1 files changed, 107 insertions, 0 deletions
diff --git a/xpcom/tests/SizeTest01.cpp b/xpcom/tests/SizeTest01.cpp
new file mode 100644
index 0000000000..790b0fa032
--- /dev/null
+++ b/xpcom/tests/SizeTest01.cpp
@@ -0,0 +1,107 @@
+// Test01.cpp
+
+#include "nsINode.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+
+NS_DEF_PTR(nsINode);
+
+/*
+        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(nsINode* 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|.
+  */
+
+  nsINode* node = aDOMNode;
+  NS_IF_ADDREF(node);
+
+  if (node) node->GetNodeName(*aResult);
+
+  NS_IF_RELEASE(node);
+}
+
+void Test01_raw_optimized(nsINode* 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;
+
+  nsINode* node = aDOMNode;
+  NS_ADDREF(node);
+  node->GetNodeName(*aResult);
+  NS_RELEASE(node);
+}
+
+void Test01_nsCOMPtr(nsINode* aDOMNode, nsString* aResult)
+// m120, w46/34
+{
+  nsCOMPtr<nsINode> node = aDOMNode;
+
+  if (node) node->GetNodeName(*aResult);
+}
+
+void Test01_nsCOMPtr_optimized(nsINode* aDOMNode, nsString* aResult)
+// m112, w42/38
+{
+  //		if ( !aDOMNode )
+  //			return;
+
+  nsCOMPtr<nsINode> node = aDOMNode;
+  node->GetNodeName(*aResult);
+}