Have InstCombine call SipmlifyCall when handling calls. Test case included.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174675 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstCombineCalls.cpp

@@ -13,6 +13,7 @@
 
 #include "InstCombine.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/Support/CallSite.h"
@@ -210,6 +211,11 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
     return &CI;
   }
 
+  CallSite CS(&CI);
+  if (Value *V = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(),
+                              TD))
+    return ReplaceInstUsesWith(CI, V);
+
   IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
   if (!II) return visitCallSite(&CI);