2 files changed, 36 insertions, 9 deletions

diff --git a/libgo/go/reflect/makefunc_ffi.go b/libgo/go/reflect/makefunc_ffi.go
index 88ffca56ca0..05c5bc00342 100644
--- a/libgo/go/reflect/makefunc_ffi.go
+++ b/libgo/go/reflect/makefunc_ffi.go
@@ -28,7 +28,7 @@ func makeCIF(ft *funcType) unsafe.Pointer
 //
 // The ffi_callback handles __go_makefunc_can_recover, and
 // then passes off the data as received from ffi here.
-func ffiCallbackGo(results unsafe.Pointer, params unsafe.Pointer, impl *makeFuncImpl) {
+func ffiCallbackGo(results unsafe.Pointer, params unsafe.Pointer, impl *makeFuncImpl, wordsize int32, bigEndian bool) {
 	ftyp := impl.typ
 	in := make([]Value, 0, len(ftyp.in))
 	ap := params
@@ -42,21 +42,46 @@ func ffiCallbackGo(results unsafe.Pointer, params unsafe.Pointer, impl *makeFunc
 
 	out := impl.call(in)
 
-	off := uintptr(0)
-	for i, typ := range ftyp.out {
-		v := out[i]
+	checkValue := func(v Value, typ *rtype, addr unsafe.Pointer) {
 		if v.flag&flagRO != 0 {
 			panic("reflect: function created by MakeFunc using " + funcName(impl.fn) +
 				" returned value obtained from unexported field")
 		}
 
-		off = align(off, uintptr(typ.fieldAlign))
-		addr := unsafe.Pointer(uintptr(results) + off)
-
 		// Convert v to type typ if v is assignable to a variable
 		// of type t in the language spec.
 		// See issue 28761.
 		v = v.assignTo("reflect.MakeFunc", typ, addr)
+	}
+
+	// In libffi a single integer return value is always promoted
+	// to a full word. This only matters for integers whose size
+	// is less than the size of a full word. There is similar code
+	// in libgo/runtime/go-reflect-call.c.
+	if len(ftyp.out) == 1 {
+		typ := ftyp.out[0]
+		switch typ.Kind() {
+		case Bool, Int8, Int16, Int32, Uint8, Uint16, Uint32:
+			v := out[0]
+			checkValue(v, typ, nil)
+
+			if bigEndian {
+				results = unsafe.Pointer(uintptr(results) + uintptr(wordsize) - typ.size)
+			}
+
+			memmove(results, v.ptr, typ.size)
+			return
+		}
+	}
+
+	off := uintptr(0)
+	for i, typ := range ftyp.out {
+		v := out[i]
+
+		off = align(off, uintptr(typ.fieldAlign))
+		addr := unsafe.Pointer(uintptr(results) + off)
+
+		checkValue(v, typ, addr)
 
 		if v.flag&flagIndir == 0 && (v.kind() == Ptr || v.kind() == UnsafePointer) {
 			*(*unsafe.Pointer)(addr) = v.ptr
diff --git a/libgo/go/reflect/makefunc_ffi_c.c b/libgo/go/reflect/makefunc_ffi_c.c
index e57bd512e87..f1890264d7f 100644
--- a/libgo/go/reflect/makefunc_ffi_c.c
+++ b/libgo/go/reflect/makefunc_ffi_c.c
@@ -25,7 +25,8 @@ void makeFuncFFI(void *cif, void *impl)
    function ffiCall with the pointer to the arguments, the results area,
    and the closure structure.  */
 
-extern void ffiCallbackGo(void *result, void **args, ffi_go_closure *closure)
+extern void ffiCallbackGo(void *result, void **args, ffi_go_closure *closure,
+                          int32 wordsize, _Bool big_endian)
   __asm__ (GOSYM_PREFIX "reflect.ffiCallbackGo");
 
 extern void makefuncfficanrecover(Slice)
@@ -72,7 +73,8 @@ ffi_callback (ffi_cif* cif __attribute__ ((unused)), void *results,
       makefuncfficanrecover (s);
     }
 
-  ffiCallbackGo(results, args, closure);
+  ffiCallbackGo(results, args, closure, sizeof(ffi_arg),
+                __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__);
 
   if (i < n)
     makefuncreturning ();