fix PR4767, a crash because fp stackifier visited blocks in
depth first order, so it wouldn't process unreachable blocks.
When compiling at -O0, late dead block elimination isn't done
and the bad instructions got to isel.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81187 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp
index af0da6f..d9a05a8 100644
--- a/lib/Target/X86/X86FloatingPoint.cpp
+++ b/lib/Target/X86/X86FloatingPoint.cpp
@@ -213,6 +213,14 @@
        I != E; ++I)
     Changed |= processBasicBlock(MF, **I);
 
+  // Process any unreachable blocks in arbitrary order now.
+  if (MF.size() == Processed.size())
+    return Changed;
+
+  for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
+    if (Processed.insert(BB))
+      Changed |= processBasicBlock(MF, *BB);
+  
   return Changed;
 }