Add edges between call instructions and (a) load/store instructions, and
(b) any instructions that use or set CC registers. Whether or not the
latter are needed really should be machine-dependent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1008 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/InstrSched/SchedGraph.cpp b/lib/CodeGen/InstrSched/SchedGraph.cpp
index acf7bb8..2bff552 100644
--- a/lib/CodeGen/InstrSched/SchedGraph.cpp
+++ b/lib/CodeGen/InstrSched/SchedGraph.cpp
@@ -45,7 +45,7 @@
SchedGraphEdge::SchedGraphEdge(SchedGraphNode* _src,
SchedGraphNode* _sink,
SchedGraphEdgeDepType _depType,
- DataDepOrderType _depOrderType,
+ unsigned int _depOrderType,
int _minDelay)
: src(_src),
sink(_sink),
@@ -63,7 +63,7 @@
SchedGraphEdge::SchedGraphEdge(SchedGraphNode* _src,
SchedGraphNode* _sink,
const Value* _val,
- DataDepOrderType _depOrderType,
+ unsigned int _depOrderType,
int _minDelay)
: src(_src),
sink(_sink),
@@ -81,7 +81,7 @@
SchedGraphEdge::SchedGraphEdge(SchedGraphNode* _src,
SchedGraphNode* _sink,
unsigned int _regNum,
- DataDepOrderType _depOrderType,
+ unsigned int _depOrderType,
int _minDelay)
: src(_src),
sink(_sink),
@@ -347,6 +347,7 @@
// Add CD edges from each instruction in the sequence to the
// *last preceding* branch instr. in the sequence
+ // Use a latency of 0 because we only need to prevent out-of-order issue.
//
for (int i = (int) termMvec.size()-1; i > (int) first; i--)
{
@@ -365,7 +366,7 @@
}
// Add CD edges from each instruction preceding the first branch
- // to the first branch
+ // to the first branch. Use a latency of 0 as above.
//
for (int i = first-1; i >= 0; i--)
{
@@ -375,8 +376,8 @@
SchedGraphEdge::NonDataDep, 0);
}
- // Now add CD edges to the first branch instruction in the sequence
- // from all preceding instructions in the basic block.
+ // Now add CD edges to the first branch instruction in the sequence from
+ // all preceding instructions in the basic block. Use 0 latency again.
//
const BasicBlock* bb = term->getParent();
for (BasicBlock::const_iterator II = bb->begin(); II != bb->end(); ++II)
@@ -416,6 +417,23 @@
}
}
+static const int SG_LOAD_REF = 0;
+static const int SG_STORE_REF = 1;
+static const int SG_CALL_REF = 2;
+
+static const unsigned int SG_DepOrderArray[][3] = {
+ { SchedGraphEdge::NonDataDep,
+ SchedGraphEdge::AntiDep,
+ SchedGraphEdge::AntiDep },
+ { SchedGraphEdge::TrueDep,
+ SchedGraphEdge::OutputDep,
+ SchedGraphEdge::TrueDep | SchedGraphEdge::OutputDep },
+ { SchedGraphEdge::TrueDep,
+ SchedGraphEdge::AntiDep | SchedGraphEdge::OutputDep,
+ SchedGraphEdge::TrueDep | SchedGraphEdge::AntiDep
+ | SchedGraphEdge::OutputDep }
+};
+
void
SchedGraph::addMemEdges(const vector<const Instruction*>& memVec,
@@ -426,35 +444,37 @@
for (unsigned im=0, NM=memVec.size(); im < NM; im++)
{
const Instruction* fromInstr = memVec[im];
- bool fromIsLoad = fromInstr->getOpcode() == Instruction::Load;
+ int fromType = (fromInstr->getOpcode() == Instruction::Call
+ ? SG_CALL_REF
+ : (fromInstr->getOpcode() == Instruction::Load
+ ? SG_LOAD_REF
+ : SG_STORE_REF));
for (unsigned jm=im+1; jm < NM; jm++)
{
const Instruction* toInstr = memVec[jm];
- bool toIsLoad = toInstr->getOpcode() == Instruction::Load;
- SchedGraphEdge::DataDepOrderType depOrderType;
-
- if (fromIsLoad)
- {
- if (toIsLoad) continue; // both instructions are loads
- depOrderType = SchedGraphEdge::AntiDep;
- }
- else
- {
- depOrderType = (toIsLoad)? SchedGraphEdge::TrueDep
- : SchedGraphEdge::OutputDep;
- }
+ int toType = (fromInstr->getOpcode() == Instruction::Call? 2
+ : ((fromInstr->getOpcode()==Instruction::Load)? 0:1));
+
+ if (fromType == SG_LOAD_REF && toType == SG_LOAD_REF)
+ continue;
+
+ unsigned int depOrderType = SG_DepOrderArray[fromType][toType];
MachineCodeForVMInstr& fromInstrMvec=fromInstr->getMachineInstrVec();
MachineCodeForVMInstr& toInstrMvec = toInstr->getMachineInstrVec();
- // We have two VM memory instructions, and at least one is a store.
- // Add edges between all machine load/store instructions.
- //
+ // We have two VM memory instructions, and at least one is a store
+ // or a call. Add edges between all machine load/store/call instrs.
+ // Use a latency of 1 to ensure that memory operations are ordered;
+ // latency does not otherwise matter (true dependences enforce that).
