Per discussion on cxx-abi-dev, don't drop leading zeroes from the

mangling of floating-point literals.  I just went ahead and
reimplemented toString() here;  if someone wants to generalize
the library routine to do this, or feels strongly that we should
be post-processing, please feel free.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149256 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
John McCall 2012-01-30 18:36:31 +00:00
Родитель 013b3668b6
Коммит 0c8731a272
2 изменённых файлов: 41 добавлений и 9 удалений

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@ -610,17 +610,41 @@ void CXXNameMangler::mangleFloat(const llvm::APFloat &f) {
// representation (IEEE on Itanium), high-order bytes first,
// without leading zeroes. For example: "Lf bf800000 E" is -1.0f
// on Itanium.
// APInt::toString uses uppercase hexadecimal, and it's not really
// worth embellishing that interface for this use case, so we just
// do a second pass to lowercase things.
typedef llvm::SmallString<20> buffer_t;
buffer_t buffer;
f.bitcastToAPInt().toString(buffer, 16, false);
// The 'without leading zeroes' thing seems to be an editorial
// mistake; see the discussion on cxx-abi-dev beginning on
// 2012-01-16.
for (buffer_t::iterator i = buffer.begin(), e = buffer.end(); i != e; ++i)
if (isupper(*i)) *i = tolower(*i);
// Our requirements here are just barely wierd enough to justify
// using a custom algorithm instead of post-processing APInt::toString().
Out.write(buffer.data(), buffer.size());
llvm::APInt valueBits = f.bitcastToAPInt();
unsigned numCharacters = (valueBits.getBitWidth() + 3) / 4;
assert(numCharacters != 0);
// Allocate a buffer of the right number of characters.
llvm::SmallVector<char, 20> buffer;
buffer.set_size(numCharacters);
// Fill the buffer left-to-right.
for (unsigned stringIndex = 0; stringIndex != numCharacters; ++stringIndex) {
// The bit-index of the next hex digit.
unsigned digitBitIndex = 4 * (numCharacters - stringIndex - 1);
// Project out 4 bits starting at 'digitIndex'.
llvm::integerPart hexDigit
= valueBits.getRawData()[digitBitIndex / llvm::integerPartWidth];
hexDigit >>= (digitBitIndex % llvm::integerPartWidth);
hexDigit &= 0xF;
// Map that over to a lowercase hex digit.
static const char charForHex[16] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
buffer[stringIndex] = charForHex[hexDigit];
}
Out.write(buffer.data(), numCharacters);
}
void CXXNameMangler::mangleNumber(const llvm::APSInt &Value) {

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@ -361,6 +361,14 @@ namespace test0 {
j<A>(buffer);
}
// CHECK: define linkonce_odr void @_ZN5test01jINS_1AEEEvRAszdtcvT__E6buffer_c(
template <class T> void k(char (&buffer)[sizeof(T() + 0.0f)]) {}
void test5() {
char buffer[sizeof(float)];
k<float>(buffer);
}
// CHECK: define linkonce_odr void @_ZN5test01kIfEEvRAszplcvT__ELf00000000E_c(
}
namespace test1 {