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Diffstat (limited to 'math/aarch64/advsimd/coshf.c')
-rw-r--r-- | math/aarch64/advsimd/coshf.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/math/aarch64/advsimd/coshf.c b/math/aarch64/advsimd/coshf.c new file mode 100644 index 000000000000..f1ed3e5161fd --- /dev/null +++ b/math/aarch64/advsimd/coshf.c @@ -0,0 +1,92 @@ +/* + * Single-precision vector cosh(x) function. + * + * Copyright (c) 2022-2024, Arm Limited. + * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + */ + +#include "v_expf_inline.h" +#include "v_math.h" +#include "test_sig.h" +#include "test_defs.h" + +static const struct data +{ + struct v_expf_data expf_consts; + uint32x4_t tiny_bound; + float32x4_t bound; +#if WANT_SIMD_EXCEPT + uint32x4_t special_bound; +#endif +} data = { + .expf_consts = V_EXPF_DATA, + .tiny_bound = V4 (0x20000000), /* 0x1p-63: Round to 1 below this. */ + /* 0x1.5a92d8p+6: expf overflows above this, so have to use special case. */ + .bound = V4 (0x1.5a92d8p+6), +#if WANT_SIMD_EXCEPT + .special_bound = V4 (0x42ad496c), +#endif +}; + +#if !WANT_SIMD_EXCEPT +static float32x4_t NOINLINE VPCS_ATTR +special_case (float32x4_t x, float32x4_t half_t, float32x4_t half_over_t, + uint32x4_t special) +{ + return v_call_f32 (coshf, x, vaddq_f32 (half_t, half_over_t), special); +} +#endif + +/* Single-precision vector cosh, using vector expf. + Maximum error is 2.38 ULP: + _ZGVnN4v_coshf (0x1.e8001ep+1) got 0x1.6a491ep+4 + want 0x1.6a4922p+4. */ +float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (cosh) (float32x4_t x) +{ + const struct data *d = ptr_barrier (&data); + +#if WANT_SIMD_EXCEPT + /* If fp exceptions are to be triggered correctly, fall back to the scalar + variant for all inputs if any input is a special value or above the bound + at which expf overflows. */ + float32x4_t ax = vabsq_f32 (x); + uint32x4_t iax = vreinterpretq_u32_f32 (ax); + uint32x4_t special = vcgeq_u32 (iax, d->special_bound); + if (unlikely (v_any_u32 (special))) + return v_call_f32 (coshf, x, x, v_u32 (-1)); + + uint32x4_t tiny = vcleq_u32 (iax, d->tiny_bound); + /* If any input is tiny, avoid underflow exception by fixing tiny lanes of + input to 0, which will generate no exceptions. */ + if (unlikely (v_any_u32 (tiny))) + ax = v_zerofy_f32 (ax, tiny); + float32x4_t t = v_expf_inline (ax, &d->expf_consts); +#else + uint32x4_t special = vcageq_f32 (x, d->bound); + float32x4_t t = v_expf_inline (x, &d->expf_consts); +#endif + + /* Calculate cosh by exp(x) / 2 + exp(-x) / 2. */ + float32x4_t half_t = vmulq_n_f32 (t, 0.5); + float32x4_t half_over_t = vdivq_f32 (v_f32 (0.5), t); + +#if WANT_SIMD_EXCEPT + if (unlikely (v_any_u32 (tiny))) + return vbslq_f32 (tiny, v_f32 (1), vaddq_f32 (half_t, half_over_t)); +#else + if (unlikely (v_any_u32 (special))) + return special_case (x, half_t, half_over_t, special); +#endif + + return vaddq_f32 (half_t, half_over_t); +} + +HALF_WIDTH_ALIAS_F1 (cosh) + +TEST_SIG (V, F, 1, cosh, -10.0, 10.0) +TEST_ULP (V_NAME_F1 (cosh), 1.89) +TEST_DISABLE_FENV_IF_NOT (V_NAME_F1 (cosh), WANT_SIMD_EXCEPT) +TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0, 0x1p-63, 100) +TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0x1p-63, 1, 1000) +TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 1, 0x1.5a92d8p+6, 80000) +TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0x1.5a92d8p+6, inf, 2000) |