ARM Technical Support Knowledge Articles

CODE GENERATOR SUPPORT FOR MULTIPLE DATA POINTERS

Applies to: C51 C Compiler

Answer


Information in this article applies to:


QUESTION

Why doesn't the C51 compiler generate code for the dual data pointers found in the Atmel, Philips, AMD, Dallas, and Infineon 8051 devices?

ANSWER

Support for multiple data pointers is provided by the library routines strcpy, strcmp, memmove, memcmp, and memcpy. The compiler does not generate code that uses multiple data pointers.

There are currently five or six completely different implementations of multiple data pointers.

Implementing a different code generator for each chip involved would take several months (each). Before launching development, performance test cases were created to analyze the advantages of using multiple data pointers.

The result was that most instances of using multiple data pointers can be classified as either A) copying a buffer from one location to another or B) comparing two buffers. Since the standard C library addresses these issues, different libraries were created for each chip that supported multiple data pointers.

Currently we have no plans to generate multiple-data-pointer-specific code.

SEE ALSO

Article last edited on: 2000-06-16 00:00:00

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