asinhf.c

/*
 * Single-precision SVE asinh(x) function.
 *
 * Copyright (c) 2023-2024, Arm Limited.
 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
 */

#include "sv_math.h"
#include "test_sig.h"
#include "test_defs.h"

#include "sv_log1pf_inline.h"

#define BigBound 0x5f800000 /* asuint(0x1p64).  */

static svfloat32_t NOINLINE
special_case (svuint32_t iax, svuint32_t sign, svfloat32_t y, svbool_t special)
{
  svfloat32_t x = svreinterpret_f32 (sveor_x (svptrue_b32 (), iax, sign));
  y = svreinterpret_f32 (
      svorr_x (svptrue_b32 (), sign, svreinterpret_u32 (y)));
  return sv_call_f32 (asinhf, x, y, special);
}

/* Single-precision SVE asinh(x) routine. Implements the same algorithm as
   vector asinhf and log1p.

   Maximum error is 1.92 ULPs:
   SV_NAME_F1 (asinh) (-0x1.0922ecp-1) got -0x1.fd0bccp-2
				      want -0x1.fd0bc8p-2.  */
svfloat32_t SV_NAME_F1 (asinh) (svfloat32_t x, const svbool_t pg)
{
  svfloat32_t ax = svabs_x (pg, x);
  svuint32_t iax = svreinterpret_u32 (ax);
  svuint32_t sign = sveor_x (pg, svreinterpret_u32 (x), iax);
  svbool_t special = svcmpge (pg, iax, BigBound);

  /* asinh(x) = log(x + sqrt(x * x + 1)).
     For positive x, asinh(x) = log1p(x + x * x / (1 + sqrt(x * x + 1))).  */
  svfloat32_t ax2 = svmul_x (pg, ax, ax);
  svfloat32_t d = svadd_x (pg, svsqrt_x (pg, svadd_x (pg, ax2, 1.0f)), 1.0f);
  svfloat32_t y
      = sv_log1pf_inline (svadd_x (pg, ax, svdiv_x (pg, ax2, d)), pg);

  if (unlikely (svptest_any (pg, special)))
    return special_case (iax, sign, y, special);
  return svreinterpret_f32 (svorr_x (pg, sign, svreinterpret_u32 (y)));
}

TEST_SIG (SV, F, 1, asinh, -10.0, 10.0)
TEST_ULP (SV_NAME_F1 (asinh), 1.43)
TEST_DISABLE_FENV (SV_NAME_F1 (asinh))
TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0, 0x1p-12, 4000)
TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0x1p-12, 1.0, 20000)
TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 1.0, 0x1p64, 20000)
TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0x1p64, inf, 4000)
CLOSE_SVE_ATTR