[llvm-commits] [llvm] r134047 - in /llvm/trunk/lib/CodeGen: RegAllocGreedy.cpp SplitKit.cpp SplitKit.h
Jim Grosbach
grosbach at apple.com
Wed Jun 29 11:09:25 PDT 2011
On Jun 28, 2011, at 5:24 PM, Jakob Stoklund Olesen wrote:
> Author: stoklund
> Date: Tue Jun 28 19:24:24 2011
> New Revision: 134047
>
> URL: http://llvm.org/viewvc/llvm-project?rev=134047&view=rev
> Log:
> Rewrite RAGreedy::splitAroundRegion, now with cool ASCII art.
>
> This function has to deal with a lot of special cases, and the old
> version got it wrong sometimes. In particular, it would sometimes leave
> multiple uses in the stack interval in a single block. That causes bad
> code with multiple reloads in the same basic block.
Aha! So that's why that was happening. Glad to see that get fixed!
-Jim
>
> The new version handles block entry and exit in a single pass. It first
> eliminates all the easy cases, and then goes on to create a local
> interval for the blocks with difficult interference. Previously, we
> would only create the local interval for completely isolated blocks.
>
> It can happen that the stack interval becomes completely empty because
> we could allocate a register in all edge bundles, and the new local
> intervals deal with the interference. The empty stack interval is
> harmless, but we need to remove a SplitKit assertion that checks for
> empty intervals.
>
> Modified:
> llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
> llvm/trunk/lib/CodeGen/SplitKit.cpp
> llvm/trunk/lib/CodeGen/SplitKit.h
>
> Modified: llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp?rev=134047&r1=134046&r2=134047&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
> +++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Tue Jun 28 19:24:24 2011
> @@ -763,32 +763,46 @@
> // Create the main cross-block interval.
> const unsigned MainIntv = SE->openIntv();
>
> - // First add all defs that are live out of a block.
> + // First handle all the blocks with uses.
> ArrayRef<SplitAnalysis::BlockInfo> UseBlocks = SA->getUseBlocks();
> for (unsigned i = 0; i != UseBlocks.size(); ++i) {
> const SplitAnalysis::BlockInfo &BI = UseBlocks[i];
> - bool RegIn = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 0)];
> - bool RegOut = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 1)];
> + bool RegIn = BI.LiveIn &&
> + LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 0)];
> + bool RegOut = BI.LiveOut &&
> + LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 1)];
>
> // Create separate intervals for isolated blocks with multiple uses.
> - if (!RegIn && !RegOut && BI.FirstUse != BI.LastUse) {
> + //
> + // |---o---o---| Enter and leave on the stack.
> + // ____-----____ Create local interval for uses.
> + //
> + // | o---o---| Defined in block, leave on stack.
> + // -----____ Create local interval for uses.
> + //
> + // |---o---x | Enter on stack, killed in block.
> + // ____----- Create local interval for uses.
> + //
> + if (!RegIn && !RegOut) {
> DEBUG(dbgs() << "BB#" << BI.MBB->getNumber() << " isolated.\n");
> - SE->splitSingleBlock(BI);
> - SE->selectIntv(MainIntv);
> + if (!BI.isOneInstr()) {
> + SE->splitSingleBlock(BI);
> + SE->selectIntv(MainIntv);
> + }
> continue;
> }
>
> - // Should the register be live out?
> - if (!BI.LiveOut || !RegOut)
> - continue;
> -
> SlotIndex Start, Stop;
> tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
> Intf.moveToBlock(BI.MBB->getNumber());
> - DEBUG(dbgs() << "BB#" << BI.MBB->getNumber() << " -> EB#"
> - << Bundles->getBundle(BI.MBB->getNumber(), 1)
> + DEBUG(dbgs() << "EB#" << Bundles->getBundle(BI.MBB->getNumber(), 0)
> + << (RegIn ? " => " : " -- ")
> + << "BB#" << BI.MBB->getNumber()
> + << (RegOut ? " => " : " -- ")
> + << " EB#" << Bundles->getBundle(BI.MBB->getNumber(), 1)
> << " [" << Start << ';'
> << SA->getLastSplitPoint(BI.MBB->getNumber()) << '-' << Stop
> + << ") uses [" << BI.FirstUse << ';' << BI.LastUse
> << ") intf [" << Intf.first() << ';' << Intf.last() << ')');
>
> // The interference interval should either be invalid or overlap MBB.
