[sledge] Factor out computation of number of actuals for Call and Invoke

Summary:
The code that computes the number of actuals is largely duplicated
between the Call and Invoke cases. But some issues have been fixed in
each that ought to be applied to the other. This factors out and
unifies this computation.

Reviewed By: jvillard

Differential Revision: D25146149

fbshipit-source-id: 78552327a

sledge/cli/frontend.ml

@@ -945,7 +945,25 @@ let norm_callee llfunc =
     | _ -> todo "callee kind %a" pp_llvalue llfunc () )
   | _ -> todo "callee kind %a" pp_llvalue llfunc ()
 
-let xlate_intrinsic_inst emit_inst x llname instr loc =
+let num_actuals instr lltyp llfunc =
+  assert (Poly.(Llvm.classify_type lltyp = Pointer)) ;
+  if not (Llvm.is_var_arg (Llvm.element_type lltyp)) then
+    Llvm.num_arg_operands instr
+  else
+    let fname = Llvm.value_name llfunc in
+    if StringS.add ignored_callees fname && not (Llvm.is_declaration llfunc)
+    then
+      warn "ignoring variable arguments to variadic function: %a" pp_llvalue
+        llfunc () ;
+    let llelt = Llvm.element_type lltyp in
+    ( match Llvm.classify_type llelt with
+    | Function -> ()
+    | _ ->
+        fail "called function not of function type: %a" pp_llvalue instr ()
+    ) ;
+    Array.length (Llvm.param_types llelt)
+
+let xlate_intrinsic_inst emit_inst x llname instr num_actuals loc =
   let emit_inst ?prefix inst = Some (emit_inst ?prefix inst) in
   match String.split_on_char llname ~by:'.' with
   | ["__llair_choice"] ->
@@ -1002,13 +1020,12 @@ let xlate_intrinsic_inst emit_inst x llname instr loc =
     match Intrinsic.of_name fname with
     | Some name ->
         let reg = xlate_name_opt x instr in
-        let num_args = Llvm.num_operands instr - 2 in
         let xlate_arg i pre =
           let pre_i, arg_i = xlate_value x (Llvm.operand instr i) in
           (arg_i, pre_i @ pre)
         in
         let prefix, args =
-          Iter.fold_map ~f:xlate_arg Iter.(0 -- num_args) []
+          Iter.fold_map ~f:xlate_arg Iter.(0 -- (num_actuals - 1)) []
         in
         let args = IArray.of_iter args in
         emit_inst ~prefix (Inst.intrinsic ~reg ~name ~args ~loc)
@@ -1073,8 +1090,8 @@ let xlate_instr :
   | Call -> (
       let llcallee = Llvm.operand instr (Llvm.num_operands instr - 1) in
       let lltyp = Llvm.type_of llcallee in
-      assert (Poly.(Llvm.classify_type lltyp = Pointer)) ;
       let llfunc = norm_callee llcallee in
+      let num_actuals = num_actuals instr lltyp llfunc in
       let fname = Llvm.value_name llfunc in
       let skip msg =
         if StringS.add ignored_callees fname then
@@ -1086,7 +1103,9 @@ let xlate_instr :
       match xlate_intrinsic_exp fname with
       | Some intrinsic -> inline_or_move (intrinsic x)
       | None -> (
-        match xlate_intrinsic_inst emit_inst x fname instr loc with
+        match
+          xlate_intrinsic_inst emit_inst x fname instr num_actuals loc
+        with
         | Some code -> code
         | None -> (
           match String.split_on_char fname ~by:'.' with
@@ -1117,27 +1136,6 @@ let xlate_instr :
               let lbl = name ^ ".ret" in
               let pre, call =
                 let pre, actuals =
-                  let num_actuals =
-                    if not (Llvm.is_var_arg (Llvm.element_type lltyp)) then
-                      Llvm.num_arg_operands instr
-                    else
-                      let fname = Llvm.value_name llfunc in
-                      if
-                        StringS.add ignored_callees fname
-                        && not (Llvm.is_declaration llfunc)
-                      then
-                        warn
-                          "ignoring variable arguments to variadic \
-                           function: %a"
-                          Exp.pp callee () ;
-                      let llfty = Llvm.element_type lltyp in
-                      ( match Llvm.classify_type llfty with
-                      | Function -> ()
-                      | _ ->
-                          fail "called function not of function type: %a"
-                            pp_llvalue instr () ) ;
-                      Array.length (Llvm.param_types llfty)
-                  in
                   xlate_values x num_actuals (Llvm.operand instr)
                 in
                 let areturn = xlate_name_opt x instr in
@@ -1150,25 +1148,13 @@ let xlate_instr :
                   let cmnd = IArray.of_list insts in
                   (pre0 @ pre, call, [Block.mk ~lbl ~cmnd ~term]) ) ) ) )
   | Invoke -> (
-      let llfunc = Llvm.operand instr (Llvm.num_operands instr - 3) in
+      let llcallee = Llvm.operand instr (Llvm.num_operands instr - 3) in
-      let lltyp = Llvm.type_of llfunc in
+      let lltyp = Llvm.type_of llcallee in
-      assert (Poly.(Llvm.classify_type lltyp = Pointer)) ;
+      let llfunc = norm_callee llcallee in
+      let num_actuals = num_actuals instr lltyp llfunc in
       let fname = Llvm.value_name llfunc in
       let return_blk = Llvm.get_normal_dest instr in
       let unwind_blk = Llvm.get_unwind_dest instr in
-      let num_actuals =
-        if not (Llvm.is_var_arg (Llvm.element_type lltyp)) then
-          Llvm.num_arg_operands instr
-        else (
-          if
-            StringS.add ignored_callees fname
-            && not (Llvm.is_declaration llfunc)
-          then
-            warn "ignoring variable arguments to variadic function: %a"
-              Global.pp (xlate_global x llfunc).name () ;
-          assert (Poly.(Llvm.classify_type lltyp = Pointer)) ;
-          Array.length (Llvm.param_types (Llvm.element_type lltyp)) )
-      in
       (* intrinsics *)
       match String.split_on_char fname ~by:'.' with
       | _ when Option.is_some (xlate_intrinsic_exp fname) ->
@@ -1197,7 +1183,7 @@ let xlate_instr :
       (* general function call that may throw *)
       | _ ->
           let pre_0, callee = xlate_value x llfunc in
-          let typ = xlate_type x (Llvm.type_of llfunc) in
+          let typ = xlate_type x lltyp in
           let pre_1, actuals =
             xlate_values x num_actuals (Llvm.operand instr)
           in