[Mesa-dev] [PATCH 4/4] AMDGPU: New control flow for SI
Christian König
deathsimple at vodafone.de
Sun Dec 9 09:02:59 PST 2012
This patch replaces the control flow handling with a new
pass which structurize the graph before transforming it to
machine instruction. This has a couple of different advantages
and currently fixes 20 piglit tests without a single regression.
It is now a general purpose transformation that could be not
only be used for SI/R6xx, but also for other hardware
implementations that use a form of structurized control flow.
Signed-off-by: Christian König <deathsimple at vodafone.de>
---
lib/Target/AMDGPU/AMDGPU.h | 3 +-
lib/Target/AMDGPU/AMDGPUStructurizeCFG.cpp | 725 +++++++++++++++++++++++++++
lib/Target/AMDGPU/AMDGPUTargetMachine.cpp | 13 +-
lib/Target/AMDGPU/AMDILCFGStructurizer.cpp | 4 -
lib/Target/AMDGPU/AMDILInstrInfo.td | 65 ---
lib/Target/AMDGPU/R600Instructions.td | 65 +++
lib/Target/AMDGPU/SIAnnotateControlFlow.cpp | 333 ++++++++++++
lib/Target/AMDGPU/SIFixSGPRLiveness.cpp | 179 -------
lib/Target/AMDGPU/SIISelLowering.cpp | 118 ++++-
lib/Target/AMDGPU/SIISelLowering.h | 2 +-
lib/Target/AMDGPU/SIInstructions.td | 72 ++-
lib/Target/AMDGPU/SIIntrinsics.td | 10 +
lib/Target/AMDGPU/SILowerControlFlow.cpp | 285 +++++++----
13 files changed, 1491 insertions(+), 383 deletions(-)
create mode 100644 lib/Target/AMDGPU/AMDGPUStructurizeCFG.cpp
create mode 100644 lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
delete mode 100644 lib/Target/AMDGPU/SIFixSGPRLiveness.cpp
diff --git a/lib/Target/AMDGPU/AMDGPU.h b/lib/Target/AMDGPU/AMDGPU.h
index 40864b0..0f5125d 100644
--- a/lib/Target/AMDGPU/AMDGPU.h
+++ b/lib/Target/AMDGPU/AMDGPU.h
@@ -25,13 +25,14 @@ FunctionPass* createR600KernelParametersPass(const DataLayout *TD);
FunctionPass *createR600ExpandSpecialInstrsPass(TargetMachine &tm);
// SI Passes
+FunctionPass *createSIAnnotateControlFlowPass();
FunctionPass *createSIAssignInterpRegsPass(TargetMachine &tm);
FunctionPass *createSILowerControlFlowPass(TargetMachine &tm);
FunctionPass *createSICodeEmitterPass(formatted_raw_ostream &OS);
FunctionPass *createSILowerLiteralConstantsPass(TargetMachine &tm);
-FunctionPass *createSIFixSGPRLivenessPass(TargetMachine &tm);
// Passes common to R600 and SI
+Pass *createAMDGPUStructurizeCFGPass();
FunctionPass *createAMDGPUConvertToISAPass(TargetMachine &tm);
} // End namespace llvm
diff --git a/lib/Target/AMDGPU/AMDGPUStructurizeCFG.cpp b/lib/Target/AMDGPU/AMDGPUStructurizeCFG.cpp
new file mode 100644
index 0000000..6ddb5bf
--- /dev/null
+++ b/lib/Target/AMDGPU/AMDGPUStructurizeCFG.cpp
@@ -0,0 +1,725 @@
+//===-- AMDGPUStructurizeCFG.cpp - ------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// The pass implemented in this file transforms the programs control flow graph
+// into a form that's suitable for code generation on hardware that implements
+// control flow by execution masking. This currently includes all AMD GPUs but
+// may as well be useful for other types of hardware.
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "llvm/Module.h"
+#include "llvm/ADT/SCCIterator.h"
+#include "llvm/Analysis/RegionIterator.h"
+#include "llvm/Analysis/RegionInfo.h"
+#include "llvm/Analysis/RegionPass.h"
+#include "llvm/Transforms/Utils/SSAUpdater.h"
+
+using namespace llvm;
+
+namespace {
+
+// Definition of the complex types used in this pass.
+
+typedef std::pair<BasicBlock *, Value *> BBValuePair;
+typedef ArrayRef<BasicBlock*> BBVecRef;
+
+typedef SmallVector<RegionNode*, 8> RNVector;
+typedef SmallVector<BasicBlock*, 8> BBVector;
+typedef SmallVector<BBValuePair, 2> BBValueVector;
+
+typedef DenseMap<PHINode *, BBValueVector> PhiMap;
+typedef DenseMap<BasicBlock *, PhiMap> BBPhiMap;
+typedef DenseMap<BasicBlock *, Value *> BBPredicates;
+typedef DenseMap<BasicBlock *, BBPredicates> PredMap;
+typedef DenseMap<BasicBlock *, unsigned> VisitedMap;
+
+// The name for newly created blocks.
+
+static const char *FlowBlockName = "Flow";
+
+// Transforms the control flow graph on one single entry/exit region at a time.
+//
+// After the transform all "If"/"Then"/"Else" style control flow looks like
+// this:
+//
+// 1
+// ||
+// | |
+// 2 |
+// | /
+// |/
+// 3
+// || Where:
+// | | 1 = "If" block, calculates the condition
+// 4 | 2 = "Then" subregion, runs if the condition is true
+// | / 3 = "Flow" blocks, newly inserted flow blocks, rejoins the control flow
+// |/ 4 = "Else" optional subregion, runs if the condition is false
+// 5 5 = "End" block, also rejoins the control flow
+//
+// Control flow is expressed as a branch where the true exit goes into the
+// "Then"/"Else" region, while the false exit skips the region
+// The condition for the optional "Else" region is expressed as a PHI node.
+// The incomming values of the PHI node are true for the "If" edge and false
+// for the "Then" edge.
+//
+// Additionally to that even complicated loops look like this:
+//
+// 1
+// ||
+// | |
+// 2 ^ Where:
+// | / 1 = "Entry" block
+// |/ 2 = "Loop" optional subregion, with all exits at "Flow" block
+// 3 3 = "Flow" block, with back edge to entry block
+// |
+//
+// The back edge of the "Flow" block is always on the false side of the branch
+// while the true side continues the general flow. So the loop condition
+// consist of a network of PHI nodes where the true incoming values expresses
+// breaks and the false values expresses continue states.
+class AMDGPUStructurizeCFG : public RegionPass {
+
+ static char ID;
+
+ Type *Boolean;
+ ConstantInt *BoolTrue;
+ ConstantInt *BoolFalse;
+ UndefValue *BoolUndef;
+
+ Function *Function;
+ Region *ParentRegion;
+
+ DominatorTree *DT;
+
+ RNVector Order;
+ VisitedMap Visited;
+ PredMap Predicates;
+ BBPhiMap DeletedPhis;
+ BBVector FlowsInserted;
+
+ BasicBlock *LoopStart;
+ BasicBlock *LoopEnd;
+ BBPredicates LoopPred;
+
+ void orderNodes();
+
+ void buildPredicate(BranchInst *Term, unsigned Idx,
+ BBPredicates &Pred, bool Invert);
+
+ void analyzeBlock(BasicBlock *BB);
+
+ void analyzeLoop(BasicBlock *BB, unsigned &LoopIdx);
+
+ void collectInfos();
+
+ bool dominatesPredicates(BasicBlock *A, BasicBlock *B);
+
+ void killTerminator(BasicBlock *BB);
+
+ RegionNode *skipChained(RegionNode *Node);
+
+ void delPhiValues(BasicBlock *From, BasicBlock *To);
+
+ void addPhiValues(BasicBlock *From, BasicBlock *To);
+
+ BasicBlock *getNextFlow(BasicBlock *Prev);
+
+ bool isPredictableTrue(BasicBlock *Prev, BasicBlock *Node);
+
+ BasicBlock *wireFlowBlock(BasicBlock *Prev, RegionNode *Node);
+
+ void createFlow();
+
+ void insertConditions();
+
+ void rebuildSSA();
+
+public:
+ AMDGPUStructurizeCFG():
+ RegionPass(ID) {
+
+ initializeRegionInfoPass(*PassRegistry::getPassRegistry());
+ }
+
+ virtual bool doInitialization(Region *R, RGPassManager &RGM);
+
+ virtual bool runOnRegion(Region *R, RGPassManager &RGM);
+
+ virtual const char *getPassName() const {
+ return "AMDGPU simplify control flow";
+ }
+
+ void getAnalysisUsage(AnalysisUsage &AU) const {
+
+ AU.addRequired<DominatorTree>();
+ AU.addPreserved<DominatorTree>();
+ RegionPass::getAnalysisUsage(AU);
+ }
+
+};
+
+} // end anonymous namespace
+
+char AMDGPUStructurizeCFG::ID = 0;
+
+// Initialize the types and constants used in the pass
+bool AMDGPUStructurizeCFG::doInitialization(Region *R, RGPassManager &RGM) {
+
+ LLVMContext &Context = R->getEntry()->getContext();
+
+ Boolean = Type::getInt1Ty(Context);
+ BoolTrue = ConstantInt::getTrue(Context);
+ BoolFalse = ConstantInt::getFalse(Context);
+ BoolUndef = UndefValue::get(Boolean);
+
+ return false;
+}
+
+// Build up the general order of nodes
+void AMDGPUStructurizeCFG::orderNodes() {
+
+ scc_iterator<Region *> I = scc_begin(ParentRegion),
+ E = scc_end(ParentRegion);
+ for (Order.clear(); I != E; ++I) {
+ std::vector<RegionNode *> &Nodes = *I;
+ Order.append(Nodes.begin(), Nodes.end());
+ }
+}
+
+// Build blocks and loop predicates
+void AMDGPUStructurizeCFG::buildPredicate(BranchInst *Term, unsigned Idx,
+ BBPredicates &Pred, bool Invert) {
+
+ Value *True = Invert ? BoolFalse : BoolTrue;
+ Value *False = Invert ? BoolTrue : BoolFalse;
+
+ RegionInfo *RI = ParentRegion->getRegionInfo();
+ BasicBlock *BB = Term->getParent();
+
+ // Handle the case where multiple regions start at the same block
+ Region *R = BB != ParentRegion->getEntry() ?
