usr/src/lib/libm/tahoe/infnan.s

# Copyright (c) 1985 Regents of the University of California.
# All rights reserved.
#
# %sccs.include.redist.sh%
#
#       @(#)infnan.s    5.5 (Berkeley) %G%
#
        .data
        .align  2
_sccsid:
.asciz  "@(#)infnan.s   5.5     (ucb.elefunt)   %G%"

/*
 * double infnan(arg)
 * int arg;
 * where arg :=    EDOM if result is  NaN
 *           :=  ERANGE if result is +INF
 *           := -ERANGE if result is -INF
 *
 * The Reserved Operand Fault is generated inside of this routine.
 */
        .globl  _infnan
        .set    EDOM,33
        .set    ERANGE,34
        .text
        .align 2
_infnan:
        .word   0x0000                  # save nothing
        cmpl    4(fp),$ERANGE
        bneq    1f
        movl    $ERANGE,_errno
        brb     2f
1:      movl    $EDOM,_errno
2:      cmpf2   $0x80000000,$0x80000000 # generates the reserved operand fault
        ret