ISel: Fix FastISel of swifterror values

The code assumed that we process instructions in basic block order.  FastISel
processes instructions in reverse basic block order. We need to pre-assign
virtual registers before selecting otherwise we get def-use relationships wrong.

This only affects code with swifterror registers.

rdar://32659327

llvm-svn: 305484

1 files changed, 26 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 606b8952f3c..b736037d71d 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -523,3 +523,29 @@ void FunctionLoweringInfo::setCurrentSwiftErrorVReg(
     const MachineBasicBlock *MBB, const Value *Val, unsigned VReg) {
   SwiftErrorVRegDefMap[std::make_pair(MBB, Val)] = VReg;
 }
+
+std::pair<unsigned, bool>
+FunctionLoweringInfo::getOrCreateSwiftErrorVRegDefAt(const Instruction *I) {
+  auto Key = PointerIntPair<const Instruction *, 1, bool>(I, true);
+  auto It = SwiftErrorVRegDefUses.find(Key);
+  if (It == SwiftErrorVRegDefUses.end()) {
+    auto &DL = MF->getDataLayout();
+    const TargetRegisterClass *RC = TLI->getRegClassFor(TLI->getPointerTy(DL));
+    unsigned VReg =  MF->getRegInfo().createVirtualRegister(RC);
+    SwiftErrorVRegDefUses[Key] = VReg;
+    return std::make_pair(VReg, true);
+  }
+  return std::make_pair(It->second, false);
+}
+
+std::pair<unsigned, bool>
+FunctionLoweringInfo::getOrCreateSwiftErrorVRegUseAt(const Instruction *I, const MachineBasicBlock *MBB, const Value *Val) {
+  auto Key = PointerIntPair<const Instruction *, 1, bool>(I, false);
+  auto It = SwiftErrorVRegDefUses.find(Key);
+  if (It == SwiftErrorVRegDefUses.end()) {
+    unsigned VReg = getOrCreateSwiftErrorVReg(MBB, Val);
+    SwiftErrorVRegDefUses[Key] = VReg;
+    return std::make_pair(VReg, true);
+  }
+  return std::make_pair(It->second, false);
+}