[Pw_forum] C_POINTER on ibm power4

Sergey Lisenkov proffess at yandex.ru
Sat Dec 16 01:34:09 CET 2006

 Dear users,

 In new version of pwscf (3.2) the parameter C_POINTER in include/fft_defs.h is defined by configure and can be integer*8 (64-bit case) and integer*4 (32-bit case), if I am not totally mistaken. On Power4+ architecture (with environment variable OBJECT_MODE=64, which enables 64-bit version) configure defines compilation option "-q64" in both FFLAGS and LDFLAGS. However, C_POINTER is defined as integer*4. I guessed that it was error and replaced it by integer*8. When my calculations started I saw in the output file:

G cutoff =  316.5977  (******* G-vectors)     FFT grid: (198,198,***)
G cutoff =    9.0456  (  93393 G-vectors)  smooth grid: ( 36, 36,168)

The system is not too big to have z component of FFT of "***". It should be around 392 (info from the another machine). So, does it mean that on IBM Power4 I have to redefine C_POINTER as integer*4 (as it was defined by configure)?


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