If converter was being too cute. It look for root BBs (which don't have

successors) and use inverse depth first search to traverse the BBs. However
that doesn't work when the CFG has infinite loops. Simply do a linear
traversal of all BBs work just fine.

rdar://9344645


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130324 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng
2011-04-27 19:32:43 +00:00
parent bddc1ca18a
commit 309db7c947
2 changed files with 62 additions and 18 deletions
+3 -18
View File
@@ -27,7 +27,6 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
@@ -146,10 +145,6 @@ namespace {
: BBI(b), Kind(k), NeedSubsumption(s), NumDups(d), NumDups2(d2) {}
};
/// Roots - Basic blocks that do not have successors. These are the starting
/// points of Graph traversal.
std::vector<MachineBasicBlock*> Roots;
/// BBAnalysis - Results of if-conversion feasibility analysis indexed by
/// basic block number.
std::vector<BBInfo> BBAnalysis;
@@ -287,11 +282,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
MF.RenumberBlocks();
BBAnalysis.resize(MF.getNumBlockIDs());
// Look for root nodes, i.e. blocks without successors.
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
if (I->succ_empty())
Roots.push_back(I);
std::vector<IfcvtToken*> Tokens;
MadeChange = false;
unsigned NumIfCvts = NumSimple + NumSimpleFalse + NumTriangle +
@@ -406,7 +396,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
}
Tokens.clear();
Roots.clear();
BBAnalysis.clear();
if (MadeChange && IfCvtBranchFold) {
@@ -924,13 +913,9 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB,
/// candidates.
void IfConverter::AnalyzeBlocks(MachineFunction &MF,
std::vector<IfcvtToken*> &Tokens) {
std::set<MachineBasicBlock*> Visited;
for (unsigned i = 0, e = Roots.size(); i != e; ++i) {
for (idf_ext_iterator<MachineBasicBlock*> I=idf_ext_begin(Roots[i],Visited),
E = idf_ext_end(Roots[i], Visited); I != E; ++I) {
MachineBasicBlock *BB = *I;
AnalyzeBlock(BB, Tokens);
}
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
MachineBasicBlock *BB = I;
AnalyzeBlock(BB, Tokens);
}
// Sort to favor more complex ifcvt scheme.