2 * Copyright (c) 1991, 1993, 1995
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5 * This code is derived from software contributed to Berkeley by
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37 #include <machine/asm.h>
39 #if defined(LIBC_SCCS)
42 #endif /* LIBC_SCCS */
45 * double modf(val, iptr)
47 * returns: xxx and n (in *iptr) where val == n.xxx
51 cfc1 t0, $31 # get the control register
52 li.d $f2, 4503599627370496e0 # f2 <- 2^52
54 or t1, t0, 0x3 # set rounding mode to round to zero
55 xor t1, t1, 0x2 # (i.e., 01)
58 mov.d $f0, $f12 # f0 <- f12
59 abs.d $f4, $f12 # f4 <- |f12|
60 c.olt.d $f4, $f2 # f4 ? < f2
61 bc1f 1f # leave f0 alone if Nan, infinity
63 c.eq.d $f12,$f4 # was f12 positive ?
64 add.d $f4,$f2,$f4 # round off to integer
65 bc1f 2f # No -> will have to negate result
66 sub.d $f0,$f4,$f2 # Remove fudge factor
67 j 1f # integer fraction got
69 sub.d $f0,$f2,$f4 # Remove fudge factor and negate
71 ctc1 t0, $31 # restore old rounding mode
72 s.d $f0, 0(a2) # save the integer part
73 sub.d $f0, $f12, $f0 # subtract val - integer part