Provide a function that ensures MBB numbering is dense and inorder. This
can be used by MachineFunctionPasses who need this property.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30706 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 4a31ee5..21f41b9 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -132,6 +132,53 @@
delete[] UsedPhysRegs;
}
+
+/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
+/// recomputes them. This guarantees that the MBB numbers are sequential,
+/// dense, and match the ordering of the blocks within the function. If a
+/// specific MachineBasicBlock is specified, only that block and those after
+/// it are renumbered.
+void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
+ if (empty()) { MBBNumbering.clear(); return; }
+ MachineFunction::iterator MBBI, E = end();
+ if (MBB == 0)
+ MBBI = begin();
+ else
+ MBBI = MBB;
+
+ // Figure out the block number this should have.
+ unsigned BlockNo = 0;
+ if (MBB != &front()) {
+ MachineFunction::iterator I = MBB;
+ --I;
+ BlockNo = I->getNumber()+1;
+ }
+
+ for (; MBBI != E; ++MBBI, ++BlockNo) {
+ if (MBBI->getNumber() != (int)BlockNo) {
+ // Remove use of the old number.
+ if (MBBI->getNumber() != -1) {
+ assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
+ "MBB number mismatch!");
+ MBBNumbering[MBBI->getNumber()] = 0;
+ }
+
+ // If BlockNo is already taken, set that block's number to -1.
+ if (MBBNumbering[BlockNo])
+ MBBNumbering[BlockNo]->setNumber(-1);
+
+ MBBNumbering[BlockNo] = MBBI;
+ MBBI->setNumber(BlockNo);
+ }
+ }
+
+ // Okay, all the blocks are renumbered. If we have compactified the block
+ // numbering, shrink MBBNumbering now.
+ assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
+ MBBNumbering.resize(BlockNo);
+}
+
+
void MachineFunction::dump() const { print(std::cerr); }
void MachineFunction::print(std::ostream &OS) const {