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40 //==============================================================
41 // 02/02/00 Initial version
42 // 04/04/00 Improved speed, corrected result for NaN input
43 // 05/30/00 Fixed bug for exponent 0x1003e
44 // 12/22/00 Fixed so inexact flag is never set, and invalid is not set for
45 // qnans nor for inputs larger than 2^63.
46 // 05/20/02 Cleaned up namespace and sf0 syntax
47 // 02/10/03 Reordered header: .section, .global, .proc, .align
50 //==============================================================
51 // long double modfl(long double x, long double *iptr)
52 // break a floating point x number into fraction and an exponent
54 // input floating point f8, address in r34
55 // output floating point f8 (x fraction), and *iptr (x integral part)
58 //==============================================================
60 // NO FRACTIONAL PART: HUGE
62 // for double-extended
63 // If the true exponent is >= 63
64 // 1003e ==> 1003e -ffff = 3f = 63(dec)
66 // we are already an integer (p9 true)
68 // NO INTEGER PART: SMALL
69 // Is f8 exponent less than register bias (that is, is it
70 // less than 1). If it is, get the right sign of
71 // zero and store this in iptr.
73 // CALCULATION: NOT HUGE, NOT SMALL
74 // To get the integer part
75 // Take the floating-point input and truncate
76 // then convert this integer to fp Call it MODF_INTEGER_PART
78 // Subtract MODF_INTEGER_PART from MODF_NORM_F8 to get fraction part
79 // Then put fraction part in f8
80 // put integer part MODF_INTEGER_PART into *iptr
83 //==============================================================
85 // predicate registers used:
89 // -----------------------+-----------------+-------------
90 // SMALL | NORMAL | HUGE
91 // p11 --------------->|<----- p12 ----->| <-------------- p9
92 // p10 --------------------------------->|
93 // p13 --------------------------------------------------->|
96 // floating-point registers used:
98 MODF_FRACTION_PART = f10
99 MODF_INTEGER_PART = f11
100 MODF_INT_INTEGER_PART = f12
103 // general registers used
105 modf_GR_no_frac = r15
113 GLOBAL_LIBM_ENTRY(modfl)
115 // Main path is p9, p11, p8 FALSE and p12 TRUE
117 // Assume input is normalized and get signexp
118 // Normalize input just in case
119 // Form exponent bias
121 getf.exp modf_signexp = f8
122 fnorm.s0 MODF_NORM_F8 = f8
123 addl modf_GR_FFFF = 0xffff, r0
125 // Get integer part of input
126 // Form exponent mask
129 fcvt.fx.trunc.s1 MODF_INT_INTEGER_PART = f8
130 mov modf_17_ones = 0x1ffff ;;
134 // qnan snan inf norm unorm 0 -+
135 // 1 1 1 0 0 0 11 = 0xe3 NAN_INF
136 // Form biased exponent where input only has an integer part
139 fclass.m.unc p6,p13 = f8, 0xe3
140 addl modf_GR_no_frac = 0x1003e, r0 ;;
143 // Mask to get exponent
145 // qnan snan inf norm unorm 0 -+
146 // 0 0 0 0 1 0 11 = 0x0b UNORM
147 // Set p13 to indicate calculation path, else p6 if nan or inf
149 and modf_exp = modf_17_ones, modf_signexp
150 fclass.m.unc p8,p0 = f8, 0x0b
154 // p11 <== SMALL, no integer part, fraction is everything
155 // p9 <== HUGE, no fraction part, integer is everything
156 // p12 <== NORMAL, fraction part and integer part
158 (p13) cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF
163 // Is x inf? p6 if inf, p7 if nan
165 (p10) cmp.ge.unc p9,p12 = modf_exp, modf_GR_no_frac
166 (p6) fclass.m.unc p6,p7 = f8, 0x23
167 (p8) br.cond.spnt MODF_DENORM ;;
171 // For HUGE set fraction to signed 0
174 (p9) fmerge.s f8 = f8,f0
177 // For HUGE set integer part to normalized input
180 (p9) fnorm.s0 MODF_INTEGER_PART = MODF_NORM_F8
184 // For SMALL set fraction to normalized input, integer part to signed 0
187 (p11) fmerge.s MODF_INTEGER_PART = f8,f0
192 (p11) fnorm.s0 f8 = MODF_NORM_F8
196 // For NORMAL float the integer part
199 (p12) fcvt.xf MODF_INTEGER_PART = MODF_INT_INTEGER_PART
203 // If x inf set integer part to INF, fraction to signed 0
205 (p6) stfe [r34] = MODF_NORM_F8
206 (p6) fmerge.s f8 = f8,f0
210 // If x nan set integer and fraction parts to NaN (quietized)
212 (p7) stfe [r34] = MODF_NORM_F8
213 (p7) fmerge.s f8 = MODF_NORM_F8, MODF_NORM_F8
218 (p9) stfe [r34] = MODF_INTEGER_PART
223 // For NORMAL compute fraction part
225 (p11) stfe [r34] = MODF_INTEGER_PART
226 (p12) fms.s0 f8 = MODF_NORM_F8,f1, MODF_INTEGER_PART
230 // For NORMAL test if fraction part is zero; if so append correct sign
233 (p12) fcmp.eq.unc.s0 p7,p0 = MODF_NORM_F8, MODF_INTEGER_PART
238 (p12) stfe [r34] = MODF_INTEGER_PART
243 // For NORMAL if fraction part is zero append sign of input
246 (p7) fmerge.s f8 = MODF_NORM_F8, f0
251 // If x unorm get signexp from normalized input
252 // If x unorm get integer part from normalized input
254 getf.exp modf_signexp = MODF_NORM_F8
255 fcvt.fx.trunc.s1 MODF_INT_INTEGER_PART = MODF_NORM_F8
259 // If x unorm mask to get exponent
261 and modf_exp = modf_17_ones, modf_signexp ;;
262 cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF
267 (p10) cmp.ge.unc p9,p12 = modf_exp, modf_GR_no_frac
269 br.cond.spnt MODF_COMMON ;;
272 GLOBAL_LIBM_END(modfl)
273 libm_alias_ldouble_other (modf, modf)