Add a version of AddString that takes a const char* so we can avoid extraneous

conversions to std::string.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52995 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2008-07-01 23:49:59 +00:00
parent aa8f8889a8
commit 72e61b8501
2 changed files with 39 additions and 0 deletions

View File

@ -220,6 +220,7 @@ public:
void AddFloat(float F);
void AddDouble(double D);
void AddString(const std::string &String);
void AddString(const char* String);
template <typename T>
inline void Add(const T& x) { FoldingSetTrait<T>::Profile(x, *this); }

View File

@ -57,6 +57,44 @@ void FoldingSetNodeID::AddFloat(float F) {
void FoldingSetNodeID::AddDouble(double D) {
AddInteger(DoubleToBits(D));
}
void FoldingSetNodeID::AddString(const char *String) {
unsigned Size = static_cast<unsigned>(strlen(String));
Bits.push_back(Size);
if (!Size) return;
unsigned Units = Size / 4;
unsigned Pos = 0;
const unsigned *Base = (const unsigned *)String;
// If the string is aligned do a bulk transfer.
if (!((intptr_t)Base & 3)) {
Bits.append(Base, Base + Units);
Pos = (Units + 1) * 4;
} else {
// Otherwise do it the hard way.
for ( Pos += 4; Pos <= Size; Pos += 4) {
unsigned V = ((unsigned char)String[Pos - 4] << 24) |
((unsigned char)String[Pos - 3] << 16) |
((unsigned char)String[Pos - 2] << 8) |
(unsigned char)String[Pos - 1];
Bits.push_back(V);
}
}
// With the leftover bits.
unsigned V = 0;
// Pos will have overshot size by 4 - #bytes left over.
switch (Pos - Size) {
case 1: V = (V << 8) | (unsigned char)String[Size - 3]; // Fall thru.
case 2: V = (V << 8) | (unsigned char)String[Size - 2]; // Fall thru.
case 3: V = (V << 8) | (unsigned char)String[Size - 1]; break;
default: return; // Nothing left.
}
Bits.push_back(V);
}
void FoldingSetNodeID::AddString(const std::string &String) {
unsigned Size = static_cast<unsigned>(String.size());
Bits.push_back(Size);