SPRUJG0B December   2024  – November 2025 F29H850DM , F29H850TU , F29H859TU-Q1 , F29P329SM-Q1 , F29P589DM-Q1 , F29P589DU-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Performance Optimization
    1. 2.1 Compiler Settings
      1. 2.1.1 Enabling Debug and Source Inter-Listing
      2. 2.1.2 Optimization Control
      3. 2.1.3 Floating-Point Math
      4. 2.1.4 Fixed-Point Division
      5. 2.1.5 Single vs Double Precision Floating-Point
      6. 2.1.6 Link-Time Optimization (LTO)
    2. 2.2 Memory Settings
      1. 2.2.1 Executing Code From RAM
      2. 2.2.2 Executing Code From Flash
      3. 2.2.3 Data Placement
    3. 2.3 Code Construction and Configuration
      1. 2.3.1 Inlining
      2. 2.3.2 Intrinsics
      3. 2.3.3 Volatile Variables
      4. 2.3.4 Function Arguments
      5. 2.3.5 Enabling Wider Data Accesses
      6. 2.3.6 Auto Code-Generation Tools
      7. 2.3.7 Accurately Profiling Code
    4. 2.4 Application Code Optimization
      1. 2.4.1 Optimized SDK Libraries
      2. 2.4.2 Optimizing Code-Size With Libraries
      3. 2.4.3 C29 Special Instructions
      4. 2.4.4 C29 Parallelism
      5. 2.4.5 32-Bit Variables and Writes Preferred
      6. 2.4.6 Coding Style and Impact on Performance
  6. 3References
  7. 4Revision History

2.3.6 Auto Code-Generation Tools

Performance optimization with auto code-generation tools, Mathworks Embedded Coder, for example, is a key focus area. Details can be found here.

Depending on the configuration settings, generated code can have double-precision floating point operations and these can lead to significant deterioration of performance when running on floating-point hardware that supports only single-precision floating point operations. It is advised that users look for the following in the generated code:

  • Any unexpected double-precision floating point constants in C code. These can be floating point numbers without a trailing 'f'. Sometimes these have specific names, such as "DBL_EPSILON".
  • Ocurrences of double-precision operations in compiler generated assembly. These might have specific names, such as "CALLD @__extendsfdf2" (double-precision multiply), or "CALLD @__muldf3" (double-precision multiply).