+ RI->getRegionFor(BB) : ParentRegion;
+
+ if (R == ParentRegion) {
+ // It's a top level block in our region
+ Value *Cond = True;
+ if (Term->isConditional()) {
+ BasicBlock *Other = Term->getSuccessor(!Idx);
+
+ if (Visited.count(Other)) {
+ if (!Pred.count(Other))
+ Pred[Other] = False;
+
+ if (!Pred.count(BB))
+ Pred[BB] = True;
+ return;
+ }
+ Cond = Term->getCondition();
+
+ if (Idx != Invert)
+ Cond = BinaryOperator::CreateNot(Cond, "", Term);
+ }
+
+ Pred[BB] = Cond;
+
+ } else if (ParentRegion->contains(R)) {
+ // It's a block in a sub region
+ while(R->getParent() != ParentRegion)
+ R = R->getParent();
+
+ Pred[R->getEntry()] = True;
+
+ } else {
+ // It's a branch from outside into our parent region
+ Pred[BB] = True;
+ }
+}
+
+// Analyze the successors of each block and build up predicates
+void AMDGPUStructurizeCFG::analyzeBlock(BasicBlock *BB) {
+
+ pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
+ BBPredicates &Pred = Predicates[BB];
+
+ for (; PI != PE; ++PI) {
+ BranchInst *Term = cast<BranchInst>((*PI)->getTerminator());
+
+ for (unsigned i = 0, e = Term->getNumSuccessors(); i != e; ++i) {
+ BasicBlock *Succ = Term->getSuccessor(i);
+ if (Succ != BB)
+ continue;
+ buildPredicate(Term, i, Pred, false);
+ }
+ }
+}
+
+// Analyze the conditions leading to loop to a previous block
+void AMDGPUStructurizeCFG::analyzeLoop(BasicBlock *BB, unsigned &LoopIdx) {
+
+ BranchInst *Term = cast<BranchInst>(BB->getTerminator());
+
+ for (unsigned i = 0, e = Term->getNumSuccessors(); i != e; ++i) {
+ BasicBlock *Succ = Term->getSuccessor(i);
+
+ // Ignore it if it's not a back edge
+ if (!Visited.count(Succ))
+ continue;
+
+ buildPredicate(Term, i, LoopPred, true);
+
+ LoopEnd = BB;
+ if (Visited[Succ] < LoopIdx) {
+ LoopIdx = Visited[Succ];
+ LoopStart = Succ;
+ }
+ }
+}
+
+// Collect various loop and predicate infos
+void AMDGPUStructurizeCFG::collectInfos()
+{
+ unsigned Number = 0, LoopIdx = ~0;
+
+ // Reset predicate
+ Predicates.clear();
+
+ // and loop infos
+ LoopStart = LoopEnd = 0;
+ LoopPred.clear();
+
+ RNVector::reverse_iterator OI = Order.rbegin(), OE = Order.rend();
+ for (Visited.clear(); OI != OE; Visited[(*OI++)->getEntry()] = ++Number) {
+
+ // Analyze all the conditions leading to a node
+ analyzeBlock((*OI)->getEntry());
+
+ if ((*OI)->isSubRegion())
+ continue;
+
+ // Find the first/last loop nodes and loop predicates
+ analyzeLoop((*OI)->getNodeAs<BasicBlock>(), LoopIdx);
+ }
+}
+
+// Does A dominate all the predicates of B ?
+bool AMDGPUStructurizeCFG::dominatesPredicates(BasicBlock *A, BasicBlock *B) {
+ BBPredicates &Preds = Predicates[B];
+ for (BBPredicates::iterator PI = Preds.begin(), PE = Preds.end();
+ PI != PE; ++PI) {
+
+ if (!DT->dominates(A, PI->first))
+ return false;
+ }
+ return true;
+}
+
+// Remove phi values from all successors and the remove the terminator.
+void AMDGPUStructurizeCFG::killTerminator(BasicBlock *BB) {
+
+ TerminatorInst *Term = BB->getTerminator();
+ if (!Term)
+ return;
+
+ for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
+ SI != SE; ++SI) {
+
+ delPhiValues(BB, *SI);
+ }
+
+ Term->eraseFromParent();
+}
+
+// First: Skip forward to the first region node that either isn't a subregion or not
+// dominating it's exit, remove all the skipped nodes from the node order.
+//
+// Second: Handle the first successor directly if the resulting nodes successor
+// predicates are still dominated by the original entry
+RegionNode *AMDGPUStructurizeCFG::skipChained(RegionNode *Node) {
+
+ BasicBlock *Entry = Node->getEntry();
+
+ // Skip forward as long as it is just a linear flow
+ while (true) {
+ BasicBlock *Entry = Node->getEntry();
+ BasicBlock *Exit;
+
+ if (Node->isSubRegion()) {
+ Exit = Node->getNodeAs<Region>()->getExit();
+ } else {
+ TerminatorInst *Term = Entry->getTerminator();
+ if (Term->getNumSuccessors() != 1)
+ break;
+ Exit = Term->getSuccessor(0);
+ }
+
+ // It's a back edge, break here so we can insert a loop node
+ if (!Visited.count(Exit))
+ return Node;
+
+ // More than node edges are pointing to exit
+ if (!DT->dominates(Entry, Exit))
+ return Node;
+
+ RegionNode *Next = ParentRegion->getNode(Exit);
+ RNVector::iterator I = std::find(Order.begin(), Order.end(), Next);
+ assert(I != Order.end());
+
+ Visited.erase(Next->getEntry());
+ Order.erase(I);
+ Node = Next;
+ }
+
+ BasicBlock *BB = Node->getEntry();
+ TerminatorInst *Term = BB->getTerminator();
+ if (Term->getNumSuccessors() != 2)
+ return Node;
+
+ // Our node has exactly two succesors, check if we can handle
+ // any of them directly
+ BasicBlock *Succ = Term->getSuccessor(0);
+ if (!Visited.count(Succ) || !dominatesPredicates(Entry, Succ)) {
+ Succ = Term->getSuccessor(1);
+ if (!Visited.count(Succ) || !dominatesPredicates(Entry, Succ))
+ return Node;
+ } else {
+ BasicBlock *Succ2 = Term->getSuccessor(1);
+ if (Visited.count(Succ2) && Visited[Succ] > Visited[Succ2] &&
+ dominatesPredicates(Entry, Succ2))
+ Succ = Succ2;
+ }
+
+ RegionNode *Next = ParentRegion->getNode(Succ);
+ RNVector::iterator E = Order.end();
+ RNVector::iterator I = std::find(Order.begin(), E, Next);
+ assert(I != E);
+
+ killTerminator(BB);
+ FlowsInserted.push_back(BB);
+ Visited.erase(Succ);
+ Order.erase(I);
+ return ParentRegion->getNode(wireFlowBlock(BB, Next));
+}
+
+// Remove all PHI values coming from "From" into "To"
+// and remember them in DeletedPhis
+void AMDGPUStructurizeCFG::delPhiValues(BasicBlock *From, BasicBlock *To) {
+
+ PhiMap &Map = DeletedPhis[To];
+ for (BasicBlock::iterator I = To->begin(), E = To->end();
+ I != E && isa<PHINode>(*I);) {
+
+ PHINode &Phi = cast<PHINode>(*I++);
+ while (Phi.getBasicBlockIndex(From) != -1) {
+ Value *Deleted = Phi.removeIncomingValue(From, false);
+ Map[&Phi].push_back(std::make_pair(From, Deleted));
+ }
+ }
+}
+
+// Add the PHI values back once we knew the new predecessor
+void AMDGPUStructurizeCFG::addPhiValues(BasicBlock *From, BasicBlock *To) {
+
+ if (!DeletedPhis.count(To))
+ return;
+
+ PhiMap &Map = DeletedPhis[To];
+ SSAUpdater Updater;
+
+ for (PhiMap::iterator I = Map.begin(), E = Map.end(); I != E; ++I) {
+
+ PHINode *Phi = I->first;
+ Updater.Initialize(Phi->getType(), "");
+ BasicBlock *Fallback = To;
+ bool HaveFallback = false;
+
+ for (BBValueVector::iterator VI = I->second.begin(), VE = I->second.end();
+ VI != VE; ++VI) {
+
+ Updater.AddAvailableValue(VI->first, VI->second);
+ BasicBlock *Dom = DT->findNearestCommonDominator(Fallback, VI->first);
+ if (Dom == VI->first)
+ HaveFallback = true;
+ else if (Dom != Fallback)
+ HaveFallback = false;
+ Fallback = Dom;
+ }
+ if (!HaveFallback) {
+ Value *Undef = UndefValue::get(Phi->getType());
+ Updater.AddAvailableValue(Fallback, Undef);
+ }
+
+ Phi->addIncoming(Updater.GetValueAtEndOfBlock(From), From);
+ }
+ DeletedPhis.erase(To);
+}
+
+// Create a new flow node and update dominator tree and region info
+BasicBlock *AMDGPUStructurizeCFG::getNextFlow(BasicBlock *Prev) {
+
+ LLVMContext &Context = Function->getContext();
+ BasicBlock *Insert = Order.empty() ? ParentRegion->getExit() :
+ Order.back()->getEntry();
+ BasicBlock *Flow = BasicBlock::Create(Context, FlowBlockName,
+ Function, Insert);
+ DT->addNewBlock(Flow, Prev);
+ ParentRegion->getRegionInfo()->setRegionFor(Flow, ParentRegion);
+ FlowsInserted.push_back(Flow);
+ return Flow;
+}
+
+// Can we predict that this node will always be called?
