/// compile_right - Emit code for '>'
void BrainFTraceRecorder::compile_right(BrainFTraceNode *node,
IRBuilder<>& builder) {
Value *OldPtr = DataPtr;
DataPtr = builder.CreateConstInBoundsGEP1_32(DataPtr, 1);
if (node->left != (BrainFTraceNode*)~0ULL)
compile_opcode(node->left, builder);
else {
HeaderPHI->addIncoming(DataPtr, builder.GetInsertBlock());
builder.CreateBr(Header);
}
DataPtr = OldPtr;
}
/// compile_if - Emit code for '['
void BrainFTraceRecorder::compile_if(BrainFTraceNode *node,
IRBuilder<>& builder) {
BasicBlock *ZeroChild = 0;
BasicBlock *NonZeroChild = 0;
BasicBlock *Parent = builder.GetInsertBlock();
LLVMContext &Context = Header->getContext();
// If both directions of the branch go back to the trace-head, just
// jump there directly.
if (node->left == (BrainFTraceNode*)~0ULL &&
node->right == (BrainFTraceNode*)~0ULL) {
HeaderPHI->addIncoming(DataPtr, builder.GetInsertBlock());
builder.CreateBr(Header);
return;
}
// Otherwise, there are two cases to handle for each direction:
// ~0ULL - A branch back to the trace head
// 0 - A branch out of the trace
// * - A branch to a node we haven't compiled yet.
// Go ahead and generate code for both targets.
if (node->left == (BrainFTraceNode*)~0ULL) {
NonZeroChild = Header;
HeaderPHI->addIncoming(DataPtr, Parent);
} else if (node->left == 0) {
NonZeroChild = BasicBlock::Create(Context,
"exit_left_"+utostr(node->pc),
Header->getParent());
builder.SetInsertPoint(NonZeroChild);
// Set the extension leaf, which is a pointer to the leaf of the trace
// tree from which we are side exiting.
ConstantInt *ExtLeaf = ConstantInt::get(int_type, (intptr_t)node);
builder.CreateStore(ExtLeaf, ext_leaf);
ConstantInt *NewPc = ConstantInt::get(int_type, node->pc+1);
Value *BytecodeIndex =
builder.CreateConstInBoundsGEP1_32(bytecode_array, node->pc+1);
Value *Target = builder.CreateLoad(BytecodeIndex);
CallInst *Call =cast<CallInst>(builder.CreateCall2(Target, NewPc, DataPtr));
Call->setTailCall();
builder.CreateRetVoid();
} else {
NonZeroChild = BasicBlock::Create(Context,
utostr(node->left->pc),
Header->getParent());
builder.SetInsertPoint(NonZeroChild);
compile_opcode(node->left, builder);
}
if (node->right == (BrainFTraceNode*)~0ULL) {
ZeroChild = Header;
HeaderPHI->addIncoming(DataPtr, Parent);
} else if (node->right == 0) {
ZeroChild = BasicBlock::Create(Context,
"exit_right_"+utostr(node->pc),
Header->getParent());
builder.SetInsertPoint(ZeroChild);
// Set the extension leaf, which is a pointer to the leaf of the trace
// tree from which we are side exiting.
ConstantInt *ExtLeaf = ConstantInt::get(int_type, (intptr_t)node);
builder.CreateStore(ExtLeaf, ext_leaf);
ConstantInt *NewPc = ConstantInt::get(int_type, JumpMap[node->pc]+1);
Value *BytecodeIndex =
builder.CreateConstInBoundsGEP1_32(bytecode_array, JumpMap[node->pc]+1);
Value *Target = builder.CreateLoad(BytecodeIndex);
CallInst *Call =cast<CallInst>(builder.CreateCall2(Target, NewPc, DataPtr));
Call->setTailCall();
builder.CreateRetVoid();
} else {
ZeroChild = BasicBlock::Create(Context,
utostr(node->right->pc),
Header->getParent());
builder.SetInsertPoint(ZeroChild);
compile_opcode(node->right, builder);
}
// Generate the test and branch to select between the targets.
builder.SetInsertPoint(Parent);
Value *Loaded = builder.CreateLoad(DataPtr);
Value *Cmp = builder.CreateICmpEQ(Loaded,
ConstantInt::get(Loaded->getType(), 0));
builder.CreateCondBr(Cmp, ZeroChild, NonZeroChild);
}