265 lines · cpp
1//===- NativeFormatting.cpp - Low level formatting helpers -------*- C++-*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/Support/NativeFormatting.h"10#include "llvm/ADT/ArrayRef.h"11#include "llvm/ADT/SmallString.h"12#include "llvm/ADT/StringExtras.h"13#include "llvm/Support/Format.h"14#include "llvm/Support/raw_ostream.h"15 16#include <cmath>17 18#if defined(_WIN32) && !defined(__MINGW32__)19#include <float.h> // For _fpclass in llvm::write_double.20#endif21 22using namespace llvm;23 24template<typename T, std::size_t N>25static int format_to_buffer(T Value, char (&Buffer)[N]) {26 char *EndPtr = std::end(Buffer);27 char *CurPtr = EndPtr;28 29 do {30 *--CurPtr = '0' + char(Value % 10);31 Value /= 10;32 } while (Value);33 return EndPtr - CurPtr;34}35 36static void writeWithCommas(raw_ostream &S, ArrayRef<char> Buffer) {37 assert(!Buffer.empty());38 39 ArrayRef<char> ThisGroup;40 int InitialDigits = ((Buffer.size() - 1) % 3) + 1;41 ThisGroup = Buffer.take_front(InitialDigits);42 S.write(ThisGroup.data(), ThisGroup.size());43 44 Buffer = Buffer.drop_front(InitialDigits);45 assert(Buffer.size() % 3 == 0);46 while (!Buffer.empty()) {47 S << ',';48 ThisGroup = Buffer.take_front(3);49 S.write(ThisGroup.data(), 3);50 Buffer = Buffer.drop_front(3);51 }52}53 54template <typename T>55static void write_unsigned_impl(raw_ostream &S, T N, size_t MinDigits,56 IntegerStyle Style, bool IsNegative) {57 static_assert(std::is_unsigned_v<T>, "Value is not unsigned!");58 59 char NumberBuffer[128];60 size_t Len = format_to_buffer(N, NumberBuffer);61 62 if (IsNegative)63 S << '-';64 65 if (Len < MinDigits && Style != IntegerStyle::Number) {66 for (size_t I = Len; I < MinDigits; ++I)67 S << '0';68 }69 70 if (Style == IntegerStyle::Number) {71 writeWithCommas(S, ArrayRef<char>(std::end(NumberBuffer) - Len, Len));72 } else {73 S.write(std::end(NumberBuffer) - Len, Len);74 }75}76 77template <typename T>78static void write_unsigned(raw_ostream &S, T N, size_t MinDigits,79 IntegerStyle Style, bool IsNegative = false) {80 // Output using 32-bit div/mod if possible.81 if (N == static_cast<uint32_t>(N))82 write_unsigned_impl(S, static_cast<uint32_t>(N), MinDigits, Style,83 IsNegative);84 else85 write_unsigned_impl(S, N, MinDigits, Style, IsNegative);86}87 88template <typename T>89static void write_signed(raw_ostream &S, T N, size_t MinDigits,90 IntegerStyle Style) {91 static_assert(std::is_signed_v<T>, "Value is not signed!");92 93 using UnsignedT = std::make_unsigned_t<T>;94 95 if (N >= 0) {96 write_unsigned(S, static_cast<UnsignedT>(N), MinDigits, Style);97 return;98 }99 100 UnsignedT UN = -(UnsignedT)N;101 write_unsigned(S, UN, MinDigits, Style, true);102}103 104void llvm::write_integer(raw_ostream &S, unsigned int N, size_t MinDigits,105 IntegerStyle Style) {106 write_unsigned(S, N, MinDigits, Style);107}108 109void llvm::write_integer(raw_ostream &S, int N, size_t MinDigits,110 IntegerStyle Style) {111 write_signed(S, N, MinDigits, Style);112}113 114void llvm::write_integer(raw_ostream &S, unsigned long N, size_t MinDigits,115 IntegerStyle Style) {116 write_unsigned(S, N, MinDigits, Style);117}118 119void llvm::write_integer(raw_ostream &S, long N, size_t MinDigits,120 IntegerStyle Style) {121 write_signed(S, N, MinDigits, Style);122}123 124void llvm::write_integer(raw_ostream &S, unsigned long long N, size_t MinDigits,125 IntegerStyle Style) {126 write_unsigned(S, N, MinDigits, Style);127}128 129void llvm::write_integer(raw_ostream &S, long long N, size_t MinDigits,130 IntegerStyle Style) {131 write_signed(S, N, MinDigits, Style);132}133 134void llvm::write_hex(raw_ostream &S, uint64_t N, HexPrintStyle Style,135 std::optional<size_t> Width) {136 const size_t kMaxWidth = 128u;137 138 size_t W = std::min(kMaxWidth, Width.value_or(0u));139 140 unsigned Nibbles = (llvm::bit_width(N) + 3) / 4;141 bool Prefix = (Style == HexPrintStyle::PrefixLower ||142 Style == HexPrintStyle::PrefixUpper);143 bool Upper =144 (Style == HexPrintStyle::Upper || Style == HexPrintStyle::PrefixUpper);145 unsigned PrefixChars = Prefix ? 