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Diffstat (limited to 'pl/math/v_log_inline.h')
-rw-r--r-- | pl/math/v_log_inline.h | 104 |
1 files changed, 0 insertions, 104 deletions
diff --git a/pl/math/v_log_inline.h b/pl/math/v_log_inline.h deleted file mode 100644 index 2df00cf4ddf4..000000000000 --- a/pl/math/v_log_inline.h +++ /dev/null @@ -1,104 +0,0 @@ -/* - * Double-precision vector log(x) function - inline version - * - * Copyright (c) 2019-2023, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#include "v_math.h" -#include "math_config.h" - -#ifndef V_LOG_INLINE_POLY_ORDER -# error Cannot use inline log helper without specifying poly order (options are 4 or 5) -#endif - -#if V_LOG_INLINE_POLY_ORDER == 4 -# define POLY \ - { \ - V2 (-0x1.ffffffffcbad3p-2), V2 (0x1.555555578ed68p-2), \ - V2 (-0x1.0000d3a1e7055p-2), V2 (0x1.999392d02a63ep-3) \ - } -#elif V_LOG_INLINE_POLY_ORDER == 5 -# define POLY \ - { \ - V2 (-0x1.ffffffffffff7p-2), V2 (0x1.55555555170d4p-2), \ - V2 (-0x1.0000000399c27p-2), V2 (0x1.999b2e90e94cap-3), \ - V2 (-0x1.554e550bd501ep-3) \ - } -#else -# error Can only choose order 4 or 5 for log poly -#endif - -struct v_log_inline_data -{ - float64x2_t poly[V_LOG_INLINE_POLY_ORDER]; - float64x2_t ln2; - uint64x2_t off, sign_exp_mask; -}; - -#define V_LOG_CONSTANTS \ - { \ - .poly = POLY, .ln2 = V2 (0x1.62e42fefa39efp-1), \ - .sign_exp_mask = V2 (0xfff0000000000000), .off = V2 (0x3fe6900900000000) \ - } - -#define A(i) d->poly[i] -#define N (1 << V_LOG_TABLE_BITS) -#define IndexMask (N - 1) - -struct entry -{ - float64x2_t invc; - float64x2_t logc; -}; - -static inline struct entry -log_lookup (uint64x2_t i) -{ - /* Since N is a power of 2, n % N = n & (N - 1). */ - struct entry e; - uint64_t i0 = (i[0] >> (52 - V_LOG_TABLE_BITS)) & IndexMask; - uint64_t i1 = (i[1] >> (52 - V_LOG_TABLE_BITS)) & IndexMask; - float64x2_t e0 = vld1q_f64 (&__v_log_data.table[i0].invc); - float64x2_t e1 = vld1q_f64 (&__v_log_data.table[i1].invc); - e.invc = vuzp1q_f64 (e0, e1); - e.logc = vuzp2q_f64 (e0, e1); - return e; -} - -static inline float64x2_t -v_log_inline (float64x2_t x, const struct v_log_inline_data *d) -{ - float64x2_t z, r, r2, p, y, kd, hi; - uint64x2_t ix, iz, tmp; - int64x2_t k; - struct entry e; - - ix = vreinterpretq_u64_f64 (x); - - /* x = 2^k z; where z is in range [Off,2*Off) and exact. - The range is split into N subintervals. - The ith subinterval contains z and c is near its center. */ - tmp = vsubq_u64 (ix, d->off); - k = vshrq_n_s64 (vreinterpretq_s64_u64 (tmp), 52); /* arithmetic shift. */ - iz = vsubq_u64 (ix, vandq_u64 (tmp, d->sign_exp_mask)); - z = vreinterpretq_f64_u64 (iz); - e = log_lookup (tmp); - - /* log(x) = log1p(z/c-1) + log(c) + k*Ln2. */ - r = vfmaq_f64 (v_f64 (-1.0), z, e.invc); - kd = vcvtq_f64_s64 (k); - - /* hi = r + log(c) + k*Ln2. */ - hi = vfmaq_f64 (vaddq_f64 (e.logc, r), kd, d->ln2); - /* y = r2*(A0 + r*A1 + r2*(A2 + r*A3 + r2*A4)) + hi. */ - r2 = vmulq_f64 (r, r); - y = vfmaq_f64 (A (2), A (3), r); - p = vfmaq_f64 (A (0), A (1), r); -#if V_LOG_POLY_ORDER == 5 - y = vfmaq_f64 (y, A (4), r2); -#endif - y = vfmaq_f64 (p, y, r2); - - return vfmaq_f64 (hi, y, r2); -} |