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32 .\" @(#)fpgetround.3 1.0 (Berkeley) 9/23/93
47 .Nd IEEE floating point interface
53 FP_RN, /* round to nearest */
54 FP_RM, /* round down to minus infinity */
55 FP_RP, /* round up to plus infinity */
62 .Fn fpsetround "fp_rnd_t direction"
66 FP_PS, /* 24 bit (single-precision) */
67 FP_PRS, /* reserved */
68 FP_PD, /* 53 bit (double-precision) */
69 FP_PE /* 64 bit (extended-precision) */
75 .Fn fpsetprec "fp_prec_t precision"
78 #define fp_except_t int
79 #define FP_X_INV 0x01 /* invalid operation */
80 #define FP_X_DNML 0x02 /* denormal */
81 #define FP_X_DZ 0x04 /* zero divide */
82 #define FP_X_OFL 0x08 /* overflow */
83 #define FP_X_UFL 0x10 /* underflow */
84 #define FP_X_IMP 0x20 /* (im)precision */
85 #define FP_X_STK 0x40 /* stack fault */
90 .Fn fpsetmask "fp_except_t mask"
94 .Fn fpresetsticky "fp_except_t sticky"
96 The routines described herein are deprecated.
97 New code should use the functionality provided by
100 When a floating point exception is detected, the exception sticky flag is
101 set and the exception mask is tested.
102 If the mask is set, then a trap
104 These routines allow both setting the floating point exception
105 masks, and resetting the exception sticky flags after an exception is
107 In addition, they allow setting the floating point rounding mode
113 returns the current floating point rounding mode.
118 sets the floating point rounding mode and returns
124 returns the current floating point precision.
129 sets the floating point precision and returns
130 the previous precision.
135 returns the current floating point exception masks.
140 sets the floating point exception masks and returns the
146 returns the current floating point sticky flags.
151 clears the floating point sticky flags and returns
154 Sample code which prevents a trap on divide-by-zero:
155 .Bd -literal -offset indent
160 fpresetsticky(FP_X_DZ);
163 .Sh IMPLEMENTATION NOTES
168 functions provide functionality unavailable on many platforms.
169 At present, they are implemented only on the i386 and amd64 platforms.
174 After a floating point exception and before a mask is set, the sticky
176 If another exception occurs before the sticky
177 flags are reset, then a wrong exception type may be signaled.
179 These routines are based on SysV/386 routines of the same name.