[raw_ostream] Raise some helper functions out of raw_ostream.
Low level functionality to format numbers were embedded in the
implementation of raw_ostream. I have need to use these through
an interface other than the overloaded stream operators, so they
need to be raised to a level that they can be used from either
raw_ostream operators or other code.
llvm-svn: 283921
diff --git a/llvm/lib/Support/NativeFormatting.cpp b/llvm/lib/Support/NativeFormatting.cpp
new file mode 100644
index 0000000..84f6c39
--- /dev/null
+++ b/llvm/lib/Support/NativeFormatting.cpp
@@ -0,0 +1,180 @@
+//===- NativeFormatting.cpp - Low level formatting helpers -------*- C++-*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/NativeFormatting.h"
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Format.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;
+
+ while (Value) {
+ *--CurPtr = '0' + char(Value % 10);
+ Value /= 10;
+ }
+ return EndPtr - CurPtr;
+}
+
+void llvm::write_ulong(raw_ostream &S, unsigned long N, std::size_t MinWidth) {
+ // Zero is a special case.
+ if (N == 0) {
+ if (MinWidth > 0)
+ S.indent(MinWidth - 1);
+ S << '0';
+ return;
+ }
+
+ char NumberBuffer[20];
+ int Len = format_to_buffer(N, NumberBuffer);
+ int Pad = (MinWidth == 0) ? 0 : MinWidth - Len;
+ if (Pad > 0)
+ S.indent(Pad);
+ S.write(std::end(NumberBuffer) - Len, Len);
+}
+
+void llvm::write_long(raw_ostream &S, long N, std::size_t MinWidth) {
+ if (N >= 0) {
+ write_ulong(S, static_cast<unsigned long>(N), MinWidth);
+ return;
+ }
+
+ unsigned long UN = -(unsigned long)N;
+ if (MinWidth > 0)
+ --MinWidth;
+
+ char NumberBuffer[20];
+ int Len = format_to_buffer(UN, NumberBuffer);
+ int Pad = (MinWidth == 0) ? 0 : MinWidth - Len;
+ if (Pad > 0)
+ S.indent(Pad);
+ S.write('-');
+ S.write(std::end(NumberBuffer) - Len, Len);
+}
+
+void llvm::write_ulonglong(raw_ostream &S, unsigned long long N,
+ std::size_t MinWidth) {
+ // Output using 32-bit div/mod when possible.
+ if (N == static_cast<unsigned long>(N)) {
+ write_ulong(S, static_cast<unsigned long>(N), MinWidth);
+ return;
+ }
+
+ char NumberBuffer[32];
+ int Len = format_to_buffer(N, NumberBuffer);
+ int Pad = (MinWidth == 0) ? 0 : MinWidth - Len;
+ if (Pad > 0)
+ S.indent(Pad);
+ S.write(std::end(NumberBuffer) - Len, Len);
+}
+
+void llvm::write_longlong(raw_ostream &S, long long N, std::size_t MinWidth) {
+ if (N >= 0) {
+ write_ulonglong(S, static_cast<unsigned long long>(N), MinWidth);
+ return;
+ }
+
+ // Avoid undefined behavior on INT64_MIN with a cast.
+ unsigned long long UN = -(unsigned long long)N;
+ if (MinWidth > 0)
+ --MinWidth;
+
+ char NumberBuffer[32];
+ int Len = format_to_buffer(UN, NumberBuffer);
+ int Pad = (MinWidth == 0) ? 0 : MinWidth - Len;
+ if (Pad > 0)
+ S.indent(Pad);
+ S.write('-');
+ S.write(std::end(NumberBuffer) - Len, Len);
+}
+
+void llvm::write_hex(raw_ostream &S, unsigned long long N, std::size_t MinWidth,
+ bool Upper, bool Prefix) {
+ unsigned Nibbles = (64 - countLeadingZeros(N) + 3) / 4;
+ unsigned PrefixChars = Prefix ? 2 : 0;
+ unsigned Width = std::max(MinWidth, std::max(1u, Nibbles) + PrefixChars);
+
+ char NumberBuffer[20] = "0x0000000000000000";
+ if (!Prefix)
+ NumberBuffer[1] = '0';
+ char *EndPtr = NumberBuffer + Width;
+ char *CurPtr = EndPtr;
+ while (N) {
+ unsigned char x = static_cast<unsigned char>(N) % 16;
+ *--CurPtr = hexdigit(x, !Upper);
+ N /= 16;
+ }
+
+ S.write(NumberBuffer, Width);
+}
+
+void llvm::write_double(raw_ostream &S, double N, std::size_t MinWidth,
+ std::size_t MinDecimals, FloatStyle Style) {
+ char Letter = (Style == FloatStyle::Exponent) ? 'e' : 'f';
+ SmallString<8> Spec;
+ llvm::raw_svector_ostream Out(Spec);
+ Out << '%';
+ if (MinWidth > 0)
+ Out << MinWidth;
+ if (MinDecimals > 0)
+ Out << '.' << MinDecimals;
+ Out << Letter;
+
+ if (Style == FloatStyle::Exponent) {
+#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)) {
+ S << "-0.000000e+00";
+ return;
+ }
+#else
+ int fpcl = _fpclass(N);
+
+ // negative zero
+ if (fpcl == _FPCLASS_NZ) {
+ S << "-0.000000e+00";
+ return;
+ }
+#endif
+
+ char buf[16];
+ 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 - 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
+ }
+
+ S << format(Spec.c_str(), N);
+}