6 files changed, 29 insertions, 9 deletions
diff --git a/src/pkg/reflect/value.go b/src/pkg/reflect/value.go
index a80112d342..8b2c1a9530 100644
--- a/src/pkg/reflect/value.go
+++ b/src/pkg/reflect/value.go
@@ -730,8 +730,6 @@ type tiny struct {
 // Call calls the function fv with input parameters in.
 // It returns the function's output parameters as Values.
 func (fv *FuncValue) Call(in []Value) []Value {
-	var structAlign = Typeof((*tiny)(nil)).(*PtrType).Elem().Size()
-
 	t := fv.Type().(*FuncType)
 	nin := len(in)
 	if fv.first != nil && !fv.isInterface {
@@ -757,7 +755,7 @@ func (fv *FuncValue) Call(in []Value) []Value {
 		size = (size + a - 1) &^ (a - 1)
 		size += tv.Size()
 	}
-	size = (size + structAlign - 1) &^ (structAlign - 1)
+	size = (size + ptrSize - 1) &^ (ptrSize - 1)
 	for i := 0; i < nout; i++ {
 		tv := t.Out(i)
 		a := uintptr(tv.Align())
@@ -767,9 +765,9 @@ func (fv *FuncValue) Call(in []Value) []Value {
 
 	// size must be > 0 in order for &args[0] to be valid.
 	// the argument copying is going to round it up to
-	// a multiple of 8 anyway, so make it 8 to begin with.
-	if size < 8 {
-		size = 8
+	// a multiple of ptrSize anyway, so make it ptrSize to begin with.
+	if size < ptrSize {
+		size = ptrSize
 	}
 
 	// round to pointer size
@@ -811,7 +809,7 @@ func (fv *FuncValue) Call(in []Value) []Value {
 		memmove(addr(ptr+off), v.getAddr(), n)
 		off += n
 	}
-	off = (off + structAlign - 1) &^ (structAlign - 1)
+	off = (off + ptrSize - 1) &^ (ptrSize - 1)
 
 	// Call
 	call(*(**byte)(fv.addr), (*byte)(addr(ptr)), uint32(size))
diff --git a/src/pkg/runtime/debug.go b/src/pkg/runtime/debug.go
index 3cc5472f6b..3ce35cc5ba 100644
--- a/src/pkg/runtime/debug.go
+++ b/src/pkg/runtime/debug.go
@@ -4,6 +4,8 @@
 
 package runtime
 
+import "unsafe"
+
 // Breakpoint() executes a breakpoint trap.
 func Breakpoint()
 
@@ -73,6 +75,15 @@ type MemStatsType struct {
 	}
 }
 
+var sizeof_C_MStats int // filled in by malloc.goc
+
+func init() {
+	if sizeof_C_MStats != unsafe.Sizeof(MemStats) {
+		println(sizeof_C_MStats, unsafe.Sizeof(MemStats))
+		panic("MStats vs MemStatsType size mismatch")
+	}
+}
+
 // MemStats holds statistics about the memory system.
 // The statistics are only approximate, as they are not interlocked on update.
 var MemStats MemStatsType
diff --git a/src/pkg/runtime/hashmap.h b/src/pkg/runtime/hashmap.h
index 40dac6e9bd..0737535b55 100644
--- a/src/pkg/runtime/hashmap.h
+++ b/src/pkg/runtime/hashmap.h
@@ -64,7 +64,6 @@
  */
 
 #define	malloc		runtime·mal
-#define	offsetof(s,m)	(uint32)(&(((s*)0)->m))
 #define	memset(a,b,c)	runtime·memclr((byte*)(a), (uint32)(c))
 #define	memcpy(a,b,c)	runtime·mcpy((byte*)(a),(byte*)(b),(uint32)(c))
 #define	assert(a)	if(!(a)) runtime·throw("assert")
diff --git a/src/pkg/runtime/malloc.goc b/src/pkg/runtime/malloc.goc
index 405b05ee96..f5ca9f9183 100644
--- a/src/pkg/runtime/malloc.goc
+++ b/src/pkg/runtime/malloc.goc
@@ -244,6 +244,8 @@ runtime·allocmcache(void)
 	return c;
 }
 
+int32 runtime·sizeof_C_MStats = sizeof(MStats);
+
 void
 runtime·mallocinit(void)
 {
diff --git a/src/pkg/runtime/runtime.c b/src/pkg/runtime/runtime.c
index f2b6c587e9..a2e31d806f 100644
--- a/src/pkg/runtime/runtime.c
+++ b/src/pkg/runtime/runtime.c
@@ -258,6 +258,13 @@ runtime·check(void)
 	float64 j;
 	void* k;
 	uint16* l;
+	struct x1 {
+		byte x;
+	};
+	struct y1 {
+		struct x1 x1;
+		byte y;
+	};
 
 	if(sizeof(a) != 1) runtime·throw("bad a");
 	if(sizeof(b) != 1) runtime·throw("bad b");
@@ -271,7 +278,9 @@ runtime·check(void)
 	if(sizeof(j) != 8) runtime·throw("bad j");
 	if(sizeof(k) != sizeof(uintptr)) runtime·throw("bad k");
 	if(sizeof(l) != sizeof(uintptr)) runtime·throw("bad l");
-//	prints(1"check ok\n");
+	if(sizeof(struct x1) != 1) runtime·throw("bad sizeof x1");
+	if(offsetof(struct y1, y) != 1) runtime·throw("bad offsetof y1.y");
+	if(sizeof(struct y1) != 2) runtime·throw("bad sizeof y1");
 
 	uint32 z;
 	z = 1;
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index b0fa3891e6..37c8103f34 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -306,6 +306,7 @@ enum {
  */
 #define	nelem(x)	(sizeof(x)/sizeof((x)[0]))
 #define	nil		((void*)0)
+#define	offsetof(s,m)	(uint32)(&(((s*)0)->m))
 
 /*
  * known to compiler