First let me say, that while I have used C++ I don't normally use it for my work and so am not throughly familiar with what it does, so if this is due to a C++ error, please be gentle. I am working on some DSP code I developed a long time ago, and now want to port it to 64 bit. I have read several articles on the differences in C and C++ between 32 and 64 bit, but this has me stymied. Here is the smallest sample I have been working with to show the current error: #include <math.h> #include <stdlib.h> #include <stdio.h> #include <string.h> main() { long double temp; printf ("M_PI=%e\n",M_PI); printf ("sin 90 = %e\n",sinf(M_PI/2)); temp=M_PI/2.0; // the following line won't compile for temp // regardless of how temp is declared (float, double, long double) // printf ("sin 90 = %e\n",sinf(temp)); } Clearly sinf is recognized, and compiles and runs. It returns 1.000 as expected for M_PI/2. But the line that is commented out will not compile. If you can see the issue here, please let me know. MY system is: Release Kernel Linux 2.6.35.``-83.fc14.x86_64 GNOME 2.32.0 Hardware Memory 7.8GiB AMD Phenom(tm) II X6 1035T Lots of disk space yum info GCC shows: Name : gcc Arch : x86_64 Version : 4.5.1 Release : 4.fc14 Thanks, Les H -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines