3 // Copyright (C) 2000, 2001, Intel Corporation
4 // All rights reserved.
6 // Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,
7 // and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.
9 // Redistribution and use in source and binary forms, with or without
10 // modification, are permitted provided that the following conditions are
13 // * Redistributions of source code must retain the above copyright
14 // notice, this list of conditions and the following disclaimer.
16 // * Redistributions in binary form must reproduce the above copyright
17 // notice, this list of conditions and the following disclaimer in the
18 // documentation and/or other materials provided with the distribution.
20 // * The name of Intel Corporation may not be used to endorse or promote
21 // products derived from this software without specific prior written
24 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
28 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
32 // OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
33 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 // Intel Corporation is the author of this code, and requests that all
37 // problem reports or change requests be submitted to it directly at
38 // http://developer.intel.com/opensource.
41 //==============================================================
42 // 2/02/00: Initial version
43 // 4/04/00: Improved speed, corrected result for NaN input
44 // 5/30/00 Fixed bug for exponent 0x1003e
45 // 12/22/00 Fixed so inexact flag is never set, and invalid is not set for
46 // qnans nor for inputs larger than 2^63.
49 //==============================================================
50 // long double modfl(long double x, long double *iptr)
51 // break a floating point x number into fraction and an exponent
53 // input floating point f8, address in r34
54 // output floating point f8 (x fraction), and *iptr (x integral part)
57 //==============================================================
59 // NO FRACTIONAL PART: HUGE
61 // for double-extended
62 // If the true exponent is >= 63
63 // 1003e ==> 1003e -ffff = 3f = 63(dec)
65 // we are already an integer (p9 true)
67 // NO INTEGER PART: SMALL
68 // Is f8 exponent less than register bias (that is, is it
69 // less than 1). If it is, get the right sign of
70 // zero and store this in iptr.
72 // CALCULATION: NOT HUGE, NOT SMALL
73 // To get the integer part
74 // Take the floating-point input and truncate
75 // then convert this integer to fp Call it MODF_INTEGER_PART
77 // Subtract MODF_INTEGER_PART from MODF_NORM_F8 to get fraction part
78 // Then put fraction part in f8
79 // put integer part MODF_INTEGER_PART into *iptr
82 //==============================================================
84 // predicate registers used:
88 // -----------------------+-----------------+-------------
89 // SMALL | NORMAL | HUGE
90 // p11 --------------->|<----- p12 ----->| <-------------- p9
91 // p10 --------------------------------->|
92 // p13 --------------------------------------------------->|
95 #include "libm_support.h"
97 // floating-point registers used:
99 MODF_FRACTION_PART = f10
100 MODF_INTEGER_PART = f11
101 MODF_INT_INTEGER_PART = f12
104 // general registers used
106 modf_GR_no_frac = r15
121 // Main path is p9, p11, p8 FALSE and p12 TRUE
123 // Assume input is normalized and get signexp
124 // Normalize input just in case
125 // Form exponent bias
128 getf.exp modf_signexp = f8
129 fnorm MODF_NORM_F8 = f8
130 addl modf_GR_FFFF = 0xffff, r0
132 // Get integer part of input
133 // Form exponent mask
136 fcvt.fx.trunc.s1 MODF_INT_INTEGER_PART = f8
137 mov modf_17_ones = 0x1ffff ;;
141 // qnan snan inf norm unorm 0 -+
142 // 1 1 1 0 0 0 11 = 0xe3 NAN_INF
143 // Form biased exponent where input only has an integer part
146 fclass.m.unc p6,p13 = f8, 0xe3
147 addl modf_GR_no_frac = 0x1003e, r0 ;;
150 // Mask to get exponent
152 // qnan snan inf norm unorm 0 -+
153 // 0 0 0 0 1 0 11 = 0x0b UNORM
154 // Set p13 to indicate calculation path, else p6 if nan or inf
156 and modf_exp = modf_17_ones, modf_signexp
157 fclass.m.unc p8,p0 = f8, 0x0b
161 // p11 <== SMALL, no integer part, fraction is everyting
162 // p9 <== HUGE, no fraction part, integer is everything
163 // p12 <== NORMAL, fraction part and integer part
165 (p13) cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF
170 // Is x inf? p6 if inf, p7 if nan
172 (p10) cmp.ge.unc p9,p12 = modf_exp, modf_GR_no_frac
173 (p6) fclass.m.unc p6,p7 = f8, 0x23
174 (p8) br.cond.spnt L(MODF_DENORM) ;;
178 // For HUGE set fraction to signed 0
181 (p9) fmerge.s f8 = f8,f0
184 // For HUGE set integer part to normalized input
187 (p9) fnorm MODF_INTEGER_PART = MODF_NORM_F8
191 // For SMALL set fraction to normalized input, integer part to signed 0
194 (p11) fmerge.s MODF_INTEGER_PART = f8,f0
199 (p11) fnorm f8 = MODF_NORM_F8
203 // For NORMAL float the integer part
206 (p12) fcvt.xf MODF_INTEGER_PART = MODF_INT_INTEGER_PART
210 // If x inf set integer part to INF, fraction to signed 0
212 (p6) stfe [r34] = MODF_NORM_F8
213 (p6) fmerge.s f8 = f8,f0
217 // If x nan set integer and fraction parts to NaN (quietized)
219 (p7) stfe [r34] = MODF_NORM_F8
220 (p7) fmerge.s f8 = MODF_NORM_F8, MODF_NORM_F8
225 (p9) stfe [r34] = MODF_INTEGER_PART
230 // For NORMAL compute fraction part
232 (p11) stfe [r34] = MODF_INTEGER_PART
233 (p12) fms.s0 f8 = MODF_NORM_F8,f1, MODF_INTEGER_PART
237 // For NORMAL test if fraction part is zero; if so append correct sign
240 (p12) fcmp.eq.unc p7,p0 = MODF_NORM_F8, MODF_INTEGER_PART
245 (p12) stfe [r34] = MODF_INTEGER_PART
250 // For NORMAL if fraction part is zero append sign of input
253 (p7) fmerge.s f8 = MODF_NORM_F8, f0
258 // If x unorm get signexp from normalized input
259 // If x unorm get integer part from normalized input
261 getf.exp modf_signexp = MODF_NORM_F8
262 fcvt.fx.trunc.s1 MODF_INT_INTEGER_PART = MODF_NORM_F8
266 // If x unorm mask to get exponent
268 and modf_exp = modf_17_ones, modf_signexp ;;
269 cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF
274 (p10) cmp.ge.unc p9,p12 = modf_exp, modf_GR_no_frac
276 br.cond.spnt L(MODF_COMMON) ;;
280 ASM_SIZE_DIRECTIVE(modfl)