diff --git a/ptx/src/ast.rs b/ptx/src/ast.rs
index 3ad61e5..a0bb023 100644
--- a/ptx/src/ast.rs
+++ b/ptx/src/ast.rs
@@ -96,6 +96,7 @@ pub struct MethodDeclaration<'input, ID> {
     pub return_arguments: Vec<Variable<ID>>,
     pub name: MethodName<'input, ID>,
     pub input_arguments: Vec<Variable<ID>>,
+    pub shared_mem: Option<Variable<ID>>,
 }
 
 pub struct Function<'a, ID, S> {
diff --git a/ptx/src/ptx.lalrpop b/ptx/src/ptx.lalrpop
index 2253f85..e8370cd 100644
--- a/ptx/src/ptx.lalrpop
+++ b/ptx/src/ptx.lalrpop
@@ -392,12 +392,12 @@ MethodDeclaration: ast::MethodDeclaration<'input, &'input str> = {
     ".entry" <name:ExtendedID> <input_arguments:KernelArguments> => {
         let return_arguments = Vec::new();
         let name = ast::MethodName::Kernel(name);
-        ast::MethodDeclaration{ return_arguments, name, input_arguments }
+        ast::MethodDeclaration{ return_arguments, name, input_arguments, shared_mem: None }
     },
     ".func" <return_arguments:FnArguments?> <name:ExtendedID> <input_arguments:FnArguments> => {
         let return_arguments = return_arguments.unwrap_or_else(|| Vec::new());
         let name = ast::MethodName::Func(name);
-        ast::MethodDeclaration{ return_arguments, name, input_arguments }
+        ast::MethodDeclaration{ return_arguments, name, input_arguments, shared_mem: None }
     }
 };
 
diff --git a/ptx/src/translate.rs b/ptx/src/translate.rs
index 90a28b7..6d5d5bc 100644
--- a/ptx/src/translate.rs
+++ b/ptx/src/translate.rs
@@ -562,7 +562,6 @@ fn emit_directives<'input>(
                     call_map,
                     &directives,
                     kernel_info,
-                    f.uses_shared_mem,
                 )?;
                 for t in f.tuning.iter() {
                     match *t {
@@ -1038,10 +1037,9 @@ fn emit_function_header<'a>(
     call_map: &HashMap<&'a str, HashSet<spirv::Word>>,
     direcitves: &[Directive],
     kernel_info: &mut HashMap<String, KernelInfo>,
-    uses_shared_mem: bool,
 ) -> Result<spirv::Word, TranslateError> {
     if let ast::MethodName::Kernel(name) = func_decl.name {
-        let input_args = if !uses_shared_mem {
+        let input_args = if func_decl.shared_mem.is_none() {
             func_decl.input_arguments.as_slice()
         } else {
             &func_decl.input_arguments[0..func_decl.input_arguments.len() - 1]
@@ -1054,7 +1052,7 @@ fn emit_function_header<'a>(
             name.to_string(),
             KernelInfo {
                 arguments_sizes: args_lens,
-                uses_shared_mem: uses_shared_mem,
+                uses_shared_mem: func_decl.shared_mem.is_some(),
             },
         );
     }
@@ -1218,7 +1216,7 @@ fn rename_fn_params<'a, 'b>(
 ) -> Vec<ast::Variable<spirv::Word>> {
     args.iter()
         .map(|a| ast::Variable {
-            name: fn_resolver.add_def(a.name, Some((a.v_type.clone(), a.state_space)), false),
+            name: fn_resolver.add_def(a.name, Some((a.v_type.clone(), a.state_space)), true),
             v_type: a.v_type.clone(),
             state_space: a.state_space,
             align: a.align,
@@ -1245,7 +1243,6 @@ fn to_ssa<'input, 'b>(
                 globals: Vec::new(),
                 import_as: None,
                 tuning,
-                uses_shared_mem: false,
             })
         }
     };
@@ -1276,7 +1273,6 @@ fn to_ssa<'input, 'b>(
         body: Some(f_body),
         import_as: None,
         tuning,
-        uses_shared_mem: false,
     })
 }
 