> @@ -797,150 +811,266 @@
> assert((!Intf.hasInterference() || Intf.last() > Start)
> && "Bad interference");
>
> - // Check interference leaving the block.
> + // We are now ready to decide where to split in the current block. There
> + // are many variables guiding the decision:
> + //
> + // - RegIn / RegOut: The global splitting algorithm's decisions for our
> + // ingoing and outgoing bundles.
> + //
> + // - BI.BlockIn / BI.BlockOut: Is the live range live-in and/or live-out
> + // from this block.
> + //
> + // - Intf.hasInterference(): Is there interference in this block.
> + //
> + // - Intf.first() / Inft.last(): The range of interference.
> + //
> + // The live range should be split such that MainIntv is live-in when RegIn
> + // is set, and live-out when RegOut is set. MainIntv should never overlap
> + // the interference, and the stack interval should never have more than one
> + // use per block.
> +
> + // No splits can be inserted after LastSplitPoint, overlap instead.
> + SlotIndex LastSplitPoint = Stop;
> + if (BI.LiveOut)
> + LastSplitPoint = SA->getLastSplitPoint(BI.MBB->getNumber());
> +
> + // At this point, we know that either RegIn or RegOut is set. We dealt with
> + // the all-stack case above.
> +
> + // Blocks without interference are relatively easy.
> if (!Intf.hasInterference()) {
> - // Block is interference-free.
> - DEBUG(dbgs() << ", no interference");
> - if (!BI.LiveThrough) {
> - DEBUG(dbgs() << ", not live-through.\n");
> - SE->useIntv(SE->enterIntvBefore(BI.FirstUse), Stop);
> - continue;
> - }
> - if (!RegIn) {
> - // Block is live-through, but entry bundle is on the stack.
> - // Reload just before the first use.
> - DEBUG(dbgs() << ", not live-in, enter before first use.\n");
> - SE->useIntv(SE->enterIntvBefore(BI.FirstUse), Stop);
> - continue;
> - }
> - DEBUG(dbgs() << ", live-through.\n");
> - continue;
> - }
> + DEBUG(dbgs() << ", no interference.\n");
> + SE->selectIntv(MainIntv);
> + // The easiest case has MainIntv live through.
> + //
> + // |---o---o---| Live-in, live-out.
> + // ============= Use MainIntv everywhere.
> + //
> + SlotIndex From = Start, To = Stop;
> +
> + // Block entry. Reload before the first use if MainIntv is not live-in.
> + //
> + // |---o-- Enter on stack.
> + // ____=== Reload before first use.
> + //
> + // | o-- Defined in block.
> + // === Use MainIntv from def.
> + //
> + if (!RegIn)
> + From = SE->enterIntvBefore(BI.FirstUse);
>
> - // Block has interference.
> - DEBUG(dbgs() << ", interference to " << Intf.last());
> + // Block exit. Handle cases where MainIntv is not live-out.
> + if (!BI.LiveOut)
> + //
> + // --x | Killed in block.
> + // === Use MainIntv up to kill.
> + //
> + To = SE->leaveIntvAfter(BI.LastUse);
> + else if (!RegOut) {
> + //
> + // --o---| Live-out on stack.
> + // ===____ Use MainIntv up to last use, switch to stack.
> + //
> + // -----o| Live-out on stack, last use after last split point.
> + // ====== Extend MainIntv to last use, overlapping.
> + // \____ Copy to stack interval before last split point.
> + //
> + if (BI.LastUse < LastSplitPoint)
> + To = SE->leaveIntvAfter(BI.LastUse);
> + else {
> + // The last use is after the last split point, it is probably an
> + // indirect branch.
> + To = SE->leaveIntvBefore(LastSplitPoint);
> + // Run a double interval from the split to the last use. This makes
> + // it possible to spill the complement without affecting the indirect
> + // branch.
> + SE->overlapIntv(To, BI.LastUse);
> + }
> + }
>
> - if (!BI.LiveThrough && Intf.last() <= BI.FirstUse) {
> - // The interference doesn't reach the outgoing segment.
