finish report!

Reports/.gitignore

@@ -2,3 +2,4 @@
 2-ir-gen-warmup/*.pdf
 3-ir-gen/*.pdf
 4.1-ssa/*.pdf
+4.2-gvn/*.pdf

src/optimization/GVN.cpp

@@ -634,7 +634,7 @@ GVN::transferFunction(Instruction *instr, Value *e, partitions pin) {
     // auto e_global = dynamic_cast<GlobalVariable *>(e);
     auto e_argument = dynamic_cast<Argument *>(e);
     assert((not e or e_instr or e_const or e_argument) &&
-           "A value must be from an instruction or constant");
+           "A value must be from instruction, constant or argument");
     // erase the old record for x
     std::set<Value *>::iterator it;
     for (auto c : pout)