powerpc: add libmvec implementations of log and logf
diff mbox series

Message ID 20190506024105.14025-1-shawn@git.icu
State New
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Series
  • powerpc: add libmvec implementations of log and logf
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Commit Message

Shawn Landden May 6, 2019, 2:41 a.m. UTC
When fed numbers in the range of 0 to 2^32-1 (as doubles) the vector log
is about 75% faster than scalar log.

When fed numbers in the range of 0 to 2^16-1 (as floats) the vector logf
is about 30% faster than scalar logf. This should probably be faster,
and did not spend much time in perf looking into this.[2]

logf requires Power 7
log requires Power 8

I have not completed a FSF copyright assignement, but would be happy to do so.
These are base on the routines here: https://github.com/ARM-software/optimized-routines
of which the ability to incorporate in glibc is a specific goal.
CCing its' maintainer Szabolcs Nagy.

[2] benchmark programs: https://github.com/shawnl/libmvec

v2: rebase on top of the appropiate branch
---
 .../powerpc/powerpc64/fpu/multiarch/Makefile  |   8 +-
 .../multiarch/test-double-vlen2-wrappers.c    |   1 +
 .../fpu/multiarch/test-float-vlen4-wrappers.c |   1 +
 .../powerpc64/fpu/multiarch/vec_s_log2_vsx.c  | 173 +++++++++++++++
 .../powerpc64/fpu/multiarch/vec_s_log_data.c  | 208 ++++++++++++++++++
 .../powerpc64/fpu/multiarch/vec_s_log_data.h  |  36 +++
 .../powerpc64/fpu/multiarch/vec_s_logf4_vsx.c | 126 +++++++++++
 .../powerpc64/fpu/multiarch/vec_s_logf_data.c |  44 ++++
 .../powerpc64/fpu/multiarch/vec_s_logf_data.h |  32 +++
 9 files changed, 627 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log2_vsx.c
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.c
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.h
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf4_vsx.c
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.c
 create mode 100644 sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.h

Patch
diff mbox series

diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
index b94fb354c6..c01f45f579 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
@@ -46,6 +46,8 @@  endif
 ifeq ($(subdir),mathvec)
 libmvec-sysdep_routines += vec_d_cos2_vsx vec_s_cosf4_vsx \
 			   vec_d_sin2_vsx vec_s_sinf4_vsx \
+                           vec_s_logf4_vsx vec_s_log2_vsx \
+                           vec_s_logf_data vec_s_log_data \
 			   vec_d_sincos2_vsx vec_s_sincosf4_vsx
 CFLAGS-vec_d_cos2_vsx.c += -mabi=altivec -maltivec -mvsx -mpower8-vector
 CFLAGS-vec_s_cosf4_vsx.c += -mabi=altivec -maltivec -mvsx
@@ -53,6 +55,8 @@  CFLAGS-vec_d_sin2_vsx.c += -mabi=altivec -maltivec -mvsx -mpower8-vector
 CFLAGS-vec_s_sinf4_vsx.c += -mabi=altivec -maltivec -mvsx
 CFLAGS-vec_d_sincos2_vsx.c += -mabi=altivec -maltivec -mvsx -mpower8-vector
 CFLAGS-vec_s_sincosf4_vsx.c += -mabi=altivec -maltivec -mvsx
+CFLAGS-vec_d_sinlog2_vsx.c += -mabi=altivec -maltivec -mvsx -mpower8-vector
+CFLAGS-vec_s_sinlogf4_vsx.c += -mabi=altivec -maltivec -mvsx
 endif
 
 # Variables for libmvec tests.
@@ -60,8 +64,8 @@  ifeq ($(subdir),math)
 ifeq ($(build-mathvec),yes)
 libmvec-tests += double-vlen2 float-vlen4
 
-double-vlen2-funcs = cos sin sincos
-float-vlen4-funcs = cos sin sincos
+double-vlen2-funcs = cos sin sincos log
+float-vlen4-funcs = cos sin sincos log
 
 double-vlen2-arch-ext-cflags = -mabi=altivec -maltivec -mvsx -DREQUIRE_VSX
 float-vlen4-arch-ext-cflags = -mabi=altivec -maltivec -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 7082a3500e..0ed2812cf6 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/test-double-vlen2-wrappers.c
@@ -23,5 +23,6 @@ 
 
 VECTOR_WRAPPER (WRAPPER_NAME (cos), _ZGVbN2v_cos)
 VECTOR_WRAPPER (WRAPPER_NAME (sin), _ZGVbN2v_sin)
+VECTOR_WRAPPER (WRAPPER_NAME (log), _ZGVbN2v_log)
 