> - DEBUG(dbgs() << " doesn't affect def from " << BI.FirstUse << '\n');
> - SE->useIntv(BI.FirstUse, Stop);
> + // Paint in MainIntv liveness for this block.
> + SE->useIntv(From, To);
> continue;
> }
>
> - SlotIndex LastSplitPoint = SA->getLastSplitPoint(BI.MBB->getNumber());
> - if (Intf.last().getBoundaryIndex() < BI.LastUse) {
> - // There are interference-free uses at the end of the block.
> - // Find the first use that can get the live-out register.
> - SmallVectorImpl<SlotIndex>::const_iterator UI =
> - std::lower_bound(SA->UseSlots.begin(), SA->UseSlots.end(),
> - Intf.last().getBoundaryIndex());
> - assert(UI != SA->UseSlots.end() && "Couldn't find last use");
> - SlotIndex Use = *UI;
> - assert(Use <= BI.LastUse && "Couldn't find last use");
> - // Only attempt a split befroe the last split point.
> - if (Use.getBaseIndex() <= LastSplitPoint) {
> - DEBUG(dbgs() << ", free use at " << Use << ".\n");
> - SlotIndex SegStart = SE->enterIntvBefore(Use);
> - assert(SegStart >= Intf.last() && "Couldn't avoid interference");
> - assert(SegStart < LastSplitPoint && "Impossible split point");
> - SE->useIntv(SegStart, Stop);
> - continue;
> - }
> - }
> + // We are now looking at a block with interference, and we know that either
> + // RegIn or RegOut is set.
> + assert(Intf.hasInterference() && (RegIn || RegOut) && "Bad invariant");
>
> - // Interference is after the last use.
> - DEBUG(dbgs() << " after last use.\n");
> - SlotIndex SegStart = SE->enterIntvAtEnd(*BI.MBB);
> - assert(SegStart >= Intf.last() && "Couldn't avoid interference");
> - }
> + // If the live range is not live through the block, it is possible that the
> + // interference doesn't even overlap. Deal with those cases first. Since
> + // no copy instructions are required, we can tolerate interference starting
> + // or ending at the same instruction that kills or defines our live range.
>
> - // Now all defs leading to live bundles are handled, do everything else.
> - for (unsigned i = 0; i != UseBlocks.size(); ++i) {
> - const SplitAnalysis::BlockInfo &BI = UseBlocks[i];
> - bool RegIn = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 0)];
> - bool RegOut = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 1)];
> + // Live-in, killed before interference.
> + //
> + // ~~~ Interference after kill.
> + // |---o---x | Killed in block.
> + // ========= Use MainIntv everywhere.
> + //
> + if (RegIn && !BI.LiveOut && BI.LastUse <= Intf.first()) {
> + DEBUG(dbgs() << ", live-in, killed before interference.\n");
> + SE->selectIntv(MainIntv);
> + SlotIndex To = SE->leaveIntvAfter(BI.LastUse);
> + SE->useIntv(Start, To);
> + continue;
> + }
>
> - // Is the register live-in?
> - if (!BI.LiveIn || !RegIn)
> + // Live-out, defined after interference.
> + //
> + // ~~~ Interference before def.
> + // | o---o---| Defined in block.
> + // ========= Use MainIntv everywhere.
> + //
> + if (RegOut && !BI.LiveIn && BI.FirstUse >= Intf.last()) {
> + DEBUG(dbgs() << ", live-out, defined after interference.\n");
> + SE->selectIntv(MainIntv);
> + SlotIndex From = SE->enterIntvBefore(BI.FirstUse);
> + SE->useIntv(From, Stop);
> continue;
> + }
>
> - // We have an incoming register. Check for interference.
> - SlotIndex Start, Stop;
> - tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
> - Intf.moveToBlock(BI.MBB->getNumber());
> - DEBUG(dbgs() << "EB#" << Bundles->getBundle(BI.MBB->getNumber(), 0)
> - << " -> BB#" << BI.MBB->getNumber() << " [" << Start << ';'
> - << SA->getLastSplitPoint(BI.MBB->getNumber()) << '-' << Stop
> - << ')');
> + // The interference is now known to overlap the live range, but it may
> + // still be easy to avoid if all the interference is on one side of the
> + // uses, and we enter or leave on the stack.
>
> - // Check interference entering the block.
