From 9aa29a4c23d6d593f8aab15bdc26835558d84910 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Wed, 4 Mar 2015 01:15:53 +0000
Subject: [PATCH] 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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231189 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/llvm/CodeGen/LiveStackAnalysis.h | 3 ++-
lib/CodeGen/StackSlotColoring.cpp | 12 ++++++++++--
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/include/llvm/CodeGen/LiveStackAnalysis.h b/include/llvm/CodeGen/LiveStackAnalysis.h
index df683983fa5..f495507c66e 100644
--- a/include/llvm/CodeGen/LiveStackAnalysis.h
+++ b/include/llvm/CodeGen/LiveStackAnalysis.h
@@ -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.
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp
index cc72e5e51f2..a5a175f2c8f 100644
--- a/lib/CodeGen/StackSlotColoring.cpp
+++ b/lib/CodeGen/StackSlotColoring.cpp
@@ -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))