Reimplement isPotentiallyReachable to make nocapture deduction much stronger.

Adds unit tests for it too.

Split BasicBlockUtils into an analysis-half and a transforms-half, and put the
analysis bits into a new Analysis/CFG.{h,cpp}. Promote isPotentiallyReachable
into llvm::isPotentiallyReachable and move it into Analysis/CFG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187283 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky
2013-07-27 01:24:00 +00:00
parent 332af10901
commit 81e480463d
13 changed files with 666 additions and 142 deletions

View File

@ -14,6 +14,7 @@
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/MemoryDependenceAnalysis.h"
@ -235,22 +236,6 @@ void llvm::ReplaceInstWithInst(Instruction *From, Instruction *To) {
ReplaceInstWithInst(From->getParent()->getInstList(), BI, To);
}
/// GetSuccessorNumber - Search for the specified successor of basic block BB
/// and return its position in the terminator instruction's list of
/// successors. It is an error to call this with a block that is not a
/// successor.
unsigned llvm::GetSuccessorNumber(BasicBlock *BB, BasicBlock *Succ) {
TerminatorInst *Term = BB->getTerminator();
#ifndef NDEBUG
unsigned e = Term->getNumSuccessors();
#endif
for (unsigned i = 0; ; ++i) {
assert(i != e && "Didn't find edge?");
if (Term->getSuccessor(i) == Succ)
return i;
}
}
/// SplitEdge - Split the edge connecting specified block. Pass P must
/// not be NULL.
BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, Pass *P) {
@ -598,52 +583,6 @@ void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
}
}
/// FindFunctionBackedges - Analyze the specified function to find all of the
/// loop backedges in the function and return them. This is a relatively cheap
/// (compared to computing dominators and loop info) analysis.
///
/// The output is added to Result, as pairs of <from,to> edge info.
void llvm::FindFunctionBackedges(const Function &F,
SmallVectorImpl<std::pair<const BasicBlock*,const BasicBlock*> > &Result) {
const BasicBlock *BB = &F.getEntryBlock();
if (succ_begin(BB) == succ_end(BB))
return;
SmallPtrSet<const BasicBlock*, 8> Visited;
SmallVector<std::pair<const BasicBlock*, succ_const_iterator>, 8> VisitStack;
SmallPtrSet<const BasicBlock*, 8> InStack;
Visited.insert(BB);
VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
InStack.insert(BB);
do {
std::pair<const BasicBlock*, succ_const_iterator> &Top = VisitStack.back();
const BasicBlock *ParentBB = Top.first;
succ_const_iterator &I = Top.second;
bool FoundNew = false;
while (I != succ_end(ParentBB)) {
BB = *I++;
if (Visited.insert(BB)) {
FoundNew = true;
break;
}
// Successor is in VisitStack, it's a back edge.
if (InStack.count(BB))
Result.push_back(std::make_pair(ParentBB, BB));
}
if (FoundNew) {
// Go down one level if there is a unvisited successor.
InStack.insert(BB);
VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
} else {
// Go up one level.
InStack.erase(VisitStack.pop_back_val().first);
}
} while (!VisitStack.empty());
}
/// FoldReturnIntoUncondBranch - This method duplicates the specified return
/// instruction into a predecessor which ends in an unconditional branch. If
/// the return instruction returns a value defined by a PHI, propagate the