> - if (!Intf.hasInterference()) {
> - // Block is interference-free.
> - DEBUG(dbgs() << ", no interference");
> - if (!BI.LiveThrough) {
> - DEBUG(dbgs() << ", killed in block.\n");
> - SE->useIntv(Start, SE->leaveIntvAfter(BI.LastUse));
> - continue;
> - }
> - if (!RegOut) {
> - SlotIndex LastSplitPoint = SA->getLastSplitPoint(BI.MBB->getNumber());
> - // Block is live-through, but exit bundle is on the stack.
> - // Spill immediately after the last use.
> - if (BI.LastUse < LastSplitPoint) {
> - DEBUG(dbgs() << ", uses, stack-out.\n");
> - SE->useIntv(Start, SE->leaveIntvAfter(BI.LastUse));
> - continue;
> - }
> - // The last use is after the last split point, it is probably an
> - // indirect jump.
> - DEBUG(dbgs() << ", uses at " << BI.LastUse << " after split point "
> - << LastSplitPoint << ", stack-out.\n");
> - SlotIndex SegEnd = SE->leaveIntvBefore(LastSplitPoint);
> - SE->useIntv(Start, SegEnd);
> - // Run a double interval from the split to the last use.
> - // This makes it possible to spill the complement without affecting the
> - // indirect branch.
> - SE->overlapIntv(SegEnd, BI.LastUse);
> - continue;
> + // Live-out on stack, interference after last use.
> + //
> + // ~~~ Interference after last use.
> + // |---o---o---| Live-out on stack.
> + // =========____ Leave MainIntv after last use.
> + //
> + // ~ Interference after last use.
> + // |---o---o--o| Live-out on stack, late last use.
> + // =========____ Copy to stack after LSP, overlap MainIntv.
> + //
> + if (!RegOut && Intf.first() > BI.LastUse.getBoundaryIndex()) {
> + assert(RegIn && "Stack-in, stack-out should already be handled");
> + if (BI.LastUse < LastSplitPoint) {
> + DEBUG(dbgs() << ", live-in, stack-out, interference after last use.\n");
> + SE->selectIntv(MainIntv);
> + SlotIndex To = SE->leaveIntvAfter(BI.LastUse);
> + assert(To <= Intf.first() && "Expected to avoid interference");
> + SE->useIntv(Start, To);
> + } else {
> + DEBUG(dbgs() << ", live-in, stack-out, avoid last split point\n");
> + SE->selectIntv(MainIntv);
> + SlotIndex To = SE->leaveIntvBefore(LastSplitPoint);
> + assert(To <= Intf.first() && "Expected to avoid interference");
> + SE->overlapIntv(To, BI.LastUse);
> + SE->useIntv(Start, To);
> }
> - // Register is live-through.
> - DEBUG(dbgs() << ", uses, live-through.\n");
> - SE->useIntv(Start, Stop);
> continue;
> }
>
> - // Block has interference.
> - DEBUG(dbgs() << ", interference from " << Intf.first());
> -
> - if (!BI.LiveThrough && Intf.first() >= BI.LastUse) {
> - // The interference doesn't reach the outgoing segment.
> - DEBUG(dbgs() << " doesn't affect kill at " << BI.LastUse << '\n');
> - SE->useIntv(Start, BI.LastUse);
> + // Live-in on stack, interference before first use.
> + //
> + // ~~~ Interference before first use.
> + // |---o---o---| Live-in on stack.
> + // ____========= Enter MainIntv before first use.
> + //
> + if (!RegIn && Intf.last() < BI.FirstUse.getBaseIndex()) {
> + assert(RegOut && "Stack-in, stack-out should already be handled");
> + DEBUG(dbgs() << ", stack-in, interference before first use.\n");
> + SE->selectIntv(MainIntv);
> + SlotIndex From = SE->enterIntvBefore(BI.FirstUse);
> + assert(From >= Intf.last() && "Expected to avoid interference");
> + SE->useIntv(From, Stop);
> continue;
> }
>
> - if (Intf.first().getBaseIndex() > BI.FirstUse) {
> - // There are interference-free uses at the beginning of the block.
> - // Find the last use that can get the register.
