PGI 18.1 vs PGI 18.4 - gpu

Question

Is there any change from the PGi version 18.1 to 18.4 regarding the
#pragma routine seq, the code I have works fine with version 18.1 but gives an error when I use the newer version. I generate kernels using the math library.
using namespace std;
#pragma acc routine
double myfunc(double x)
{
return(fabs(x));
}
The default parallelism for routine directive is (or was) sequential.
i.e. #pragma acc routine is equivalent to #pragma acc routine seq
This works fine in version 18.1.
But I think there might be some change in the new version since when I compile with 18.4 version, it gives an error complaining about the math library function.
Oddly enough also causes error
#include cmath
#include "openacc.h"
using namespace std;
#pragma acc routine seq
double sine( double x )
{
return ( sin( x ) );
}
Gives compilation error but when I change the math library to math.h, it is perfectly fine, Can anyone explain why is not working with pgc++ ?

Answer 1

What's the actual error you get? I get the same error with both PGI 18.1 and 18.4:
% pgc++ -c test1.cpp -ta=tesla -Minfo=accel -w -V18.1
PGCC-S-1000-Call in OpenACC region to procedure 'sin' which has no acc routine information (test1.cpp: 10)
PGCC-S-0155-Compiler failed to translate accelerator region (see -Minfo messages) (test1.cpp: 10)
sine(double):
10, Generating acc routine seq
Generating Tesla code
11, Accelerator restriction: call to 'sin' with no acc routine information
The solution here is to include the PGI header "accelmath.h" to get the device version for the C99 math intrinsics.
% diff test1.cpp test2.cpp
4a5
> #include "accelmath.h"
% pgc++ -c test2.cpp -ta=tesla -Minfo=accel -w -V18.1
sine(double):
12, Generating acc routine seq
Generating Tesla code
% pgc++ -c test2.cpp -ta=tesla -Minfo=accel -w -V18.4
sine(double):
12, Generating acc routine seq
Generating Tesla code