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Your comm DSP's performance depends heavily on your compiler choice, so it pays to know your options.
It's time for a re-education about compilers, those critical tools that tell your code how to work with the hardware. Contrary to popular belief, the options provided by a DSP vendor aren't the only ones. In some cases they are the best, but with a few simple considerations engineers can determine the optimal approach for creating the most efficient design for an application.
For many, choosing a DSP C compiler is a pre-made decision. By choosing the DSP processor, the choice is reduced to a small number of options. The choice comes down to the C compiler offered by the DSP hardware vendor and one or two third-party suppliers. But, the engineering quality of C compilers offered by the supplier and independent vendors is becoming one of the critical decision factors in picking a DSP.
Savvy compiler providers have a large number of tools at their disposal to make their compilers perform well on benchmark programs. Unfortunately, these benchmark optimizations often do not apply to real-world design. Often, the discovery of less than anticipated performance comes at the end of a project - just when the need for performance margin is greatest.
If compilers can be manipulated to score well on benchmark programs, how can a designer discover the truth about a compiler before it's too late? The answer is to employ modified versions of standardized benchmarks and programs that are similar in nature to the intended application. It is important to run these programs through the compiler with several different sets of optimization switch settings to better understand the effects of optimization switches and their use in various combinations.
Three parts
Compilers have three logical parts: syntactic analysis, instruction set independent optimization, and code generation combined with machine specific optimization.
Syntactic analysis is the part of the compiler that scans the source code and recognizes the constituent parts of the source such as keywords, reserved words, and other syntactical elements. This front end normally doesn't need to be tested, providing the compiler vendor is an established company in the compiler business.
Regardless of the vendor, compilers normally accept standard-defined code without problems. Because syntactical analyzers...