mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 04:02:41 +01:00
107 lines
3.5 KiB
C++
107 lines
3.5 KiB
C++
//===- Dominators.cpp - Dominator Calculation -----------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements simple dominator construction algorithms for finding
|
|
// forward dominators. Postdominators are available in libanalysis, but are not
|
|
// included in libvmcore, because it's not needed. Forward dominators are
|
|
// needed to support the Verifier pass.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Analysis/Dominators.h"
|
|
#include "llvm/Support/CFG.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/ADT/DepthFirstIterator.h"
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/Analysis/DominatorInternals.h"
|
|
#include "llvm/Assembly/Writer.h"
|
|
#include "llvm/Instructions.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include <algorithm>
|
|
using namespace llvm;
|
|
|
|
// Always verify dominfo if expensive checking is enabled.
|
|
#ifdef XDEBUG
|
|
static bool VerifyDomInfo = true;
|
|
#else
|
|
static bool VerifyDomInfo = false;
|
|
#endif
|
|
static cl::opt<bool,true>
|
|
VerifyDomInfoX("verify-dom-info", cl::location(VerifyDomInfo),
|
|
cl::desc("Verify dominator info (time consuming)"));
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DominatorTree Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Provide public access to DominatorTree information. Implementation details
|
|
// can be found in DominatorInternals.h.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
TEMPLATE_INSTANTIATION(class llvm::DomTreeNodeBase<BasicBlock>);
|
|
TEMPLATE_INSTANTIATION(class llvm::DominatorTreeBase<BasicBlock>);
|
|
|
|
char DominatorTree::ID = 0;
|
|
INITIALIZE_PASS(DominatorTree, "domtree",
|
|
"Dominator Tree Construction", true, true)
|
|
|
|
bool DominatorTree::runOnFunction(Function &F) {
|
|
DT->recalculate(F);
|
|
return false;
|
|
}
|
|
|
|
void DominatorTree::verifyAnalysis() const {
|
|
if (!VerifyDomInfo) return;
|
|
|
|
Function &F = *getRoot()->getParent();
|
|
|
|
DominatorTree OtherDT;
|
|
OtherDT.getBase().recalculate(F);
|
|
if (compare(OtherDT)) {
|
|
errs() << "DominatorTree is not up to date!\nComputed:\n";
|
|
print(errs());
|
|
errs() << "\nActual:\n";
|
|
OtherDT.print(errs());
|
|
abort();
|
|
}
|
|
}
|
|
|
|
void DominatorTree::print(raw_ostream &OS, const Module *) const {
|
|
DT->print(OS);
|
|
}
|
|
|
|
// dominates - Return true if A dominates a use in B. This performs the
|
|
// special checks necessary if A and B are in the same basic block.
|
|
bool DominatorTree::dominates(const Instruction *A, const Instruction *B) const{
|
|
const BasicBlock *BBA = A->getParent(), *BBB = B->getParent();
|
|
|
|
// If A is an invoke instruction, its value is only available in this normal
|
|
// successor block.
|
|
if (const InvokeInst *II = dyn_cast<InvokeInst>(A))
|
|
BBA = II->getNormalDest();
|
|
|
|
if (BBA != BBB) return dominates(BBA, BBB);
|
|
|
|
// It is not possible to determine dominance between two PHI nodes
|
|
// based on their ordering.
|
|
if (isa<PHINode>(A) && isa<PHINode>(B))
|
|
return false;
|
|
|
|
// Loop through the basic block until we find A or B.
|
|
BasicBlock::const_iterator I = BBA->begin();
|
|
for (; &*I != A && &*I != B; ++I)
|
|
/*empty*/;
|
|
|
|
return &*I == A;
|
|
}
|