 VECTOR_WRAPPER_fFF (WRAPPER_NAME (sincos), _ZGVbN2vvv_sincos)
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/test-float-vlen4-wrappers.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/test-float-vlen4-wrappers.c
index 87be9de0be..79b671c601 100644
--- a/sysdeps/powerpc/powerpc64/fpu/multiarch/test-float-vlen4-wrappers.c
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/test-float-vlen4-wrappers.c
@@ -23,5 +23,6 @@ 
 
 VECTOR_WRAPPER (WRAPPER_NAME (cosf), _ZGVbN4v_cosf)
 VECTOR_WRAPPER (WRAPPER_NAME (sinf), _ZGVbN4v_sinf)
+VECTOR_WRAPPER (WRAPPER_NAME (logf), _ZGVbN4v_logf)
 
 VECTOR_WRAPPER_fFF (WRAPPER_NAME (sincosf), _ZGVbN4vvv_sincosf)
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log2_vsx.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log2_vsx.c
new file mode 100644
index 0000000000..96c3911dbc
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log2_vsx.c
@@ -0,0 +1,173 @@ 
+/* Double-precision vector log(x) function.
+   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 <altivec.h>
+#include <stdint.h>
+
+#include "vec_s_log_data.h"
+
+typedef vector long long unsigned v64u;
+typedef vector long long v64i;
+
+typedef union {
+  vector double d;
+  v64u l;
+} u;
+
+typedef union {
+  double d;
+  uint64_t l;
+  unsigned u;
+  float f;
+} us;
+
+#define T __log_data.tab
+#define T2 __log_data.tab2
+#define B __log_data.poly1
+#define A __log_data.poly
+#define Ln2hi __log_data.ln2hi
+#define Ln2lo __log_data.ln2lo
+#define N (1 << LOG_TABLE_BITS)
+#define OFF 0x3fe6000000000000
+
+#define INF 0x7ff0000000000000
+
+vector double _ZGVN2v_log(vector double x) {
+  v64u inf = {INF, INF};
+  v64u ninf = inf | (1ULL << 63);
+  v64u zero = {0, 0};
+
+  u un;
+  un.d = x;
+  v64u xi = un.l;
+
+  us lo;
+  us hi;
+  lo.d = 1.0 - 0x1p-4;
+  hi.d = 1.0 + 0x1.09p-4;
+  v64u lov = {lo.l, lo.l};
+  v64u hiv = {hi.l, hi.l};
+  u res;
+  v64u is_close_to_one = (v64u)vec_cmplt(xi - lov, hiv - lov);
+  if (!vec_all_eq(is_close_to_one, zero)) {
+    vector double r = x - 1.0;
+    vector double r2 = r * r;
+    vector double r3 = r * r2;
+    vector double b0 = {B[0], B[0]};
+    vector double b12 = {B[1], B[2]};
+    vector double b1 = vec_splat(b12, 0);
+    vector double b2 = vec_splat(b12, 1);
+    vector double b34 = {B[3], B[4]};
+    vector double b3 = vec_splat(b34, 0);
+    vector double b4 = vec_splat(b34, 1);
+    vector double b56 = {B[5], B[6]};
+    vector double b5 = vec_splat(b56, 0);
+    vector double b6 = vec_splat(b56, 1);
+    vector double b78 = {B[7], B[8]};
+    vector double b7 = vec_splat(b78, 0);
+    vector double b8 = vec_splat(b78, 1);
+    vector double b910 = {B[9], B[10]};
+    vector double b9 = vec_splat(b910, 0);
+    vector double b10 = vec_splat(b910, 1);
+
+    res.d = r3 * (b1 + r * b2 + r2 * b3 + r3 *
+      (b4 + r * b5 + r2 * b6 + r3 *
+        (b7 + r * b8 + r2 * b9 + r3 * b10)));
+    /* Worst-case error is around 0.507 ULP.  */
+    vector double w = r * 0x1p27;
+    vector double rhi = r + w - w;
