+
+  /* SignX: -ve sign bit of X.  */
+  vector double neg_sign
+      = (vector double) vec_andc ((vector bool long long) x, __d_abs_mask);
+
+  /* RECONSTRUCTION: Final sign setting: Res = Poly^SignX.  */
+  vector double out
+      = (vector double) ((vector long long) poly ^ (vector long long) neg_sign);
+
+  if (large_in[0] != 0)
+    out[0] = sin (x[0]);
+
+  if (large_in[1] != 0)
+    out[1] = sin (x[1]);
+
+  return out;
+
+} /* _ZGVbN2v_sin function.  */
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h
index ecd47d258f..bc823ef19c 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_d_trig_data.h
@@ -23,38 +23,50 @@ 
 #include <altivec.h>
 
 /* PI/2.  */
-const vector double __d_half_pi  = {0x1.921fb54442d18p+0, 0x1.921fb54442d18p+0};
+static 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};
+static 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};
+static const vector double __d_rshifter = {0x1.8p+52, 0x1.8p+52};
 
 /* Working range threshold.  */
-const vector double __d_rangeval = {0x1p+23, 0x1p+23};
+static const vector double __d_rangeval = {0x1p+23, 0x1p+23};
 
 /* One-half.  */
-const vector double __d_one_half = {0x1p-1, 0x1p-1};
+static 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};
+static 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};
+static const vector double __d_pi2_fma = {0x1.1a62633145c06p-53, 0x1.1a62633145c06p-53};
 
 /* PI low part  (FMA available).  */
-const vector double __d_pi3_fma
+static 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};
+/* Polynomial coefficients for cosine (relative error 2^(-52.115)).  */
+static const vector double __d_coeff7 = {-0x1.9f0d60811aac8p-41,-0x1.9f0d60811aac8p-41};
+static const vector double __d_coeff6 = {0x1.60e6857a2f22p-33,0x1.60e6857a2f22p-33};
+static const vector double __d_coeff5 = {-0x1.ae63546002231p-26,-0x1.ae63546002231p-26};
+static const vector double __d_coeff4 = {0x1.71de38030feap-19,0x1.71de38030feap-19};
+static const vector double __d_coeff3 = {-0x1.a01a019a5b86dp-13,-0x1.a01a019a5b86dp-13};
+static const vector double __d_coeff2 = {0x1.111111110a4a8p-7,0x1.111111110a4a8p-7};
+static const vector double __d_coeff1 = {-0x1.55555555554a7p-3,-0x1.55555555554a7p-3};
+
+/* Absolute value mask.  */
+static const vector bool long long __d_abs_mask = { 0x7fffffffffffffff, 0x7fffffffffffffff };
+
+/* Polynomial coefficients for sine (relative error 2^(-52.115)).  */
+static const vector double __d_coeff7_sin = { -0x1.9f1517e9f65fp-41, -0x1.9f1517e9f65fp-41 };
+static const vector double __d_coeff6_sin = { 0x1.60e6bee01d83ep-33, 0x1.60e6bee01d83ep-33 };
+static const vector double __d_coeff5_sin = { -0x1.ae6355aaa4a53p-26, -0x1.ae6355aaa4a53p-26 };
+static const vector double __d_coeff4_sin = { 0x1.71de3806add1ap-19, 0x1.71de3806add1ap-19 };
+static const vector double __d_coeff3_sin = { -0x1.a01a019a659ddp-13, -0x1.a01a019a659ddp-13 };
+static const vector double __d_coeff2_sin = { 0x1.111111110a573p-7, 0x1.111111110a573p-7 };
+static const vector double __d_coeff1_sin = { -0x1.55555555554a8p-3, -0x1.55555555554a8p-3 };
 
 #endif /* D_TRIG_DATA_H.  */
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist
index 8eef5e1e72..a1a7f69d4c 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libmvec.abilist
@@ -1,2 +1,3 @@ 
 GLIBC_2.30 _ZGVbN2v_cos F
+GLIBC_2.30 _ZGVbN2v_sin F
 GLIBC_2.30 _ZGVbN4v_cosf F
-- 
2.20.1