+bool AMDGPUStructurizeCFG::isPredictableTrue(BasicBlock *Prev,
+ BasicBlock *Node) {
+
+ BBPredicates &Preds = Predicates[Node];
+ bool Dominated = false;
+
+ for (BBPredicates::iterator I = Preds.begin(), E = Preds.end();
+ I != E; ++I) {
+
+ if (I->second != BoolTrue)
+ return false;
+
+ if (!Dominated && DT->dominates(I->first, Prev))
+ Dominated = true;
+ }
+ return Dominated;
+}
+
+// Wire up the new control flow by inserting or updating the branch
+// instructions at node exits
+BasicBlock *AMDGPUStructurizeCFG::wireFlowBlock(BasicBlock *Prev,
+ RegionNode *Node) {
+
+ BasicBlock *Entry = Node->getEntry();
+
+ if (LoopStart == Entry) {
+ LoopStart = Prev;
+ LoopPred[Prev] = BoolTrue;
+ }
+
+ // Wire it up temporary, skipChained may recurse into us
+ BranchInst::Create(Entry, Prev);
+ DT->changeImmediateDominator(Entry, Prev);
+ addPhiValues(Prev, Entry);
+
+ Node = skipChained(Node);
+
+ BasicBlock *Next = getNextFlow(Prev);
+ if (!isPredictableTrue(Prev, Entry)) {
+ // Let Prev point to entry and next block
+ Prev->getTerminator()->eraseFromParent();
+ BranchInst::Create(Entry, Next, BoolUndef, Prev);
+ } else {
+ DT->changeImmediateDominator(Next, Entry);
+ }
+
+ // Let node exit(s) point to next block
+ if (Node->isSubRegion()) {
+ Region *SubRegion = Node->getNodeAs<Region>();
+ BasicBlock *Exit = SubRegion->getExit();
+
+ // Find all the edges from the sub region to the exit
+ BBVector ToDo;
+ for (pred_iterator I = pred_begin(Exit), E = pred_end(Exit); I != E; ++I) {
+ if (SubRegion->contains(*I))
+ ToDo.push_back(*I);
+ }
+
+ // Modify the edges to point to the new flow block
+ for (BBVector::iterator I = ToDo.begin(), E = ToDo.end(); I != E; ++I) {
+ delPhiValues(*I, Exit);
+ TerminatorInst *Term = (*I)->getTerminator();
+ Term->replaceUsesOfWith(Exit, Next);
+ }
+
+ // Update the region info
+ SubRegion->replaceExit(Next);
+
+ } else {
+ BasicBlock *BB = Node->getNodeAs<BasicBlock>();
+ killTerminator(BB);
+ BranchInst::Create(Next, BB);
+
+ if (BB == LoopEnd)
+ LoopEnd = 0;
+ }
+
+ return Next;
+}
+
+// Destroy node order and visited map, build up flow order instead.
+// After this function control flow looks like it should be, but
+// branches only have undefined conditions.
+void AMDGPUStructurizeCFG::createFlow() {
+
+ DeletedPhis.clear();
+
+ BasicBlock *Prev = Order.pop_back_val()->getEntry();
+ assert(Prev == ParentRegion->getEntry() && "Incorrect node order!");
+ Visited.erase(Prev);
+
+ if (LoopStart == Prev) {
+ // Loop starts at entry, split entry so that we can predicate it
+ BasicBlock::iterator Insert = Prev->getFirstInsertionPt();
+ BasicBlock *Split = Prev->splitBasicBlock(Insert, FlowBlockName);
+ DT->addNewBlock(Split, Prev);
+ ParentRegion->getRegionInfo()->setRegionFor(Split, ParentRegion);
+ Predicates[Split] = Predicates[Prev];
+ Order.push_back(ParentRegion->getBBNode(Split));
+ LoopPred[Prev] = BoolTrue;
+
+ } else if (LoopStart == Order.back()->getEntry()) {
+ // Loop starts behind entry, split entry so that we can jump to it
+ Instruction *Term = Prev->getTerminator();
+ BasicBlock *Split = Prev->splitBasicBlock(Term, FlowBlockName);
+ DT->addNewBlock(Split, Prev);
+ ParentRegion->getRegionInfo()->setRegionFor(Split, ParentRegion);
+ Prev = Split;
+ }
+
+ killTerminator(Prev);
+ FlowsInserted.clear();
+ FlowsInserted.push_back(Prev);
+
+ while (!Order.empty()) {
+ RegionNode *Node = Order.pop_back_val();
+ Visited.erase(Node->getEntry());
+ Prev = wireFlowBlock(Prev, Node);
+ if (LoopStart && !LoopEnd) {
+ // Create an extra loop end node
+ LoopEnd = Prev;
+ Prev = getNextFlow(LoopEnd);
+ BranchInst::Create(Prev, LoopStart, BoolUndef, LoopEnd);
+ addPhiValues(LoopEnd, LoopStart);
+ }
+ }
+
+ BasicBlock *Exit = ParentRegion->getExit();
+ BranchInst::Create(Exit, Prev);
+ addPhiValues(Prev, Exit);
+ if (DT->dominates(ParentRegion->getEntry(), Exit))
+ DT->changeImmediateDominator(Exit, Prev);
+
+ if (LoopStart && LoopEnd) {
+ BBVector::iterator FI = std::find(FlowsInserted.begin(),
+ FlowsInserted.end(),
+ LoopStart);
+ for (; *FI != LoopEnd; ++FI) {
+ addPhiValues(*FI, (*FI)->getTerminator()->getSuccessor(0));
+ }
+ }
+
+ assert(Order.empty());
+ assert(Visited.empty());
+ assert(DeletedPhis.empty());
+}
+
+// Insert the missing branch conditions
+void AMDGPUStructurizeCFG::insertConditions() {
+
+ SSAUpdater PhiInserter;
+
+ for (BBVector::iterator FI = FlowsInserted.begin(), FE = FlowsInserted.end();
+ FI != FE; ++FI) {
+
+ BranchInst *Term = cast<BranchInst>((*FI)->getTerminator());
+ if (Term->isUnconditional())
+ continue;
+
+ PhiInserter.Initialize(Boolean, "");
+ PhiInserter.AddAvailableValue(&Function->getEntryBlock(), BoolFalse);
+
+ BasicBlock *Succ = Term->getSuccessor(0);
+ BBPredicates &Preds = (*FI == LoopEnd) ? LoopPred : Predicates[Succ];
+ for (BBPredicates::iterator PI = Preds.begin(), PE = Preds.end();
+ PI != PE; ++PI) {
+
+ PhiInserter.AddAvailableValue(PI->first, PI->second);
+ }
+
+ Term->setCondition(PhiInserter.GetValueAtEndOfBlock(*FI));
+ }
+}
+
+// Handle a rare case where the disintegrated nodes instructions
+// no longer dominate all their uses
+// Not sure if this is really nessasary
+void AMDGPUStructurizeCFG::rebuildSSA() {
+
+ SSAUpdater Updater;
+ for (Region::block_iterator I = ParentRegion->block_begin(),
+ E = ParentRegion->block_end();
+ I != E; ++I) {
+
+ BasicBlock *BB = *I;
+ for (BasicBlock::iterator II = BB->begin(), IE = BB->end();
+ II != IE; ++II) {
+
+ bool Initialized = false;
+ for (Use *I = &II->use_begin().getUse(), *Next; I; I = Next) {
+
+ Next = I->getNext();
+
+ Instruction *User = cast<Instruction>(I->getUser());
+ if (User->getParent() == BB) {
+ continue;
+
+ } else if (PHINode *UserPN = dyn_cast<PHINode>(User)) {
+ if (UserPN->getIncomingBlock(*I) == BB)
+ continue;
+ }
+
+ if (DT->dominates(II, User))
+ continue;
+
+ if (!Initialized) {
+ Value *Undef = UndefValue::get(II->getType());
+ Updater.Initialize(II->getType(), "");
+ Updater.AddAvailableValue(&Function->getEntryBlock(), Undef);
+ Updater.AddAvailableValue(BB, II);
+ Initialized = true;
+ }
+ Updater.RewriteUseAfterInsertions(*I);
+ }
+ }
+ }
+}
+
+// Run the transformation for each region found
+bool AMDGPUStructurizeCFG::runOnRegion(Region *R, RGPassManager &RGM) {
+
+ if (R->isTopLevelRegion())
+ return false;
+
+ Function = R->getEntry()->getParent();
+ ParentRegion = R;
+
+ DT = &getAnalysis<DominatorTree>();
+
+ orderNodes();
+ collectInfos();
+ createFlow();
+ insertConditions();
+ rebuildSSA();
+
+ Order.clear();
+ Visited.clear();
+ Predicates.clear();
+ DeletedPhis.clear();
+ FlowsInserted.clear();
+
+ return true;
+}
+
+// Create the pass
+Pass *llvm::createAMDGPUStructurizeCFGPass()
+{
+ return new AMDGPUStructurizeCFG();
+}
diff --git a/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index e42fa8a..098d42e 100644
--- a/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -91,6 +91,11 @@ TargetPassConfig *AMDGPUTargetMachine::createPassConfig(PassManagerBase &PM) {
bool
AMDGPUPassConfig::addPreISel() {
+ const AMDGPUSubtarget &ST = TM->getSubtarget<AMDGPUSubtarget>();
+ if (ST.device()->getGeneration() > AMDGPUDeviceInfo::HD6XXX) {
+ addPass(createAMDGPUStructurizeCFGPass());
+ addPass(createSIAnnotateControlFlowPass());
+ }
return false;
}
@@ -107,9 +112,6 @@ bool AMDGPUPassConfig::addPreRegAlloc() {
addPass(createSIAssignInterpRegsPass(*TM));
}
addPass(createAMDGPUConvertToISAPass(*TM));
- if (ST.device()->getGeneration() > AMDGPUDeviceInfo::HD6XXX) {
- addPass(createSIFixSGPRLivenessPass(*TM));
- }
return false;
}
@@ -124,11 +126,10 @@ bool AMDGPUPassConfig::addPreSched2() {
}
bool AMDGPUPassConfig::addPreEmitPass() {
- addPass(createAMDGPUCFGPreparationPass(*TM));
- addPass(createAMDGPUCFGStructurizerPass(*TM));
-
const AMDGPUSubtarget &ST = TM->getSubtarget<AMDGPUSubtarget>();
if (ST.device()->getGeneration() <= AMDGPUDeviceInfo::HD6XXX) {
+ addPass(createAMDGPUCFGPreparationPass(*TM));
+ addPass(createAMDGPUCFGStructurizerPass(*TM));
addPass(createR600ExpandSpecialInstrsPass(*TM));