+    vector double rlo = r - rhi;
+    w = rhi * rhi * b0; /* B[0] == -0.5 */
+    vector double hi = r + w;
+    vector double lo = r - hi + w;
+    lo += b0 * rlo * (rhi + r);
+    res.d += lo;
+    res.d += hi;
+
+    /* 1.0 -> 0 */
+    u oned;
+    vector double one = {1.0, 1.0};
+    oned.d = one;
+    v64u is_one = (v64u)vec_cmpeq(xi, oned.l);
+    res.l = vec_sel(res.l, zero, is_one);
+  } else
+    res.l = zero;
+
+  v64u infexp = {0x7ff0000000000000, 0x7ff0000000000000};
+  v64u is_special_cases = (v64u)vec_cmpge(xi - 0x0010000000000000, infexp - 0x0010000000000000);
+  if (!vec_all_eq(is_special_cases, zero)) {
+    v64u is_zero = (v64u)vec_cmpeq(xi << 1, zero);
+    res.l = vec_sel(res.l, ninf, is_zero);
+
+    v64u is_inf = (v64u)vec_cmpeq(xi, inf);
+    res.l = vec_sel(res.l, inf, is_inf);
+
+    v64u is_neg = (v64u)vec_cmpne(xi >> 63, zero);
+    v64u is_nan = (v64u)vec_cmpeq(xi & infexp, infexp) & ~is_inf;
+    res.l = vec_sel(res.l, infexp + 1/*NaN*/, is_nan | (is_neg & ~is_zero));
+
+    /* subnormals: normalize, remove from is_special_cases */
+    v64u is_not_subnormal = is_nan | is_neg | is_zero | is_inf;
+    un.d = x * 0x1p52;
+    xi = vec_sel(xi, un.l - (52ULL << 52), is_special_cases & ~is_not_subnormal);
+    is_special_cases = is_not_subnormal;
+  }
+  /* x = 2^k z; where z is in range [OFF,2*OFF) and exact.
+	   The range is split into N subintervals.
+	   The ith subinterval contains z and c is near its center.  */
+  v64u tmp = xi - OFF;
+  v64u i = (tmp >> (52 - LOG_TABLE_BITS)) % N;
+  v64i k = ((v64i)tmp >> 52);
+  v64u iz = xi - (tmp & 0xfffULL << 52);
+
+  vector double invc = {T[i[0]].invc, T[i[1]].invc};
+  vector double logc = {T[i[0]].logc, T[i[1]].logc};
+
+  u z;
+  z.l = iz;
+  vector double neg1 = {-1.0, -1.0};
+  vector double r = vec_madd(z.d, invc, neg1);
+  vector double ln2hi = {Ln2hi, Ln2hi};
+  vector double ln2lo = {Ln2lo, Ln2lo};
+  vector double kd = {(double)k[0], (double)k[1]};
+  vector double w2 = kd * ln2hi + logc;
+  vector double hid = w2 + r;
+  vector double lod = w2 - hid + r + kd * ln2lo;
+
+
+  /* log(x) = lo + (log1p(r) - r) + hi.  */
+  vector double r2 = r * r; /* rounding error: 0x1p-54/N^2.  */
+
+  /* Worst case error if |y| > 0x1p-5:
+  0.5 + 4.13/N + abs-poly-error*2^57 ULP
+  Worst case error if |y| > 0x1p-4:
+  0.5 + 2.06/N + abs-poly-error*2^56 ULP.  */
+  vector double a0 = {A[0], A[0]};
+  vector double a1 = {A[1], A[1]};
+  vector double a2 = {A[2], A[2]};
+  vector double a3 = {A[3], A[3]};
+  vector double a4 = {A[4], A[4]};
+  vector double y = lod + r2 * a0 + r * r2 *
+    (a1 + r * a2 + r2 *
+      (a3 + r * a4)) + hid;
+  res.d = vec_sel(res.d, y, ~is_close_to_one & ~is_special_cases);
+  return res.d;
+}
+#ifndef USE_MULTIARCH
+#error test
+ libmvec_hidden_def (_ZGVN2v_log)
+#endif
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.c
new file mode 100644
index 0000000000..6645a4cf6a
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.c
