================ @@ -0,0 +1,145 @@ +//===-- Half-precision tanh(x) function -----------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "src/math/tanhf16.h" +#include "expxf16.h" +#include "hdr/fenv_macros.h" +#include "src/__support/CPP/array.h" +#include "src/__support/FPUtil/FEnvImpl.h" +#include "src/__support/FPUtil/FPBits.h" +#include "src/__support/FPUtil/PolyEval.h" +#include "src/__support/FPUtil/cast.h" +#include "src/__support/FPUtil/except_value_utils.h" +#include "src/__support/FPUtil/multiply_add.h" +#include "src/__support/FPUtil/nearest_integer.h" +#include "src/__support/FPUtil/rounding_mode.h" +#include "src/__support/common.h" +#include "src/__support/macros/config.h" +#include "src/__support/macros/optimization.h" + +namespace LIBC_NAMESPACE_DECL { + +static constexpr fputil::ExceptValues<float16, 2> TANHF16_EXCEPTS = {{ + // x = 0x1.f54p+0, tanhf16(x) = 0x1.ecp-1 (RZ) + {0x3fd5U, 0x3bb0U, 1U, 0U, 0U}, + // x = -0x1.f54p+0, tanhf16(x) = -0x1.ecp-1 (RZ) + {0xbfd5U, 0xbbb0U, 0U, 1U, 0U}, +}}; + +LLVM_LIBC_FUNCTION(float16, tanhf16, (float16 x)) { + using FPBits = fputil::FPBits<float16>; + FPBits x_bits(x); + + uint16_t x_u = x_bits.uintval(); + uint16_t x_abs = x_u & 0x7fffU; + + // When -2^(-14) <= x <= -2^(-9), or |x| <= 0x1.d2p-4, + // or |x| >= atanh(1 - 2^(-11)), or x is NaN. + if (LIBC_UNLIKELY((x_u >= 0x8400U && x_u <= 0x9800U) || x_abs <= 0x2f48U || ---------------- lntue wrote:
The condition `-2^(-14) <= x <= -2^(-9)` implies `|x| <= 0x1.d2p-4`, so you only need the check `x_abs <= 0x2f48U` here. https://github.com/llvm/llvm-project/pull/106006 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
