Executable machine code

A compiler is a computer program that translates high-level language statements into directly executable machine code. A single high-level statement generally results in many machine instructions. The compiler translates the machine code into binary code (O s and I s) for the computer to understand. 

Although much easier to assemble, a software program written in a high-level language requires more time for the computer to execute, since all the instructions must be translated into machine code before the computer can understand them. Even a simple statement like start in a high-level language requires several machine-code moves to execute. 

Executable statements, which are translated into machine code, are instructions by which operations are performed on data or by which the sequence of execution is changed. Statements producing operations on data are ... 

A solution to avoid all the pain of machine-language or assembler is a series of high-level languages, a "compiler," which translates, much as a dictionary would, these instructions into machine code, and a "linker," which connects parts of the task with each other, with "library" routines such as sin(x), cos(x), random(x), and so on, and with input/output (I/O) calls, to create an executable program. The compilers should allow the same "source" code to be compiled, with minor modifications, on any computer "platform" that supports a compiler for that language. 

Another feature that makes Visual Basic into a Rapid Application Development tool is that it supports both interpreted and compiled execution. When VB is used in interpreted mode, the tool allows the programmer to quickly see the effects of their code changes without a lengthy compilation directly to machine code. Of course, run-time performance is better when the code is actually compiled, and this can be done before distributing the application. 

A common way of accomplishing this is to have the compiler generate assembly code for the target machine, and to rely on the system s assembler to convert the textual representation into an executable binary form. This removes much of the knowledge about the actual machine code from the compiler and lets many compilers for the machine share a single assembler. 

The compiler may need to perform one final task. Before the code can execute, it must be expressed in the native language of the target machine. The result of instruction selection, instruction scheduling, and register allocation is a program that represents the target machine code. How-... 

As discussed above, for safe stack size analysis it is important to work on fully linked binary code, i.e., here the static analysis is not based on the source code but on the executable code. It approximates the semantics of the machine code of the microprocessor by using an abstract model of the processor architecture. The abstract model does not need to cover the entire state of the microprocessor, only the parts affecting the stack are needed. The hardware state relevant for worst-case stack analysis includes the processor registers and the memory cells. For a naive analysis only the stack pointer register is needed, but for precise results it is important to perform an elaborate value analysis on the contents of processor register and memory cells (cf. Sec. 4.2). In the following we will give an overview of the structure and analysis phases of the tool StackAnalyzer [14,11]. 

In general, the ability of a computer system to detect and recover from hardware errors depends on both the hardware architecture and the machine code of the executed software. Hence, when we conduct out-of-context fault injection experiments to assess a software component s ability to handle hardware errors, we must run the experiments on a hardware platform that is similar to the one used in the real product. However, to generalize the benchmarking outcome, different hardware platforms should be considered. 

You can implement an action s specification by designing a refinement into a smaller set of actions—ultimately, in software, messages. Program code is the most detailed kind of action implementation. Implementations cannot be joined in the same way that specifications can be joined (see Figure 8.2). First, it isn t clear what anding two programs together would mean. The machine must follow one list of instructions or the other, which one should it execute Both In what order Therefore, your support tool should complain if you try to provide code for two operations with the same name in the same class or for two refinements of the same action into different sets of smaller steps. 

Conduct software unit testing. The machine executable form of the code is tested to uncover errors in function, logic, or implementation Integrate modules and perform integration testing Test the Part 11 technical controls... 

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