Provide LiveIntervalUnion::Query::checkLoopInterference.
This is a three-way interval list intersection between a virtual register, a
live interval union, and a loop. It will be used to identify interference-free
loops for live range splitting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122034 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalUnion.cpp b/lib/CodeGen/LiveIntervalUnion.cpp
index 079468a..7ebe96f 100644
--- a/lib/CodeGen/LiveIntervalUnion.cpp
+++ b/lib/CodeGen/LiveIntervalUnion.cpp
@@ -16,6 +16,7 @@
#define DEBUG_TYPE "regalloc"
#include "LiveIntervalUnion.h"
#include "llvm/ADT/SparseBitVector.h"
+#include "llvm/CodeGen/MachineLoopRanges.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetRegisterInfo.h"
@@ -284,3 +285,30 @@
SeenAllInterferences = true;
return InterferingVRegs.size();
}
+
+bool LiveIntervalUnion::Query::checkLoopInterference(MachineLoopRange *Loop) {
+ // VirtReg is likely live throughout the loop, so start by checking LIU-Loop
+ // overlaps.
+ IntervalMapOverlaps<LiveIntervalUnion::Map, MachineLoopRange::Map>
+ Overlaps(LiveUnion->getMap(), Loop->getMap());
+ if (!Overlaps.valid())
+ return false;
+
+ // The loop is overlapping an LIU assignment. Check VirtReg as well.
+ LiveInterval::iterator VRI = VirtReg->find(Overlaps.start());
+
+ for (;;) {
+ if (VRI == VirtReg->end())
+ return false;
+ if (VRI->start < Overlaps.stop())
+ return true;
+
+ Overlaps.advanceTo(VRI->start);
+ if (!Overlaps.valid())
+ return false;
+ if (Overlaps.start() < VRI->end)
+ return true;
+
+ VRI = VirtReg->advanceTo(VRI, Overlaps.start());
+ }
+}
diff --git a/lib/CodeGen/LiveIntervalUnion.h b/lib/CodeGen/LiveIntervalUnion.h
index d8dcbda..ff23cf6 100644
--- a/lib/CodeGen/LiveIntervalUnion.h
+++ b/lib/CodeGen/LiveIntervalUnion.h
@@ -24,6 +24,7 @@
namespace llvm {
+class MachineLoopRange;
class TargetRegisterInfo;
#ifndef NDEBUG
@@ -76,6 +77,10 @@
bool empty() const { return Segments.empty(); }
SlotIndex startIndex() const { return Segments.start(); }
+ // Provide public access to the underlying map to allow overlap iteration.
+ typedef LiveSegments Map;
+ const Map &getMap() { return Segments; }
+
// Add a live virtual register to this union and merge its segments.
void unify(LiveInterval &VirtReg);
@@ -223,6 +228,10 @@
return InterferingVRegs;
}
+ /// checkLoopInterference - Return true if there is interference overlapping
+ /// Loop.
+ bool checkLoopInterference(MachineLoopRange*);
+
void print(raw_ostream &OS, const TargetRegisterInfo *TRI);
private:
Query(const Query&); // DO NOT IMPLEMENT
diff --git a/lib/CodeGen/MachineLoopRanges.cpp b/lib/CodeGen/MachineLoopRanges.cpp
index 9af49b0..9ee6c5b 100644
--- a/lib/CodeGen/MachineLoopRanges.cpp
+++ b/lib/CodeGen/MachineLoopRanges.cpp
@@ -69,13 +69,13 @@
/// overlaps - Return true if this loop overlaps the given range of machine
/// instructions.
bool MachineLoopRange::overlaps(SlotIndex Start, SlotIndex Stop) {
- RangeMap::const_iterator I = Intervals.find(Start);
+ Map::const_iterator I = Intervals.find(Start);
return I.valid() && Stop > I.start();
}
void MachineLoopRange::print(raw_ostream &OS) const {
OS << "Loop#" << Loop->getHeader()->getNumber() << " =";
- for (RangeMap::const_iterator I = Intervals.begin(); I.valid(); ++I)
+ for (Map::const_iterator I = Intervals.begin(); I.valid(); ++I)
OS << " [" << I.start() << ';' << I.stop() << ')';
}