diff options
Diffstat (limited to 'src/libs/xpcom18a4/xpcom/tests/SizeTest01.cpp')
-rw-r--r-- | src/libs/xpcom18a4/xpcom/tests/SizeTest01.cpp | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/xpcom/tests/SizeTest01.cpp b/src/libs/xpcom18a4/xpcom/tests/SizeTest01.cpp new file mode 100644 index 00000000..2d552a36 --- /dev/null +++ b/src/libs/xpcom18a4/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 |NULL|. 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 + |NULL| 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); + } |