llvm-for-llvmta/lib/Support/NativeFormatting.cpp

263 lines
7.5 KiB
C++

//===- NativeFormatting.cpp - Low level formatting helpers -------*- C++-*-===//
//
// 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 "llvm/Support/NativeFormatting.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <float.h>
using namespace llvm;
template<typename T, std::size_t N>
static int format_to_buffer(T Value, char (&Buffer)[N]) {
char *EndPtr = std::end(Buffer);
char *CurPtr = EndPtr;
do {
*--CurPtr = '0' + char(Value % 10);
Value /= 10;
} while (Value);
return EndPtr - CurPtr;
}
static void writeWithCommas(raw_ostream &S, ArrayRef<char> Buffer) {
assert(!Buffer.empty());
ArrayRef<char> ThisGroup;
int InitialDigits = ((Buffer.size() - 1) % 3) + 1;
ThisGroup = Buffer.take_front(InitialDigits);
S.write(ThisGroup.data(), ThisGroup.size());
Buffer = Buffer.drop_front(InitialDigits);
assert(Buffer.size() % 3 == 0);
while (!Buffer.empty()) {
S << ',';
ThisGroup = Buffer.take_front(3);
S.write(ThisGroup.data(), 3);
Buffer = Buffer.drop_front(3);
}
}
template <typename T>
static void write_unsigned_impl(raw_ostream &S, T N, size_t MinDigits,
IntegerStyle Style, bool IsNegative) {
static_assert(std::is_unsigned<T>::value, "Value is not unsigned!");
char NumberBuffer[128];
std::memset(NumberBuffer, '0', sizeof(NumberBuffer));
size_t Len = 0;
Len = format_to_buffer(N, NumberBuffer);
if (IsNegative)
S << '-';
if (Len < MinDigits && Style != IntegerStyle::Number) {
for (size_t I = Len; I < MinDigits; ++I)
S << '0';
}
if (Style == IntegerStyle::Number) {
writeWithCommas(S, ArrayRef<char>(std::end(NumberBuffer) - Len, Len));
} else {
S.write(std::end(NumberBuffer) - Len, Len);
}
}
template <typename T>
static void write_unsigned(raw_ostream &S, T N, size_t MinDigits,
IntegerStyle Style, bool IsNegative = false) {
// Output using 32-bit div/mod if possible.
if (N == static_cast<uint32_t>(N))
write_unsigned_impl(S, static_cast<uint32_t>(N), MinDigits, Style,
IsNegative);
else
write_unsigned_impl(S, N, MinDigits, Style, IsNegative);
}
template <typename T>
static void write_signed(raw_ostream &S, T N, size_t MinDigits,
IntegerStyle Style) {
static_assert(std::is_signed<T>::value, "Value is not signed!");
using UnsignedT = std::make_unsigned_t<T>;
if (N >= 0) {
write_unsigned(S, static_cast<UnsignedT>(N), MinDigits, Style);
return;
}
UnsignedT UN = -(UnsignedT)N;
write_unsigned(S, UN, MinDigits, Style, true);
}
void llvm::write_integer(raw_ostream &S, unsigned int N, size_t MinDigits,
IntegerStyle Style) {
write_unsigned(S, N, MinDigits, Style);
}
void llvm::write_integer(raw_ostream &S, int N, size_t MinDigits,
IntegerStyle Style) {
write_signed(S, N, MinDigits, Style);
}
void llvm::write_integer(raw_ostream &S, unsigned long N, size_t MinDigits,
IntegerStyle Style) {
write_unsigned(S, N, MinDigits, Style);
}
void llvm::write_integer(raw_ostream &S, long N, size_t MinDigits,
IntegerStyle Style) {
write_signed(S, N, MinDigits, Style);
}
void llvm::write_integer(raw_ostream &S, unsigned long long N, size_t MinDigits,
IntegerStyle Style) {
write_unsigned(S, N, MinDigits, Style);
}
void llvm::write_integer(raw_ostream &S, long long N, size_t MinDigits,
IntegerStyle Style) {
write_signed(S, N, MinDigits, Style);
}