> - SmallVectorImpl<SlotIndex>::const_iterator UI =
> - std::lower_bound(SA->UseSlots.begin(), SA->UseSlots.end(),
> - Intf.first().getBaseIndex());
> - assert(UI != SA->UseSlots.begin() && "Couldn't find first use");
> - SlotIndex Use = (--UI)->getBoundaryIndex();
> - DEBUG(dbgs() << ", free use at " << *UI << ".\n");
> - SlotIndex SegEnd = SE->leaveIntvAfter(Use);
> - assert(SegEnd <= Intf.first() && "Couldn't avoid interference");
> - SE->useIntv(Start, SegEnd);
> - continue;
> + // The interference is overlapping somewhere we wanted to use MainIntv. That
> + // means we need to create a local interval that can be allocated a
> + // different register.
> + DEBUG(dbgs() << ", creating local interval.\n");
> + unsigned LocalIntv = SE->openIntv();
> +
> + // We may be creating copies directly between MainIntv and LocalIntv,
> + // bypassing the stack interval. When we do that, we should never use the
> + // leaveIntv* methods as they define values in the stack interval. By
> + // starting from the end of the block and working our way backwards, we can
> + // get by with only enterIntv* methods.
> + //
> + // When selecting split points, we generally try to maximize the stack
> + // interval as long at it contains no uses, maximize the main interval as
> + // long as it doesn't overlap interference, and minimize the local interval
> + // that we don't know how to allocate yet.
> +
> + // Handle the block exit, set Pos to the first handled slot.
> + SlotIndex Pos = BI.LastUse;
> + if (RegOut) {
> + assert(Intf.last() < LastSplitPoint && "Cannot be live-out in register");
> + // Create a snippet of MainIntv that is live-out.
> + //
> + // ~~~ Interference overlapping uses.
> + // --o---| Live-out in MainIntv.
> + // ----=== Switch from LocalIntv to MainIntv after interference.
> + //
> + SE->selectIntv(MainIntv);
> + Pos = SE->enterIntvAfter(Intf.last());
> + assert(Pos >= Intf.last() && "Expected to avoid interference");
> + SE->useIntv(Pos, Stop);
> + SE->selectIntv(LocalIntv);
> + } else if (BI.LiveOut) {
> + if (BI.LastUse < LastSplitPoint) {
> + // Live-out on the stack.
> + //
> + // ~~~ Interference overlapping uses.
> + // --o---| Live-out on stack.
> + // ---____ Switch from LocalIntv to stack after last use.
> + //
> + Pos = SE->leaveIntvAfter(BI.LastUse);
> + } else {
> + // Live-out on the stack, last use after last split point.
> + //
> + // ~~~ Interference overlapping uses.
> + // --o--o| Live-out on stack, late use.
> + // ------ Copy to stack before LSP, overlap LocalIntv.
> + // \__
> + //
> + Pos = SE->leaveIntvBefore(LastSplitPoint);
> + // We need to overlap LocalIntv so it can reach LastUse.
> + SE->overlapIntv(Pos, BI.LastUse);
> + }
> }
>
> - // Interference is before the first use.
> - DEBUG(dbgs() << " before first use.\n");
> - SlotIndex SegEnd = SE->leaveIntvAtTop(*BI.MBB);
> - assert(SegEnd <= Intf.first() && "Couldn't avoid interference");
> + // When not live-out, leave Pos at LastUse. We have handled everything from
> + // Pos to Stop. Find the starting point for LocalIntv.
> + assert(SE->currentIntv() == LocalIntv && "Expecting local interval");
> +
> + if (RegIn) {
> + assert(Start < Intf.first() && "Cannot be live-in with interference");
> + // Live-in in MainIntv, only use LocalIntv for interference.
> + //
> + // ~~~ Interference overlapping uses.
> + // |---o-- Live-in in MainIntv.
> + // ====--- Switch to LocalIntv before interference.
> + //
> + SlotIndex Switch = SE->enterIntvBefore(Intf.first());
> + assert(Switch <= Intf.first() && "Expected to avoid interference");
> + SE->useIntv(Switch, Pos);
> + SE->selectIntv(MainIntv);
> + SE->useIntv(Start, Switch);
> + } else {
> + // Live-in on stack, enter LocalIntv before first use.
> + //
> + // ~~~ Interference overlapping uses.
> + // |---o-- Live-in in MainIntv.
