[DebugInfo] Simplify and speedup .debug_aranges parsing

Parsing .debug_aranges section now takes O(nlogn) operations instead
of O(n^2), where "n" is the number of address ranges. With this change,
the time required to symbolize an address from a random large
Clang-generated binary drops from 165 seconds to 1.5 seconds.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191781 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Alexey Samsonov 2013-10-01 16:52:46 +00:00
parent 52c9016db0
commit 041f7c8d65

View File

@ -16,69 +16,36 @@
#include <cassert>
using namespace llvm;
namespace {
class CountArangeDescriptors {
public:
CountArangeDescriptors(uint32_t &count_ref) : Count(count_ref) {}
void operator()(const DWARFDebugArangeSet &Set) {
Count += Set.getNumDescriptors();
}
uint32_t &Count;
};
class AddArangeDescriptors {
public:
AddArangeDescriptors(DWARFDebugAranges::RangeColl &Ranges,
DWARFDebugAranges::ParsedCUOffsetColl &CUOffsets)
: RangeCollection(Ranges),
CUOffsetCollection(CUOffsets) {}
void operator()(const DWARFDebugArangeSet &Set) {
DWARFDebugAranges::Range Range;
Range.CUOffset = Set.getCompileUnitDIEOffset();
CUOffsetCollection.insert(Range.CUOffset);
for (uint32_t i = 0, n = Set.getNumDescriptors(); i < n; ++i) {
const DWARFDebugArangeSet::Descriptor *ArangeDescPtr =
Set.getDescriptor(i);
Range.LowPC = ArangeDescPtr->Address;
Range.Length = ArangeDescPtr->Length;
// Insert each item in increasing address order so binary searching
// can later be done!
DWARFDebugAranges::RangeColl::iterator InsertPos =
std::lower_bound(RangeCollection.begin(), RangeCollection.end(),
Range);
RangeCollection.insert(InsertPos, Range);
}
}
DWARFDebugAranges::RangeColl &RangeCollection;
DWARFDebugAranges::ParsedCUOffsetColl &CUOffsetCollection;
};
}
void DWARFDebugAranges::extract(DataExtractor DebugArangesData) {
if (!DebugArangesData.isValidOffset(0))
return;
uint32_t offset = 0;
uint32_t Offset = 0;
typedef std::vector<DWARFDebugArangeSet> RangeSetColl;
RangeSetColl Sets;
DWARFDebugArangeSet Set;
uint32_t TotalRanges = 0;
typedef std::vector<DWARFDebugArangeSet> SetCollection;
SetCollection sets;
DWARFDebugArangeSet set;
Range range;
while (set.extract(DebugArangesData, &offset))
sets.push_back(set);
uint32_t count = 0;
std::for_each(sets.begin(), sets.end(), CountArangeDescriptors(count));
if (count > 0) {
Aranges.reserve(count);
AddArangeDescriptors range_adder(Aranges, ParsedCUOffsets);
std::for_each(sets.begin(), sets.end(), range_adder);
while (Set.extract(DebugArangesData, &Offset)) {
Sets.push_back(Set);
TotalRanges += Set.getNumDescriptors();
}
if (TotalRanges == 0)
return;
Aranges.reserve(TotalRanges);
for (RangeSetColl::const_iterator I = Sets.begin(), E = Sets.end(); I != E;
++I) {
uint32_t CUOffset = I->getCompileUnitDIEOffset();
for (uint32_t i = 0, n = I->getNumDescriptors(); i < n; ++i) {
const DWARFDebugArangeSet::Descriptor *ArangeDescPtr =
I->getDescriptor(i);
uint64_t LowPC = ArangeDescPtr->Address;
uint64_t HighPC = LowPC + ArangeDescPtr->Length;
appendRange(CUOffset, LowPC, HighPC);
}
}
sortAndMinimize();
}
void DWARFDebugAranges::generate(DWARFContext *CTX) {