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Altera_Forum's avatar
Altera_Forum
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12 years ago

problem with math.h 's function in Eclipse

hello,

I made a system with Qsys which just contain a Nios II processor and its On-chip-memory.

then , I use the .sopcinfo File generated by Qsys to create a nios II application with Eclipse.

My problem is that I didn't succeed in using the library math.h

I wrote the following simple code :

# include <stdio.h># include <math.h>

int main()

{

double result =5;

result = floor(result);

return 0;

}

And I obtain the error : undefined reference to `floor' main.c /testnios line 24 C/C++ Problem

Do you have any idea about my problem or what I did wrong ?

thank you

7 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Gotta link it against the library libm... "-lm" needs to be added at the tail end of your compilation command. This is not specific to Nios II. It wouldn't work with any GCC compiler without linking against libm.

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    thank you slacker,

    Do you or someone else knows where I can edit the compilation command ? I didnt find in project->properties

    thanks
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Hi,

    I have the same problem with Quartus 13 / Nios II EDS 13.0.

    It's a linker error.

    You can try to add manualy "-lm" option for the linker but no effect on my computer.

    http://www.kirikoo.net/images/14Anonyme-20130716-104232.png 

    
**** Build of configuration Nios II for project test_math ****
make all 
Info: Building D:/test_math_bsp/
make --no-print-directory -C D:/test_math_bsp/
Info: Compiling hello_world.c to obj/default/hello_world.o
nios2-elf-gcc -xc -MP -MMD -c -ID:/test_math_bsp//HAL/inc -ID:/test_math_bsp/ -ID:/test_math_bsp//drivers/inc  -DSYSTEM_BUS_WIDTH=32 -pipe -D__hal__ -DALT_NO_INSTRUCTION_EMULATION -DALT_SINGLE_THREADED    -O0 -g -Wall   -EL -mhw-div -mhw-mul -mhw-mulx  -o obj/default/hello_world.o hello_world.c
hello_world.c: In function 'main':
hello_world.c:23: warning: unused variable 'test'
Info: Linking test_math.elf
nios2-elf-g++  -T'D:/test_math_bsp//linker.x' -msys-crt0='D:/test_math_bsp//obj/HAL/src/crt0.o' -msys-lib=hal_bsp -LD:/test_math_bsp/   -Wl,-Map=test_math.map   -O0 -g -Wall   -EL -mhw-div -mhw-mul -mhw-mulx  -o test_math.elf obj/default/hello_world.o -lm 
obj/default/hello_world.o: In function `main':
D:\test_math/hello_world.c:23: undefined reference to `cos'
collect2: ld returned 1 exit status
make: ***  Error 1
**** Build Finished ****


    # include <stdio.h># include <math.h>
int main()
{
  printf("Hello from Nios II!\n");
  double test = cos(3.14);
  return 0;
}

    It seems Altera has some problems with tests before releasing theirs softwares...
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Thanks you force-pc

    I tried but there is no effect on my computer too.

    I work also with Quartus 13 / Nios II EDS 13.0.
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Hi LETS,

    I try to read differents posts on the web like:

    http://stackoverflow.com/questions/7824439/c-math-linker-problems-on-ubuntu-11-10

    http://stackoverflow.com/questions/16344445/im-using-math-h-and-the-library-link-lm-but-undefined-reference-to-pow-st

    http://stackoverflow.com/questions/8480013/eclipse-c-c-cdt-add-l-option-linking-math-module-gcc-lm

    The generated Makefile seems to be good because Eclipse places the -lm argument at the end...

    I'm now installing Quartus 13.0sp1 to see if the problem persists.
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    ==>> No more problem with 13.0sp1. F***ing software!

    ==>> Don't use 13.0 with math.h lib & nios II.