Path: utzoo!attcan!uunet!dino!atanasoff!hascall
From: hascall@atanasoff.cs.iastate.edu (John Hascall)
Newsgroups: comp.lang.c
Subject: Re: Short code to determine compiler's register use
Message-ID: <1237@atanasoff.cs.iastate.edu>
Date: 22 Jul 89 14:03:04 GMT
References: <396@uop.uop.EDU> <2811@internal.Apple.COM>
Reply-To: hascall@atanasoff.cs.iastate.edu.UUCP (John Hascall)
Organization: Iowa State Univ. Computation Center
Lines: 34

In <untold articles> <everyone@everywhere> "hordes o' people" have wrote:

    [.. various schemes (all flamed) to count used registers ..]

  Well, I think we've decided this is machine dependent, so I submit for your
kind flamage a VMS version (tested even, imagine that :-)

REG.C:
main()
{     
        register int        a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p;
        int                 fn(); 
        short               *regs;

        a = fn(); b = fn(); c = fn(); d = fn();
        e = fn(); f = fn(); g = fn(); h = fn();
        i = fn(); j = fn(); k = fn(); l = fn();
        m = fn(); n = fn(); o = fn(); p = fn();

        regs = (short*)main;

        printf("Register mask = %04.4x\n", *regs);

        fx(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p);
}
RDUMMY.C:
fn()
{return(1);}
fx(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)
int a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p;
{}
------------------------------------------------------

John