diff options
Diffstat (limited to 'pl/math/v_log2f_2u5.c')
-rw-r--r-- | pl/math/v_log2f_2u5.c | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/pl/math/v_log2f_2u5.c b/pl/math/v_log2f_2u5.c deleted file mode 100644 index c64d88742136..000000000000 --- a/pl/math/v_log2f_2u5.c +++ /dev/null @@ -1,77 +0,0 @@ -/* - * Single-precision vector log2 function. - * - * Copyright (c) 2022-2023, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#include "v_math.h" -#include "poly_advsimd_f32.h" -#include "pl_sig.h" -#include "pl_test.h" - -static const struct data -{ - uint32x4_t min_norm; - uint16x8_t special_bound; - uint32x4_t off, mantissa_mask; - float32x4_t poly[9]; -} data = { - /* Coefficients generated using Remez algorithm approximate - log2(1+r)/r for r in [ -1/3, 1/3 ]. - rel error: 0x1.c4c4b0cp-26. */ - .poly = { V4 (0x1.715476p0f), /* (float)(1 / ln(2)). */ - V4 (-0x1.715458p-1f), V4 (0x1.ec701cp-2f), V4 (-0x1.7171a4p-2f), - V4 (0x1.27a0b8p-2f), V4 (-0x1.e5143ep-3f), V4 (0x1.9d8ecap-3f), - V4 (-0x1.c675bp-3f), V4 (0x1.9e495p-3f) }, - .min_norm = V4 (0x00800000), - .special_bound = V8 (0x7f00), /* asuint32(inf) - min_norm. */ - .off = V4 (0x3f2aaaab), /* 0.666667. */ - .mantissa_mask = V4 (0x007fffff), -}; - -static float32x4_t VPCS_ATTR NOINLINE -special_case (float32x4_t x, float32x4_t n, float32x4_t p, float32x4_t r, - uint16x4_t cmp) -{ - /* Fall back to scalar code. */ - return v_call_f32 (log2f, x, vfmaq_f32 (n, p, r), vmovl_u16 (cmp)); -} - -/* Fast implementation for single precision AdvSIMD log2, - relies on same argument reduction as AdvSIMD logf. - Maximum error: 2.48 ULPs - _ZGVnN4v_log2f(0x1.558174p+0) got 0x1.a9be84p-2 - want 0x1.a9be8p-2. */ -float32x4_t VPCS_ATTR V_NAME_F1 (log2) (float32x4_t x) -{ - const struct data *d = ptr_barrier (&data); - uint32x4_t u = vreinterpretq_u32_f32 (x); - uint16x4_t special = vcge_u16 (vsubhn_u32 (u, d->min_norm), - vget_low_u16 (d->special_bound)); - - /* x = 2^n * (1+r), where 2/3 < 1+r < 4/3. */ - u = vsubq_u32 (u, d->off); - float32x4_t n = vcvtq_f32_s32 ( - vshrq_n_s32 (vreinterpretq_s32_u32 (u), 23)); /* signextend. */ - u = vaddq_u32 (vandq_u32 (u, d->mantissa_mask), d->off); - float32x4_t r = vsubq_f32 (vreinterpretq_f32_u32 (u), v_f32 (1.0f)); - - /* y = log2(1+r) + n. */ - float32x4_t r2 = vmulq_f32 (r, r); - float32x4_t p = v_pw_horner_8_f32 (r, r2, d->poly); - - if (unlikely (v_any_u16h (special))) - return special_case (x, n, p, r, special); - return vfmaq_f32 (n, p, r); -} - -PL_SIG (V, F, 1, log2, 0.01, 11.1) -PL_TEST_ULP (V_NAME_F1 (log2), 1.99) -PL_TEST_EXPECT_FENV_ALWAYS (V_NAME_F1 (log2)) -PL_TEST_INTERVAL (V_NAME_F1 (log2), -0.0, -0x1p126, 100) -PL_TEST_INTERVAL (V_NAME_F1 (log2), 0x1p-149, 0x1p-126, 4000) -PL_TEST_INTERVAL (V_NAME_F1 (log2), 0x1p-126, 0x1p-23, 50000) -PL_TEST_INTERVAL (V_NAME_F1 (log2), 0x1p-23, 1.0, 50000) -PL_TEST_INTERVAL (V_NAME_F1 (log2), 1.0, 100, 50000) -PL_TEST_INTERVAL (V_NAME_F1 (log2), 100, inf, 50000) |