mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-11-01 00:11:00 +00:00
9cb7f49ee9
Also, add a FIXME for a bug in PostDomTree calculation I noticed while writing this, git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42593 91177308-0d34-0410-b5e6-96231b3b80d8
99 lines
3.4 KiB
C++
99 lines
3.4 KiB
C++
//===- PostDominators.cpp - Post-Dominator Calculation --------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements the post-dominator construction algorithms.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Analysis/PostDominators.h"
|
|
#include "llvm/Instructions.h"
|
|
#include "llvm/Support/CFG.h"
|
|
#include "llvm/ADT/DepthFirstIterator.h"
|
|
#include "llvm/ADT/SetOperations.h"
|
|
#include "llvm/Analysis/DominatorInternals.h"
|
|
using namespace llvm;
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// PostDominatorTree Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
char PostDominatorTree::ID = 0;
|
|
char PostDominanceFrontier::ID = 0;
|
|
static RegisterPass<PostDominatorTree>
|
|
F("postdomtree", "Post-Dominator Tree Construction", true);
|
|
|
|
bool PostDominatorTree::runOnFunction(Function &F) {
|
|
reset(); // Reset from the last time we were run...
|
|
|
|
// Initialize the roots list
|
|
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
|
|
TerminatorInst *Insn = I->getTerminator();
|
|
if (Insn->getNumSuccessors() == 0) {
|
|
// Unreachable block is not a root node.
|
|
if (!isa<UnreachableInst>(Insn))
|
|
Roots.push_back(I);
|
|
}
|
|
|
|
// Prepopulate maps so that we don't get iterator invalidation issues later.
|
|
IDoms[I] = 0;
|
|
DomTreeNodes[I] = 0;
|
|
}
|
|
|
|
Vertex.push_back(0);
|
|
|
|
Calculate<Inverse<BasicBlock*> >(*this, F);
|
|
return false;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// PostDominanceFrontier Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
static RegisterPass<PostDominanceFrontier>
|
|
H("postdomfrontier", "Post-Dominance Frontier Construction", true);
|
|
|
|
const DominanceFrontier::DomSetType &
|
|
PostDominanceFrontier::calculate(const PostDominatorTree &DT,
|
|
const DomTreeNode *Node) {
|
|
// Loop over CFG successors to calculate DFlocal[Node]
|
|
BasicBlock *BB = Node->getBlock();
|
|
DomSetType &S = Frontiers[BB]; // The new set to fill in...
|
|
if (getRoots().empty()) return S;
|
|
|
|
if (BB)
|
|
for (pred_iterator SI = pred_begin(BB), SE = pred_end(BB);
|
|
SI != SE; ++SI) {
|
|
// Does Node immediately dominate this predecessor?
|
|
DomTreeNode *SINode = DT[*SI];
|
|
if (SINode && SINode->getIDom() != Node)
|
|
S.insert(*SI);
|
|
}
|
|
|
|
// At this point, S is DFlocal. Now we union in DFup's of our children...
|
|
// Loop through and visit the nodes that Node immediately dominates (Node's
|
|
// children in the IDomTree)
|
|
//
|
|
for (DomTreeNode::const_iterator
|
|
NI = Node->begin(), NE = Node->end(); NI != NE; ++NI) {
|
|
DomTreeNode *IDominee = *NI;
|
|
const DomSetType &ChildDF = calculate(DT, IDominee);
|
|
|
|
DomSetType::const_iterator CDFI = ChildDF.begin(), CDFE = ChildDF.end();
|
|
for (; CDFI != CDFE; ++CDFI) {
|
|
if (!DT.properlyDominates(Node, DT[*CDFI]))
|
|
S.insert(*CDFI);
|
|
}
|
|
}
|
|
|
|
return S;
|
|
}
|
|
|
|
// Ensure that this .cpp file gets linked when PostDominators.h is used.
|
|
DEFINING_FILE_FOR(PostDominanceFrontier)
|