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Valued Contributor III
1,566 Views

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
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7 Replies
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Valued Contributor III
44 Views

Hi, 

Try to set additional linker key: -lm 

http://cboard.cprogramming.com/c-programming/45664-gcc-math-h.html
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Valued Contributor III
44 Views

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.

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Valued Contributor III
44 Views

thank you slacker, 

 

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

 

thanks
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Highlighted
Valued Contributor III
44 Views

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...
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Valued Contributor III
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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.
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Valued Contributor III
44 Views

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-re... 

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.
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Valued Contributor III
44 Views

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

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