addPass(&FinalizeMachineBundlesID);
} else {
diff --git a/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp b/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
index 1f276dc..568d281 100644
--- a/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
+++ b/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
@@ -2596,7 +2596,6 @@ struct CFGStructTraits<AMDGPUCFGStructurizer> {
case AMDGPU::JUMP: return AMDGPU::IF_PREDICATE_SET;
case AMDGPU::BRANCH_COND_i32:
case AMDGPU::BRANCH_COND_f32: return AMDGPU::IF_LOGICALNZ_f32;
- case AMDGPU::SI_IF_NZ: return AMDGPU::SI_IF_NZ;
default:
assert(0 && "internal error");
}
@@ -2608,7 +2607,6 @@ struct CFGStructTraits<AMDGPUCFGStructurizer> {
case AMDGPU::JUMP: return AMDGPU::IF_PREDICATE_SET;
case AMDGPU::BRANCH_COND_i32:
case AMDGPU::BRANCH_COND_f32: return AMDGPU::IF_LOGICALZ_f32;
- case AMDGPU::SI_IF_Z: return AMDGPU::SI_IF_Z;
default:
assert(0 && "internal error");
}
@@ -2658,8 +2656,6 @@ struct CFGStructTraits<AMDGPUCFGStructurizer> {
return instr->getOperand(instr->findFirstPredOperandIdx()).getReg() != 0;
case AMDGPU::BRANCH_COND_i32:
case AMDGPU::BRANCH_COND_f32:
- case AMDGPU::SI_IF_NZ:
- case AMDGPU::SI_IF_Z:
break;
default:
return false;
diff --git a/lib/Target/AMDGPU/AMDILInstrInfo.td b/lib/Target/AMDGPU/AMDILInstrInfo.td
index ac67451..e969bbf 100644
--- a/lib/Target/AMDGPU/AMDILInstrInfo.td
+++ b/lib/Target/AMDGPU/AMDILInstrInfo.td
@@ -206,68 +206,3 @@ multiclass BranchInstr2<string name> {
// Intrinsics support
//===--------------------------------------------------------------------===//
include "AMDILIntrinsics.td"
-
-//===--------------------------------------------------------------------===//
-// Instructions support
-//===--------------------------------------------------------------------===//
-//===---------------------------------------------------------------------===//
-// Custom Inserter for Branches and returns, this eventually will be a
-// seperate pass
-//===---------------------------------------------------------------------===//
-let isTerminator = 1, usesCustomInserter = 1, isBranch = 1, isBarrier = 1 in {
- def BRANCH : ILFormat<(outs), (ins brtarget:$target),
- "; Pseudo unconditional branch instruction",
- [(br bb:$target)]>;
- defm BRANCH_COND : BranchConditional<IL_brcond>;
-}
-
-//===---------------------------------------------------------------------===//
-// Flow and Program control Instructions
-//===---------------------------------------------------------------------===//
-let isTerminator=1 in {
- def SWITCH : ILFormat< (outs), (ins GPRI32:$src),
- !strconcat("SWITCH", " $src"), []>;
- def CASE : ILFormat< (outs), (ins GPRI32:$src),
- !strconcat("CASE", " $src"), []>;
- def BREAK : ILFormat< (outs), (ins),
- "BREAK", []>;
- def CONTINUE : ILFormat< (outs), (ins),
- "CONTINUE", []>;
- def DEFAULT : ILFormat< (outs), (ins),
- "DEFAULT", []>;
- def ELSE : ILFormat< (outs), (ins),
- "ELSE", []>;
- def ENDSWITCH : ILFormat< (outs), (ins),
- "ENDSWITCH", []>;
- def ENDMAIN : ILFormat< (outs), (ins),
- "ENDMAIN", []>;
- def END : ILFormat< (outs), (ins),
- "END", []>;
- def ENDFUNC : ILFormat< (outs), (ins),
- "ENDFUNC", []>;
- def ENDIF : ILFormat< (outs), (ins),
- "ENDIF", []>;
- def WHILELOOP : ILFormat< (outs), (ins),
- "WHILE", []>;
- def ENDLOOP : ILFormat< (outs), (ins),
- "ENDLOOP", []>;
- def FUNC : ILFormat< (outs), (ins),
- "FUNC", []>;
- def RETDYN : ILFormat< (outs), (ins),
- "RET_DYN", []>;
- // This opcode has custom swizzle pattern encoded in Swizzle Encoder
- defm IF_LOGICALNZ : BranchInstr<"IF_LOGICALNZ">;
- // This opcode has custom swizzle pattern encoded in Swizzle Encoder
- defm IF_LOGICALZ : BranchInstr<"IF_LOGICALZ">;
- // This opcode has custom swizzle pattern encoded in Swizzle Encoder
- defm BREAK_LOGICALNZ : BranchInstr<"BREAK_LOGICALNZ">;
- // This opcode has custom swizzle pattern encoded in Swizzle Encoder
- defm BREAK_LOGICALZ : BranchInstr<"BREAK_LOGICALZ">;
- // This opcode has custom swizzle pattern encoded in Swizzle Encoder
- defm CONTINUE_LOGICALNZ : BranchInstr<"CONTINUE_LOGICALNZ">;
- // This opcode has custom swizzle pattern encoded in Swizzle Encoder
- defm CONTINUE_LOGICALZ : BranchInstr<"CONTINUE_LOGICALZ">;
- defm IFC : BranchInstr2<"IFC">;
- defm BREAKC : BranchInstr2<"BREAKC">;
- defm CONTINUEC : BranchInstr2<"CONTINUEC">;
-}
diff --git a/lib/Target/AMDGPU/R600Instructions.td b/lib/Target/AMDGPU/R600Instructions.td
index bd5e9d6..db24c29 100644
--- a/lib/Target/AMDGPU/R600Instructions.td
+++ b/lib/Target/AMDGPU/R600Instructions.td
@@ -1481,6 +1481,71 @@ let isTerminator = 1, isReturn = 1, isBarrier = 1, hasCtrlDep = 1 in {
"RETURN", [(IL_retflag)]>;
}
+//===--------------------------------------------------------------------===//
+// Instructions support
+//===--------------------------------------------------------------------===//
+//===---------------------------------------------------------------------===//
+// Custom Inserter for Branches and returns, this eventually will be a
+// seperate pass
+//===---------------------------------------------------------------------===//
+let isTerminator = 1, usesCustomInserter = 1, isBranch = 1, isBarrier = 1 in {
+ def BRANCH : ILFormat<(outs), (ins brtarget:$target),
+ "; Pseudo unconditional branch instruction",
+ [(br bb:$target)]>;
+ defm BRANCH_COND : BranchConditional<IL_brcond>;
+}
+
+//===---------------------------------------------------------------------===//
+// Flow and Program control Instructions
+//===---------------------------------------------------------------------===//
+let isTerminator=1 in {
+ def SWITCH : ILFormat< (outs), (ins GPRI32:$src),
+ !strconcat("SWITCH", " $src"), []>;
+ def CASE : ILFormat< (outs), (ins GPRI32:$src),
+ !strconcat("CASE", " $src"), []>;
+ def BREAK : ILFormat< (outs), (ins),
+ "BREAK", []>;
+ def CONTINUE : ILFormat< (outs), (ins),
+ "CONTINUE", []>;
+ def DEFAULT : ILFormat< (outs), (ins),
+ "DEFAULT", []>;
+ def ELSE : ILFormat< (outs), (ins),
+ "ELSE", []>;
+ def ENDSWITCH : ILFormat< (outs), (ins),
+ "ENDSWITCH", []>;
+ def ENDMAIN : ILFormat< (outs), (ins),
+ "ENDMAIN", []>;
+ def END : ILFormat< (outs), (ins),
+ "END", []>;
+ def ENDFUNC : ILFormat< (outs), (ins),
+ "ENDFUNC", []>;
+ def ENDIF : ILFormat< (outs), (ins),
+ "ENDIF", []>;
+ def WHILELOOP : ILFormat< (outs), (ins),
+ "WHILE", []>;
+ def ENDLOOP : ILFormat< (outs), (ins),
+ "ENDLOOP", []>;
+ def FUNC : ILFormat< (outs), (ins),
+ "FUNC", []>;
+ def RETDYN : ILFormat< (outs), (ins),
+ "RET_DYN", []>;
+ // This opcode has custom swizzle pattern encoded in Swizzle Encoder
+ defm IF_LOGICALNZ : BranchInstr<"IF_LOGICALNZ">;
+ // This opcode has custom swizzle pattern encoded in Swizzle Encoder
+ defm IF_LOGICALZ : BranchInstr<"IF_LOGICALZ">;
+ // This opcode has custom swizzle pattern encoded in Swizzle Encoder
+ defm BREAK_LOGICALNZ : BranchInstr<"BREAK_LOGICALNZ">;
+ // This opcode has custom swizzle pattern encoded in Swizzle Encoder
+ defm BREAK_LOGICALZ : BranchInstr<"BREAK_LOGICALZ">;
+ // This opcode has custom swizzle pattern encoded in Swizzle Encoder
+ defm CONTINUE_LOGICALNZ : BranchInstr<"CONTINUE_LOGICALNZ">;
+ // This opcode has custom swizzle pattern encoded in Swizzle Encoder
+ defm CONTINUE_LOGICALZ : BranchInstr<"CONTINUE_LOGICALZ">;
+ defm IFC : BranchInstr2<"IFC">;
+ defm BREAKC : BranchInstr2<"BREAKC">;
+ defm CONTINUEC : BranchInstr2<"CONTINUEC">;
+}
+
//===----------------------------------------------------------------------===//
// ISel Patterns
//===----------------------------------------------------------------------===//
diff --git a/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp b/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
new file mode 100644
index 0000000..d1cc0b8
--- /dev/null
+++ b/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
@@ -0,0 +1,333 @@
+//===-- SIAnnotateControlFlow.cpp - ------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Annotates the control flow with hardware specific intrinsics.