@@ -0,0 +1,208 @@ 
+/* Constants used in polynomial approximations for vectorized log
+   funtion.
+   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/>.  */
+#include "vec_s_log_data.h"
+
+#define N (1 << LOG_TABLE_BITS)
+
+const struct log_data __log_data = {
+.ln2hi = 0x1.62e42fefa3800p-1,
+.ln2lo = 0x1.ef35793c76730p-45,
+.poly1 = {
+// relative error: 0x1.c04d76cp-63
+// in -0x1p-4 0x1.09p-4 (|log(1+x)| > 0x1p-4 outside the interval)
+-0x1p-1,
+0x1.5555555555577p-2,
+-0x1.ffffffffffdcbp-3,
+0x1.999999995dd0cp-3,
+-0x1.55555556745a7p-3,
+0x1.24924a344de3p-3,
+-0x1.fffffa4423d65p-4,
+0x1.c7184282ad6cap-4,
+-0x1.999eb43b068ffp-4,
+0x1.78182f7afd085p-4,
+-0x1.5521375d145cdp-4,
+},
+.poly = {
+// relative error: 0x1.926199e8p-56
+// abs error: 0x1.882ff33p-65
+// in -0x1.fp-9 0x1.fp-9
+-0x1.0000000000001p-1,
+0x1.555555551305bp-2,
+-0x1.fffffffeb459p-3,
+0x1.999b324f10111p-3,
+-0x1.55575e506c89fp-3,
+},
+/* Algorithm:
+
+	x = 2^k z
+	log(x) = k ln2 + log(c) + log(z/c)
+	log(z/c) = poly(z/c - 1)
+
+where z is in [1.6p-1; 1.6p0] which is split into N subintervals and z falls
+into the ith one, then table entries are computed as
+
+	tab[i].invc = 1/c
+	tab[i].logc = (double)log(c)
+	tab2[i].chi = (double)c
+	tab2[i].clo = (double)(c - (double)c)
+
+where c is near the center of the subinterval and is chosen by trying +-2^29
+floating point invc candidates around 1/center and selecting one for which
+
+	1) the rounding error in 0x1.8p9 + logc is 0,
+	2) the rounding error in z - chi - clo is < 0x1p-66 and
+	3) the rounding error in (double)log(c) is minimized (< 0x1p-66).
+
+Note: 1) ensures that k*ln2hi + logc can be computed without rounding error,
+2) ensures that z/c - 1 can be computed as (z - chi - clo)*invc with close to
+a single rounding error when there is no fast fma for z*invc - 1, 3) ensures
+that logc + poly(z/c - 1) has small error, however near x == 1 when
+|log(x)| < 0x1p-4, this is not enough so that is special cased.  */
+.tab = {
+{0x1.734f0c3e0de9fp+0, -0x1.7cc7f79e69000p-2},
+{0x1.713786a2ce91fp+0, -0x1.76feec20d0000p-2},
+{0x1.6f26008fab5a0p+0, -0x1.713e31351e000p-2},
+{0x1.6d1a61f138c7dp+0, -0x1.6b85b38287800p-2},
+{0x1.6b1490bc5b4d1p+0, -0x1.65d5590807800p-2},
+{0x1.69147332f0cbap+0, -0x1.602d076180000p-2},
+{0x1.6719f18224223p+0, -0x1.5a8ca86909000p-2},
+{0x1.6524f99a51ed9p+0, -0x1.54f4356035000p-2},
+{0x1.63356aa8f24c4p+0, -0x1.4f637c36b4000p-2},
+{0x1.614b36b9ddc14p+0, -0x1.49da7fda85000p-2},
+{0x1.5f66452c65c4cp+0, -0x1.445923989a800p-2},
+{0x1.5d867b5912c4fp+0, -0x1.3edf439b0b800p-2},
+{0x1.5babccb5b90dep+0, -0x1.396ce448f7000p-2},
+{0x1.59d61f2d91a78p+0, -0x1.3401e17bda000p-2},
+{0x1.5805612465687p+0, -0x1.2e9e2ef468000p-2},
+{0x1.56397cee76bd3p+0, -0x1.2941b3830e000p-2},
+{0x1.54725e2a77f93p+0, -0x1.23ec58cda8800p-2},
+{0x1.52aff42064583p+0, -0x1.1e9e129279000p-2},
+{0x1.50f22dbb2bddfp+0, -0x1.1956d2b48f800p-2},
+{0x1.4f38f4734ded7p+0, -0x1.141679ab9f800p-2},
+{0x1.4d843cfde2840p+0, -0x1.0edd094ef9800p-2},
