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-rw-r--r--pl/math/sv_sinf_1u9.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/pl/math/sv_sinf_1u9.c b/pl/math/sv_sinf_1u9.c
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+++ b/pl/math/sv_sinf_1u9.c
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+/*
+ * Single-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"
+
+#if SV_SUPPORTED
+
+#define A3 (sv_f32 (__sv_sinf_data.coeffs[3]))
+#define A5 (sv_f32 (__sv_sinf_data.coeffs[2]))
+#define A7 (sv_f32 (__sv_sinf_data.coeffs[1]))
+#define A9 (sv_f32 (__sv_sinf_data.coeffs[0]))
+
+#define NegPi1 (sv_f32 (-0x1.921fb6p+1f))
+#define NegPi2 (sv_f32 (0x1.777a5cp-24f))
+#define NegPi3 (sv_f32 (0x1.ee59dap-49f))
+#define RangeVal (sv_f32 (0x1p20f))
+#define InvPi (sv_f32 (0x1.45f306p-2f))
+#define Shift (sv_f32 (0x1.8p+23f))
+#define AbsMask (0x7fffffff)
+
+static NOINLINE sv_f32_t
+__sv_sinf_specialcase (sv_f32_t x, sv_f32_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_sinf(0x1.9247a4p+0) got 0x1.fffff6p-1 want 0x1.fffffap-1. */
+sv_f32_t
+__sv_sinf_x (sv_f32_t x, const svbool_t pg)
+{
+ sv_f32_t n, r, r2, y;
+ sv_u32_t sign, odd;
+ svbool_t cmp;
+
+ r = sv_as_f32_u32 (svand_n_u32_x (pg, sv_as_u32_f32 (x), AbsMask));
+ sign = svand_n_u32_x (pg, sv_as_u32_f32 (x), ~AbsMask);
+ cmp = svcmpge_u32 (pg, sv_as_u32_f32 (r), sv_as_u32_f32 (RangeVal));
+
+ /* n = rint(|x|/pi). */
+ n = sv_fma_f32_x (pg, InvPi, r, Shift);
+ odd = svlsl_n_u32_x (pg, sv_as_u32_f32 (n), 31);
+ n = svsub_f32_x (pg, n, Shift);
+
+ /* r = |x| - n*pi (range reduction into -pi/2 .. pi/2). */
+ r = sv_fma_f32_x (pg, NegPi1, n, r);
+ r = sv_fma_f32_x (pg, NegPi2, n, r);
+ r = sv_fma_f32_x (pg, NegPi3, n, r);
+
+ /* sin(r) approx using a degree 9 polynomial from the Taylor series
+ expansion. Note that only the odd terms of this are non-zero. */
+ r2 = svmul_f32_x (pg, r, r);
+ y = sv_fma_f32_x (pg, A9, r2, A7);
+ y = sv_fma_f32_x (pg, y, r2, A5);
+ y = sv_fma_f32_x (pg, y, r2, A3);
+ y = sv_fma_f32_x (pg, svmul_f32_x (pg, y, r2), r, r);
+
+ /* sign = y^sign^odd. */
+ y = sv_as_f32_u32 (
+ sveor_u32_x (pg, sv_as_u32_f32 (y), sveor_u32_x (pg, sign, odd)));
+
+ /* No need to pass pg to specialcase here since cmp is a strict subset,
+ guaranteed by the cmpge above. */
+ if (unlikely (svptest_any (pg, cmp)))
+ return __sv_sinf_specialcase (x, y, cmp);
+ return y;
+}
+
+PL_ALIAS (__sv_sinf_x, _ZGVsMxv_sinf)
+
+PL_SIG (SV, F, 1, sin, -3.1, 3.1)
+PL_TEST_ULP (__sv_sinf, 1.40)
+PL_TEST_INTERVAL (__sv_sinf, 0, 0xffff0000, 10000)
+PL_TEST_INTERVAL (__sv_sinf, 0x1p-4, 0x1p4, 500000)
+#endif