/*
 * Single-precision vector asinh(x) function.
 *
 * Copyright (c) 2022-2023, Arm Limited.
 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
 */

#include "v_math.h"
#include "pl_sig.h"
#include "pl_test.h"
#include "v_log1pf_inline.h"

#define SignMask v_u32 (0x80000000)

const static struct data
{
  struct v_log1pf_data log1pf_consts;
  uint32x4_t big_bound;
#if WANT_SIMD_EXCEPT
  uint32x4_t tiny_bound;
#endif
} data = {
  .log1pf_consts = V_LOG1PF_CONSTANTS_TABLE,
  .big_bound = V4 (0x5f800000), /* asuint(0x1p64).  */
#if WANT_SIMD_EXCEPT
  .tiny_bound = V4 (0x30800000) /* asuint(0x1p-30).  */
#endif
};

static float32x4_t NOINLINE VPCS_ATTR
special_case (float32x4_t x, float32x4_t y, uint32x4_t special)
{
  return v_call_f32 (asinhf, x, y, special);
}

/* Single-precision implementation of vector asinh(x), using vector log1p.
   Worst-case error is 2.66 ULP, at roughly +/-0.25:
   __v_asinhf(0x1.01b04p-2) got 0x1.fe163ep-3 want 0x1.fe1638p-3.  */
VPCS_ATTR float32x4_t V_NAME_F1 (asinh) (float32x4_t x)
{
  const struct data *dat = ptr_barrier (&data);
  uint32x4_t iax = vbicq_u32 (vreinterpretq_u32_f32 (x), SignMask);
  float32x4_t ax = vreinterpretq_f32_u32 (iax);
  uint32x4_t special = vcgeq_u32 (iax, dat->big_bound);
  float32x4_t special_arg = x;

#if WANT_SIMD_EXCEPT
  /* Sidestep tiny and large values to avoid inadvertently triggering
     under/overflow.  */
  special = vorrq_u32 (special, vcltq_u32 (iax, dat->tiny_bound));
  if (unlikely (v_any_u32 (special)))
    {
      ax = v_zerofy_f32 (ax, special);
      x = v_zerofy_f32 (x, special);
    }
#endif

  /* asinh(x) = log(x + sqrt(x * x + 1)).
     For positive x, asinh(x) = log1p(x + x * x / (1 + sqrt(x * x + 1))).  */
  float32x4_t d
      = vaddq_f32 (v_f32 (1), vsqrtq_f32 (vfmaq_f32 (v_f32 (1), x, x)));
  float32x4_t y = log1pf_inline (
      vaddq_f32 (ax, vdivq_f32 (vmulq_f32 (ax, ax), d)), dat->log1pf_consts);

  if (unlikely (v_any_u32 (special)))
    return special_case (special_arg, vbslq_f32 (SignMask, x, y), special);
  return vbslq_f32 (SignMask, x, y);
}

PL_SIG (V, F, 1, asinh, -10.0, 10.0)
PL_TEST_ULP (V_NAME_F1 (asinh), 2.17)
PL_TEST_EXPECT_FENV (V_NAME_F1 (asinh), WANT_SIMD_EXCEPT)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), 0, 0x1p-12, 40000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), 0x1p-12, 1.0, 40000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), 1.0, 0x1p11, 40000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), 0x1p11, inf, 40000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), -0, -0x1p-12, 20000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), -0x1p-12, -1.0, 20000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), -1.0, -0x1p11, 20000)
PL_TEST_INTERVAL (V_NAME_F1 (asinh), -0x1p11, -inf, 20000)