+{0x1.4bd3ec078a3c8p+0, -0x1.09aa518db1000p-2},
+{0x1.4a27fc3e0258ap+0, -0x1.047e65263b800p-2},
+{0x1.4880524d48434p+0, -0x1.feb224586f000p-3},
+{0x1.46dce1b192d0bp+0, -0x1.f474a7517b000p-3},
+{0x1.453d9d3391854p+0, -0x1.ea4443d103000p-3},
+{0x1.43a2744b4845ap+0, -0x1.e020d44e9b000p-3},
+{0x1.420b54115f8fbp+0, -0x1.d60a22977f000p-3},
+{0x1.40782da3ef4b1p+0, -0x1.cc00104959000p-3},
+{0x1.3ee8f5d57fe8fp+0, -0x1.c202956891000p-3},
+{0x1.3d5d9a00b4ce9p+0, -0x1.b81178d811000p-3},
+{0x1.3bd60c010c12bp+0, -0x1.ae2c9ccd3d000p-3},
+{0x1.3a5242b75dab8p+0, -0x1.a45402e129000p-3},
+{0x1.38d22cd9fd002p+0, -0x1.9a877681df000p-3},
+{0x1.3755bc5847a1cp+0, -0x1.90c6d69483000p-3},
+{0x1.35dce49ad36e2p+0, -0x1.87120a645c000p-3},
+{0x1.34679984dd440p+0, -0x1.7d68fb4143000p-3},
+{0x1.32f5cceffcb24p+0, -0x1.73cb83c627000p-3},
+{0x1.3187775a10d49p+0, -0x1.6a39a9b376000p-3},
+{0x1.301c8373e3990p+0, -0x1.60b3154b7a000p-3},
+{0x1.2eb4ebb95f841p+0, -0x1.5737d76243000p-3},
+{0x1.2d50a0219a9d1p+0, -0x1.4dc7b8fc23000p-3},
+{0x1.2bef9a8b7fd2ap+0, -0x1.4462c51d20000p-3},
+{0x1.2a91c7a0c1babp+0, -0x1.3b08abc830000p-3},
+{0x1.293726014b530p+0, -0x1.31b996b490000p-3},
+{0x1.27dfa5757a1f5p+0, -0x1.2875490a44000p-3},
+{0x1.268b39b1d3bbfp+0, -0x1.1f3b9f879a000p-3},
+{0x1.2539d838ff5bdp+0, -0x1.160c8252ca000p-3},
+{0x1.23eb7aac9083bp+0, -0x1.0ce7f57f72000p-3},
+{0x1.22a012ba940b6p+0, -0x1.03cdc49fea000p-3},
+{0x1.2157996cc4132p+0, -0x1.f57bdbc4b8000p-4},
+{0x1.201201dd2fc9bp+0, -0x1.e370896404000p-4},
+{0x1.1ecf4494d480bp+0, -0x1.d17983ef94000p-4},
+{0x1.1d8f5528f6569p+0, -0x1.bf9674ed8a000p-4},
+{0x1.1c52311577e7cp+0, -0x1.adc79202f6000p-4},
+{0x1.1b17c74cb26e9p+0, -0x1.9c0c3e7288000p-4},
+{0x1.19e010c2c1ab6p+0, -0x1.8a646b372c000p-4},
+{0x1.18ab07bb670bdp+0, -0x1.78d01b3ac0000p-4},
+{0x1.1778a25efbcb6p+0, -0x1.674f145380000p-4},
+{0x1.1648d354c31dap+0, -0x1.55e0e6d878000p-4},
+{0x1.151b990275fddp+0, -0x1.4485cdea1e000p-4},
+{0x1.13f0ea432d24cp+0, -0x1.333d94d6aa000p-4},
+{0x1.12c8b7210f9dap+0, -0x1.22079f8c56000p-4},
+{0x1.11a3028ecb531p+0, -0x1.10e4698622000p-4},
+{0x1.107fbda8434afp+0, -0x1.ffa6c6ad20000p-5},
+{0x1.0f5ee0f4e6bb3p+0, -0x1.dda8d4a774000p-5},
+{0x1.0e4065d2a9fcep+0, -0x1.bbcece4850000p-5},
+{0x1.0d244632ca521p+0, -0x1.9a1894012c000p-5},
+{0x1.0c0a77ce2981ap+0, -0x1.788583302c000p-5},
+{0x1.0af2f83c636d1p+0, -0x1.5715e67d68000p-5},
+{0x1.09ddb98a01339p+0, -0x1.35c8a49658000p-5},
+{0x1.08cabaf52e7dfp+0, -0x1.149e364154000p-5},
+{0x1.07b9f2f4e28fbp+0, -0x1.e72c082eb8000p-6},
+{0x1.06ab58c358f19p+0, -0x1.a55f152528000p-6},
+{0x1.059eea5ecf92cp+0, -0x1.63d62cf818000p-6},
+{0x1.04949cdd12c90p+0, -0x1.228fb8caa0000p-6},
+{0x1.038c6c6f0ada9p+0, -0x1.c317b20f90000p-7},
+{0x1.02865137932a9p+0, -0x1.419355daa0000p-7},
+{0x1.0182427ea7348p+0, -0x1.81203c2ec0000p-8},
+{0x1.008040614b195p+0, -0x1.0040979240000p-9},
+{0x1.fe01ff726fa1ap-1, 0x1.feff384900000p-9},
+{0x1.fa11cc261ea74p-1, 0x1.7dc41353d0000p-7},
+{0x1.f6310b081992ep-1, 0x1.3cea3c4c28000p-6},
+{0x1.f25f63ceeadcdp-1, 0x1.b9fc114890000p-6},
