2 files changed, 26 insertions, 8 deletions
diff --git a/ext/ffi/jit_trampoline.rs b/ext/ffi/jit_trampoline.rs
index 40c14dfb0..2c3c519c0 100644
--- a/ext/ffi/jit_trampoline.rs
+++ b/ext/ffi/jit_trampoline.rs
@@ -22,6 +22,10 @@ fn native_arg_to_c(ty: &NativeType) -> &'static str {
   match ty {
     NativeType::U8 | NativeType::U16 | NativeType::U32 => "uint32_t",
     NativeType::I8 | NativeType::I16 | NativeType::I32 => "int32_t",
+    NativeType::U64
+    | NativeType::I64
+    | NativeType::USize
+    | NativeType::ISize => "uint64_t",
     NativeType::Void => "void",
     NativeType::F32 => "float",
     NativeType::F64 => "double",
@@ -40,6 +44,8 @@ fn native_to_c(ty: &NativeType) -> &'static str {
     NativeType::Void => "void",
     NativeType::F32 => "float",
     NativeType::F64 => "double",
+    NativeType::U64 | NativeType::USize => "uint64_t",
+    NativeType::I64 | NativeType::ISize => "int64_t",
     _ => unimplemented!(),
   }
 }
@@ -148,6 +154,14 @@ mod tests {
     assert_eq!(
       codegen(vec![NativeType::I8, NativeType::U8], NativeType::I8),
       "#include <stdint.h>\n\nextern int8_t func(int8_t p0, uint8_t p1);\n\nint8_t func_trampoline(void* recv, int32_t p0, uint32_t p1) {\n  return func(p0, p1);\n}\n\n"
-    )
+    );
+    assert_eq!(
+      codegen(vec![NativeType::ISize, NativeType::U64], NativeType::Void),
+      "#include <stdint.h>\n\nextern void func(int64_t p0, uint64_t p1);\n\nvoid func_trampoline(void* recv, uint64_t p0, uint64_t p1) {\n  return func(p0, p1);\n}\n\n"
+    );
+    assert_eq!(
+      codegen(vec![NativeType::USize, NativeType::USize], NativeType::U32),
+      "#include <stdint.h>\n\nextern uint32_t func(uint64_t p0, uint64_t p1);\n\nuint32_t func_trampoline(void* recv, uint64_t p0, uint64_t p1) {\n  return func(p0, p1);\n}\n\n"
+    );
   }
 }
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index feb879aba..eddfed039 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -673,12 +673,11 @@ impl From<&NativeType> for fast_api::Type {
       NativeType::F32 => fast_api::Type::Float32,
       NativeType::F64 => fast_api::Type::Float64,
       NativeType::Void => fast_api::Type::Void,
-      NativeType::Function
-      | NativeType::Pointer
-      | NativeType::I64
+      NativeType::I64
       | NativeType::ISize
       | NativeType::U64
-      | NativeType::USize => {
+      | NativeType::USize => fast_api::Type::Uint64,
+      NativeType::Function | NativeType::Pointer => {
         panic!("Cannot be fast api")
       }
     }
@@ -686,7 +685,7 @@ impl From<&NativeType> for fast_api::Type {
 }
 
 #[cfg(not(target_os = "windows"))]
-fn is_fast_api(rv: NativeType) -> bool {
+fn is_fast_api_rv(rv: NativeType) -> bool {
   !matches!(
     rv,
     NativeType::Function
@@ -698,6 +697,11 @@ fn is_fast_api(rv: NativeType) -> bool {
   )
 }
 
+#[cfg(not(target_os = "windows"))]
+fn is_fast_api_arg(rv: NativeType) -> bool {
+  !matches!(rv, NativeType::Function | NativeType::Pointer)
+}
+
 // Create a JavaScript function for synchronous FFI call to
 // the given symbol.
 fn make_sync_fn<'s>(
@@ -714,8 +718,8 @@ fn make_sync_fn<'s>(
   let mut fast_allocations: Option<*mut ()> = None;
   #[cfg(not(target_os = "windows"))]
   if !sym.can_callback
-    && !sym.parameter_types.iter().any(|t| !is_fast_api(*t))
-    && is_fast_api(sym.result_type)
+    && !sym.parameter_types.iter().any(|t| !is_fast_api_arg(*t))
+    && is_fast_api_rv(sym.result_type)
   {
     let ret = fast_api::Type::from(&sym.result_type);