[m-rev.] diff: support 64-bit integers in static ground terms with the MLDS backend

[Julien Fischer]

Support 64-bit integers in static ground terms with the MLDS backend.

compiler/ml_code_util.m:
     As above

compiler/mlds.m:
     Extend the type describing the different kinds of global variable
     holding constant immutable data to convert 64-bit integers.

Julien.

diff --git a/compiler/ml_code_util.m b/compiler/ml_code_util.m
index bfb9a60..9711547 100644
--- a/compiler/ml_code_util.m
+++ b/compiler/ml_code_util.m
@@ -1010,6 +1010,7 @@ ml_must_box_field_type(ModuleInfo, Type, Width) :-
      module_info_get_globals(ModuleInfo, Globals),
      globals.get_target(Globals, Target),
      globals.lookup_bool_option(Globals, unboxed_float, UnboxedFloat),
+    globals.lookup_bool_option(Globals, unboxed_int64s, UnboxedInt64s),
      (
          ( Target = target_c
          ; Target = target_csharp
@@ -1017,20 +1018,56 @@ ml_must_box_field_type(ModuleInfo, Type, Width) :-
          ),
          classify_type(ModuleInfo, Type) = Category,
          MustBox = ml_must_box_field_type_category(Category, UnboxedFloat,
-            Width)
+            UnboxedInt64s, Width)
      ;
          Target = target_java,
          MustBox = no
      ),
      MustBox = yes.

-:- func ml_must_box_field_type_category(type_ctor_category, bool, arg_width)
-    = bool.
+:- func ml_must_box_field_type_category(type_ctor_category, bool, bool,
+    arg_width) = bool.

