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Diffstat (limited to 'pl/math/v_coshf_2u4.c')
-rw-r--r-- | pl/math/v_coshf_2u4.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/pl/math/v_coshf_2u4.c b/pl/math/v_coshf_2u4.c new file mode 100644 index 0000000..1422d4d --- /dev/null +++ b/pl/math/v_coshf_2u4.c @@ -0,0 +1,74 @@ +/* + * Single-precision vector cosh(x) function. + * + * Copyright (c) 2022-2023, Arm Limited. + * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + */ + +#include "v_math.h" +#include "mathlib.h" +#include "pl_sig.h" +#include "pl_test.h" + +#define AbsMask 0x7fffffff +#define TinyBound 0x20000000 /* 0x1p-63: Round to 1 below this. */ +#define SpecialBound \ + 0x42ad496c /* 0x1.5a92d8p+6: expf overflows above this, so have to use \ + special case. */ +#define Half v_f32 (0.5) + +#if V_SUPPORTED + +v_f32_t V_NAME (expf) (v_f32_t); + +/* Single-precision vector cosh, using vector expf. + Maximum error is 2.38 ULP: + __v_coshf(0x1.e8001ep+1) got 0x1.6a491ep+4 want 0x1.6a4922p+4. */ +VPCS_ATTR v_f32_t V_NAME (coshf) (v_f32_t x) +{ + v_u32_t ix = v_as_u32_f32 (x); + v_u32_t iax = ix & AbsMask; + v_f32_t ax = v_as_f32_u32 (iax); + v_u32_t special = v_cond_u32 (iax >= SpecialBound); + +#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. */ + if (unlikely (v_any_u32 (special))) + return v_call_f32 (coshf, x, x, v_u32 (-1)); + + v_u32_t tiny = v_cond_u32 (iax <= TinyBound); + /* If any input is tiny, avoid underflow exception by fixing tiny lanes of + input to 1, which will generate no exceptions, and then also fixing tiny + lanes of output to 1 just before return. */ + if (unlikely (v_any_u32 (tiny))) + ax = v_sel_f32 (tiny, v_f32 (1), ax); +#endif + + /* Calculate cosh by exp(x) / 2 + exp(-x) / 2. */ + v_f32_t t = V_NAME (expf) (ax); + v_f32_t y = t * Half + Half / t; + +#if WANT_SIMD_EXCEPT + if (unlikely (v_any_u32 (tiny))) + return v_sel_f32 (tiny, v_f32 (1), y); +#else + if (unlikely (v_any_u32 (special))) + return v_call_f32 (coshf, x, y, special); +#endif + + return y; +} +VPCS_ALIAS + +PL_SIG (V, F, 1, cosh, -10.0, 10.0) +PL_TEST_ULP (V_NAME (coshf), 1.89) +PL_TEST_EXPECT_FENV (V_NAME (coshf), WANT_SIMD_EXCEPT) +PL_TEST_INTERVAL (V_NAME (coshf), 0, 0x1p-63, 100) +PL_TEST_INTERVAL (V_NAME (coshf), 0, 0x1.5a92d8p+6, 80000) +PL_TEST_INTERVAL (V_NAME (coshf), 0x1.5a92d8p+6, inf, 2000) +PL_TEST_INTERVAL (V_NAME (coshf), -0, -0x1p-63, 100) +PL_TEST_INTERVAL (V_NAME (coshf), -0, -0x1.5a92d8p+6, 80000) +PL_TEST_INTERVAL (V_NAME (coshf), -0x1.5a92d8p+6, -inf, 2000) +#endif |