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/Transforms/Utils/SSAUpdater.h"
+
+using namespace llvm;
+
+namespace {
+
+// Complex types used in this pass
+typedef std::pair<BasicBlock *, Value *> StackEntry;
+typedef SmallVector<StackEntry, 16> StackVector;
+
+// Intrinsic names the control flow is annotated with
+static const char *IfIntrinsic = "llvm.SI.if";
+static const char *ElseIntrinsic = "llvm.SI.else";
+static const char *BreakIntrinsic = "llvm.SI.break";
+static const char *IfBreakIntrinsic = "llvm.SI.if.break";
+static const char *ElseBreakIntrinsic = "llvm.SI.else.break";
+static const char *LoopIntrinsic = "llvm.SI.loop";
+static const char *EndCfIntrinsic = "llvm.SI.end.cf";
+
+class SIAnnotateControlFlow : public FunctionPass {
+
+ static char ID;
+
+ Type *Boolean;
+ Type *Void;
+ Type *Int64;
+ Type *ReturnStruct;
+
+ ConstantInt *BoolTrue;
+ ConstantInt *BoolFalse;
+ UndefValue *BoolUndef;
+ Constant *Int64Zero;
+
+ Constant *If;
+ Constant *Else;
+ Constant *Break;
+ Constant *IfBreak;
+ Constant *ElseBreak;
+ Constant *Loop;
+ Constant *EndCf;
+
+ DominatorTree *DT;
+ StackVector Stack;
+ SSAUpdater PhiInserter;
+
+ bool isTopOfStack(BasicBlock *BB);
+
+ Value *popSaved();
+
+ void push(BasicBlock *BB, Value *Saved);
+
+ bool isElse(PHINode *Phi);
+
+ void eraseIfUnused(PHINode *Phi);
+
+ void openIf(BranchInst *Term);
+
+ void insertElse(BranchInst *Term);
+
+ void handleLoopCondition(Value *Cond);
+
+ void handleLoop(BranchInst *Term);
+
+ void closeControlFlow(BasicBlock *BB);
+
+public:
+ SIAnnotateControlFlow():
+ FunctionPass(ID) { }
+
+ virtual bool doInitialization(Module &M);
+
+ virtual bool runOnFunction(Function &F);
+
+ virtual const char *getPassName() const {
+ return "SI annotate control flow";
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+
+ AU.addRequired<DominatorTree>();
+ AU.addPreserved<DominatorTree>();
+ FunctionPass::getAnalysisUsage(AU);
+ }
+
+};
+
+} // end anonymous namespace
+
+char SIAnnotateControlFlow::ID = 0;
+
+// Initialize all the types and constants used in the pass
+bool SIAnnotateControlFlow::doInitialization(Module &M) {
+
+ LLVMContext &Context = M.getContext();
+
+ Void = Type::getVoidTy(Context);
+ Boolean = Type::getInt1Ty(Context);
+ Int64 = Type::getInt64Ty(Context);
+ ReturnStruct = StructType::get(Boolean, Int64, (Type *)0);
+
+ BoolTrue = ConstantInt::getTrue(Context);
+ BoolFalse = ConstantInt::getFalse(Context);
+ BoolUndef = UndefValue::get(Boolean);
+ Int64Zero = ConstantInt::get(Int64, 0);
+
+ If = M.getOrInsertFunction(
+ IfIntrinsic, ReturnStruct, Boolean, (Type *)0);
+
+ Else = M.getOrInsertFunction(
+ ElseIntrinsic, ReturnStruct, Int64, (Type *)0);
+
+ Break = M.getOrInsertFunction(
+ BreakIntrinsic, Int64, Int64, (Type *)0);
+
+ IfBreak = M.getOrInsertFunction(
+ IfBreakIntrinsic, Int64, Boolean, Int64, (Type *)0);
+
+ ElseBreak = M.getOrInsertFunction(
+ ElseBreakIntrinsic, Int64, Int64, Int64, (Type *)0);
+
+ Loop = M.getOrInsertFunction(
+ LoopIntrinsic, Boolean, Int64, (Type *)0);
+
+ EndCf = M.getOrInsertFunction(
+ EndCfIntrinsic, Void, Int64, (Type *)0);
+
+ return false;
+}
+
+// Is BB the last block saved on the stack ?
+bool SIAnnotateControlFlow::isTopOfStack(BasicBlock *BB) {
+ return Stack.back().first == BB;
+}
+
+// Pop the last saved value from the control flow stack
+Value *SIAnnotateControlFlow::popSaved() {
+ return Stack.pop_back_val().second;
+}
+
+// Push a BB and saved value to the control flow stack
+void SIAnnotateControlFlow::push(BasicBlock *BB, Value *Saved) {
+ Stack.push_back(std::make_pair(BB, Saved));
+}
+
+// Can the condition represented by this PHI node treated like an "Else" block?
+bool SIAnnotateControlFlow::isElse(PHINode *Phi) {
+
+ BasicBlock *IDom = DT->getNode(Phi->getParent())->getIDom()->getBlock();
+ for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
+ if (Phi->getIncomingBlock(i) == IDom) {
+
+ if (Phi->getIncomingValue(i) != BoolTrue)
+ return false;
+
+ } else {
+ if (Phi->getIncomingValue(i) != BoolFalse)
+ return false;
+
+ }
+ }
+ return true;
+}
+
+// Erase "Phi" if it is not used any more
+void SIAnnotateControlFlow::eraseIfUnused(PHINode *Phi) {
+ if (!Phi->hasNUsesOrMore(1))
+ Phi->eraseFromParent();
+}
+
+// Open a new "If" block
+void SIAnnotateControlFlow::openIf(BranchInst *Term) {
+ Value *Ret = CallInst::Create(If, Term->getCondition(), "", Term);
+ Term->setCondition(ExtractValueInst::Create(Ret, 0, "", Term));
+ push(Term->getSuccessor(1), ExtractValueInst::Create(Ret, 1, "", Term));
+}
+
+// Close the last "If" block and open a new "Else" block
+void SIAnnotateControlFlow::insertElse(BranchInst *Term) {
+ Value *Ret = CallInst::Create(Else, popSaved(), "", Term);
+ Term->setCondition(ExtractValueInst::Create(Ret, 0, "", Term));
+ push(Term->getSuccessor(1), ExtractValueInst::Create(Ret, 1, "", Term));
+}
+
+// Recursively handle the condition leading to a loop
+void SIAnnotateControlFlow::handleLoopCondition(Value *Cond) {
+
+ if (PHINode *Phi = dyn_cast<PHINode>(Cond)) {
+
+ // Handle all non constant incoming values first
+ for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
+ Value *Incoming = Phi->getIncomingValue(i);
+ if (isa<ConstantInt>(Incoming))
+ continue;
+
+ Phi->setIncomingValue(i, BoolFalse);
+ handleLoopCondition(Incoming);
+ }
+
+ BasicBlock *Parent = Phi->getParent();
+ BasicBlock *IDom = DT->getNode(Parent)->getIDom()->getBlock();
+
+ for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
+
+ Value *Incoming = Phi->getIncomingValue(i);
+ if (Incoming != BoolTrue)
+ continue;
+
+ BasicBlock *From = Phi->getIncomingBlock(i);
+ if (From == IDom) {
+ CallInst *OldEnd = dyn_cast<CallInst>(Parent->getFirstInsertionPt());
+ if (OldEnd && OldEnd->getCalledFunction() == EndCf) {
+ Value *Args[] = {
+ OldEnd->getArgOperand(0),
+ PhiInserter.GetValueAtEndOfBlock(Parent)
+ };
+ Value *Ret = CallInst::Create(ElseBreak, Args, "", OldEnd);
+ PhiInserter.AddAvailableValue(Parent, Ret);
+ continue;
+ }
+ }
+
+ TerminatorInst *Insert = From->getTerminator();
+ Value *Arg = PhiInserter.GetValueAtEndOfBlock(From);
+ Value *Ret = CallInst::Create(Break, Arg, "", Insert);
+ PhiInserter.AddAvailableValue(From, Ret);
+ }
+ eraseIfUnused(Phi);
+
+ } else if (Instruction *Inst = dyn_cast<Instruction>(Cond)) {
+ BasicBlock *Parent = Inst->getParent();
+ TerminatorInst *Insert = Parent->getTerminator();
+ Value *Args[] = { Cond, PhiInserter.GetValueAtEndOfBlock(Parent) };
+ Value *Ret = CallInst::Create(IfBreak, Args, "", Insert);
+ PhiInserter.AddAvailableValue(Parent, Ret);
+
+ } else {
+ assert(0 && "Unhandled loop condition!");
+ }
+}
+
+// Handle a back edge (loop)
+void SIAnnotateControlFlow::handleLoop(BranchInst *Term) {
+
+ BasicBlock *Target = Term->getSuccessor(1);
+ PHINode *Broken = PHINode::Create(Int64, 0, "", &Target->front());
+
+ PhiInserter.Initialize(Int64, "");
+ PhiInserter.AddAvailableValue(Target, Broken);
+
+ Value *Cond = Term->getCondition();
+ Term->setCondition(BoolTrue);
+ handleLoopCondition(Cond);
+
+ BasicBlock *BB = Term->getParent();
+ Value *Arg = PhiInserter.GetValueAtEndOfBlock(BB);
+ for (pred_iterator PI = pred_begin(Target), PE = pred_end(Target);
+ PI != PE; ++PI) {
+
+ Broken->addIncoming(*PI == BB ? Arg : Int64Zero, *PI);
+ }
+
+ Term->setCondition(CallInst::Create(Loop, Arg, "", Term));
+ push(Term->getSuccessor(0), Arg);
+}
+
+// Close the last opened control flow
+void SIAnnotateControlFlow::closeControlFlow(BasicBlock *BB) {
+ CallInst::Create(EndCf, popSaved(), "", BB->getFirstInsertionPt());
+}
+
+// Annotate the control flow with intrinsics so the backend can
+// recognize if/then/else and loops.
