1 /* 2 * Single-precision sin/cos function. 3 * 4 * Copyright (c) 2018-2019, Arm Limited. 5 * SPDX-License-Identifier: MIT 6 */ 7 8 #include <stdint.h> 9 #include <math.h> 10 #include "math_config.h" 11 #include "sincosf.h" 12 13 /* Fast sincosf implementation. Worst-case ULP is 0.5607, maximum relative 14 error is 0.5303 * 2^-23. A single-step range reduction is used for 15 small values. Large inputs have their range reduced using fast integer 16 arithmetic. */ 17 void 18 sincosf (float y, float *sinp, float *cosp) 19 { 20 double x = y; 21 double s; 22 int n; 23 const sincos_t *p = &__sincosf_table[0]; 24 25 if (abstop12 (y) < abstop12 (pio4)) 26 { 27 double x2 = x * x; 28 29 if (unlikely (abstop12 (y) < abstop12 (0x1p-12f))) 30 { 31 if (unlikely (abstop12 (y) < abstop12 (0x1p-126f))) 32 /* Force underflow for tiny y. */ 33 force_eval_float (x2); 34 *sinp = y; 35 *cosp = 1.0f; 36 return; 37 } 38 39 sincosf_poly (x, x2, p, 0, sinp, cosp); 40 } 41 else if (abstop12 (y) < abstop12 (120.0f)) 42 { 43 x = reduce_fast (x, p, &n); 44 45 /* Setup the signs for sin and cos. */ 46 s = p->sign[n & 3]; 47 48 if (n & 2) 49 p = &__sincosf_table[1]; 50 51 sincosf_poly (x * s, x * x, p, n, sinp, cosp); 52 } 53 else if (likely (abstop12 (y) < abstop12 (INFINITY))) 54 { 55 uint32_t xi = asuint (y); 56 int sign = xi >> 31; 57 58 x = reduce_large (xi, &n); 59 60 /* Setup signs for sin and cos - include original sign. */ 61 s = p->sign[(n + sign) & 3]; 62 63 if ((n + sign) & 2) 64 p = &__sincosf_table[1]; 65 66 sincosf_poly (x * s, x * x, p, n, sinp, cosp); 67 } 68 else 69 { 70 /* Return NaN if Inf or NaN for both sin and cos. */ 71 *sinp = *cosp = y - y; 72 #if WANT_ERRNO 73 /* Needed to set errno for +-Inf, the add is a hack to work 74 around a gcc register allocation issue: just passing y 75 affects code generation in the fast path. */ 76 __math_invalidf (y + y); 77 #endif 78 } 79 } 80