@@ -1529,18 +1525,8 @@ fn convert_to_typed_statements(
         match s {
             Statement::Instruction(inst) => match inst {
                 ast::Instruction::Call(call) => {
-                    // TODO: error out if lengths don't match
-                    let fn_def = (**fn_defs.get_fn_decl(call.func)?).borrow();
-                    let return_arguments =
-                        to_resolved_fn_args(call.ret_params, &*fn_def.return_arguments);
-                    let input_arguments =
-                        to_resolved_fn_args(call.param_list, &*fn_def.input_arguments);
-                    let resolved_call = ResolvedCall {
-                        uniform: call.uniform,
-                        return_arguments,
-                        name: call.func,
-                        input_arguments,
-                    };
+                    let resolver = fn_defs.get_fn_sig_resolver(call.func)?;
+                    let resolved_call = resolver.resolve_in_spirv_repr(call)?;
                     let mut visitor = VectorRepackVisitor::new(&mut result, id_defs);
                     let reresolved_call = resolved_call.visit(&mut visitor)?;
                     visitor.func.push(reresolved_call);
@@ -1683,6 +1669,7 @@ fn to_ptx_impl_atomic_call(
                         array_init: Vec::new(),
                     },
                 ],
+                shared_mem: None,
             };
             let func = Function {
                 func_decl: Rc::new(RefCell::new(func_decl)),
@@ -1690,7 +1677,6 @@ fn to_ptx_impl_atomic_call(
                 body: None,
                 import_as: Some(entry.key().clone()),
                 tuning: Vec::new(),
-                uses_shared_mem: false,
             };
             entry.insert(Directive::Method(func));
             fn_id
@@ -1772,6 +1758,7 @@ fn to_ptx_impl_bfe_call(
                         array_init: Vec::new(),
                     },
                 ],
+                shared_mem: None,
             };
             let func = Function {
                 func_decl: Rc::new(RefCell::new(func_decl)),
@@ -1779,7 +1766,6 @@ fn to_ptx_impl_bfe_call(
                 body: None,
                 import_as: Some(entry.key().clone()),
                 tuning: Vec::new(),
-                uses_shared_mem: false,
             };
             entry.insert(Directive::Method(func));
             fn_id
@@ -1871,6 +1857,7 @@ fn to_ptx_impl_bfi_call(
                         array_init: Vec::new(),
                     },
                 ],
+                shared_mem: None,
             };
             let func = Function {
                 func_decl: Rc::new(RefCell::new(func_decl)),
@@ -1878,7 +1865,6 @@ fn to_ptx_impl_bfi_call(
                 body: None,
                 import_as: Some(entry.key().clone()),
                 tuning: Vec::new(),
-                uses_shared_mem: false,
             };
             entry.insert(Directive::Method(func));
             fn_id
@@ -2009,42 +1995,44 @@ fn normalize_predicates(
     Ok(result)
 }
 
