1 files changed, 107 insertions, 0 deletions
diff --git a/xpcom/tests/SizeTest01.cpp b/xpcom/tests/SizeTest01.cpp
new file mode 100644
index 000000000..cdb7f00c0
--- /dev/null
+++ b/xpcom/tests/SizeTest01.cpp
@@ -0,0 +1,107 @@
+// Test01.cpp
+
+#include "nsIDOMNode.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+
+NS_DEF_PTR(nsIDOMNode);
+
+	/*
+		This test file compares the generated code size of similar functions between raw
+                COM interface pointers (|AddRef|ing and |Release|ing by hand) and |nsCOMPtr|s.
+
+		Function size results were determined by examining dissassembly of the generated code.
+		mXXX is the size of the generated code on the Macintosh.  wXXX is the size on Windows.
+		For these tests, all reasonable optimizations were enabled and exceptions were
+		disabled (just as we build for release).
+
+		The tests in this file explore only the simplest functionality: assigning a pointer
+                to be reference counted into a [raw, nsCOMPtr] object; ensuring that it is
+		|AddRef|ed and |Release|d appropriately; calling through the pointer to a function
+		supplied by the underlying COM interface.
+
+		Windows:
+			raw_optimized														 31 bytes
+			raw, nsCOMPtr*													 34
+			nsCOMPtr_optimized*											 38
+			nsCOMPtr_optimized											 42
+			nsCOMPtr																 46
+
+		Macintosh:
+			raw_optimized, nsCOMPtr_optimized				112 bytes 	(1.0000)
+			nsCOMPtr																120					(1.0714)	i.e., 7.14% bigger than raw_optimized et al
+			raw																			140 				(1.2500)
+
+		The overall difference in size between Windows and Macintosh is caused by the
+		the PowerPC RISC architecture where every instruction is 4 bytes.
+
+                On Macintosh, nsCOMPtr generates out-of-line destructors which are
+		not referenced, and which can be stripped by the linker.
+	*/
+
+void
+Test01_raw( nsIDOMNode* aDOMNode, nsString* aResult )
+		// m140, w34
+	{
+			/*
+				This test is designed to be more like a typical large function where,
+				because you are working with several resources, you don't just return when
+				one of them is |nullptr|.  Similarly: |Test01_nsCOMPtr00|, and |Test01_nsIPtr00|.
+			*/
+
+		nsIDOMNode* node = aDOMNode;
+		NS_IF_ADDREF(node);
+
+		if ( node )
+			node->GetNodeName(*aResult);
+
+		NS_IF_RELEASE(node);
+	}
+
+void
+Test01_raw_optimized( nsIDOMNode* aDOMNode, nsString* aResult )
+		// m112, w31
+	{
+			/*
+				This test simulates smaller functions where you _do_ just return
+				|nullptr| at the first sign of trouble.  Similarly: |Test01_nsCOMPtr01|,
+				and |Test01_nsIPtr01|.
+			*/
+
+			/*
+				This test produces smaller code that |Test01_raw| because it avoids
+				the three tests: |NS_IF_...|, and |if ( node )|.
+			*/
+
+// -- the following code is assumed, but is commented out so we compare only
+//		 the relevent generated code
+
+//		if ( !aDOMNode )
+//			return;
+
+		nsIDOMNode* node = aDOMNode;
+		NS_ADDREF(node);
+		node->GetNodeName(*aResult);
+		NS_RELEASE(node);
+	}
+
+void
+Test01_nsCOMPtr( nsIDOMNode* aDOMNode, nsString* aResult )
+		// m120, w46/34
+	{
+		nsCOMPtr<nsIDOMNode> node = aDOMNode;
+
+		if ( node )
+			node->GetNodeName(*aResult);
+	}
+
+void
+Test01_nsCOMPtr_optimized( nsIDOMNode* aDOMNode, nsString* aResult )
+		// m112, w42/38
+	{
+//		if ( !aDOMNode )
+//			return;
+
+		nsCOMPtr<nsIDOMNode> node = aDOMNode;
+		node->GetNodeName(*aResult);
+	}