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Annotation of 43BSD/usr.lib/libF77/traper_.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 1980 Regents of the University of California.
                      3:  * All rights reserved.  The Berkeley software License Agreement
                      4:  * specifies the terms and conditions for redistribution.
                      5:  *
                      6:  *     @(#)traper_.c   5.2     6/7/85
                      7:  *
                      8:  * Full of Magic! DON'T CHANGE ANYTHING !!
                      9:  *
                     10:  * To use from f77:
                     11:  *     integer oldmsk, traper
                     12:  *     oldmsk = traper (mask)
                     13:  * where:
                     14:  *     mask = 1 to trap integer overflow
                     15:  *     mask = 2 to trap floating underflow
                     16:  *     mask = 3 to trap both
                     17:  *     These 2 bits will be set into the PSW.
                     18:  *     The old state will be returned.
                     19:  */
                     20: 
                     21: long traper_(msk)
                     22: long   *msk;
                     23: {
                     24:        int     old = 0;
                     25: #if    vax
                     26: #define IOV_MASK       0140
                     27:        int     **s = &msk;
                     28:        int     psw;
                     29: 
                     30:        s -= 5;
                     31:        psw = (int)*s;
                     32:        old = (psw & IOV_MASK) >> 5;
                     33:        psw = (psw & ~IOV_MASK) | ((*msk << 5) & IOV_MASK);
                     34:        *s = (int *)psw;
                     35: #endif vax
                     36:        return((long)old);
                     37: }

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