Offline CR fixes

Author: Cellule

lib/Backend/IR.cpp

@@ -2697,8 +2697,8 @@ Instr::GetNextBranchOrLabel() const
 IR::Instr *
 Instr::GetNextByteCodeInstr() const
 {
-    uint32 currentOffset = GetByteCodeOffset();
     IR::Instr * nextInstr = GetNextRealInstrOrLabel();
+    uint32 currentOffset = GetByteCodeOffset();
     const auto getNext = [](IR::Instr* nextInstr) -> IR::Instr*
     {
         if (nextInstr->IsBranchInstr())
@@ -2712,28 +2712,27 @@ Instr::GetNextByteCodeInstr() const
         }
         return nextInstr->GetNextRealInstrOrLabel();
     };
-    if (currentOffset == Js::Constants::NoByteCodeOffset)
+    while (nextInstr->GetByteCodeOffset() == Js::Constants::NoByteCodeOffset ||
+        nextInstr->GetByteCodeOffset() == currentOffset)
     {
-        while (nextInstr->GetByteCodeOffset() == Js::Constants::NoByteCodeOffset)
-        {
-            nextInstr = getNext(nextInstr);
-        }
-        AssertMsg(nextInstr->GetByteCodeOffset() == 0, "Only instrs before the first one are allowed to not have a bytecode offset");
+        nextInstr = getNext(nextInstr);
     }
-    else
+
+    // Do not check if the instr trying to bailout is in the function prologue
+    // nextInstr->GetByteCodeOffset() < currentOffset would always be true and we would crash
+    if (currentOffset != Js::Constants::NoByteCodeOffset)
     {
-        while (nextInstr->GetByteCodeOffset() == Js::Constants::NoByteCodeOffset ||
-            nextInstr->GetByteCodeOffset() == currentOffset)
-        {
-            nextInstr = getNext(nextInstr);
-        }
         // This can happen due to break block removal
         while (nextInstr->GetByteCodeOffset() == Js::Constants::NoByteCodeOffset ||
             nextInstr->GetByteCodeOffset() < currentOffset)
         {
             nextInstr = getNext(nextInstr);
         }
     }
+    else
+    {
+        AssertMsg(nextInstr->GetByteCodeOffset() == 0, "Only instrs before the first one are allowed to not have a bytecode offset");
+    }
     return nextInstr;
 }