Early CFG simplification can fold conditionals down to selects, which is often a good thing, but it can also

hide jump threading opportunities by turning control flow into data flow.  Run an early JumpThreading pass
(adds approximately an additional 1% to optimization time on SPEC), allowing it to get a shot at these cases
first.  Fixes <rdar://problem/8447345>.

llvm-svn: 115099

llvm/include/llvm/Support/StandardPasses.h

@@ -104,6 +104,7 @@ namespace llvm {
       PM->add(createDeadArgEliminationPass());  // Dead argument elimination
     }
     PM->add(createInstructionCombiningPass());  // Clean up after IPCP & DAE
+    PM->add(createJumpThreadingPass());         // Clean up after IPCP & DAE
     PM->add(createCFGSimplificationPass());     // Clean up after IPCP & DAE
     
     // Start of CallGraph SCC passes.