Added optional pass-by-reference argument "isExact" to

NumericLiteralParser::GetFloatValue(). Upon method return, this flag has the value
true if the returned APFloat can exactly represent the number in the parsed text,
and false otherwise.

Modified the implementation of GetFloatValue() to parse literals using APFloat's
convertFromString method (which allows us to set the value of isExact).

llvm-svn: 44339
This commit is contained in:
Ted Kremenek 2007-11-26 23:12:30 +00:00
parent 871422eca9
commit fbb08bc2e2
2 changed files with 21 additions and 8 deletions

View File

@ -410,17 +410,27 @@ bool NumericLiteralParser::GetIntegerValue(llvm::APInt &Val) {
}
llvm::APFloat NumericLiteralParser::
GetFloatValue(const llvm::fltSemantics &Format) {
GetFloatValue(const llvm::fltSemantics &Format, bool* isExact) {
using llvm::APFloat;
char floatChars[256];
strncpy(floatChars, ThisTokBegin, ThisTokEnd-ThisTokBegin);
floatChars[ThisTokEnd-ThisTokBegin] = '\0';
#if 0
// This doesn't work yet.
return llvm::APFloat(Format, floatChars);
#if 1
APFloat V (Format, APFloat::fcZero, false);
APFloat::opStatus status;
status = V.convertFromString(floatChars,APFloat::rmTowardZero);
if (isExact)
*isExact = status == APFloat::opOK;
return V;
#else
// FIXME: this is horrible!
llvm::APFloat V(strtod(floatChars, 0));
V.convert(Format, llvm::APFloat::rmTowardZero);
APFloat V(strtod(floatChars, 0));
V.convert(Format, APFloat::rmTowardZero);
return V;
#endif
}

View File

@ -77,8 +77,11 @@ public:
/// GetFloatValue - Convert this numeric literal to a floating value, using
/// the specified APFloat fltSemantics (specifying float, double, etc).
///
llvm::APFloat GetFloatValue(const llvm::fltSemantics &Format);
/// The optional bool isExact (passed-by-reference) has its value
/// set to true if the returned APFloat can represent the number in the
/// literal exactly, and false otherwise.
llvm::APFloat GetFloatValue(const llvm::fltSemantics &Format,
bool* isExact = NULL);
private:
void Diag(SourceLocation Loc, unsigned DiagID,