Intel® High Level Synthesis Compiler Standard Edition: Reference Manual

ID 683310
Date 12/18/2019
Document Table of Contents

8.5. AC Data Types and Native Compilers

The reference version of the Mentor Graphics* Algorithmic C (AC) data types is also provided with the Intel® HLS Compiler. Do not use these reference header files in your component if you want to compile your component with an FPGA target.

Use the reference header files for AC data types to confirm functional correctness in your component when you are compiling your component with native compilers (g++ or MSVC).

If you use the reference header files and compile your component to an FPGA target, your component can compile successfully but your component QoR will be poor.

All of your code must use the same header files (either the reference header files or the FPGA-optimized header files). For example, your code cannot use the reference header files in your testbench and, at the same time, use the FPGA-optimized header file in your component code.

The following reference header files are provided with the Intel® HLS Compiler:
AC data type Reference Header File Description
ac_int ref/ac_int.h Arbitrary width integer support
ac_fixed ref/ac_fixed.h Arbitrary precision fixed-point number support