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/*
RCC-Project
Copyright (C) 2026 Richard Qin
This file is part of RCC-Project.
RCC-Project is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your option) any
later version.
RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
RCC-Project; see the file COPYING. If not see
<http://www.gnu.org/licenses/>.
*/
//===-- MathExtras.cpp - Implement the MathExtras header --------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements the MathExtras.h header
//
//===----------------------------------------------------------------------===//
#include "rcc/Support/MathExtras.h"
#ifdef _MSC_VER
#include <limits>
#else
#include <cmath>
#endif
namespace rcc
{
#if defined(_MSC_VER)
// Visual Studio defines the HUGE_VAL class of macros using purposeful
// constant arithmetic overflow, which it then warns on when encountered.
const float huge_valf = std::numeric_limits<float>::infinity ();
#else
const float huge_valf = HUGE_VALF;
#endif
/// Returns the number of digits in the given integer.
int
NumDigitsBase10 (uint64_t X)
{
static constexpr struct ConstexprData
{
uint8_t AtLeast[65] = {};
uint64_t Boundaries[20] = {};
static constexpr int
NumDigitsConstexpr (uint64_t N)
{
int res = 1;
while (N >= 10)
{
res++;
N /= 10;
}
return res;
}
constexpr ConstexprData ()
{
uint64_t Val = ~0ull;
for (uint64_t i = 0; i <= 64; i++)
{
uint64_t Digits = NumDigitsConstexpr (Val) - 1;
AtLeast[i] = Digits;
Val >>= 1;
}
// Special case because X=0 should return 1 and not 0
Boundaries[0] = 0;
Val = 10;
for (uint64_t i = 1; i < 20; i++)
{
Boundaries[i] = Val;
Val *= 10;
}
}
} Data;
uint64_t Base2 = X ? std::countl_zero (X) : 64;
uint64_t Digits = Data.AtLeast[Base2];
return Digits + (X >= Data.Boundaries[Digits]);
}
} // namespace rcc
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