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Recommit r231175: Change LiveStackAnalysis::SS2IntervalMap from std::map to std::unordered_map 

The order of this container was needed at one point - so, at that point
create a temporary array of pointers, sort those, then iterate them.
This keeps lookup efficient (& the lesser issue, of allowing the use of
emplace... ), object identity preserved, and ordered iteration in the
one place that requires it.

While this has no functional change, I realize it does mean allocating
an extra data structure and performing a sort - so if this looks suspect
to anyone regarding perf characteristics, I'm all ears.

llvm-svn: 231189
This commit is contained in:
David Blaikie 2015-03-04 01:15:53 +00:00
parent 2ac86d6fee
commit 55c6222538
2 changed files with 12 additions and 3 deletions
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3
llvm/include/llvm/CodeGen/LiveStackAnalysis.h
View File

@ -21,6 +21,7 @@
#include "llvm/Support/Allocator.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include <map>
#include <unordered_map>
namespace llvm {
@ -33,7 +34,7 @@ namespace llvm {
/// S2IMap - Stack slot indices to live interval mapping.
///
typedef std::map<int, LiveInterval> SS2IntervalMap;
typedef std::unordered_map<int, LiveInterval> SS2IntervalMap;
SS2IntervalMap S2IMap;
/// S2RCMap - Stack slot indices to register class mapping.

12
llvm/lib/CodeGen/StackSlotColoring.cpp
View File

@ -184,10 +184,18 @@ void StackSlotColoring::InitializeSlots() {
UsedColors.resize(LastFI);
Assignments.resize(LastFI);
typedef std::iterator_traits<LiveStacks::iterator>::value_type Pair;
SmallVector<Pair *, 16> Intervals;
Intervals.reserve(LS->getNumIntervals());
for (auto &I : *LS)
Intervals.push_back(&I);
std::sort(Intervals.begin(), Intervals.end(),
[](Pair *LHS, Pair *RHS) { return LHS->first < RHS->first; });
// Gather all spill slots into a list.
DEBUG(dbgs() << "Spill slot intervals:\n");
for (LiveStacks::iterator i = LS->begin(), e = LS->end(); i != e; ++i) {
LiveInterval &li = i->second;
for (auto *I : Intervals) {
LiveInterval &li = I->second;
DEBUG(li.dump());
int FI = TargetRegisterInfo::stackSlot2Index(li.reg);
if (MFI->isDeadObjectIndex(FI))