[BranchRelaxation] Strengthen post condition assertions

The whole point of this pass is to rewrite branches so that branches are in bounds. We should assert that we succeeded rather than just that we kept our internal data structure in sync.

Differential Revision: https://reviews.llvm.org/D142778

diff --git a/llvm/lib/CodeGen/BranchRelaxation.cpp b/llvm/lib/CodeGen/BranchRelaxation.cpp
index 016c81d..45c09a1 100644 (file)
--- a/llvm/lib/CodeGen/BranchRelaxation.cpp
+++ b/llvm/lib/CodeGen/BranchRelaxation.cpp
@@ -132,6 +132,19 @@ void BranchRelaxation::verify() {
     assert(BlockInfo[Num].Size == computeBlockSize(MBB));
     PrevNum = Num;
   }
+
+  for (MachineBasicBlock &MBB : *MF) {
+    for (MachineBasicBlock::iterator J = MBB.getFirstTerminator();
+         J != MBB.end(); J = std::next(J)) {
+      MachineInstr &MI = *J;
+      if (!MI.isConditionalBranch() && !MI.isUnconditionalBranch())
+        continue;
+      if (MI.getOpcode() == TargetOpcode::FAULTING_OP)
+        continue;
+      MachineBasicBlock *DestBB = TII->getBranchDestBlock(MI);
+      assert(isBlockInRange(MI, *DestBB));
+    }
+  }
 #endif
 }