Misc/abrash-black-book
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Use backtick code blocks for syntax highlighting

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James Gregory 2013-12-31 11:38:48 +11:00
commit f658bfbb40
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12
07-02.md
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@ -13,13 +13,17 @@ pages: 139-141
By the way, don't fall victim to the lures of **JCXZ** and do something
like this:
and cx,ofh ;Isolate the desired field
jcxz SkipLoop ;If field is 0, don't bother
```nasm
and cx,ofh ;Isolate the desired field
jcxz SkipLoop ;If field is 0, don't bother
```
The **AND** instruction has already set the Zero flag, so this
and cx,0fh ;Isolate the desired field
jz SkipLoop ;If field is 0, don't bother
```nasm
and cx,0fh ;Isolate the desired field
jz SkipLoop ;If field is 0, don't bother
```
will do just fine and is faster on all processors. Use **JCXZ** only
when the Zero flag isn't already set to reflect the status of CX.