+bool SIAnnotateControlFlow::runOnFunction(Function &F) {
+
+ DT = &getAnalysis<DominatorTree>();
+
+ for (df_iterator<BasicBlock *> I = df_begin(&F.getEntryBlock()),
+ E = df_end(&F.getEntryBlock()); I != E; ++I) {
+
+ BranchInst *Term = dyn_cast<BranchInst>((*I)->getTerminator());
+
+ if (!Term || Term->isUnconditional()) {
+ if (isTopOfStack(*I))
+ closeControlFlow(*I);
+ continue;
+ }
+
+ if (I.nodeVisited(Term->getSuccessor(1))) {
+ if (isTopOfStack(*I))
+ closeControlFlow(*I);
+ handleLoop(Term);
+ continue;
+ }
+
+ if (isTopOfStack(*I)) {
+ PHINode *Phi = dyn_cast<PHINode>(Term->getCondition());
+ if (Phi && Phi->getParent() == *I && isElse(Phi)) {
+ insertElse(Term);
+ eraseIfUnused(Phi);
+ continue;
+ }
+ closeControlFlow(*I);
+ }
+ openIf(Term);
+ }
+
+ assert(Stack.empty());
+ return true;
+}
+
+// Create the annotation pass
+FunctionPass *llvm::createSIAnnotateControlFlowPass()
+{
+ return new SIAnnotateControlFlow();
+}
diff --git a/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp b/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp
deleted file mode 100644
index 0fecd7a..0000000
--- a/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp
+++ /dev/null
@@ -1,179 +0,0 @@
-//===-- SIFixSGPRLiveness.cpp - SGPR liveness adjustment ------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-/// \file
-///
-/// SGPRs are not affected by control flow. This pass adjusts SGPR liveness in
-/// so that the register allocator can still correctly allocate them.
-//
-//===----------------------------------------------------------------------===//
-
-#include "AMDGPU.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/MachineDominators.h"
-#include "llvm/CodeGen/MachinePostDominators.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-
-using namespace llvm;
-
-namespace {
-
-class SIFixSGPRLiveness : public MachineFunctionPass {
-private:
- static char ID;
-
- const TargetInstrInfo *TII;
- MachineRegisterInfo *MRI;
- MachineDominatorTree *MD;
- MachinePostDominatorTree *MPD;
-
- bool isSGPR(const TargetRegisterClass *RegClass) {
- return RegClass == &AMDGPU::SReg_1RegClass ||
- RegClass == &AMDGPU::SReg_32RegClass ||
- RegClass == &AMDGPU::SReg_64RegClass ||
- RegClass == &AMDGPU::SReg_128RegClass ||
- RegClass == &AMDGPU::SReg_256RegClass;
- }
-
- void addKill(MachineBasicBlock::iterator I, unsigned Reg);
- MachineBasicBlock *handleUses(unsigned VirtReg, MachineBasicBlock *Begin);
- void handlePreds(MachineBasicBlock *Begin, MachineBasicBlock *End,
- unsigned VirtReg);
-
- bool handleVirtReg(unsigned VirtReg);
-
-public:
- SIFixSGPRLiveness(TargetMachine &tm);
-
- virtual bool runOnMachineFunction(MachineFunction &MF);
-
- virtual const char *getPassName() const {
- return "SI fix SGPR liveness pass";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const;
-};
-
-} // end anonymous namespace
-
-char SIFixSGPRLiveness::ID = 0;
-
-SIFixSGPRLiveness::SIFixSGPRLiveness(TargetMachine &tm):
- MachineFunctionPass(ID),
- TII(tm.getInstrInfo()) {
- initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
-}
-
-void SIFixSGPRLiveness::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<MachineDominatorTree>();
- AU.addRequired<MachinePostDominatorTree>();
- AU.setPreservesCFG();
- MachineFunctionPass::getAnalysisUsage(AU);
-}
-
-void SIFixSGPRLiveness::addKill(MachineBasicBlock::iterator I, unsigned Reg) {
- MachineBasicBlock *MBB = I->getParent();
-
- BuildMI(*MBB, I, DebugLoc(), TII->get(TargetOpcode::KILL)).addReg(Reg);
-}
-
-// Find the common post dominator of all uses
-MachineBasicBlock *SIFixSGPRLiveness::handleUses(unsigned VirtReg,
- MachineBasicBlock *Begin) {
- MachineBasicBlock *LastUse = Begin, *End = Begin;
- bool EndUsesReg = true;
-
- MachineRegisterInfo::use_iterator i, e;
- for (i = MRI->use_begin(VirtReg), e = MRI->use_end(); i != e; ++i) {
- MachineBasicBlock *MBB = i->getParent();
- if (LastUse == MBB)
- continue;
-
- LastUse = MBB;
- MBB = MPD->findNearestCommonDominator(End, MBB);
-
- if (MBB == LastUse)
- EndUsesReg = true;
- else if (MBB != End)
- EndUsesReg = false;
-
- End = MBB;
- }
-
- return EndUsesReg ? Begin : End;
-}
-
-// Handles predecessors separately, only add KILLs to dominated ones
-void SIFixSGPRLiveness::handlePreds(MachineBasicBlock *Begin,
- MachineBasicBlock *End,
- unsigned VirtReg) {
- MachineBasicBlock::pred_iterator i, e;
- for (i = End->pred_begin(), e = End->pred_end(); i != e; ++i) {
-
- if (MD->dominates(End, *i))
- continue; // ignore loops
-
- if (MD->dominates(*i, Begin))
- continue; // too far up, abort search
-
- if (MD->dominates(Begin, *i)) {
- // found end of livetime
- addKill((*i)->getFirstTerminator(), VirtReg);
- continue;
- }
-
- handlePreds(Begin, *i, VirtReg);
- }
-}
-
-bool SIFixSGPRLiveness::handleVirtReg(unsigned VirtReg) {
-
- MachineInstr *Def = MRI->getVRegDef(VirtReg);
- if (!Def || MRI->use_empty(VirtReg))
- return false; // No definition or not used
-
- MachineBasicBlock *Begin = Def->getParent();
- MachineBasicBlock *End = handleUses(VirtReg, Begin);
- if (Begin == End)
- return false; // Defined and only used in the same block
-
- if (MD->dominates(Begin, End)) {
- // Lifetime dominate the end node, just kill it here
- addKill(End->getFirstNonPHI(), VirtReg);
- } else {
- // only some predecessors are dominate, handle them separately
- handlePreds(Begin, End, VirtReg);
- }
- return true;
-}
-
-bool SIFixSGPRLiveness::runOnMachineFunction(MachineFunction &MF) {
- bool Changes = false;
-
- MRI = &MF.getRegInfo();
- MD = &getAnalysis<MachineDominatorTree>();
- MPD = &getAnalysis<MachinePostDominatorTree>();
-
- for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
- unsigned VirtReg = TargetRegisterInfo::index2VirtReg(i);
-
- const TargetRegisterClass *RegClass = MRI->getRegClass(VirtReg);
- if (!isSGPR(RegClass))
- continue;
-
- Changes |= handleVirtReg(VirtReg);
- }
-
- return Changes;
-}
-
-FunctionPass *llvm::createSIFixSGPRLivenessPass(TargetMachine &tm) {
- return new SIFixSGPRLiveness(tm);
-}
diff --git a/lib/Target/AMDGPU/SIISelLowering.cpp b/lib/Target/AMDGPU/SIISelLowering.cpp
index 292ce85..599c526 100644
--- a/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -44,8 +44,6 @@ SITargetLowering::SITargetLowering(TargetMachine &TM) :
setOperationAction(ISD::ADD, MVT::i64, Legal);
setOperationAction(ISD::ADD, MVT::i32, Legal);
- setOperationAction(ISD::BR_CC, MVT::i32, Custom);
-
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
// We need to custom lower loads from the USER_SGPR address space, so we can
@@ -254,7 +252,7 @@ EVT SITargetLowering::getSetCCResultType(EVT VT) const {
SDValue SITargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
switch (Op.getOpcode()) {
default: return AMDGPUTargetLowering::LowerOperation(Op, DAG);
- case ISD::BR_CC: return LowerBR_CC(Op, DAG);
+ case ISD::BRCOND: return LowerBRCOND(Op, DAG);
case ISD::LOAD: return LowerLOAD(Op, DAG);
case ISD::SELECT_CC: return LowerSELECT_CC(Op, DAG);
case ISD::AND: return Loweri1ContextSwitch(Op, DAG, ISD::AND);
@@ -298,27 +296,99 @@ SDValue SITargetLowering::Loweri1ContextSwitch(SDValue Op,
return DAG.getNode(SIISD::VCC_BITCAST, DL, MVT::i1, OpNode);
}
-SDValue SITargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
- SDValue Chain = Op.getOperand(0);
- SDValue CC = Op.getOperand(1);
- SDValue LHS = Op.getOperand(2);
- SDValue RHS = Op.getOperand(3);
- SDValue JumpT = Op.getOperand(4);
- SDValue CmpValue;
- SDValue Result;
- CmpValue = DAG.getNode(
- ISD::SETCC,
- Op.getDebugLoc(),
- MVT::i1,
- LHS, RHS,
- CC);
-
- Result = DAG.getNode(
- AMDGPUISD::BRANCH_COND,
- CmpValue.getDebugLoc(),
- MVT::Other, Chain,
- JumpT, CmpValue);
- return Result;
+// Helper function for LowerBRCOND
+static SDNode *findUser(SDValue Value, unsigned Opcode) {
+
+ SDNode *Parent = Value.getNode();
+ for (SDNode::use_iterator I = Parent->use_begin(), E = Parent->use_end();
+ I != E; ++I) {
+
+ if (I.getUse().get() != Value)
+ continue;
+
+ if (I->getOpcode() == Opcode)
+ return *I;
+ }
+ return 0;
+}
+
