diff options
Diffstat (limited to 'math/v_exp2f.c')
| -rw-r--r-- | math/v_exp2f.c | 117 |
1 files changed, 0 insertions, 117 deletions
diff --git a/math/v_exp2f.c b/math/v_exp2f.c deleted file mode 100644 index 7f40dbaa6679..000000000000 --- a/math/v_exp2f.c +++ /dev/null @@ -1,117 +0,0 @@ -/* - * Single-precision vector 2^x function. - * - * Copyright (c) 2019-2022, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#include "mathlib.h" -#include "v_math.h" -#if V_SUPPORTED - -static const float Poly[] = { - /* maxerr: 1.962 ulp. */ - 0x1.59977ap-10f, - 0x1.3ce9e4p-7f, - 0x1.c6bd32p-5f, - 0x1.ebf9bcp-3f, - 0x1.62e422p-1f, -}; -#define C0 v_f32 (Poly[0]) -#define C1 v_f32 (Poly[1]) -#define C2 v_f32 (Poly[2]) -#define C3 v_f32 (Poly[3]) -#define C4 v_f32 (Poly[4]) - -#define Shift v_f32 (0x1.8p23f) - -#if WANT_SIMD_EXCEPT - -#define TinyBound 0x20000000 /* asuint (0x1p-63). */ -#define BigBound 0x42800000 /* asuint (0x1p6). */ - -VPCS_ATTR -static NOINLINE v_f32_t -specialcase (v_f32_t x, v_f32_t y, v_u32_t cmp) -{ - /* If fenv exceptions are to be triggered correctly, fall back to the scalar - routine to special lanes. */ - return v_call_f32 (exp2f, x, y, cmp); -} - -#else - -VPCS_ATTR -static v_f32_t -specialcase (v_f32_t poly, v_f32_t n, v_u32_t e, v_f32_t absn, v_u32_t cmp1, v_f32_t scale) -{ - /* 2^n may overflow, break it up into s1*s2. */ - v_u32_t b = v_cond_u32 (n <= v_f32 (0.0f)) & v_u32 (0x82000000); - v_f32_t s1 = v_as_f32_u32 (v_u32 (0x7f000000) + b); - v_f32_t s2 = v_as_f32_u32 (e - b); - v_u32_t cmp2 = v_cond_u32 (absn > v_f32 (192.0f)); - v_u32_t r2 = v_as_u32_f32 (s1 * s1); - v_u32_t r1 = v_as_u32_f32 (v_fma_f32 (poly, s2, s2) * s1); - /* Similar to r1 but avoids double rounding in the subnormal range. */ - v_u32_t r0 = v_as_u32_f32 (v_fma_f32 (poly, scale, scale)); - return v_as_f32_u32 ((cmp2 & r2) | (~cmp2 & cmp1 & r1) | (~cmp1 & r0)); -} - -#endif - -VPCS_ATTR -v_f32_t -V_NAME(exp2f) (v_f32_t x) -{ - v_f32_t n, r, r2, scale, p, q, poly; - v_u32_t cmp, e; - -#if WANT_SIMD_EXCEPT - cmp = v_cond_u32 ((v_as_u32_f32 (x) & 0x7fffffff) - TinyBound - >= BigBound - TinyBound); - v_f32_t xm = x; - /* If any lanes are special, mask them with 1 and retain a copy of x to allow - specialcase to fix special lanes later. This is only necessary if fenv - exceptions are to be triggered correctly. */ - if (unlikely (v_any_u32 (cmp))) - x = v_sel_f32 (cmp, v_f32 (1), x); -#endif - - /* exp2(x) = 2^n (1 + poly(r)), with 1 + poly(r) in [1/sqrt(2),sqrt(2)] - x = n + r, with r in [-1/2, 1/2]. */ -#if 0 - v_f32_t z; - z = x + Shift; - n = z - Shift; - r = x - n; - e = v_as_u32_f32 (z) << 23; -#else - n = v_round_f32 (x); - r = x - n; - e = v_as_u32_s32 (v_round_s32 (x)) << 23; -#endif - scale = v_as_f32_u32 (e + v_u32 (0x3f800000)); - -#if !WANT_SIMD_EXCEPT - v_f32_t absn = v_abs_f32 (n); - cmp = v_cond_u32 (absn > v_f32 (126.0f)); -#endif - - r2 = r * r; - p = v_fma_f32 (C0, r, C1); - q = v_fma_f32 (C2, r, C3); - q = v_fma_f32 (p, r2, q); - p = C4 * r; - poly = v_fma_f32 (q, r2, p); - - if (unlikely (v_any_u32 (cmp))) -#if WANT_SIMD_EXCEPT - return specialcase (xm, v_fma_f32 (poly, scale, scale), cmp); -#else - return specialcase (poly, n, e, absn, cmp, scale); -#endif - - return v_fma_f32 (poly, scale, scale); -} -VPCS_ALIAS -#endif |
