Use of isnan() gives "controlling expression is constant" warning

Please show a short test case which demonstrates the problem.  Please supply source code that includes nothing except <math.h>, the compiler version, and the build options exactly as the compiler sees them. Note the test case does not have to execute, just build.

Thanks and regards,

-George

Thank you for reply.

Currently I use CGT6x 7.4.11 for Linux x86.

#include <math.h>

extern volatile float x;
extern volatile int y;

void main(void)
{
    y += isnan(x);
    y += isinf(x);
    y += isnormal(x);
    y += fpclassify(x);
}

Compile:

$ cl6x -pdr -pdv main.c

Output:

"main.c", line 8: remark: controlling expression is constant
      y += isnan(x);
           ^

"main.c", line 8: remark: controlling expression is constant
      y += isnan(x);
           ^

"main.c", line 9: remark: controlling expression is constant
      y += isinf(x);
           ^

"main.c", line 9: remark: controlling expression is constant
      y += isinf(x);
           ^

"main.c", line 10: remark: controlling expression is constant
      y += isnormal(x);
           ^

"main.c", line 10: remark: controlling expression is constant
      y += isnormal(x);
           ^

"main.c", line 11: remark: controlling expression is constant
      y += fpclassify(x);
           ^

"main.c", line 11: remark: controlling expression is constant
      y += fpclassify(x);
           ^

Sorry I forgot about my Eclipse CDT helper that replaces "remark" to "warning". So it is not warning but remarks in library code is not good too.

This particular problem is fixed in compiler version 8.0.x.  There are few ways you can workaround it in version 7.4.x.  One of them is to suppress the remark with the option --diag_suppress=238.  You can read more about that option (and related methods) in the section of the C6000 compiler manual titled Understanding Diagnostic Messages.

Thanks and regards,

-George

Glad to hear that this problem was fixed.

Is it possible to use DSP/BIOS & DSPLink with CGT v8?

Thank you.

Andrey Mozzhuhin said:

Is it possible to use DSP/BIOS & DSPLink with CGT v8?

Generally speaking, yes.  That said, you need to check the documentation for those packages to see what compiler versions they are tested with.

Thanks and regards,

-George