+// This transforms the control flow intrinsics to get the branch destination as
+// last parameter, also switches branch target with BR if the need arise
+SDValue SITargetLowering::LowerBRCOND(SDValue BRCOND,
+ SelectionDAG &DAG) const {
+
+ DebugLoc DL = BRCOND.getDebugLoc();
+
+ SDNode *Intr = BRCOND.getOperand(1).getNode();
+ SDValue Target = BRCOND.getOperand(2);
+ SDNode *BR = 0;
+
+ if (Intr->getOpcode() == ISD::SETCC) {
+ // As long as we negate the condition everything is fine
+ SDNode *SetCC = Intr;
+ assert(SetCC->getConstantOperandVal(1) == 1);
+
+ CondCodeSDNode *CC = cast<CondCodeSDNode>(SetCC->getOperand(2).getNode());
+ assert(CC->get() == ISD::SETNE);
+ Intr = SetCC->getOperand(0).getNode();
+
+ } else {
+ // Get the target from BR if we don't negate the condition
+ BR = findUser(BRCOND, ISD::BR);
+ Target = BR->getOperand(1);
+ }
+
+ assert(Intr->getOpcode() == ISD::INTRINSIC_W_CHAIN);
+
+ // Build the result and
+ SmallVector<EVT, 4> Res;
+ for (unsigned i = 1, e = Intr->getNumValues(); i != e; ++i)
+ Res.push_back(Intr->getValueType(i));
+
+ // operands of the new intrinsic call
+ SmallVector<SDValue, 4> Ops;
+ Ops.push_back(BRCOND.getOperand(0));
+ for (unsigned i = 1, e = Intr->getNumOperands(); i != e; ++i)
+ Ops.push_back(Intr->getOperand(i));
+ Ops.push_back(Target);
+
+ // build the new intrinsic call
+ SDNode *Result = DAG.getNode(
+ Res.size() > 1 ? ISD::INTRINSIC_W_CHAIN : ISD::INTRINSIC_VOID, DL,
+ DAG.getVTList(Res.data(), Res.size()), Ops.data(), Ops.size()).getNode();
+
+ if (BR) {
+ // Give the branch instruction our target
+ SDValue Ops[] = {
+ BR->getOperand(0),
+ BRCOND.getOperand(2)
+ };
+ DAG.MorphNodeTo(BR, ISD::BR, BR->getVTList(), Ops, 2);
+ }
+
+ SDValue Chain = SDValue(Result, Result->getNumValues() - 1);
+
+ // Copy the intrinsic results to registers
+ for (unsigned i = 1, e = Intr->getNumValues() - 1; i != e; ++i) {
+ SDNode *CopyToReg = findUser(SDValue(Intr, i), ISD::CopyToReg);
+ if (!CopyToReg)
+ continue;
+
+ Chain = DAG.getCopyToReg(
+ Chain, DL,
+ CopyToReg->getOperand(1),
+ SDValue(Result, i - 1),
+ SDValue());
+
+ DAG.ReplaceAllUsesWith(SDValue(CopyToReg, 0), CopyToReg->getOperand(0));
+ }
+
+ // Remove the old intrinsic from the chain
+ DAG.ReplaceAllUsesOfValueWith(
+ SDValue(Intr, Intr->getNumValues() - 1),
+ Intr->getOperand(0));
+
+ return Chain;
}
SDValue SITargetLowering::LowerLOAD(SDValue Op, SelectionDAG &DAG) const {
diff --git a/lib/Target/AMDGPU/SIISelLowering.h b/lib/Target/AMDGPU/SIISelLowering.h
index 27c2a1c..c088112 100644
--- a/lib/Target/AMDGPU/SIISelLowering.h
+++ b/lib/Target/AMDGPU/SIISelLowering.h
@@ -43,9 +43,9 @@ class SITargetLowering : public AMDGPUTargetLowering {
SDValue Loweri1ContextSwitch(SDValue Op, SelectionDAG &DAG,
unsigned VCCNode) const;
- SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
+ SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
public:
SITargetLowering(TargetMachine &tm);
diff --git a/lib/Target/AMDGPU/SIInstructions.td b/lib/Target/AMDGPU/SIInstructions.td
index 42fa8e6..51cd5b4 100644
--- a/lib/Target/AMDGPU/SIInstructions.td
+++ b/lib/Target/AMDGPU/SIInstructions.td
@@ -696,7 +696,7 @@ def S_ENDPGM : SOPP <0x00000001, (ins), "S_ENDPGM",
let isBranch = 1 in {
def S_BRANCH : SOPP <
0x00000002, (ins brtarget:$target), "S_BRANCH",
- []
+ [(br bb:$target)]
>;
let DisableEncoding = "$scc" in {
@@ -1095,26 +1095,70 @@ def SI_WQM : InstSI <
} // end usesCustomInserter
-// SI Psuedo branch instructions. These are used by the CFG structurizer pass
+// SI Psuedo instructions. These are used by the CFG structurizer pass
// and should be lowered to ISA instructions prior to codegen.
-let isBranch = 1, isTerminator = 1, mayLoad = 0, mayStore = 0,
- hasSideEffects = 0 in {
-def SI_IF_NZ : InstSI <
+let mayLoad = 1, mayStore = 1, hasSideEffects = 1,
+ Uses = [EXEC], Defs = [EXEC] in {
+
+let isBranch = 1, isTerminator = 1 in {
+
+def SI_IF : InstSI <
+ (outs SReg_64:$dst),
+ (ins SReg_1:$vcc, brtarget:$target),
+ "SI_IF",
+ [(set SReg_64:$dst, (int_SI_if SReg_1:$vcc, bb:$target))]
+>;
+
+def SI_ELSE : InstSI <
+ (outs SReg_64:$dst),
+ (ins SReg_64:$src, brtarget:$target),
+ "SI_ELSE",
+ [(set SReg_64:$dst, (int_SI_else SReg_64:$src, bb:$target))]> {
+
+ let Constraints = "$src = $dst";
+}
+
+def SI_LOOP : InstSI <
(outs),
- (ins brtarget:$target, SReg_1:$vcc),
- "SI_BRANCH_NZ",
- [(IL_brcond bb:$target, SReg_1:$vcc)]
+ (ins SReg_64:$saved, brtarget:$target),
+ "SI_LOOP",
+ [(int_SI_loop SReg_64:$saved, bb:$target)]
>;
-def SI_IF_Z : InstSI <
+} // end isBranch = 1, isTerminator = 1
+
+def SI_BREAK : InstSI <
+ (outs SReg_64:$dst),
+ (ins SReg_64:$src),
+ "SI_ELSE",
+ [(set SReg_64:$dst, (int_SI_break SReg_64:$src))]
+>;
+
+def SI_IF_BREAK : InstSI <
+ (outs SReg_64:$dst),
+ (ins SReg_1:$vcc, SReg_64:$src),
+ "SI_IF_BREAK",
+ [(set SReg_64:$dst, (int_SI_if_break SReg_1:$vcc, SReg_64:$src))]
+>;
+
+def SI_ELSE_BREAK : InstSI <
+ (outs SReg_64:$dst),
+ (ins SReg_64:$src0, SReg_64:$src1),
+ "SI_ELSE_BREAK",
+ [(set SReg_64:$dst, (int_SI_else_break SReg_64:$src0, SReg_64:$src1))]
+>;
+
+def SI_END_CF : InstSI <
(outs),
- (ins brtarget:$target, SReg_1:$vcc),
- "SI_BRANCH_Z",
- []
+ (ins SReg_64:$saved),
+ "SI_END_CF",
+ [(int_SI_end_cf SReg_64:$saved)]
>;
-} // end isBranch = 1, isTerminator = 1, mayLoad = 0, mayStore = 0,
- // hasSideEffects = 0
+
+} // end mayLoad = 1, mayStore = 1, hasSideEffects = 1
+ // Uses = [EXEC], Defs = [EXEC]
+
} // end IsCodeGenOnly, isPseudo
/* int_SI_vs_load_input */
diff --git a/lib/Target/AMDGPU/SIIntrinsics.td b/lib/Target/AMDGPU/SIIntrinsics.td
index 1008fc4..c322fef 100644
--- a/lib/Target/AMDGPU/SIIntrinsics.td
+++ b/lib/Target/AMDGPU/SIIntrinsics.td
@@ -39,4 +39,14 @@ let TargetPrefix = "SI", isTarget = 1 in {
def int_SI_fs_read_face : Intrinsic <[llvm_float_ty], [], [IntrNoMem]>;
def int_SI_fs_read_pos : Intrinsic <[llvm_float_ty], [llvm_i32_ty], [IntrNoMem]>;
+
+ /* Control flow Intrinsics */
+
+ def int_SI_if : Intrinsic<[llvm_i64_ty], [llvm_i1_ty, llvm_empty_ty], []>;
+ def int_SI_else : Intrinsic<[llvm_i64_ty], [llvm_i64_ty, llvm_empty_ty], []>;
+ def int_SI_break : Intrinsic<[llvm_i64_ty], [llvm_i64_ty], []>;
+ def int_SI_if_break : Intrinsic<[llvm_i64_ty], [llvm_i1_ty, llvm_i64_ty], []>;
+ def int_SI_else_break : Intrinsic<[llvm_i64_ty], [llvm_i64_ty, llvm_i64_ty], []>;
+ def int_SI_loop : Intrinsic<[], [llvm_i64_ty, llvm_empty_ty], []>;
+ def int_SI_end_cf : Intrinsic<[], [llvm_i64_ty], []>;
}
diff --git a/lib/Target/AMDGPU/SILowerControlFlow.cpp b/lib/Target/AMDGPU/SILowerControlFlow.cpp
index 277b647..594e6f7 100644
--- a/lib/Target/AMDGPU/SILowerControlFlow.cpp
+++ b/lib/Target/AMDGPU/SILowerControlFlow.cpp
@@ -8,10 +8,10 @@
//===----------------------------------------------------------------------===//
//
/// \file
-/// \brief This pass lowers the pseudo control flow instructions (SI_IF_NZ, ELSE, ENDIF)
-/// to predicated instructions.
+/// \brief This pass lowers the pseudo control flow instructions to real
+/// machine instructions.
///
-/// All control flow (except loops) is handled using predicated instructions and
+/// All control flow is handled using predicated instructions and
/// a predicate stack. Each Scalar ALU controls the operations of 64 Vector
/// ALUs. The Scalar ALU can update the predicate for any of the Vector ALUs
/// by writting to the 64-bit EXEC register (each bit corresponds to a
@@ -22,17 +22,17 @@
///
/// For example:
/// %VCC = V_CMP_GT_F32 %VGPR1, %VGPR2
-/// SI_IF_NZ %VCC
+/// %SGPR0 = SI_IF %VCC
/// %VGPR0 = V_ADD_F32 %VGPR0, %VGPR0
-/// ELSE
+/// %SGPR0 = SI_ELSE %SGPR0
/// %VGPR0 = V_SUB_F32 %VGPR0, %VGPR0
-/// ENDIF
+/// SI_END_CF %SGPR0
///
/// becomes:
///
/// %SGPR0 = S_AND_SAVEEXEC_B64 %VCC // Save and update the exec mask
/// %SGPR0 = S_XOR_B64 %SGPR0, %EXEC // Clear live bits from saved exec mask
-/// S_CBRANCH_EXECZ label0 // This instruction is an
+/// S_CBRANCH_EXECZ label0 // This instruction is an optional
/// // optimization which allows us to
/// // branch if all the bits of
/// // EXEC are zero.
