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comparison: xpcom/tests/SizeTest01.cpp
xpcom/tests/SizeTest01.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:f48d0e3c68a5 |
|---|---|
| 1 // Test01.cpp | |
| 2 | |
| 3 #include "nsIDOMNode.h" | |
| 4 #include "nsCOMPtr.h" | |
| 5 #include "nsString.h" | |
| 6 | |
| 7 NS_DEF_PTR(nsIDOMNode); | |
| 8 | |
| 9 /* | |
| 10 This test file compares the generated code size of similar functions between raw | |
| 11 COM interface pointers (|AddRef|ing and |Release|ing by hand) and |nsCOMPtr|s. | |
| 12 | |
| 13 Function size results were determined by examining dissassembly of the generated code. | |
| 14 mXXX is the size of the generated code on the Macintosh. wXXX is the size on Windows. | |
| 15 For these tests, all reasonable optimizations were enabled and exceptions were | |
| 16 disabled (just as we build for release). | |
| 17 | |
| 18 The tests in this file explore only the simplest functionality: assigning a pointer | |
| 19 to be reference counted into a [raw, nsCOMPtr] object; ensuring that it is | |
| 20 |AddRef|ed and |Release|d appropriately; calling through the pointer to a function | |
| 21 supplied by the underlying COM interface. | |
| 22 | |
| 23 Windows: | |
| 24 raw_optimized 31 bytes | |
| 25 raw, nsCOMPtr* 34 | |
| 26 nsCOMPtr_optimized* 38 | |
| 27 nsCOMPtr_optimized 42 | |
| 28 nsCOMPtr 46 | |
| 29 | |
| 30 Macintosh: | |
| 31 raw_optimized, nsCOMPtr_optimized 112 bytes (1.0000) | |
| 32 nsCOMPtr 120 (1.0714) i.e., 7.14% bigger than raw_optimized et al | |
| 33 raw 140 (1.2500) | |
| 34 | |
| 35 The overall difference in size between Windows and Macintosh is caused by the | |
| 36 the PowerPC RISC architecture where every instruction is 4 bytes. | |
| 37 | |
| 38 On Macintosh, nsCOMPtr generates out-of-line destructors which are | |
| 39 not referenced, and which can be stripped by the linker. | |
| 40 */ | |
| 41 | |
| 42 void | |
| 43 Test01_raw( nsIDOMNode* aDOMNode, nsString* aResult ) | |
| 44 // m140, w34 | |
| 45 { | |
| 46 /* | |
| 47 This test is designed to be more like a typical large function where, | |
| 48 because you are working with several resources, you don't just return when | |
| 49 one of them is |nullptr|. Similarly: |Test01_nsCOMPtr00|, and |Test01_nsIPtr00|. | |
| 50 */ | |
| 51 | |
| 52 nsIDOMNode* node = aDOMNode; | |
| 53 NS_IF_ADDREF(node); | |
| 54 | |
| 55 if ( node ) | |
| 56 node->GetNodeName(*aResult); | |
| 57 | |
| 58 NS_IF_RELEASE(node); | |
| 59 } | |
| 60 | |
| 61 void | |
| 62 Test01_raw_optimized( nsIDOMNode* aDOMNode, nsString* aResult ) | |
| 63 // m112, w31 | |
| 64 { | |
| 65 /* | |
| 66 This test simulates smaller functions where you _do_ just return | |
| 67 |nullptr| at the first sign of trouble. Similarly: |Test01_nsCOMPtr01|, | |
| 68 and |Test01_nsIPtr01|. | |
| 69 */ | |
| 70 | |
| 71 /* | |
| 72 This test produces smaller code that |Test01_raw| because it avoids | |
| 73 the three tests: |NS_IF_...|, and |if ( node )|. | |
| 74 */ | |
| 75 | |
| 76 // -- the following code is assumed, but is commented out so we compare only | |
| 77 // the relevent generated code | |
| 78 | |
| 79 // if ( !aDOMNode ) | |
| 80 // return; | |
| 81 | |
| 82 nsIDOMNode* node = aDOMNode; | |
| 83 NS_ADDREF(node); | |
| 84 node->GetNodeName(*aResult); | |
| 85 NS_RELEASE(node); | |
| 86 } | |
| 87 | |
| 88 void | |
| 89 Test01_nsCOMPtr( nsIDOMNode* aDOMNode, nsString* aResult ) | |
| 90 // m120, w46/34 | |
| 91 { | |
| 92 nsCOMPtr<nsIDOMNode> node = aDOMNode; | |
| 93 | |
| 94 if ( node ) | |
| 95 node->GetNodeName(*aResult); | |
| 96 } | |
| 97 | |
| 98 void | |
| 99 Test01_nsCOMPtr_optimized( nsIDOMNode* aDOMNode, nsString* aResult ) | |
| 100 // m112, w42/38 | |
| 101 { | |
| 102 // if ( !aDOMNode ) | |
| 103 // return; | |
| 104 | |
| 105 nsCOMPtr<nsIDOMNode> node = aDOMNode; | |
| 106 node->GetNodeName(*aResult); | |
| 107 } |
