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messn036's avatar
messn036
Icon for New Contributor rankNew Contributor
4 years ago
Solved

Sample project with RTL module library not working

Hello Intel Support, I am attempting to compile a library of RTL components to use in my HLS project. The HLS project compiles when testing for x86-64 simulation, but the compiler complains about...
  • messn036's avatar
    messn036
    3 years ago

    The issue is in my expHBU.h file. I put

    uint8_t expHBU(uint8_t input);

    Rather than the CORRECT

    extern "C" {
    uint8_t expHBU(uint8_t input);
}

    This extern is extremely esoteric and should be included in the reference manual.

messn036's avatar
messn036
Icon for New Contributor rankNew Contributor
3 years ago

Here are the source files I am using. I am trying to model the basic rtl library tutorial the best I can (which compiles fine in my environment). I'm sure its some easy syntax error that none of the compilers or packagers is catching.

I cannot upload the .cpp and .h files because this site rejects them. Here is the source

expHBU.h

#include <stdint.h>
#include "HLS/math.h"
uint8_t expHBU(uint8_t input);

expHBU.cpp

#include "expHBU.h"

uint8_t expHBU(uint8_t input){
    return (uint8_t)exp(input);
}

component_testbench.cpp

#include "HLS/hls.h"
#include "HLS/stdio.h"
#include "HLS/math.h"
#include "expHBU.h"


component uint8_t executeexp(uint8_t exponent)
{
    return expHBU(exponent);
}
component uint8_t executeexp_basic(uint8_t exponent)
{
    return exp(exponent);
}

int main()
{   
    uint8_t exponent = 3;
    uint8_t result = executeexp(exponent);
    printf("result %d \n", result);
    return 0;
}

Reminder: the x86 simulation works, but the FPGA compile does NOT

Thanks,

messn036

messn036's avatar
messn036
Icon for New Contributor rankNew Contributor
3 years ago

The issue is in my expHBU.h file. I put

uint8_t expHBU(uint8_t input);

Rather than the CORRECT

extern "C" {
    uint8_t expHBU(uint8_t input);
}

This extern is extremely esoteric and should be included in the reference manual.

  • YoshiakiS_Altera's avatar
    YoshiakiS_Altera
    Icon for Occasional Contributor rankOccasional Contributor
    3 years ago

    Hello messn036,

    Thank you for the update.

    Basically, you need to add the extern “C” to call a function from C++ to C. This is general rule of C++.

    C++ Language adds a prefix to a function name to support the class feature.

    But, this feature is disabled when you add extern “C”.

    So many C/C++ headers include:

    #ifdef __cplusplus
extern "C" {
#endif

rtl_inet_uint16 rtl_htons(rtl_inet_uint16 hostshort);
rtl_inet_uint16 rtl_ntohs(rtl_inet_uint16 netshort);
rtl_inet_uint32 rtl_htonl(rtl_inet_uint32 hostlong);
rtl_inet_uint32 rtl_ntohl(rtl_inet_uint32 netlong);

#ifdef __cplusplus
}
#endif

    Best regards,

    Yoshiaki Saito

    • YoshiakiS_Altera's avatar
      YoshiakiS_Altera
      Icon for Occasional Contributor rankOccasional Contributor
      3 years ago

      Hello messn036,

      I will close this thread if no further questions from you.

      Best regards,

      Yoshiaki Saito