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// 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);
}