@@ -45,7 +45,7 @@
/// // instruction again.
/// %VGPR0 = V_SUB_F32 %VGPR0, %VGPR // Do the THEN block
/// label1:
-/// %EXEC = S_OR_B64 %EXEC, %SGPR2 // Re-enable saved exec mask bits
+/// %EXEC = S_OR_B64 %EXEC, %SGPR0 // Re-enable saved exec mask bits
//===----------------------------------------------------------------------===//
#include "AMDGPU.h"
@@ -65,11 +65,14 @@ class SILowerControlFlowPass : public MachineFunctionPass {
private:
static char ID;
const TargetInstrInfo *TII;
- std::vector<unsigned> PredicateStack;
- std::vector<unsigned> UnusedRegisters;
- unsigned allocReg();
- void freeReg(unsigned Reg);
+ void If(MachineInstr &MI);
+ void Else(MachineInstr &MI);
+ void Break(MachineInstr &MI);
+ void IfBreak(MachineInstr &MI);
+ void ElseBreak(MachineInstr &MI);
+ void Loop(MachineInstr &MI);
+ void EndCf(MachineInstr &MI);
public:
SILowerControlFlowPass(TargetMachine &tm) :
@@ -91,101 +94,205 @@ FunctionPass *llvm::createSILowerControlFlowPass(TargetMachine &tm) {
return new SILowerControlFlowPass(tm);
}
+void SILowerControlFlowPass::If(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+ unsigned Reg = MI.getOperand(0).getReg();
+ unsigned Vcc = MI.getOperand(1).getReg();
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_AND_SAVEEXEC_B64), Reg)
+ .addReg(Vcc);
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_XOR_B64), Reg)
+ .addReg(AMDGPU::EXEC)
+ .addReg(Reg);
+
+ //BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_CBRANCH_EXECZ))
+ // .addOperand(MI.getOperand(2));
+
+ MI.eraseFromParent();
+}
+
+void SILowerControlFlowPass::Else(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+ unsigned Dst = MI.getOperand(0).getReg();
+ unsigned Src = MI.getOperand(1).getReg();
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_OR_SAVEEXEC_B64), Dst)
+ .addReg(Src); // Saved EXEC
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_XOR_B64), AMDGPU::EXEC)
+ .addReg(AMDGPU::EXEC)
+ .addReg(Dst);
+
+ //BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_CBRANCH_EXECZ))
+ // .addOperand(MI.getOperand(2));
+
+ MI.eraseFromParent();
+}
+
+void SILowerControlFlowPass::Break(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+
+ unsigned Dst = MI.getOperand(0).getReg();
+ unsigned Src = MI.getOperand(1).getReg();
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_OR_B64), Dst)
+ .addReg(AMDGPU::EXEC)
+ .addReg(Src);
+
+ MI.eraseFromParent();
+}
+
+void SILowerControlFlowPass::IfBreak(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+
+ unsigned Dst = MI.getOperand(0).getReg();
+ unsigned Vcc = MI.getOperand(1).getReg();
+ unsigned Src = MI.getOperand(2).getReg();
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_OR_B64), Dst)
+ .addReg(Vcc)
+ .addReg(Src);
+
+ MI.eraseFromParent();
+}
+
+void SILowerControlFlowPass::ElseBreak(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+
+ unsigned Dst = MI.getOperand(0).getReg();
+ unsigned Saved = MI.getOperand(1).getReg();
+ unsigned Src = MI.getOperand(2).getReg();
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_OR_B64), Dst)
+ .addReg(Saved)
+ .addReg(Src);
+
+ MI.eraseFromParent();
+}
+
+void SILowerControlFlowPass::Loop(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+ unsigned Src = MI.getOperand(0).getReg();
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_ANDN2_B64), AMDGPU::EXEC)
+ .addReg(AMDGPU::EXEC)
+ .addReg(Src);
+
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_CBRANCH_EXECNZ))
+ .addOperand(MI.getOperand(1))
+ .addReg(AMDGPU::EXEC);
+
+ MI.eraseFromParent();
+}
+
+void SILowerControlFlowPass::EndCf(MachineInstr &MI) {
+
+ MachineBasicBlock &MBB = *MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+ unsigned Reg = MI.getOperand(0).getReg();
+
+ BuildMI(MBB, MBB.getFirstNonPHI(), DL,
+ TII->get(AMDGPU::S_OR_B64), AMDGPU::EXEC)
+ .addReg(AMDGPU::EXEC)
+ .addReg(Reg);
+
+ MI.eraseFromParent();
+}
+
bool SILowerControlFlowPass::runOnMachineFunction(MachineFunction &MF) {
- // Find all the unused registers that can be used for the predicate stack.
- for (TargetRegisterClass::iterator I = AMDGPU::SReg_64RegClass.begin(),
- S = AMDGPU::SReg_64RegClass.end();
- I != S; ++I) {
- unsigned Reg = *I;
- if (!MF.getRegInfo().isPhysRegUsed(Reg)) {
- UnusedRegisters.insert(UnusedRegisters.begin(), Reg);
- }
- }
+ bool HaveCf = false;
+
+ for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
+ BI != BE; ++BI) {
- for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
- BB != BB_E; ++BB) {
- MachineBasicBlock &MBB = *BB;
+ MachineBasicBlock &MBB = *BI;
for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I);
- I != MBB.end(); I = Next) {
+ I != MBB.end(); I = Next) {
+
Next = llvm::next(I);
MachineInstr &MI = *I;
- unsigned Reg;
switch (MI.getOpcode()) {
default: break;
- case AMDGPU::SI_IF_NZ:
- Reg = allocReg();
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_AND_SAVEEXEC_B64),
- Reg)
- .addOperand(MI.getOperand(0)); // VCC
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_XOR_B64),
- Reg)
- .addReg(Reg)
- .addReg(AMDGPU::EXEC);
- MI.eraseFromParent();
- PredicateStack.push_back(Reg);
+ case AMDGPU::SI_IF:
+ If(MI);
+ break;
+
+ case AMDGPU::SI_ELSE:
+ Else(MI);
break;
- case AMDGPU::ELSE:
- Reg = PredicateStack.back();
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_OR_SAVEEXEC_B64),
- Reg)
- .addReg(Reg);
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_XOR_B64),
- AMDGPU::EXEC)
- .addReg(Reg)
- .addReg(AMDGPU::EXEC);
- MI.eraseFromParent();
+ case AMDGPU::SI_BREAK:
+ Break(MI);
break;
- case AMDGPU::ENDIF:
- Reg = PredicateStack.back();
- PredicateStack.pop_back();
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_OR_B64),
- AMDGPU::EXEC)
- .addReg(AMDGPU::EXEC)
- .addReg(Reg);
- freeReg(Reg);
-
- if (MF.getInfo<SIMachineFunctionInfo>()->ShaderType == ShaderType::PIXEL &&
- PredicateStack.empty()) {
- // If the exec mask is non-zero, skip the next two instructions
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_CBRANCH_EXECNZ))
- .addImm(3)
- .addReg(AMDGPU::EXEC);
-
- // Exec mask is zero: Export to NULL target...
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::EXP))
- .addImm(0)
- .addImm(0x09) // V_008DFC_SQ_EXP_NULL
- .addImm(0)
- .addImm(1)
- .addImm(1)
- .addReg(AMDGPU::SREG_LIT_0)
- .addReg(AMDGPU::SREG_LIT_0)
- .addReg(AMDGPU::SREG_LIT_0)
- .addReg(AMDGPU::SREG_LIT_0);
-
- // ... and terminate wavefront
- BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_ENDPGM));
- }
- MI.eraseFromParent();
+ case AMDGPU::SI_IF_BREAK:
+ IfBreak(MI);
+ break;
+
+ case AMDGPU::SI_ELSE_BREAK:
+ ElseBreak(MI);
+ break;
+
+ case AMDGPU::SI_LOOP:
+ Loop(MI);
+ break;
+
+ case AMDGPU::SI_END_CF:
+ HaveCf = true;
+ EndCf(MI);
break;
}
}
}
- return true;
-}
-unsigned SILowerControlFlowPass::allocReg() {
+ // TODO: What is this good for?
+ unsigned ShaderType = MF.getInfo<SIMachineFunctionInfo>()->ShaderType;
+ if (HaveCf && ShaderType == ShaderType::PIXEL) {
+ for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
+ BI != BE; ++BI) {
- assert(!UnusedRegisters.empty() && "Ran out of registers for predicate stack");
- unsigned Reg = UnusedRegisters.back();
- UnusedRegisters.pop_back();
- return Reg;
-}
+ MachineBasicBlock &MBB = *BI;
+ if (MBB.succ_begin() == MBB.succ_end()) {
-void SILowerControlFlowPass::freeReg(unsigned Reg) {
+ MachineInstr &MI = *MBB.getFirstNonPHI();
+ DebugLoc DL = MI.getDebugLoc();
- UnusedRegisters.push_back(Reg);
+ // If the exec mask is non-zero, skip the next two instructions
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_CBRANCH_EXECNZ))
+ .addImm(3)
+ .addReg(AMDGPU::EXEC);
+
+ // Exec mask is zero: Export to NULL target...
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::EXP))
+ .addImm(0)
+ .addImm(0x09) // V_008DFC_SQ_EXP_NULL
+ .addImm(0)
+ .addImm(1)
+ .addImm(1)
+ .addReg(AMDGPU::SREG_LIT_0)
+ .addReg(AMDGPU::SREG_LIT_0)
+ .addReg(AMDGPU::SREG_LIT_0)
+ .addReg(AMDGPU::SREG_LIT_0);
+
+ // ... and terminate wavefront
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_ENDPGM));
+ }
+ }
+ }
+
+ return true;
}
--
1.7.9.5
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