+/*
+    How do we handle arguments:
+    - input .params
+        .param .b64 in_arg
+      get turned into this SPIR-V:
+        %1 = OpFunctionParameter %ulong
+        %2 = OpVariable %%_ptr_Function_ulong Function
+             OpStore %2 %1
+      We do this for two reasons. One, common treatment for argument-declared
+      .param variables and .param variables inside function (we assume that
+      at SPIR-V level every .param is a pointer in Function storage class). Two,
+      PTX devs in their infinite wisdom decided that .reg arguments are writable
+    - input .regs
+        .reg .b64 in_arg
+      get turned into this SPIR-V:
+        %1 = OpFunctionParameter %ulong
+        %2 = OpVariable %%_ptr_Function_ulong Function
+             OpStore %2 %1
+      with the difference that %2 is defined as a variable and not temp
+    - output .regs
+        .reg .b64 out_arg
+      get just a variable declaration:
+        %2 = OpVariable %%_ptr_Function_ulong Function
+    - output .params
+        .param .b64 out_arg
+      get treated the same as input .params, because there's no difference
+*/
 fn insert_mem_ssa_statements<'a, 'b>(
     func: Vec<TypedStatement>,
     id_def: &mut NumericIdResolver,
     fn_decl: &'a mut ast::MethodDeclaration<'b, spirv::Word>,
 ) -> Result<Vec<TypedStatement>, TranslateError> {
     let mut result = Vec::with_capacity(func.len());
-    for arg in fn_decl.return_arguments.iter() {
-        result.push(Statement::Variable(ast::Variable {
-            align: arg.align,
-            v_type: arg.v_type.clone(),
-            state_space: arg.state_space,
-            name: arg.name,
-            array_init: arg.array_init.clone(),
-        }));
-    }
     for arg in fn_decl.input_arguments.iter_mut() {
-        let typ = arg.v_type.clone();
-        let state_space = arg.state_space;
-        let new_id = id_def.register_intermediate(Some((typ.clone(), state_space)));
-        result.push(Statement::Variable(ast::Variable {
-            align: arg.align,
-            v_type: arg.v_type.clone(),
-            state_space: arg.state_space,
-            name: arg.name,
-            array_init: Vec::new(),
-        }));
-        result.push(Statement::StoreVar(StoreVarDetails {
-            arg: ast::Arg2St {
-                src1: arg.name,
-                src2: new_id,
-            },
-            state_space,
-            typ,
-            member_index: None,
-        }));
-        arg.name = new_id;
+        insert_mem_ssa_argument(id_def, &mut result, arg);
+    }
+    for arg in fn_decl.return_arguments.iter() {
+        insert_mem_ssa_argument_reg_return(&mut result, arg);
     }
     for s in func {
         match s {
@@ -2054,22 +2042,26 @@ fn insert_mem_ssa_statements<'a, 'b>(
             Statement::Instruction(inst) => match inst {
                 ast::Instruction::Ret(d) => {
                     // TODO: handle multiple output args
-                    if let &[out_param] = &fn_decl.return_arguments.as_slice() {
-                        let (typ, space, _) = id_def.get_typed(out_param.name)?;
-                        let new_id = id_def.register_intermediate(Some((typ.clone(), space)));
-                        result.push(Statement::LoadVar(LoadVarDetails {
-                            arg: ast::Arg2 {
-                                dst: new_id,
-                                src: out_param.name,
-                            },
-                            // TODO: ret with stateful conversion
-                            state_space: new_todo!(),
-                            typ: typ.clone(),
-                            member_index: None,
-                        }));
-                        result.push(Statement::RetValue(d, new_id));
-                    } else {
-                        result.push(Statement::Instruction(ast::Instruction::Ret(d)))
+                    match &fn_decl.return_arguments[..] {
+                        [return_reg] => {
+                            let new_id = id_def.register_intermediate(Some((
+                                return_reg.v_type.clone(),
+                                ast::StateSpace::Reg,
+                            )));
+                            result.push(Statement::LoadVar(LoadVarDetails {
+                                arg: ast::Arg2 {
+                                    dst: new_id,
+                                    src: return_reg.name,
+                                },
+                                // TODO: ret with stateful conversion
+                                state_space: ast::StateSpace::Reg,
+                                typ: return_reg.v_type.clone(),
+                                member_index: None,
+                            }));
+                            result.push(Statement::RetValue(d, new_id));
+                        }
+                        [] => result.push(Statement::Instruction(ast::Instruction::Ret(d))),
+                        _ => unimplemented!(),
                     }
                 }
                 inst => insert_mem_ssa_statement_default(id_def, &mut result, inst)?,
@@ -2107,6 +2099,43 @@ fn insert_mem_ssa_statements<'a, 'b>(
     Ok(result)
 }
 