+{0x1.ee9c8039113e7p-1, 0x1.1b0d8ce110000p-5},
+{0x1.eae8078cbb1abp-1, 0x1.58a5bd001c000p-5},
+{0x1.e741aa29d0c9bp-1, 0x1.95c8340d88000p-5},
+{0x1.e3a91830a99b5p-1, 0x1.d276aef578000p-5},
+{0x1.e01e009609a56p-1, 0x1.07598e598c000p-4},
+{0x1.dca01e577bb98p-1, 0x1.253f5e30d2000p-4},
+{0x1.d92f20b7c9103p-1, 0x1.42edd8b380000p-4},
+{0x1.d5cac66fb5ccep-1, 0x1.606598757c000p-4},
+{0x1.d272caa5ede9dp-1, 0x1.7da76356a0000p-4},
+{0x1.cf26e3e6b2ccdp-1, 0x1.9ab434e1c6000p-4},
+{0x1.cbe6da2a77902p-1, 0x1.b78c7bb0d6000p-4},
+{0x1.c8b266d37086dp-1, 0x1.d431332e72000p-4},
+{0x1.c5894bd5d5804p-1, 0x1.f0a3171de6000p-4},
+{0x1.c26b533bb9f8cp-1, 0x1.067152b914000p-3},
+{0x1.bf583eeece73fp-1, 0x1.147858292b000p-3},
+{0x1.bc4fd75db96c1p-1, 0x1.2266ecdca3000p-3},
+{0x1.b951e0c864a28p-1, 0x1.303d7a6c55000p-3},
+{0x1.b65e2c5ef3e2cp-1, 0x1.3dfc33c331000p-3},
+{0x1.b374867c9888bp-1, 0x1.4ba366b7a8000p-3},
+{0x1.b094b211d304ap-1, 0x1.5933928d1f000p-3},
+{0x1.adbe885f2ef7ep-1, 0x1.66acd2418f000p-3},
+{0x1.aaf1d31603da2p-1, 0x1.740f8ec669000p-3},
+{0x1.a82e63fd358a7p-1, 0x1.815c0f51af000p-3},
+{0x1.a5740ef09738bp-1, 0x1.8e92954f68000p-3},
+{0x1.a2c2a90ab4b27p-1, 0x1.9bb3602f84000p-3},
+{0x1.a01a01393f2d1p-1, 0x1.a8bed1c2c0000p-3},
+{0x1.9d79f24db3c1bp-1, 0x1.b5b515c01d000p-3},
+{0x1.9ae2505c7b190p-1, 0x1.c2967ccbcc000p-3},
+{0x1.9852ef297ce2fp-1, 0x1.cf635d5486000p-3},
+{0x1.95cbaeea44b75p-1, 0x1.dc1bd3446c000p-3},
+{0x1.934c69de74838p-1, 0x1.e8c01b8cfe000p-3},
+{0x1.90d4f2f6752e6p-1, 0x1.f5509c0179000p-3},
+{0x1.8e6528effd79dp-1, 0x1.00e6c121fb800p-2},
+{0x1.8bfce9fcc007cp-1, 0x1.071b80e93d000p-2},
+{0x1.899c0dabec30ep-1, 0x1.0d46b9e867000p-2},
+{0x1.87427aa2317fbp-1, 0x1.13687334bd000p-2},
+{0x1.84f00acb39a08p-1, 0x1.1980d67234800p-2},
+{0x1.82a49e8653e55p-1, 0x1.1f8ffe0cc8000p-2},
+{0x1.8060195f40260p-1, 0x1.2595fd7636800p-2},
+{0x1.7e22563e0a329p-1, 0x1.2b9300914a800p-2},
+{0x1.7beb377dcb5adp-1, 0x1.3187210436000p-2},
+{0x1.79baa679725c2p-1, 0x1.377266dec1800p-2},
+{0x1.77907f2170657p-1, 0x1.3d54ffbaf3000p-2},
+{0x1.756cadbd6130cp-1, 0x1.432eee32fe000p-2},
+},
+};
+
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.h b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.h
new file mode 100644
index 0000000000..2a78a2065c
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_log_data.h
@@ -0,0 +1,36 @@ 
+/* Constants used in polynomial approximations for vectorized log
+   funtion.
+   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/>.  */
+#ifndef S_LOG_DATA_H
+#define S_LOG_DATA_H
+
+#define LOG_TABLE_BITS 7
+#define LOG_POLY_ORDER 6
+#define LOG_POLY1_ORDER 12
+extern hidden const struct log_data {
+	double ln2hi;
+	double ln2lo;
+	double poly[LOG_POLY_ORDER - 1]; /* First coefficient is 1.  */
+	double poly1[LOG_POLY1_ORDER - 1];
+	struct {
+		double invc, logc;
+	} tab[1 << LOG_TABLE_BITS];
+} __log_data;
+
+#endif
+
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf4_vsx.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf4_vsx.c
new file mode 100644