void llvm::write_hex(raw_ostream &S, uint64_t N, HexPrintStyle Style,
Optional<size_t> Width) {
const size_t kMaxWidth = 128u;
size_t W = std::min(kMaxWidth, Width.getValueOr(0u));
unsigned Nibbles = (64 - countLeadingZeros(N) + 3) / 4;
bool Prefix = (Style == HexPrintStyle::PrefixLower ||
Style == HexPrintStyle::PrefixUpper);
bool Upper =
(Style == HexPrintStyle::Upper || Style == HexPrintStyle::PrefixUpper);
unsigned PrefixChars = Prefix ? 2 : 0;
unsigned NumChars =
std::max(static_cast<unsigned>(W), std::max(1u, Nibbles) + PrefixChars);
char NumberBuffer[kMaxWidth];
::memset(NumberBuffer, '0', llvm::array_lengthof(NumberBuffer));
if (Prefix)
NumberBuffer[1] = 'x';
char *EndPtr = NumberBuffer + NumChars;
char *CurPtr = EndPtr;
while (N) {
unsigned char x = static_cast<unsigned char>(N) % 16;
*--CurPtr = hexdigit(x, !Upper);
N /= 16;
}
S.write(NumberBuffer, NumChars);
}
void llvm::write_double(raw_ostream &S, double N, FloatStyle Style,
Optional<size_t> Precision) {
size_t Prec = Precision.getValueOr(getDefaultPrecision(Style));
if (std::isnan(N)) {
S << "nan";
return;
} else if (std::isinf(N)) {
S << "INF";
return;
}
char Letter;
if (Style == FloatStyle::Exponent)
Letter = 'e';
else if (Style == FloatStyle::ExponentUpper)
Letter = 'E';
else
Letter = 'f';
SmallString<8> Spec;
llvm::raw_svector_ostream Out(Spec);
Out << "%." << Prec << Letter;
if (Style == FloatStyle::Exponent || Style == FloatStyle::ExponentUpper) {
#ifdef _WIN32
// On MSVCRT and compatible, output of %e is incompatible to Posix
// by default. Number of exponent digits should be at least 2. "%+03d"
// FIXME: Implement our formatter to here or Support/Format.h!
#if defined(__MINGW32__)
// FIXME: It should be generic to C++11.
if (N == 0.0 && std::signbit(N)) {
char NegativeZero[] = "-0.000000e+00";
if (Style == FloatStyle::ExponentUpper)
NegativeZero[strlen(NegativeZero) - 4] = 'E';
S << NegativeZero;
return;
}
#else
int fpcl = _fpclass(N);
// negative zero
if (fpcl == _FPCLASS_NZ) {
char NegativeZero[] = "-0.000000e+00";
if (Style == FloatStyle::ExponentUpper)
NegativeZero[strlen(NegativeZero) - 4] = 'E';
S << NegativeZero;
return;
}
#endif
char buf[32];
unsigned len;
len = format(Spec.c_str(), N).snprint(buf, sizeof(buf));
if (len <= sizeof(buf) - 2) {
if (len >= 5 && (buf[len - 5] == 'e' || buf[len - 5] == 'E') &&
buf[len - 3] == '0') {
int cs = buf[len - 4];
if (cs == '+' || cs == '-') {
int c1 = buf[len - 2];
int c0 = buf[len - 1];
if (isdigit(static_cast<unsigned char>(c1)) &&
isdigit(static_cast<unsigned char>(c0))) {
// Trim leading '0': "...e+012" -> "...e+12\0"
buf[len - 3] = c1;
buf[len - 2] = c0;
buf[--len] = 0;
}
}
}
S << buf;
return;
}
#endif
}
if (Style == FloatStyle::Percent)
N *= 100.0;
char Buf[32];
format(Spec.c_str(), N).snprint(Buf, sizeof(Buf));
S << Buf;
if (Style == FloatStyle::Percent)
S << '%';
}
bool llvm::isPrefixedHexStyle(HexPrintStyle S) {
return (S == HexPrintStyle::PrefixLower || S == HexPrintStyle::PrefixUpper);
}
size_t llvm::getDefaultPrecision(FloatStyle Style) {
switch (Style) {
case FloatStyle::Exponent:
case FloatStyle::ExponentUpper:
return 6; // Number of decimal places.
case FloatStyle::Fixed:
case FloatStyle::Percent:
return 2; // Number of decimal places.
}
LLVM_BUILTIN_UNREACHABLE;
}