reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 3b305ae..3611b8e 100644
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -744,7 +744,7 @@
   const Type *ArgTys[3] = { M->getRawDest()->getType(),
                             M->getRawSource()->getType(),
                             M->getLength()->getType() };
-  M->setOperand(0,Intrinsic::getDeclaration(Mod, Intrinsic::memcpy, ArgTys, 3));
+  M->setCalledFunction(Intrinsic::getDeclaration(Mod, Intrinsic::memcpy, ArgTys, 3));
 
   // MemDep may have over conservative information about this instruction, just
   // conservatively flush it from the cache.