1 files changed, 96 insertions, 0 deletions
diff --git a/sysdeps/aarch64/fpu/sinf_sve.c b/sysdeps/aarch64/fpu/sinf_sve.c
new file mode 100644
index 0000000000..4d2ce7a846
--- /dev/null
+++ b/sysdeps/aarch64/fpu/sinf_sve.c
@@ -0,0 +1,96 @@
+/* Single-precision vector (SVE) sin function.
+
+   Copyright (C) 2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include "sv_math.h"
+
+static const struct data
+{
+  float poly[4];
+  /* Pi-related values to be loaded as one quad-word and used with
+     svmla_lane_f32.  */
+  float negpi1, negpi2, negpi3, invpi;
+  float shift;
+} data = {
+  .poly = {
+    /* Non-zero coefficients from the degree 9 Taylor series expansion of
+       sin.  */
+    -0x1.555548p-3f, 0x1.110df4p-7f, -0x1.9f42eap-13f, 0x1.5b2e76p-19f
+  },
+  .negpi1 = -0x1.921fb6p+1f,
+  .negpi2 = 0x1.777a5cp-24f,
+  .negpi3 = 0x1.ee59dap-49f,
+  .invpi = 0x1.45f306p-2f,
+  .shift = 0x1.8p+23f
+};
+
+#define RangeVal 0x49800000 /* asuint32 (0x1p20f).  */
+#define C(i) sv_f32 (d->poly[i])
+
+static svfloat32_t NOINLINE
+special_case (svfloat32_t x, svfloat32_t y, svbool_t cmp)
+{
+  return sv_call_f32 (sinf, x, y, cmp);
+}
+
+/* A fast SVE implementation of sinf.
+   Maximum error: 1.89 ULPs.
+   This maximum error is achieved at multiple values in [-2^18, 2^18]
+   but one example is:
+   SV_NAME_F1 (sin)(0x1.9247a4p+0) got 0x1.fffff6p-1 want 0x1.fffffap-1.  */
+svfloat32_t SV_NAME_F1 (sin) (svfloat32_t x, const svbool_t pg)
+{
+  const struct data *d = ptr_barrier (&data);
+
+  svfloat32_t ax = svabs_f32_x (pg, x);
+  svuint32_t sign = sveor_u32_x (pg, svreinterpret_u32_f32 (x),
+				 svreinterpret_u32_f32 (ax));
+  svbool_t cmp = svcmpge_n_u32 (pg, svreinterpret_u32_f32 (ax), RangeVal);
+
+  /* pi_vals are a quad-word of helper values - the first 3 elements contain
+     -pi in extended precision, the last contains 1 / pi.  */
+  svfloat32_t pi_vals = svld1rq_f32 (svptrue_b32 (), &d->negpi1);
+
+  /* n = rint(|x|/pi).  */
+  svfloat32_t n = svmla_lane_f32 (sv_f32 (d->shift), ax, pi_vals, 3);
+  svuint32_t odd = svlsl_n_u32_x (pg, svreinterpret_u32_f32 (n), 31);
+  n = svsub_n_f32_x (pg, n, d->shift);
+
+  /* r = |x| - n*pi  (range reduction into -pi/2 .. pi/2).  */
+  svfloat32_t r;
+  r = svmla_lane_f32 (ax, n, pi_vals, 0);
+  r = svmla_lane_f32 (r, n, pi_vals, 1);
+  r = svmla_lane_f32 (r, n, pi_vals, 2);
+
+  /* sin(r) approx using a degree 9 polynomial from the Taylor series
+     expansion. Note that only the odd terms of this are non-zero.  */
+  svfloat32_t r2 = svmul_f32_x (pg, r, r);
+  svfloat32_t y;
+  y = svmla_f32_x (pg, C (2), r2, C (3));
+  y = svmla_f32_x (pg, C (1), r2, y);
+  y = svmla_f32_x (pg, C (0), r2, y);
+  y = svmla_f32_x (pg, r, r, svmul_f32_x (pg, y, r2));
+
+  /* sign = y^sign^odd.  */
+  y = svreinterpret_f32_u32 (sveor_u32_x (pg, svreinterpret_u32_f32 (y),
+					  sveor_u32_x (pg, sign, odd)));
+
+  if (__glibc_unlikely (svptest_any (pg, cmp)))
+    return special_case (x, y, cmp);
+  return y;
+}