fix: Correct JS conversion of i64 & float64_bits literals (#96)

Co-authored-by: Blaine Bublitz <blaine.bublitz@gmail.com>

js/expression.ml

@@ -115,18 +115,17 @@ let const wasm_mod lit =
   | Int32 value ->
       let scope = get wasm_mod "i32" in
       meth_call scope "const" [| inject value |]
-  | Int64 value ->
+  | Int64 (low, high) ->
       let scope = get wasm_mod "i64" in
-      meth_call scope "const" [| inject value |]
+      meth_call scope "const" [| inject low; inject high |]
   | Float32Bits value ->
       let scope = get wasm_mod "f32" in
       meth_call scope "const_bits" [| inject value |]
-  | Float64Bits value ->
+  | Float64Bits (low, high) ->
       let scope = get wasm_mod "f64" in
-      meth_call scope "const_bits" [| inject value |]
+      meth_call scope "const_bits" [| inject low; inject high |]
   | Float32 value ->
       let scope = get wasm_mod "f32" in
-      (* TODO: Investigate if this needs the Int32 conversion stuff *)
       meth_call scope "const" [| inject value |]
   | Float64 value ->
       let scope = get wasm_mod "f64" in

js/literal.ml

@@ -1,21 +1,25 @@
 (* This is a hack around Binaryen's stack allocations *)
 type jsoo =
   | Int32 of int32
-  | Int64 of int64
+  | Int64 of int32 * int32
   | Float32Bits of int32
-  | Float64Bits of int64
+  | Float64Bits of int32 * int32
   | Float32 of float
   | Float64 of float
 
 type t = jsoo
 
 let int32 value = Int32 value
 
-let int64 value = Int64 value
+let int64 value =
+  Int64
+    (Int64.to_int32 value, Int64.to_int32 (Int64.shift_right_logical value 32))
 
 let float32_bits value = Float32Bits value
 
-let float64_bits value = Float64Bits value
+let float64_bits value =
+  Float64Bits
+    (Int64.to_int32 value, Int64.to_int32 (Int64.shift_right_logical value 32))
 
 let float32 value = Float32 value
 

src/literal.ml

@@ -15,9 +15,9 @@ external float64 : float -> t = "caml_binaryen_literal_float64"
 (* Hacks for Binaryen.js stack allocations, Don't use in binaryen.native *)
 type jsoo =
   | Int32 of int32
-  | Int64 of int64
+  | Int64 of int32 * int32
   | Float32Bits of int32
-  | Float64Bits of int64
+  | Float64Bits of int32 * int32
   | Float32 of float
   | Float64 of float
 

test/test.expected

@@ -4,6 +4,8 @@
  (memory $0 1)
  (table $table 1 1 funcref)
  (elem (i32.const 0) $adder)
+ (global $max_int64 i64 (i64.const 9223372036854775807))
+ (global $test_float64_bits f64 (f64.const 1.23))
  (export "adder" (func $adder))
  (export "memory" (memory $0))
  (start $start)

test/test.ml

@@ -48,6 +48,14 @@ let start =
 
 let _ = Export.add_function_export wasm_mod "adder" "adder"
 
+let _ =
+  Global.add_global wasm_mod "max_int64" Type.int64 false
+    (Expression.const wasm_mod (Literal.int64 Int64.max_int))
+
+let _ =
+  Global.add_global wasm_mod "test_float64_bits" Type.float64 false
+    (Expression.const wasm_mod (Literal.float64_bits 0x3FF3AE147AE147AEL))
+
 let _ =
   Table.add_table wasm_mod "table" 1 1 [ "adder" ]
     (Expression.const wasm_mod (Literal.int32 0l))

virtual/literal.mli

@@ -15,9 +15,9 @@ val float64 : float -> t
 (* Hacks for Binaryen.js stack allocations *)
 type jsoo =
   | Int32 of int32
-  | Int64 of int64
+  | Int64 of int32 * int32
   | Float32Bits of int32
-  | Float64Bits of int64
+  | Float64Bits of int32 * int32
   | Float32 of float
   | Float64 of float