+ //
for (unsigned i=0, N=fromInstrMvec.size(); i < N; i++)
{
MachineOpCode fromOpCode = fromInstrMvec[i]->getOpCode();
- if (mii.isLoad(fromOpCode) || mii.isStore(fromOpCode))
+
+ if (mii.isLoad(fromOpCode) || mii.isStore(fromOpCode) ||
+ mii.isCall(fromOpCode))
{
SchedGraphNode* fromNode =
this->getGraphNodeForInstr(fromInstrMvec[i]);
@@ -463,7 +483,8 @@
for (unsigned j=0, M=toInstrMvec.size(); j < M; j++)
{
MachineOpCode toOpCode = toInstrMvec[j]->getOpCode();
- if (mii.isLoad(toOpCode) || mii.isStore(toOpCode))
+ if (mii.isLoad(toOpCode) || mii.isStore(toOpCode)
+ || mii.isCall(fromOpCode))
{
SchedGraphNode* toNode =
this->getGraphNodeForInstr(toInstrMvec[j]);
@@ -482,6 +503,56 @@
void
+SchedGraph::addCallCCEdges(const vector<const Instruction*>& memVec,
+ MachineCodeForBasicBlock& bbMvec,
+ const TargetMachine& target)
+{
+ const MachineInstrInfo& mii = target.getInstrInfo();
+ vector<SchedGraphNode*> callNodeVec;
+
+ // Find the call machine instructions and put them in a vector.
+ // By using memVec, we avoid searching the entire machine code of the BB.
+ //
+ for (unsigned im=0, NM=memVec.size(); im < NM; im++)
+ if (memVec[im]->getOpcode() == Instruction::Call)
+ {
+ MachineCodeForVMInstr& callMvec=memVec[im]->getMachineInstrVec();
+ for (unsigned i=0; i < callMvec.size(); ++i)
+ if (mii.isCall(callMvec[i]->getOpCode()))
+ callNodeVec.push_back(this->getGraphNodeForInstr(callMvec[i]));
+ }
+
+ // Now add additional edges from/to CC reg instrs to/from call instrs.
+ // Essentially this prevents anything that sets or uses a CC reg from being
+ // reordered w.r.t. a call.
+ // Use a latency of 0 because we only need to prevent out-of-order issue,
+ // like with control dependences.
+ //
+ int lastCallNodeIdx = -1;
+ for (unsigned i=0, N=bbMvec.size(); i < N; i++)
+ if (mii.isCall(bbMvec[i]->getOpCode()))
+ {
+ ++lastCallNodeIdx;
+ for ( ; lastCallNodeIdx < (int)callNodeVec.size(); ++lastCallNodeIdx)
+ if (callNodeVec[lastCallNodeIdx]->getMachineInstr() == bbMvec[i])
+ break;
+ assert(lastCallNodeIdx < (int)callNodeVec.size() && "Missed Call?");
+ }
+ else if (mii.isCCInstr(bbMvec[i]->getOpCode()))
+ { // Add incoming/outgoing edges from/to preceding/later calls
+ SchedGraphNode* ccNode = this->getGraphNodeForInstr(bbMvec[i]);
+ int j=0;
+ for ( ; j <= lastCallNodeIdx; j++)
+ (void) new SchedGraphEdge(callNodeVec[j], ccNode,
+ MachineCCRegsRID, 0);
+ for ( ; j < (int) callNodeVec.size(); j++)
+ (void) new SchedGraphEdge(ccNode, callNodeVec[j],
+ MachineCCRegsRID, 0);
+ }
+}
+
+
+void
SchedGraph::addMachineRegEdges(RegToRefVecMap& regToRefVecMap,
const TargetMachine& target)
{
@@ -749,7 +820,7 @@
assert(bbVec.size() == 1 && "Only handling a single basic block here");
- // Use this data structures to note all LLVM memory instructions.
+ // Use these data structures to note all LLVM memory instructions.
// We use this to add memory dependence edges without a second full walk.
//
vector<const Instruction*> memVec;
@@ -782,11 +853,12 @@
// Build graph nodes for this VM instruction
buildNodesforVMInstr(target, instr);
- // Remember the load/store instructions to add memory deps later.
+ // Remember the load/store/call instructions to add memory deps later.
if (instr->getOpcode() == Instruction::Load ||
- instr->getOpcode() == Instruction::Store)
+ instr->getOpcode() == Instruction::Store ||
+ instr->getOpcode() == Instruction::Call)
memVec.push_back(instr);
- }
+ }
//----------------------------------------------------------------
// Now add edges for the following (all are incoming edges except (4)):
@@ -804,17 +876,22 @@
//
//----------------------------------------------------------------
+ MachineCodeForBasicBlock& bbMvec = bb->getMachineInstrVec();
+
// First, add edges to the terminator instruction of the basic block.
this->addCDEdges(bb->getTerminator(), target);
- // Then add memory dep edges: store->load, load->store, and store->store
+ // Then add memory dep edges: store->load, load->store, and store->store.
+ // Call instructions are treated as both load and store.
this->addMemEdges(memVec, target);
-
+
+ // Then add edges between call instructions and CC set/use instructions
+ this->addCallCCEdges(memVec, bbMvec, target);
+
// Then add other edges for all instructions in the block.
// Do this in machine code order and find all references to machine regs.
- MachineCodeForBasicBlock& mvec = bb->getMachineInstrVec();
- for (unsigned i=0, N=mvec.size(); i < N; i++)
- addEdgesForInstruction(*mvec[i], regToRefVecMap, target);
+ for (unsigned i=0, N=bbMvec.size(); i < N; i++)
+ addEdgesForInstruction(*bbMvec[i], regToRefVecMap, target);
// Since the code is no longer in SSA form, add output dep. edges
// between machine instructions that define the same Value, and anti-dep.