> + // ____--- Reload to LocalIntv before interference.
> + //
> + // Defined in block.
> + //
> + // ~~~ Interference overlapping uses.
> + // | o-- Defined in block.
> + // --- Begin LocalIntv at first use.
> + //
> + SlotIndex Switch = SE->enterIntvBefore(BI.FirstUse);
> + SE->useIntv(Switch, Pos);
> + }
> }
>
> // Handle live-through blocks.
> + SE->selectIntv(MainIntv);
> for (unsigned i = 0, e = Cand.ActiveBlocks.size(); i != e; ++i) {
> unsigned Number = Cand.ActiveBlocks[i];
> bool RegIn = LiveBundles[Bundles->getBundle(Number, 0)];
>
> Modified: llvm/trunk/lib/CodeGen/SplitKit.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SplitKit.cpp?rev=134047&r1=134046&r2=134047&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/SplitKit.cpp (original)
> +++ llvm/trunk/lib/CodeGen/SplitKit.cpp Tue Jun 28 19:24:24 2011
> @@ -636,6 +636,7 @@
> void SplitEditor::selectIntv(unsigned Idx) {
> assert(Idx != 0 && "Cannot select the complement interval");
> assert(Idx < Edit->size() && "Can only select previously opened interval");
> + DEBUG(dbgs() << " selectIntv " << OpenIdx << " -> " << Idx << '\n');
> OpenIdx = Idx;
> }
>
> @@ -656,6 +657,24 @@
> return VNI->def;
> }
>
> +SlotIndex SplitEditor::enterIntvAfter(SlotIndex Idx) {
> + assert(OpenIdx && "openIntv not called before enterIntvAfter");
> + DEBUG(dbgs() << " enterIntvAfter " << Idx);
> + Idx = Idx.getBoundaryIndex();
> + VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
> + if (!ParentVNI) {
> + DEBUG(dbgs() << ": not live\n");
> + return Idx;
> + }
> + DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n');
> + MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
> + assert(MI && "enterIntvAfter called with invalid index");
> +
> + VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Idx, *MI->getParent(),
> + llvm::next(MachineBasicBlock::iterator(MI)));
> + return VNI->def;
> +}
> +
> SlotIndex SplitEditor::enterIntvAtEnd(MachineBasicBlock &MBB) {
> assert(OpenIdx && "openIntv not called before enterIntvAtEnd");
> SlotIndex End = LIS.getMBBEndIdx(&MBB);
> @@ -1007,12 +1026,6 @@
> markComplexMapped(i, ParentVNI);
> }
>
> -#ifndef NDEBUG
> - // Every new interval must have a def by now, otherwise the split is bogus.
> - for (LiveRangeEdit::iterator I = Edit->begin(), E = Edit->end(); I != E; ++I)
> - assert((*I)->hasAtLeastOneValue() && "Split interval has no value");
> -#endif
> -
> // Transfer the simply mapped values, check if any are skipped.
> bool Skipped = transferValues();
> if (Skipped)
>
> Modified: llvm/trunk/lib/CodeGen/SplitKit.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SplitKit.h?rev=134047&r1=134046&r2=134047&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/SplitKit.h (original)
> +++ llvm/trunk/lib/CodeGen/SplitKit.h Tue Jun 28 19:24:24 2011
> @@ -81,6 +81,12 @@
> bool LiveThrough; ///< Live in whole block (Templ 5. above).
> bool LiveIn; ///< Current reg is live in.
> bool LiveOut; ///< Current reg is live out.
> +
> + /// isOneInstr - Returns true when this BlockInfo describes a single
> + /// instruction.
> + bool isOneInstr() const {
> + return SlotIndex::isSameInstr(FirstUse, LastUse);
> + }
> };
>
> private:
> @@ -360,6 +366,10 @@
> /// Return the beginning of the new live range.
> SlotIndex enterIntvBefore(SlotIndex Idx);
>
> + /// enterIntvAfter - Enter the open interval after the instruction at Idx.
> + /// Return the beginning of the new live range.
> + SlotIndex enterIntvAfter(SlotIndex Idx);
> +
> /// enterIntvAtEnd - Enter the open interval at the end of MBB.
> /// Use the open interval from he inserted copy to the MBB end.
> /// Return the beginning of the new live range.
>
>
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