index 0000000000..83a4ee265f
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf4_vsx.c
@@ -0,0 +1,126 @@ 
+/* Single-precision vector logf(x) function.
+   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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+#include <altivec.h>
+/*
+LOGF_TABLE_BITS = 4
+LOGF_POLY_ORDER = 4
+
+ULP error: 0.818 (nearest rounding.)
+Relative error: 1.957 * 2^-26 (before rounding.)
+*/
+#include "vec_s_logf_data.h"
+
+#define INF 0x7F800000
+#define NINF 0xFF800000
+
+typedef union {
+  vector float f;
+  vector unsigned i;
+  vector int s;
+  vector double d;
+  vector long long unsigned l;
+} u;
+
+#define T __logf_data.tab
+#define A __logf_data.poly
+#define Ln2 __logf_data.ln2
+#define N (1 << LOGF_TABLE_BITS)
+#define OFF 0x3f330000
+
+vector float _ZGVbN4v_logf(vector float x) {
+  vector unsigned inf = {INF, INF, INF, INF};
+  vector unsigned ninf = inf | (1 << 31);
+  vector unsigned zero = {0, 0, 0, 0};
+  vector unsigned special_cases, is_subnormal;
+
+  u un;
+  un.f = x;
+  vector unsigned xi = un.i;
+  vector unsigned is_special_cases = (vector unsigned)vec_cmpge(xi - 0x00800000, inf - 0x00800000);
+  if (!vec_all_eq(is_special_cases, zero)) {
+    // 0 pos -> -inf, 0 neg -> NaN
+    vector unsigned is_zero = (vector unsigned)vec_cmpeq(xi << 1, zero);
+    special_cases = is_zero & ninf;
+
+    // inf -> inf
+    vector unsigned is_inf = (vector unsigned)vec_cmpeq(xi, inf);;
+    special_cases = vec_sel(special_cases, inf, is_inf);
+
+    // Invalid
+    vector unsigned is_negative = (vector unsigned)vec_cmpne(xi & 0x80000000, zero);
+    vector unsigned splat = {0xff000000, 0xff000000, 0xff000000, 0xff000000};
+    vector unsigned is_outofrange = (vector unsigned)vec_cmpge(xi << 1, splat);
+    vector unsigned not_inf_or_zero = ~is_inf & ~is_zero;
+    vector unsigned is_invalid = (is_negative | is_outofrange) & not_inf_or_zero;
+    vector unsigned nan = {0x7f800001, 0x7f800001, 0x7f800001, 0x7f800001};
+    special_cases = vec_sel(special_cases, nan, is_invalid);
+
+    // normalize subnormals
+    is_subnormal = is_special_cases & ~is_invalid & not_inf_or_zero;
+    vector unsigned subnormals = is_subnormal & xi;
+    un.i = subnormals;
+    u un2;
+    un2.f = un.f * 0x1p23f;
+    subnormals = un2.i - (23 << 23);
+
+    // clear subnormals, and merge in normalized ones
+    xi = vec_sel(xi, subnormals, is_subnormal);
+  } else {
+    special_cases = zero;
+    is_subnormal = zero;
+  }
+
+  // back to the main part
+  vector unsigned tmp = xi - OFF;
+  vector unsigned i = (tmp >> (23 - LOGF_TABLE_BITS)) % N;
+  vector int k = ((vector int)tmp >> 23);
+  vector unsigned iz = xi - (tmp & 0x1ff << 23);
+
+  vector double abinv = {(double)T[i[0]].invc, (double)T[i[1]].invc};
+  vector double ablogc = {(double)T[i[0]].logc, (double)T[i[1]].logc};
+  vector double cdinv = {(double)T[i[2]].invc, (double)T[i[3]].invc};
+  vector double cdlogc = {(double)T[i[2]].logc, (double)T[i[3]].logc};
+
