replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Make StringTableBuilder to cache hash values. 

This change seems to speed up LLD a bit if it has a lot of mergeable
sections. The number is below. It's not too bad for a small patch.

Time to link Clang (debug build):

w/o patch 6.3696 seconds
w/patch   6.2746 seconds (-1.5%)

Differential Revision: http://reviews.llvm.org/D19933

llvm-svn: 268698
This commit is contained in:
Rui Ueyama 2016-05-06 00:51:58 +00:00
parent 2a42da996d
commit 02d71ade06
2 changed files with 9 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
llvm/include/llvm/MC/StringTableBuilder.h
View File

@ -23,7 +23,7 @@ public:
private:
SmallString<256> StringTable;
DenseMap<StringRef, size_t> StringIndexMap;
DenseMap<CachedHash<StringRef>, size_t> StringIndexMap;
size_t Size = 0;
Kind K;
unsigned Alignment;
@ -57,7 +57,10 @@ public:
/// after the table is finalized.
size_t getOffset(StringRef S) const;
const DenseMap<StringRef, size_t> &getMap() const { return StringIndexMap; }
const DenseMap<CachedHash<StringRef>, size_t> &getMap() const {
return StringIndexMap;
}
size_t getSize() const { return Size; }
void clear();

8
llvm/lib/MC/StringTableBuilder.cpp
View File

@ -34,11 +34,11 @@ StringTableBuilder::StringTableBuilder(Kind K, unsigned Alignment)
}
}
typedef std::pair<StringRef, size_t> StringPair;
typedef std::pair<CachedHash<StringRef>, size_t> StringPair;
// Returns the character at Pos from end of a string.
static int charTailAt(StringPair *P, size_t Pos) {
StringRef S = P->first;
StringRef S = P->first.Val;
if (Pos >= S.size())
return -1;
return (unsigned char)S[S.size() - Pos - 1];
@ -86,7 +86,7 @@ void StringTableBuilder::finalizeInOrder() {
}
void StringTableBuilder::finalizeStringTable(bool Optimize) {
typedef std::pair<StringRef, size_t> StringOffsetPair;
typedef std::pair<CachedHash<StringRef>, size_t> StringOffsetPair;
std::vector<StringOffsetPair *> Strings;
Strings.reserve(StringIndexMap.size());
for (StringOffsetPair &P : StringIndexMap)
@ -121,7 +121,7 @@ void StringTableBuilder::finalizeStringTable(bool Optimize) {
StringRef Previous;
for (StringOffsetPair *P : Strings) {
StringRef S = P->first;
StringRef S = P->first.Val;
if (K == WinCOFF)
assert(S.size() > COFF::NameSize && "Short string in COFF string table!");