+fn insert_mem_ssa_argument(
+    id_def: &mut NumericIdResolver,
+    func: &mut Vec<TypedStatement>,
+    arg: &mut ast::Variable<spirv::Word>,
+) {
+    let new_id = id_def.register_intermediate(Some((arg.v_type.clone(), arg.state_space)));
+    func.push(Statement::Variable(ast::Variable {
+        align: arg.align,
+        v_type: arg.v_type.clone(),
+        state_space: ast::StateSpace::Reg,
+        name: arg.name,
+        array_init: Vec::new(),
+    }));
+    func.push(Statement::StoreVar(StoreVarDetails {
+        arg: ast::Arg2St {
+            src1: arg.name,
+            src2: new_id,
+        },
+        typ: arg.v_type.clone(),
+        member_index: None,
+    }));
+    arg.name = new_id;
+}
+
+fn insert_mem_ssa_argument_reg_return(
+    func: &mut Vec<TypedStatement>,
+    arg: &ast::Variable<spirv::Word>,
+) {
+    func.push(Statement::Variable(ast::Variable {
+        align: arg.align,
+        v_type: arg.v_type.clone(),
+        state_space: arg.state_space,
+        name: arg.name,
+        array_init: arg.array_init.clone(),
+    }));
+}
+
 trait Visitable<From: ArgParamsEx, To: ArgParamsEx>: Sized {
     fn visit(
         self,
@@ -2202,7 +2231,6 @@ impl<'a, 'input> InsertMemSSAVisitor<'a, 'input> {
                         src1: symbol,
                         src2: generated_id,
                     },
-                    state_space: ast::StateSpace::Reg,
                     typ: var_type,
                     member_index: member_index.map(|(idx, _)| idx),
                 }));
@@ -4162,10 +4190,10 @@ fn emit_load_var(
     Ok(())
 }
 
-fn normalize_identifiers<'a, 'b>(
-    id_defs: &mut FnStringIdResolver<'a, 'b>,
-    fn_defs: &GlobalFnDeclResolver<'a, 'b>,
-    func: Vec<ast::Statement<ast::ParsedArgParams<'a>>>,
+fn normalize_identifiers<'input, 'b>(
+    id_defs: &mut FnStringIdResolver<'input, 'b>,
+    fn_defs: &GlobalFnDeclResolver<'input, 'b>,
+    func: Vec<ast::Statement<ast::ParsedArgParams<'input>>>,
 ) -> Result<Vec<NormalizedStatement>, TranslateError> {
     for s in func.iter() {
         match s {
@@ -4796,12 +4824,92 @@ impl SpecialRegistersMap {
     }
 }
 
