From ff2e9b4225ab55ee049b33158a9cce1ef138c2f7 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Fri, 17 Dec 2010 04:09:47 +0000 Subject: 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 --- lib/CodeGen/LiveIntervalUnion.cpp | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'lib/CodeGen/LiveIntervalUnion.cpp') diff --git a/lib/CodeGen/LiveIntervalUnion.cpp b/lib/CodeGen/LiveIntervalUnion.cpp index 079468a4f0..7ebe96f066 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 @@ collectInterferingVRegs(unsigned MaxInterferingRegs) { 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 + 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()); + } +} -- cgit v1.2.3