Move ReplaceUsesOfBlockWith() out of BranchFolding into a MachineBasicBlock general facility.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37408 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 44f7f90..af36764 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -198,3 +198,30 @@
std::find(Successors.begin(), Successors.end(), MBB);
return I != Successors.end();
}
+
+/// ReplaceUsesOfBlockWith - Given a machine basic block that branched to
+/// 'Old', change the code and CFG so that it branches to 'New' instead.
+void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old,
+ MachineBasicBlock *New) {
+ assert(Old != New && "Cannot replace self with self!");
+
+ MachineBasicBlock::iterator I = end();
+ while (I != begin()) {
+ --I;
+ if (!(I->getInstrDescriptor()->Flags & M_TERMINATOR_FLAG)) break;
+
+ // Scan the operands of this machine instruction, replacing any uses of Old
+ // with New.
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
+ if (I->getOperand(i).isMachineBasicBlock() &&
+ I->getOperand(i).getMachineBasicBlock() == Old)
+ I->getOperand(i).setMachineBasicBlock(New);
+ }
+
+ // Update the successor information. If New was already a successor, just
+ // remove the link to Old instead of creating another one. PR 1444.
+ removeSuccessor(Old);
+ if (!isSuccessor(New))
+ addSuccessor(New);
+}
+