Reapply r55191 and r55192.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55205 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 1462472..fb4de57 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -145,6 +145,8 @@
FastISel::SelectInstructions(BasicBlock::iterator Begin,
BasicBlock::iterator End,
DenseMap<const Value*, unsigned> &ValueMap,
+ std::map<const BasicBlock*,
+ MachineBasicBlock *> &MBBMap,
MachineBasicBlock *mbb) {
MBB = mbb;
BasicBlock::iterator I = Begin;
@@ -195,19 +197,24 @@
case Instruction::Br: {
BranchInst *BI = cast<BranchInst>(I);
- // For now, check for and handle just the most trivial case: an
- // unconditional fall-through branch.
if (BI->isUnconditional()) {
- MachineFunction::iterator NextMBB =
+ MachineFunction::iterator NextMBB =
next(MachineFunction::iterator(MBB));
- if (NextMBB != MF.end() &&
- NextMBB->getBasicBlock() == BI->getSuccessor(0)) {
- MBB->addSuccessor(NextMBB);
- break;
+ BasicBlock *LLVMSucc = BI->getSuccessor(0);
+ MachineBasicBlock *MSucc = MBBMap[LLVMSucc];
+
+ if (NextMBB != MF.end() && MSucc == NextMBB) {
+ // The unconditional fall-through case, which needs no instructions.
+ } else {
+ // The unconditional branch case.
+ TII.InsertBranch(*MBB, MSucc, NULL, SmallVector<MachineOperand, 0>());
}
+ MBB->addSuccessor(MSucc);
+ break;
}
- // Something more complicated. Halt "fast" selection and bail.
+ // Conditional branches are not handed yet.
+ // Halt "fast" selection and bail.
return I;
}