aboutsummaryrefslogtreecommitdiff
path: root/pl/math/sv_sin_3u5.c
diff options
context:
space:
mode:
Diffstat (limited to 'pl/math/sv_sin_3u5.c')
-rw-r--r--pl/math/sv_sin_3u5.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/pl/math/sv_sin_3u5.c b/pl/math/sv_sin_3u5.c
new file mode 100644
index 000000000000..a81f3fc80f3d
--- /dev/null
+++ b/pl/math/sv_sin_3u5.c
@@ -0,0 +1,96 @@
+/*
+ * Double-precision SVE sin(x) function.
+ *
+ * Copyright (c) 2019-2023, Arm Limited.
+ * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
+ */
+
+#include "sv_math.h"
+#include "pl_sig.h"
+#include "pl_test.h"
+
+static const struct data
+{
+ double inv_pi, pi_1, pi_2, pi_3, shift, range_val;
+ double poly[7];
+} data = {
+ .poly = { -0x1.555555555547bp-3, 0x1.1111111108a4dp-7, -0x1.a01a019936f27p-13,
+ 0x1.71de37a97d93ep-19, -0x1.ae633919987c6p-26,
+ 0x1.60e277ae07cecp-33, -0x1.9e9540300a1p-41, },
+
+ .inv_pi = 0x1.45f306dc9c883p-2,
+ .pi_1 = 0x1.921fb54442d18p+1,
+ .pi_2 = 0x1.1a62633145c06p-53,
+ .pi_3 = 0x1.c1cd129024e09p-106,
+ .shift = 0x1.8p52,
+ .range_val = 0x1p23,
+};
+
+#define C(i) sv_f64 (d->poly[i])
+
+static svfloat64_t NOINLINE
+special_case (svfloat64_t x, svfloat64_t y, svbool_t cmp)
+{
+ return sv_call_f64 (sin, x, y, cmp);
+}
+
+/* A fast SVE implementation of sin.
+ Maximum observed error in [-pi/2, pi/2], where argument is not reduced,
+ is 2.87 ULP:
+ _ZGVsMxv_sin (0x1.921d5c6a07142p+0) got 0x1.fffffffa7dc02p-1
+ want 0x1.fffffffa7dc05p-1
+ Maximum observed error in the entire non-special domain ([-2^23, 2^23])
+ is 3.22 ULP:
+ _ZGVsMxv_sin (0x1.5702447b6f17bp+22) got 0x1.ffdcd125c84fbp-3
+ want 0x1.ffdcd125c84f8p-3. */
+svfloat64_t SV_NAME_D1 (sin) (svfloat64_t x, const svbool_t pg)
+{
+ const struct data *d = ptr_barrier (&data);
+
+ /* Load some values in quad-word chunks to minimise memory access. */
+ const svbool_t ptrue = svptrue_b64 ();
+ svfloat64_t shift = sv_f64 (d->shift);
+ svfloat64_t inv_pi_and_pi1 = svld1rq (ptrue, &d->inv_pi);
+ svfloat64_t pi2_and_pi3 = svld1rq (ptrue, &d->pi_2);
+
+ /* n = rint(|x|/pi). */
+ svfloat64_t n = svmla_lane (shift, x, inv_pi_and_pi1, 0);
+ svuint64_t odd = svlsl_x (pg, svreinterpret_u64 (n), 63);
+ n = svsub_x (pg, n, shift);
+
+ /* r = |x| - n*(pi/2) (range reduction into -pi/2 .. pi/2). */
+ svfloat64_t r = x;
+ r = svmls_lane (r, n, inv_pi_and_pi1, 1);
+ r = svmls_lane (r, n, pi2_and_pi3, 0);
+ r = svmls_lane (r, n, pi2_and_pi3, 1);
+
+ /* sin(r) poly approx. */
+ svfloat64_t r2 = svmul_x (pg, r, r);
+ svfloat64_t r3 = svmul_x (pg, r2, r);
+ svfloat64_t r4 = svmul_x (pg, r2, r2);
+
+ svfloat64_t t1 = svmla_x (pg, C (4), C (5), r2);
+ svfloat64_t t2 = svmla_x (pg, C (2), C (3), r2);
+ svfloat64_t t3 = svmla_x (pg, C (0), C (1), r2);
+
+ svfloat64_t y = svmla_x (pg, t1, C (6), r4);
+ y = svmla_x (pg, t2, y, r4);
+ y = svmla_x (pg, t3, y, r4);
+ y = svmla_x (pg, r, y, r3);
+
+ svbool_t cmp = svacle (pg, x, d->range_val);
+ cmp = svnot_z (pg, cmp);
+ if (unlikely (svptest_any (pg, cmp)))
+ return special_case (x,
+ svreinterpret_f64 (sveor_z (
+ svnot_z (pg, cmp), svreinterpret_u64 (y), odd)),
+ cmp);
+
+ /* Copy sign. */
+ return svreinterpret_f64 (sveor_z (pg, svreinterpret_u64 (y), odd));
+}
+
+PL_SIG (SV, D, 1, sin, -3.1, 3.1)
+PL_TEST_ULP (SV_NAME_D1 (sin), 2.73)
+PL_TEST_SYM_INTERVAL (SV_NAME_D1 (sin), 0, 0x1p23, 1000000)
+PL_TEST_SYM_INTERVAL (SV_NAME_D1 (sin), 0x1p23, inf, 10000)