+struct FnSigMapper<'input> {
+    // true - stays as return argument
+    // false - is moved to input argument
+    return_param_args: Vec<bool>,
+    func_decl: Rc<RefCell<ast::MethodDeclaration<'input, spirv::Word>>>,
+}
+
+impl<'input> FnSigMapper<'input> {
+    fn remap_to_spirv_repr(mut method: ast::MethodDeclaration<'input, spirv::Word>) -> Self {
+        let return_param_args = method
+            .return_arguments
+            .iter()
+            .map(|a| a.state_space != ast::StateSpace::Param)
+            .collect::<Vec<_>>();
+        let mut new_return_arguments = Vec::new();
+        for arg in method.return_arguments.into_iter() {
+            if arg.state_space == ast::StateSpace::Param {
+                method.input_arguments.push(arg);
+            } else {
+                new_return_arguments.push(arg);
+            }
+        }
+        method.return_arguments = new_return_arguments;
+        FnSigMapper {
+            return_param_args,
+            func_decl: Rc::new(RefCell::new(method)),
+        }
+    }
+
+    fn resolve_in_spirv_repr(
+        &self,
+        call_inst: ast::CallInst<NormalizedArgParams>,
+    ) -> Result<ResolvedCall<NormalizedArgParams>, TranslateError> {
+        let func_decl = (*self.func_decl).borrow();
+        let mut return_arguments = Vec::new();
+        let mut input_arguments = call_inst
+            .param_list
+            .into_iter()
+            .zip(func_decl.input_arguments.iter())
+            .map(|(id, var)| (id, var.v_type.clone(), var.state_space))
+            .collect::<Vec<_>>();
+        let mut func_decl_return_iter = func_decl.return_arguments.iter();
+        let mut func_decl_input_iter = func_decl.input_arguments[input_arguments.len()..].iter();
+        for (idx, id) in call_inst.ret_params.iter().enumerate() {
+            let stays_as_return = match self.return_param_args.get(idx) {
+                Some(x) => *x,
+                None => return Err(TranslateError::MismatchedType),
+            };
+            if stays_as_return {
+                if let Some(var) = func_decl_return_iter.next() {
+                    return_arguments.push((*id, var.v_type.clone(), var.state_space));
+                } else {
+                    return Err(TranslateError::MismatchedType);
+                }
+            } else {
+                if let Some(var) = func_decl_input_iter.next() {
+                    input_arguments.push((
+                        ast::Operand::Reg(*id),
+                        var.v_type.clone(),
+                        var.state_space,
+                    ));
+                } else {
+                    return Err(TranslateError::MismatchedType);
+                }
+            }
+        }
+        if return_arguments.len() != func_decl.return_arguments.len()
+            || input_arguments.len() != func_decl.input_arguments.len()
+        {
+            return Err(TranslateError::MismatchedType);
+        }
+        Ok(ResolvedCall {
+            return_arguments,
+            input_arguments,
+            uniform: call_inst.uniform,
+            name: call_inst.func,
+        })
+    }
+}
+
 struct GlobalStringIdResolver<'input> {
     current_id: spirv::Word,
     variables: HashMap<Cow<'input, str>, spirv::Word>,
     variables_type_check: HashMap<u32, Option<(ast::Type, ast::StateSpace, bool)>>,
     special_registers: SpecialRegistersMap,
-    fns: HashMap<spirv::Word, Rc<RefCell<ast::MethodDeclaration<'input, spirv::Word>>>>,
+    fns: HashMap<spirv::Word, FnSigMapper<'input>>,
 }
 
 impl<'input> GlobalStringIdResolver<'input> {
@@ -4885,45 +4993,36 @@ impl<'input> GlobalStringIdResolver<'input> {
             ast::MethodName::Kernel(name) => ast::MethodName::Kernel(name),
             ast::MethodName::Func(_) => ast::MethodName::Func(name_id),
         };
-        let new_fn_decl = Rc::new(RefCell::new(ast::MethodDeclaration {
+        let fn_decl = ast::MethodDeclaration {
             return_arguments,
             name,
             input_arguments,
-        }));
-        self.fns.insert(name_id, Rc::clone(&new_fn_decl));
+            shared_mem: None,
+        };
+        let new_fn_decl = if !fn_decl.name.is_kernel() {
+            let resolver = FnSigMapper::remap_to_spirv_repr(fn_decl);
+            let new_fn_decl = resolver.func_decl.clone();
+            self.fns.insert(name_id, resolver);
+            new_fn_decl
+        } else {
+            Rc::new(RefCell::new(fn_decl))
+        };
         Ok((
             fn_resolver,
-            GlobalFnDeclResolver {
-                variables: &self.variables,
-                fns: &self.fns,
-            },
+            GlobalFnDeclResolver { fns: &self.fns },
             new_fn_decl,
         ))
     }
 }
 
 pub struct GlobalFnDeclResolver<'input, 'a> {
-    variables: &'a HashMap<Cow<'input, str>, spirv::Word>,
-    fns: &'a HashMap<spirv::Word, Rc<RefCell<ast::MethodDeclaration<'input, spirv::Word>>>>,
+    fns: &'a HashMap<spirv::Word, FnSigMapper<'input>>,
 }
 