-ml_must_box_field_type_category(CtorCat, UnboxedFloat, Width) = MustBox :-
+ml_must_box_field_type_category(CtorCat, UnboxedFloat, UnboxedInt64s,
+        Width) = MustBox :-
      (
-        ( CtorCat = ctor_cat_builtin(cat_builtin_int(_))
-        ; CtorCat = ctor_cat_builtin(cat_builtin_string)
+        CtorCat = ctor_cat_builtin(cat_builtin_int(IntType)),
+        (
+            ( IntType = int_type_int
+            ; IntType = int_type_uint
+            ; IntType = int_type_int8
+            ; IntType = int_type_uint8
+            ; IntType = int_type_int16
+            ; IntType = int_type_uint16
+            ; IntType = int_type_int32
+            ; IntType = int_type_uint32
+            ),
+            MustBox = no
+        ;
+            ( IntType = int_type_int64
+            ; IntType = int_type_uint64
+            ),
+            (
+                UnboxedInt64s = yes,
+                MustBox = no
+            ;
+                UnboxedInt64s = no,
+                (
+                    Width = full_word,
+                    MustBox=  yes
+                ;
+                    Width = double_word,
+                    unexpected($pred, "double word for 64-bit integer")
+                ;
+                    ( Width = partial_word_first(_)
+                    ; Width = partial_word_shifted(_, _)
+                    ),
+                    unexpected($pred, "partial word for 64-bit integer")
+                )
+            )
+        )
+    ;
+        ( CtorCat = ctor_cat_builtin(cat_builtin_string)
          ; CtorCat = ctor_cat_builtin_dummy
          ; CtorCat = ctor_cat_higher_order
          ; CtorCat = ctor_cat_tuple
@@ -1106,6 +1143,35 @@ ml_gen_box_const_rval(ModuleInfo, Context, MLDS_Type, DoubleWidth, Rval,
              % may be further cast to pointer types.
              BoxedRval = ml_unop(box(MLDS_Type), Rval)
          )
+    else if
+        MLDS_Type = mercury_type(builtin_type(builtin_type_int(IntType)), _, _),
+        ( IntType = int_type_int64, ConstVarKind = mgcv_int64
+        ; IntType = int_type_uint64, ConstVarKind = mgcv_uint64
+        ),
+        module_info_get_globals(ModuleInfo, Globals),
+        globals.get_target(Globals, Target),
+        Target = target_c
+    then
+        HaveUnboxedInt64s = ml_global_data_have_unboxed_int64s(!.GlobalData),
+        ( if
+            HaveUnboxedInt64s = do_not_have_unboxed_int64s,
+            DoubleWidth = no
+        then
+            % Generate a local static constant for this int64 / uint64.
+            module_info_get_name(ModuleInfo, ModuleName),
+            MLDS_ModuleName = mercury_module_name_to_mlds(ModuleName),
+            Initializer = init_obj(Rval),
+            ml_gen_static_scalar_const_addr(MLDS_ModuleName, ConstVarKind,
+                MLDS_Type, Initializer, Context, ConstAddrRval, !GlobalData),
+
+            % Return as the boxed rval the address of that constant,
+            % cast to mlds_generic_type.
+            BoxedRval = ml_unop(cast(mlds_generic_type), ConstAddrRval)
+        else
+            % This is not a real box, but a cast. The "box" is required as it
+            % may be further cast to pointer types.
+            BoxedRval = ml_unop(box(MLDS_Type), Rval)
+        )
      else
          BoxedRval = ml_unop(box(MLDS_Type), Rval)
      ).
@@ -1152,6 +1218,31 @@ ml_gen_box_or_unbox_rval(ModuleInfo, SourceType, DestType, BoxPolicy, VarRval,
              ArgRval = ml_unop(cast(MLDS_DestType),
                  ml_unop(box(MLDS_SourceType), VarRval))
          else if
+            % If converting to int64 / uint64, cast to mlds_generic_type and
+            % then unbox.
+            DestType = builtin_type(builtin_type_int(IntType)),
+            ( IntType = int_type_int64
+            ; IntType = int_type_uint64
+            ),
+            SourceType \= builtin_type(builtin_type_int(IntType))
+        then
+            MLDS_DestType = mercury_type_to_mlds_type(ModuleInfo, DestType),
+            ArgRval = ml_unop(unbox(MLDS_DestType),
+                ml_unop(cast(mlds_generic_type), VarRval))
+        else if
+            % If converting from int64 / uint64, box then cast the result.
+            SourceType = builtin_type(builtin_type_int(IntType)),
+            ( IntType = int_type_int64
+            ; IntType = int_type_uint64
+            ),
+            DestType \= builtin_type(builtin_type_int(IntType))
+        then
+            MLDS_SourceType =
+                mercury_type_to_mlds_type(ModuleInfo, SourceType),
+            MLDS_DestType = mercury_type_to_mlds_type(ModuleInfo, DestType),
+            ArgRval = ml_unop(cast(MLDS_DestType),
+                ml_unop(box(MLDS_SourceType), VarRval))
+        else if
              % If converting from an array(T) to array(X) where X is a concrete
              % instance, we should insert a cast to the concrete instance.
              % Also when converting to array(T) from array(X) we should cast
diff --git a/compiler/mlds.m b/compiler/mlds.m
index b7d324a..140f899 100644
--- a/compiler/mlds.m
+++ b/compiler/mlds.m
@@ -1986,6 +1986,8 @@
  :- type mlds_global_const_var
      --->    mgcv_const_var
      ;       mgcv_float
+    ;       mgcv_int64
+    ;       mgcv_uint64
      ;       mgcv_closure_layout
      ;       mgcv_typevar_vector
      ;       mgcv_bit_vector.
@@ -2634,6 +2636,12 @@ ml_global_const_var_name_to_string(ConstVar, Num) = Str :-
          ConstVar = mgcv_float,
          ConstVarStr = "float"
      ;
+        ConstVar = mgcv_int64,
+        ConstVarStr = "int64"
+    ;
+        ConstVar = mgcv_uint64,
+        ConstVarStr = "uint64"
+    ;
          ConstVar = mgcv_closure_layout,
          ConstVarStr = "closure_layout"
      ;