True 64 vs. Linux code on an Alpha

Greg Lindahl lindahl at
Wed Apr 11 13:08:13 PDT 2001

> > finding that compiling under True64 and executing under Linux is
> > yielding 20-35% faster code than compiling using the DEC Linux FORTRAN
> > compiler and running under Linux. Can this be the page coloring issue
> > raising it's head?

No, because page coloring is an OS issue, and Linux doesn't have it
even if you cross-compile. Apparently you're doing something
pathological that the Tru64 compiler handles and the Linux Compaq
compiler does not. Has he tried the new beta-test Linux Compaq

> However, incorrect 'getcwd' results under Linux are causing the
> following problem:

I haven't seen that, perhaps it is a botch in more recent kernels.

Here's a simple workaround:

Before the program runs, put the working directory in an environment
variable. Then write a C routine getcwd_ which returns that variable.
Odds are the getenv library routine works OK.

-- g

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