Keil Logo

C51: Code Generator Support for Multiple Data Pointers


Information in this article applies to:

  • C51 Version 5.50a and later

QUESTION

Why doesn't the C51 compiler generate code for the dual data pointers found in the Atmel, NXP, 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


Last Reviewed: Thursday, February 25, 2021


Did this article provide the answer you needed?
 
Yes
No
Not Sure
 
  Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.

Change Settings

Privacy Policy Update

Arm’s Privacy Policy has been updated. By continuing to use our site, you consent to Arm’s Privacy Policy. Please review our Privacy Policy to learn more about our collection, use and transfers
of your data.