| /* |
| * 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" |
| |
| #if SV_SUPPORTED |
| |
| #define InvPi (sv_f64 (0x1.45f306dc9c883p-2)) |
| #define HalfPi (sv_f64 (0x1.921fb54442d18p+0)) |
| #define InvPio2 (sv_f64 (0x1.45f306dc9c882p-1)) |
| #define NegPio2_1 (sv_f64 (-0x1.921fb50000000p+0)) |
| #define NegPio2_2 (sv_f64 (-0x1.110b460000000p-26)) |
| #define NegPio2_3 (sv_f64 (-0x1.1a62633145c07p-54)) |
| #define Shift (sv_f64 (0x1.8p52)) |
| #define RangeVal (sv_f64 (0x1p23)) |
| #define AbsMask (0x7fffffffffffffff) |
| |
| static NOINLINE sv_f64_t |
| __sv_sin_specialcase (sv_f64_t x, sv_f64_t y, svbool_t cmp) |
| { |
| return sv_call_f64 (sin, x, y, cmp); |
| } |
| |
| /* A fast SVE implementation of sin based on trigonometric |
| instructions (FTMAD, FTSSEL, FTSMUL). |
| Maximum observed error in 2.52 ULP: |
| __sv_sin(0x1.2d2b00df69661p+19) got 0x1.10ace8f3e786bp-40 |
| want 0x1.10ace8f3e7868p-40. */ |
| sv_f64_t |
| __sv_sin_x (sv_f64_t x, const svbool_t pg) |
| { |
| sv_f64_t n, r, r2, y; |
| sv_u64_t sign; |
| svbool_t cmp; |
| |
| r = sv_as_f64_u64 (svand_n_u64_x (pg, sv_as_u64_f64 (x), AbsMask)); |
| sign = svand_n_u64_x (pg, sv_as_u64_f64 (x), ~AbsMask); |
| cmp = svcmpge_u64 (pg, sv_as_u64_f64 (r), sv_as_u64_f64 (RangeVal)); |
| |
| /* n = rint(|x|/(pi/2)). */ |
| sv_f64_t q = sv_fma_f64_x (pg, InvPio2, r, Shift); |
| n = svsub_f64_x (pg, q, Shift); |
| |
| /* r = |x| - n*(pi/2) (range reduction into -pi/4 .. pi/4). */ |
| r = sv_fma_f64_x (pg, NegPio2_1, n, r); |
| r = sv_fma_f64_x (pg, NegPio2_2, n, r); |
| r = sv_fma_f64_x (pg, NegPio2_3, n, r); |
| |
| /* Final multiplicative factor: 1.0 or x depending on bit #0 of q. */ |
| sv_f64_t f = svtssel_f64 (r, sv_as_u64_f64 (q)); |
| |
| /* sin(r) poly approx. */ |
| r2 = svtsmul_f64 (r, sv_as_u64_f64 (q)); |
| y = sv_f64 (0.0); |
| y = svtmad_f64 (y, r2, 7); |
| y = svtmad_f64 (y, r2, 6); |
| y = svtmad_f64 (y, r2, 5); |
| y = svtmad_f64 (y, r2, 4); |
| y = svtmad_f64 (y, r2, 3); |
| y = svtmad_f64 (y, r2, 2); |
| y = svtmad_f64 (y, r2, 1); |
| y = svtmad_f64 (y, r2, 0); |
| |
| /* Apply factor. */ |
| y = svmul_f64_x (pg, f, y); |
| |
| /* sign = y^sign. */ |
| y = sv_as_f64_u64 (sveor_u64_x (pg, sv_as_u64_f64 (y), sign)); |
| |
| /* 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_sin_specialcase (x, y, cmp); |
| return y; |
| } |
| |
| PL_ALIAS (__sv_sin_x, _ZGVsMxv_sin) |
| |
| PL_SIG (SV, D, 1, sin, -3.1, 3.1) |
| PL_TEST_ULP (__sv_sin, 2.03) |
| PL_TEST_INTERVAL (__sv_sin, 0, 0xffff0000, 10000) |
| PL_TEST_INTERVAL (__sv_sin, 0x1p-4, 0x1p4, 500000) |
| #endif |