TargetInstrInfo: Change duplicate() to work on bundles.

Adds infrastructure to clone whole instruction bundles rather than just
single instructions. This fixes a bug where tail duplication would
unbundle instructions while cloning.

This should unbreak the "Clang Stage 1: cmake, RA, with expensive checks
enabled" build on greendragon. The bot broke with r311139 hitting this
pre-existing bug.

A proper testcase will come next.

llvm-svn: 311511

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
index 742b095d955..c4c0dff7bdf 100644
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -270,6 +270,26 @@ MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
              MachineInstr(*this, *Orig);
 }
 
+MachineInstr &MachineFunction::CloneMachineInstrBundle(MachineBasicBlock &MBB,
+    MachineBasicBlock::iterator InsertBefore, const MachineInstr &Orig) {
+  MachineInstr *FirstClone = nullptr;
+  MachineBasicBlock::const_instr_iterator I = Orig.getIterator();
+  for (;;) {
+    MachineInstr *Cloned = CloneMachineInstr(&*I);
+    MBB.insert(InsertBefore, Cloned);
+    if (FirstClone == nullptr) {
+      FirstClone = Cloned;
+    } else {
+      Cloned->bundleWithPred();
+    }
+
+    if (!I->isBundledWithSucc())
+      break;
+    ++I;
+  }
+  return *FirstClone;
+}
+
 /// Delete the given MachineInstr.
 ///
 /// This function also serves as the MachineInstr destructor - the real