+  u izu;
+  izu.i = iz;
+  vector double izl = vec_unpackh(izu.f);
+  vector double izr = vec_unpackl(izu.f);;
+  vector double rl = izl * abinv - 1;
+  vector double rr = izr * cdinv - 1;
+  vector double kl = {(double)k[0], (double)k[1]};
+  vector double kr = {(double)k[2], (double)k[3]};
+  vector double Ln2v = {Ln2, Ln2};
+  vector double y0l = ablogc + kl * Ln2v;
+  vector double y0r = cdlogc + kr * Ln2v;
+
+  vector double r2l = rl * rl;
+  vector double r2r = rr * rr;
+  vector double yl = A[1] * rl + A[2];
+  vector double yr = A[1] * rr + A[2];
+  yl = A[0] * r2l + yl;
+  yr = A[0] * r2r + yr;
+  yl = yl * r2l + (y0l + rl);
+  yr = yr * r2r + (y0r + rr);
+  vector float y = {(float)yl[0], (float)yl[1], (float)yr[0], (float)yr[1]};
+  un.f = y;
+  un.i = vec_sel(un.i, special_cases, is_special_cases & ~is_subnormal);
+  return un.f;
+}
+#ifndef USE_MULTIARCH
+ libmvec_hidden_def (_ZGVbN4v_logf)
+#endif
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.c
new file mode 100644
index 0000000000..58902ee77b
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.c
@@ -0,0 +1,44 @@ 
+/* Constants used in polynomial approximations for vectorized logf
+   Copyright (C) 2017-2018 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/>.  */
+
+#include "vec_s_logf_data.h"
+
+const struct logf_data __logf_data = {
+  .tab = {
+  { 0x1.661ec79f8f3bep+0, -0x1.57bf7808caadep-2 },
+  { 0x1.571ed4aaf883dp+0, -0x1.2bef0a7c06ddbp-2 },
+  { 0x1.49539f0f010bp+0, -0x1.01eae7f513a67p-2 },
+  { 0x1.3c995b0b80385p+0, -0x1.b31d8a68224e9p-3 },
+  { 0x1.30d190c8864a5p+0, -0x1.6574f0ac07758p-3 },
+  { 0x1.25e227b0b8eap+0, -0x1.1aa2bc79c81p-3 },
+  { 0x1.1bb4a4a1a343fp+0, -0x1.a4e76ce8c0e5ep-4 },
+  { 0x1.12358f08ae5bap+0, -0x1.1973c5a611cccp-4 },
+  { 0x1.0953f419900a7p+0, -0x1.252f438e10c1ep-5 },
+  { 0x1p+0, 0x0p+0 },
+  { 0x1.e608cfd9a47acp-1, 0x1.aa5aa5df25984p-5 },
+  { 0x1.ca4b31f026aap-1, 0x1.c5e53aa362eb4p-4 },
+  { 0x1.b2036576afce6p-1, 0x1.526e57720db08p-3 },
+  { 0x1.9c2d163a1aa2dp-1, 0x1.bc2860d22477p-3 },
+  { 0x1.886e6037841edp-1, 0x1.1058bc8a07ee1p-2 },
+  { 0x1.767dcf5534862p-1, 0x1.4043057b6ee09p-2 },
+  },
+  .ln2 = 0x1.62e42fefa39efp-1,
+  .poly = {
+  -0x1.00ea348b88334p-2, 0x1.5575b0be00b6ap-2, -0x1.ffffef20a4123p-2,
+  }
+};
diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.h b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.h
new file mode 100644
index 0000000000..7d97cc6dbb
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/vec_s_logf_data.h
@@ -0,0 +1,32 @@ 
+/* Constants used in polynomial approximations for vectorized logf
+   Copyright (C) 2017-2018 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/>.  */
+#ifndef S_LOGF_DATA_H
+#define S_LOGF_DATA_H
+
+#define LOGF_TABLE_BITS 4
+#define LOGF_POLY_ORDER 4
+extern hidden const struct logf_data {
+	struct {
+		double invc, logc;
+	} tab[1 << LOGF_TABLE_BITS];
+	double ln2;
+	double poly[LOGF_POLY_ORDER - 1]; /* First order coefficient is 1.  */
+} __logf_data;
+
+#endif
+