 impl<'input, 'a> GlobalFnDeclResolver<'input, 'a> {
-    fn get_fn_decl(
-        &self,
-        id: spirv::Word,
-    ) -> Result<&Rc<RefCell<ast::MethodDeclaration<'input, spirv::Word>>>, TranslateError> {
+    fn get_fn_sig_resolver(&self, id: spirv::Word) -> Result<&FnSigMapper<'input>, TranslateError> {
         self.fns.get(&id).ok_or(TranslateError::UnknownSymbol)
     }
-
-    fn get_fn_decl_str(
-        &self,
-        id: &str,
-    ) -> Result<&'a Rc<RefCell<ast::MethodDeclaration<'input, spirv::Word>>>, TranslateError> {
-        match self.variables.get(id).map(|var_id| self.fns.get(var_id)) {
-            Some(Some(fn_d)) => Ok(fn_d),
-            _ => Err(TranslateError::UnknownSymbol),
-        }
-    }
 }
 
 struct FnStringIdResolver<'input, 'b> {
@@ -5209,7 +5308,6 @@ struct LoadVarDetails {
 struct StoreVarDetails {
     arg: ast::Arg2St<ExpandedArgParams>,
     typ: ast::Type,
-    state_space: ast::StateSpace,
     member_index: Option<u8>,
 }
 
@@ -5300,7 +5398,7 @@ impl<From: ArgParamsEx<Id = spirv::Word>> ResolvedCall<From> {
         self,
         visitor: &mut V,
     ) -> Result<ResolvedCall<To>, TranslateError> {
-        let ret_params = self
+        let return_arguments = self
             .return_arguments
             .into_iter()
             .map::<Result<_, TranslateError>, _>(|(id, typ, space)| {
@@ -5324,7 +5422,7 @@ impl<From: ArgParamsEx<Id = spirv::Word>> ResolvedCall<From> {
             },
             None,
         )?;
-        let param_list = self
+        let input_arguments = self
             .input_arguments
             .into_iter()
             .map::<Result<_, TranslateError>, _>(|(id, typ, space)| {
@@ -5342,9 +5440,9 @@ impl<From: ArgParamsEx<Id = spirv::Word>> ResolvedCall<From> {
             .collect::<Result<Vec<_>, _>>()?;
         Ok(ResolvedCall {
             uniform: self.uniform,
-            return_arguments: ret_params,
+            return_arguments,
             name: func,
-            input_arguments: param_list,
+            input_arguments,
         })
     }
 }
@@ -5485,7 +5583,6 @@ struct Function<'input> {
     pub func_decl: Rc<RefCell<ast::MethodDeclaration<'input, spirv::Word>>>,
     pub globals: Vec<ast::Variable<spirv::Word>>,
     pub body: Option<Vec<ExpandedStatement>>,
-    pub uses_shared_mem: bool,
     import_as: Option<String>,
     tuning: Vec<ast::TuningDirective>,
 }
@@ -7185,6 +7282,19 @@ fn default_implicit_conversion_space(
             },
             _ => Err(TranslateError::MismatchedType),
         }
+    } else if instruction_space.is_compatible(ast::StateSpace::Reg) {
+        match instruction_type {
+            ast::Type::Pointer(instruction_ptr_type, instruction_ptr_space)
+                if operand_space == *instruction_ptr_space =>
+            {
+                if operand_type != &ast::Type::Scalar(*instruction_ptr_type) {
+                    Ok(Some(ConversionKind::PtrToPtr))
+                } else {
+                    Ok(None)
+                }
+            }
+            _ => Err(TranslateError::MismatchedType),
+        }
     } else {
         Err(TranslateError::MismatchedType)
     }
@@ -7432,6 +7542,15 @@ impl<'a> ast::MethodDeclaration<'a, &'a str> {
     }
 }
 
+impl<'input, ID> ast::MethodName<'input, ID> {
+    fn is_kernel(&self) -> bool {
+        match self {
+            ast::MethodName::Kernel(..) => true,
+            ast::MethodName::Func(..) => false,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;