Fix phi bug on exception edges.
Change-Id: Icb6bf5b2ee87a12a9728166a588ef7259dfa88df
diff --git a/src/compiler_llvm/gbc_expander.cc b/src/compiler_llvm/gbc_expander.cc
index 88505ee..412dbf7 100644
--- a/src/compiler_llvm/gbc_expander.cc
+++ b/src/compiler_llvm/gbc_expander.cc
@@ -32,6 +32,8 @@
#include <llvm/Support/InstIterator.h>
#include <vector>
+#include <map>
+#include <utility>
using namespace art;
using namespace compiler_llvm;
@@ -69,6 +71,9 @@
std::vector<llvm::BasicBlock*> basic_blocks_;
std::vector<llvm::BasicBlock*> basic_block_landing_pads_;
+ llvm::BasicBlock* old_basic_block_;
+ std::map<llvm::BasicBlock*, std::vector<std::pair<llvm::BasicBlock*, llvm::BasicBlock*> > >
+ landing_pad_phi_mapping_;
llvm::BasicBlock* basic_block_unwind_;
bool changed_;
@@ -418,11 +423,15 @@
// because we will create new basic block while expanding the intrinsics.
// We only want to iterate through the input basic blocks.
+ landing_pad_phi_mapping_.clear();
+
for (llvm::Function::iterator bb_iter = func_->begin();
num_basic_blocks > 0; ++bb_iter, --num_basic_blocks) {
// Set insert point to current basic block.
irb_.SetInsertPoint(bb_iter);
+ old_basic_block_ = bb_iter;
+
// Rewrite the basic block
RewriteBasicBlock(bb_iter);
@@ -432,6 +441,73 @@
UpdatePhiInstruction(bb_iter, last_block);
}
}
+
+ typedef std::map<llvm::PHINode*, llvm::PHINode*> HandlerPHIMap;
+ HandlerPHIMap handler_phi;
+ // Iterate every used landing pad basic block
+ for (size_t i = 0, ei = basic_block_landing_pads_.size(); i != ei; ++i) {
+ llvm::BasicBlock* lbb = basic_block_landing_pads_[i];
+ if (lbb == NULL) {
+ continue;
+ }
+
+ llvm::TerminatorInst* term_inst = lbb->getTerminator();
+ std::vector<std::pair<llvm::BasicBlock*, llvm::BasicBlock*> >& rewrite_pair
+ = landing_pad_phi_mapping_[lbb];
+ irb_.SetInsertPoint(lbb->begin());
+
+ // Iterate every succeeding basic block (catch block)
+ for (unsigned succ_iter = 0, succ_end = term_inst->getNumSuccessors();
+ succ_iter != succ_end; ++succ_iter) {
+ llvm::BasicBlock* succ_basic_block = term_inst->getSuccessor(succ_iter);
+
+ // Iterate every phi instructions in the succeeding basic block
+ for (llvm::BasicBlock::iterator
+ inst_iter = succ_basic_block->begin(),
+ inst_end = succ_basic_block->end();
+ inst_iter != inst_end; ++inst_iter) {
+ llvm::PHINode *phi = llvm::dyn_cast<llvm::PHINode>(inst_iter);
+
+ if (!phi) {
+ break; // Meet non-phi instruction. Done.
+ }
+
+ if (handler_phi[phi] == NULL) {
+ handler_phi[phi] = llvm::PHINode::Create(phi->getType(), 1);
+ }
+
+ // Create new_phi in landing pad
+ llvm::PHINode* new_phi = irb_.CreatePHI(phi->getType(), rewrite_pair.size());
+ // Insert all incoming value into new_phi by rewrite_pair
+ for (size_t j = 0, ej = rewrite_pair.size(); j != ej; ++j) {
+ llvm::BasicBlock* old_bb = rewrite_pair[j].first;
+ llvm::BasicBlock* new_bb = rewrite_pair[j].second;
+ new_phi->addIncoming(phi->getIncomingValueForBlock(old_bb), new_bb);
+ }
+ // Delete all incoming value from phi by rewrite_pair
+ for (size_t j = 0, ej = rewrite_pair.size(); j != ej; ++j) {
+ llvm::BasicBlock* old_bb = rewrite_pair[j].first;
+ int old_bb_idx = phi->getBasicBlockIndex(old_bb);
+ if (old_bb_idx >= 0) {
+ phi->removeIncomingValue(old_bb_idx, false);
+ }
+ }
+ // Insert new_phi into new handler phi
+ handler_phi[phi]->addIncoming(new_phi, lbb);
+ }
+ }
+ }
+
+ // Replace all handler phi
+ // We can't just use the old handler phi, because some exception edges will disappear after we
+ // compute fast-path.
+ for (HandlerPHIMap::iterator it = handler_phi.begin(); it != handler_phi.end(); ++it) {
+ llvm::PHINode* old_phi = it->first;
+ llvm::PHINode* new_phi = it->second;
+ new_phi->insertBefore(old_phi);
+ old_phi->replaceAllUsesWith(new_phi);
+ old_phi->eraseFromParent();
+ }
}
void GBCExpanderPass::UpdatePhiInstruction(llvm::BasicBlock* old_basic_block,
@@ -2522,6 +2598,8 @@
void GBCExpanderPass::EmitBranchExceptionLandingPad(uint32_t dex_pc) {
if (llvm::BasicBlock* lpad = GetLandingPadBasicBlock(dex_pc)) {
+ landing_pad_phi_mapping_[lpad].push_back(std::make_pair(old_basic_block_,
+ irb_.GetInsertBlock()));
irb_.CreateBr(lpad);
} else {
irb_.CreateBr(GetUnwindBasicBlock());
@@ -2534,6 +2612,8 @@
llvm::BasicBlock* block_cont = CreateBasicBlockWithDexPC(dex_pc, "cont");
if (llvm::BasicBlock* lpad = GetLandingPadBasicBlock(dex_pc)) {
+ landing_pad_phi_mapping_[lpad].push_back(std::make_pair(old_basic_block_,
+ irb_.GetInsertBlock()));
irb_.CreateCondBr(exception_pending, lpad, block_cont, kUnlikely);
} else {
irb_.CreateCondBr(exception_pending, GetUnwindBasicBlock(), block_cont, kUnlikely);
