MachineDominators: Move applySplitCriticalEdges into the cpp file.

It's too big for inlining anyways. Also clean it up slightly. No functionality
change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230806 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer 2015-02-27 23:13:13 +00:00
parent 7de1732297
commit 0a7ed28ea6
2 changed files with 68 additions and 72 deletions

View File

@ -45,9 +45,6 @@ class MachineDominatorTree : public MachineFunctionPass {
MachineBasicBlock *FromBB;
MachineBasicBlock *ToBB;
MachineBasicBlock *NewBB;
CriticalEdge(MachineBasicBlock *FromBB, MachineBasicBlock *ToBB,
MachineBasicBlock *NewBB)
: FromBB(FromBB), ToBB(ToBB), NewBB(NewBB) {}
};
/// \brief Pile up all the critical edges to be split.
@ -67,74 +64,7 @@ class MachineDominatorTree : public MachineFunctionPass {
/// the fast query path of DT as much as possible.
///
/// \post CriticalEdgesToSplit.empty().
void applySplitCriticalEdges() const {
// Bail out early if there is nothing to do.
if (CriticalEdgesToSplit.empty())
return;
// For each element in CriticalEdgesToSplit, remember whether or
// not element is the new immediate domminator of its successor.
// The mapping is done by index, i.e., the information for the ith
// element of CriticalEdgesToSplit is the ith element of IsNewIDom.
SmallVector<bool, 32> IsNewIDom;
IsNewIDom.resize(CriticalEdgesToSplit.size());
size_t Idx = 0;
// Collect all the dominance properties info, before invalidating
// the underlying DT.
for (CriticalEdge &Edge : CriticalEdgesToSplit) {
// Update dominator information.
MachineBasicBlock *Succ = Edge.ToBB;
MachineDomTreeNode *SucccDTNode = DT->getNode(Succ);
IsNewIDom[Idx] = true;
for (MachineBasicBlock *PredBB : Succ->predecessors()) {
if (PredBB == Edge.NewBB)
continue;
// If we are in this situation:
// FromBB1 FromBB2
// + +
// + + + +
// + + + +
// ... Split1 Split2 ...
// + +
// + +
// +
// Succ
// Instead of checking the domiance property with Split2, we
// check it with FromBB2 since Split2 is still unknown of the
// underlying DT structure.
if (NewBBs.count(PredBB)) {
assert(PredBB->pred_size() == 1 && "A basic block resulting from a "
"critical edge split has more "
"than one predecessor!");
PredBB = *PredBB->pred_begin();
}
if (!DT->dominates(SucccDTNode, DT->getNode(PredBB))) {
IsNewIDom[Idx] = false;
break;
}
}
++Idx;
}
// Now, update DT with the collected dominance properties info.
Idx = 0;
for (CriticalEdge &Edge : CriticalEdgesToSplit) {
// We know FromBB dominates NewBB.
MachineDomTreeNode *NewDTNode = DT->addNewBlock(Edge.NewBB, Edge.FromBB);
MachineDomTreeNode *SucccDTNode = DT->getNode(Edge.ToBB);
// If all the other predecessors of "Succ" are dominated by "Succ" itself
// then the new block is the new immediate dominator of "Succ". Otherwise,
// the new block doesn't dominate anything.
if (IsNewIDom[Idx])
DT->changeImmediateDominator(SucccDTNode, NewDTNode);
++Idx;
}
NewBBs.clear();
CriticalEdgesToSplit.clear();
}
void applySplitCriticalEdges() const;
public:
static char ID; // Pass ID, replacement for typeid
@ -307,7 +237,7 @@ public:
(void)Inserted;
assert(Inserted &&
"A basic block inserted via edge splitting cannot appear twice");
CriticalEdgesToSplit.push_back(CriticalEdge(FromBB, ToBB, NewBB));
CriticalEdgesToSplit.push_back({FromBB, ToBB, NewBB});
}
};

View File

@ -14,6 +14,7 @@
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/ADT/SmallBitVector.h"
using namespace llvm;
@ -59,3 +60,68 @@ void MachineDominatorTree::releaseMemory() {
void MachineDominatorTree::print(raw_ostream &OS, const Module*) const {
DT->print(OS);
}
void MachineDominatorTree::applySplitCriticalEdges() const {
// Bail out early if there is nothing to do.
if (CriticalEdgesToSplit.empty())
return;
// For each element in CriticalEdgesToSplit, remember whether or not element
// is the new immediate domminator of its successor. The mapping is done by
// index, i.e., the information for the ith element of CriticalEdgesToSplit is
// the ith element of IsNewIDom.
SmallBitVector IsNewIDom(CriticalEdgesToSplit.size(), true);
size_t Idx = 0;
// Collect all the dominance properties info, before invalidating
// the underlying DT.
for (CriticalEdge &Edge : CriticalEdgesToSplit) {
// Update dominator information.
MachineBasicBlock *Succ = Edge.ToBB;
MachineDomTreeNode *SuccDTNode = DT->getNode(Succ);
for (MachineBasicBlock *PredBB : Succ->predecessors()) {
if (PredBB == Edge.NewBB)
continue;
// If we are in this situation:
// FromBB1 FromBB2
// + +
// + + + +
// + + + +
// ... Split1 Split2 ...
// + +
// + +
// +
// Succ
// Instead of checking the domiance property with Split2, we check it with
// FromBB2 since Split2 is still unknown of the underlying DT structure.
if (NewBBs.count(PredBB)) {
assert(PredBB->pred_size() == 1 && "A basic block resulting from a "
"critical edge split has more "
"than one predecessor!");
PredBB = *PredBB->pred_begin();
}
if (!DT->dominates(SuccDTNode, DT->getNode(PredBB))) {
IsNewIDom[Idx] = false;
break;
}
}
++Idx;
}
// Now, update DT with the collected dominance properties info.
Idx = 0;
for (CriticalEdge &Edge : CriticalEdgesToSplit) {
// We know FromBB dominates NewBB.
MachineDomTreeNode *NewDTNode = DT->addNewBlock(Edge.NewBB, Edge.FromBB);
// If all the other predecessors of "Succ" are dominated by "Succ" itself
// then the new block is the new immediate dominator of "Succ". Otherwise,
// the new block doesn't dominate anything.
if (IsNewIDom[Idx])
DT->changeImmediateDominator(DT->getNode(Edge.ToBB), NewDTNode);
++Idx;
}
NewBBs.clear();
CriticalEdgesToSplit.clear();
}