Beginning in .NET

Add QR-Code in .NET Beginning
QR Code ISO/IEC18004 recognizer in .net
Using Barcode Control SDK for .net framework Control to generate, create, read, scan barcode image in .net framework applications.
cmp eax,1100 jg Above1100 Proceed to 1100_Or_Below
Draw qr-codes with .net
using .net touse quick response code in web,windows application
recognize denso qr bar code with .net
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Cmp eax, 1100 je Case_1100 cmp eax, 501 jg Case_1001 Proceed to 501_Or_Below
VS .NET barcode decoderfor .net
Using Barcode reader for VS .NET Control to read, scan read, scan image in VS .NET applications.
Generate bar code for .net
using barcode integrating for .net vs 2010 crystal control to generate, create barcode image in .net vs 2010 crystal applications.
eax, 501 cmp je Case_501 sub eax, 120 je Case_120 sub eax, 20 jne AfterSwBlock Case120: ...
Control qr code 2d barcode size for
quick response code size with
Qr-codes barcode library on .net
use qr integrated toembed qr codes with .net
Case 1001
Control quick response code size on visual basic
qr code jis x 0510 size in visual basic
Case 1100
Receive ean / ucc - 13 on .net
use .net ean128 encoding tocreate ucc ean 128 on .net
cmp eax, 3400 jg Case_4100 je Case_3400 cmp eax, 1400 je Case_1400 cmp eax, 2000 jne AfterSwBlock Case_2000: ...
USS Code 128 encoding with .net
using .net framework crystal todraw code 128 for web,windows application
Figure A.12 Tree-implementation of a switch block including assembly language code.
Bar Code integrating on .net
use visual .net barcode generation todeploy barcode with .net
Case 120 Case 140 Case 501 Case 1400 Case 2000 Case 3400 Case 4100
Monarch barcode library for .net
use visual studio .net crystal nw-7 creation togenerate code-27 on .net
Figure A.12 demonstrates how the preceding switch block can be viewed as a tree by the compiler and presents the compiler-generated assembly code that implements each tree node.
Control datamatrix 2d barcode size in excel spreadsheets
to produce barcode data matrix and ecc200 data, size, image with excel barcode sdk
Deciphering Code Structures 503
Upc Barcodes implement for .net
using web service tocreate upc a for web,windows application
Appendix A
Barcode drawer with objective-c
using ipad tocompose barcode on web,windows application
One relatively unusual quality of tree-based n-way conditionals that makes them a bit easier to make out while reading disassembled code is the numerous subtractions often performed on a single register. These subtractions are usually followed by conditional jumps that lead to the specific case blocks (this layout can be clearly seen in the 501_Or_Below case in Figure A.12). The compiler typically starts with the original value passed to the conditional block and gradually subtracts certain values from it (these are usually the case block values), constantly checking if the result is zero. This is simply an efficient way to determine which case block to jump into using the smallest possible code.
Access code-39 on visual
use .net winforms crystal code 39 creator toaccess uss code 39 with
Control 2d data matrix barcode image in c#
using visual studio .net toencode data matrix ecc200 in web,windows application
When you think about it, a loop is merely a chunk of conditional code just like the ones discussed earlier, with the difference that it is repeatedly executed, usually until the condition is no longer satisfied. Loops typically (but not always) include a counter of some sort that is used to control the number of iterations left to go before the loop is terminated. Fundamentally, loops in any high-level language can be divided into two categories, pretested loops, which contain logic followed by the loop s body (that s the code that will be repeatedly executed) and posttested loops, which contain the loop body followed by the logic. Let s take a look at the various types of loops and examine how they are represented in assembly language,
EAN13 barcode library on .net
generate, create ean13 none for .net projects
Pretested Loops
Control uss-128 data in excel
to use uss-128 and ean 128 data, size, image with excel spreadsheets barcode sdk
Pretested loops are probably the most popular loop construct, even though they are slightly less efficient compared to posttested ones. The problem is that to represent a pretested loop the assembly language code must contain two jump instructions: a conditional branch instruction in the beginning (that will terminate the loop when the condition is no longer satisfied) and an unconditional jump at the end that jumps back to the beginning of the loop. Let s take a look at a simple pretested loop and see how it is implemented by the compiler:
Build upc symbol in vb
using .net vs 2010 toconnect upc a on web,windows application
c = 0; while (c < 1000) { array[c] = c; c++; }
You can easily see that this is a pretested loop, because the loop first checks that c is lower than 1,000 and then performs the loop s body. Here is the assembly language code most compilers would generate from the preceding code:
Deciphering Code Structures
mov xor LoopStart: mov add cmp jl ecx, DWORD PTR [array] eax, eax DWORD PTR [ecx+eax*4], eax eax, 1 eax, 1000 LoopStart
It appears that even though the condition in the source code was located before the loop, the compiler saw fit to relocate it. The reason that this happens is that testing the counter after the loop provides a (relatively minor) performance improvement. As I ve explained, converting this loop to a posttested one means that the compiler can eliminate the unconditional JMP instruction at the end of the loop. There is one potential risk with this implementation. What happens if the counter starts out at an out-of-bounds value That could cause problems because the loop body uses the loop counter for accessing an array. The programmer was expecting that the counter be tested before running the loop body, not after! The reason that this is not a problem in this particular case is that the counter is explicitly initialized to zero before the loop starts, so the compiler knows that it is zero and that there s nothing to check. If the counter were to come from an unknown source (as a parameter passed from some other, unknown function for instance), the compiler would probably place the logic where it belongs: in the beginning of the sequence. Let s try this out by changing the above C loop to take the value of counter c from an external source, and recompile this sequence. The following is the output from the Microsoft compiler in this case:
mov mov cmp jge LoopStart: mov add cmp jl EndOfLoop: eax, DWORD PTR [c] ecx, DWORD PTR [array] eax, 1000 EndOfLoop DWORD PTR [ecx+eax*4], eax eax, 1 eax, 1000 LoopStart
It seems that even in this case the compiler is intent on avoiding the two jumps. Instead of moving the comparison to the beginning of the loop and adding an unconditional jump at the end, the compiler leaves everything as it is and simply adds another condition at the beginning of the loop. This initial check (which only gets executed once) will make sure that the loop is not entered if the counter has an illegal value. The rest of the loop remains the same.