Add assert to avoid unexpected situation

In line 68, func getBlockFreqRelativeToEntryBlock assume getEntryFreq() is
non-zero, but the function could return 0, add assert to confirm it.

Reviewed By: HaohaiWen

Differential Revision: https://reviews.llvm.org/D148606

diff --git a/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h b/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
index 2290d26..6d58c7a 100644 (file)
--- a/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
@@ -66,6 +66,7 @@ public:
   /// Compute the frequency of the block, relative to the entry block.
   /// This API assumes getEntryFreq() is non-zero.
   float getBlockFreqRelativeToEntryBlock(const MachineBasicBlock *MBB) const {
+    assert(getEntryFreq() != 0 && "getEntryFreq() should not return 0 here!");
     return getBlockFreq(MBB).getFrequency() * (1.0f / getEntryFreq());
   }