2 : 0;146 unsigned NumChars =147 std::max(static_cast<unsigned>(W), std::max(1u, Nibbles) + PrefixChars);148 149 char NumberBuffer[kMaxWidth];150 ::memset(NumberBuffer, '0', std::size(NumberBuffer));151 if (Prefix)152 NumberBuffer[1] = 'x';153 char *EndPtr = NumberBuffer + NumChars;154 char *CurPtr = EndPtr;155 while (N) {156 unsigned char x = static_cast<unsigned char>(N) % 16;157 *--CurPtr = hexdigit(x, !Upper);158 N /= 16;159 }160 161 S.write(NumberBuffer, NumChars);162}163 164void llvm::write_double(raw_ostream &S, double N, FloatStyle Style,165 std::optional<size_t> Precision) {166 size_t Prec = Precision.value_or(getDefaultPrecision(Style));167 168 if (std::isnan(N)) {169 S << "nan";170 return;171 } else if (std::isinf(N)) {172 S << (std::signbit(N) ? "-INF" : "INF");173 return;174 }175 176 char Letter;177 if (Style == FloatStyle::Exponent)178 Letter = 'e';179 else if (Style == FloatStyle::ExponentUpper)180 Letter = 'E';181 else182 Letter = 'f';183 184 SmallString<8> Spec;185 llvm::raw_svector_ostream Out(Spec);186 Out << "%." << Prec << Letter;187 188 if (Style == FloatStyle::Exponent || Style == FloatStyle::ExponentUpper) {189#ifdef _WIN32190// On MSVCRT and compatible, output of %e is incompatible to Posix191// by default. Number of exponent digits should be at least 2. "%+03d"192// FIXME: Implement our formatter to here or Support/Format.h!193#if defined(__MINGW32__)194 // FIXME: It should be generic to C++11.195 if (N == 0.0 && std::signbit(N)) {196 char NegativeZero[] = "-0.000000e+00";197 if (Style == FloatStyle::ExponentUpper)198 NegativeZero[strlen(NegativeZero) - 4] = 'E';199 S << NegativeZero;200 return;201 }202#else203 int fpcl = _fpclass(N);204 205 // negative zero206 if (fpcl == _FPCLASS_NZ) {207 char NegativeZero[] = "-0.000000e+00";208 if (Style == FloatStyle::ExponentUpper)209 NegativeZero[strlen(NegativeZero) - 4] = 'E';210 S << NegativeZero;211 return;212 }213#endif214 215 char buf[32];216 unsigned len;217 len = format(Spec.c_str(), N).snprint(buf, sizeof(buf));218 if (len <= sizeof(buf) - 2) {219 if (len >= 5 && (buf[len - 5] == 'e' || buf[len - 5] == 'E') &&220 buf[len - 3] == '0') {221 int cs = buf[len - 4];222 if (cs == '+' || cs == '-') {223 int c1 = buf[len - 2];224 int c0 = buf[len - 1];225 if (isdigit(static_cast<unsigned char>(c1)) &&226 isdigit(static_cast<unsigned char>(c0))) {227 // Trim leading '0': "...e+012" -> "...e+12\0"228 buf[len - 3] = c1;229 buf[len - 2] = c0;230 buf[--len] = 0;231 }232 }233 }234 S << buf;235 return;236 }237#endif238 }239 240 if (Style == FloatStyle::Percent)241 N *= 100.0;242 243 char Buf[32];244 format(Spec.c_str(), N).snprint(Buf, sizeof(Buf));245 S << Buf;246 if (Style == FloatStyle::Percent)247 S << '%';248}249 250bool llvm::isPrefixedHexStyle(HexPrintStyle S) {251 return (S == HexPrintStyle::PrefixLower || S == HexPrintStyle::PrefixUpper);252}253 254size_t llvm::getDefaultPrecision(FloatStyle Style) {255 switch (Style) {256 case FloatStyle::Exponent:257 case FloatStyle::ExponentUpper:258 return 6; // Number of decimal places.259 case FloatStyle::Fixed:260 case FloatStyle::Percent:261 return 2; // Number of decimal places.262 }263 llvm_unreachable("Unknown FloatStyle enum");264}265