1 /* Copyright (C) 2007-2016 Free Software Foundation, Inc.
3 This file is part of GCC.
5 GCC is free software; you can redistribute it and/or modify it under
6 the terms of the GNU General Public License as published by the Free
7 Software Foundation; either version 3, or (at your option) any later
10 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
11 WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 Under Section 7 of GPL version 3, you are granted additional
16 permissions described in the GCC Runtime Library Exception, version
17 3.1, as published by the Free Software Foundation.
19 You should have received a copy of the GNU General Public License and
20 a copy of the GCC Runtime Library Exception along with this program;
21 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
22 <http://www.gnu.org/licenses/>. */
25 #include "bid_internal.h"
28 * Takes a BID64 as input and converts it to a BID128 and returns it.
30 TYPE0_FUNCTION_ARGTYPE1_NORND (UINT128
, bid64_to_bid128
, UINT64
, x
)
32 UINT128 new_coeff
, res
;
37 if (!unpack_BID64 (&sign_x
, &exponent_x
, &coefficient_x
, x
)) {
38 if (((x
) << 1) >= 0xf000000000000000ull
) {
39 #ifdef SET_STATUS_FLAGS
40 if (((x
) & SNAN_MASK64
) == SNAN_MASK64
) // sNaN
41 __set_status_flags (pfpsf
, INVALID_EXCEPTION
);
43 res
.w
[0] = (coefficient_x
& 0x0003ffffffffffffull
);
44 __mul_64x64_to_128 (res
, res
.w
[0], power10_table_128
[18].w
[0]);
45 res
.w
[1] |= ((coefficient_x
) & 0xfc00000000000000ull
);
50 new_coeff
.w
[0] = coefficient_x
;
52 get_BID128_very_fast (&res
, sign_x
,
53 exponent_x
+ DECIMAL_EXPONENT_BIAS_128
-
54 DECIMAL_EXPONENT_BIAS
, new_coeff
);
56 } // convert_bid64_to_bid128
61 * Takes a BID128 as input and converts it to a BID64 and returns it.
63 #if DECIMAL_CALL_BY_REFERENCE
66 bid128_to_bid64 (UINT64
* pres
,
68 px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
74 bid128_to_bid64 (UINT128 x _RND_MODE_PARAM _EXC_FLAGS_PARAM
75 _EXC_MASKS_PARAM _EXC_INFO_PARAM
) {
77 UINT128 CX
, T128
, TP128
, Qh
, Ql
, Qh1
, Stemp
, Tmp
, Tmp1
, CX1
;
78 UINT64 sign_x
, carry
, cy
, res
;
81 int exponent_x
, extra_digits
, amount
, bin_expon_cx
;
82 unsigned rmode
, status
, uf_check
= 0;
84 #if DECIMAL_CALL_BY_REFERENCE
85 #if !DECIMAL_GLOBAL_ROUNDING
86 _IDEC_round rnd_mode
= *prnd_mode
;
91 // unpack arguments, check for NaN or Infinity or 0
92 if (!unpack_BID128_value (&sign_x
, &exponent_x
, &CX
, x
)) {
93 if ((x
.w
[1] << 1) >= 0xf000000000000000ull
) {
94 Tmp
.w
[1] = (CX
.w
[1] & 0x00003fffffffffffull
);
96 TP128
= reciprocals10_128
[18];
97 __mul_128x128_full (Qh
, Ql
, Tmp
, TP128
);
98 amount
= recip_scale
[18];
99 __shr_128 (Tmp
, Qh
, amount
);
100 res
= (CX
.w
[1] & 0xfc00000000000000ull
) | Tmp
.w
[0];
101 #ifdef SET_STATUS_FLAGS
102 if ((x
.w
[1] & SNAN_MASK64
) == SNAN_MASK64
) // sNaN
103 __set_status_flags (pfpsf
, INVALID_EXCEPTION
);
105 BID_RETURN_VAL (res
);
108 exponent_x
- DECIMAL_EXPONENT_BIAS_128
+ DECIMAL_EXPONENT_BIAS
;
109 if (exponent_x
< 0) {
111 BID_RETURN_VAL (res
);
113 if (exponent_x
> DECIMAL_MAX_EXPON_64
)
114 exponent_x
= DECIMAL_MAX_EXPON_64
;
115 res
= sign_x
| (((UINT64
) exponent_x
) << 53);
116 BID_RETURN_VAL (res
);
119 if (CX
.w
[1] || (CX
.w
[0] >= 10000000000000000ull)) {
120 // find number of digits in coefficient
124 fx
.d
= (float) CX
.w
[1] * f64
.d
+ (float) CX
.w
[0];
125 bin_expon_cx
= ((fx
.i
>> 23) & 0xff) - 0x7f;
126 extra_digits
= estimate_decimal_digits
[bin_expon_cx
] - 16;
127 // scale = 38-estimate_decimal_digits[bin_expon_cx];
128 D
= CX
.w
[1] - power10_index_binexp_128
[bin_expon_cx
].w
[1];
131 && CX
.w
[0] >= power10_index_binexp_128
[bin_expon_cx
].w
[0]))
134 exponent_x
+= extra_digits
;
136 #ifndef IEEE_ROUND_NEAREST_TIES_AWAY
137 #ifndef IEEE_ROUND_NEAREST
139 if (sign_x
&& (unsigned) (rmode
- 1) < 2)
147 if (exponent_x
< DECIMAL_EXPONENT_BIAS_128
- DECIMAL_EXPONENT_BIAS
) {
149 if (-extra_digits
+ exponent_x
- DECIMAL_EXPONENT_BIAS_128
+
150 DECIMAL_EXPONENT_BIAS
+ 35 >= 0) {
152 DECIMAL_EXPONENT_BIAS_128
- DECIMAL_EXPONENT_BIAS
- 1) {
153 T128
= round_const_table_128
[rmode
][extra_digits
];
154 __add_carry_out (CX1
.w
[0], carry
, T128
.w
[0], CX
.w
[0]);
155 CX1
.w
[1] = CX
.w
[1] + T128
.w
[1] + carry
;
156 if (__unsigned_compare_ge_128
157 (CX1
, power10_table_128
[extra_digits
+ 16]))
161 extra_digits
+ DECIMAL_EXPONENT_BIAS_128
-
162 DECIMAL_EXPONENT_BIAS
- exponent_x
;
163 exponent_x
= DECIMAL_EXPONENT_BIAS_128
- DECIMAL_EXPONENT_BIAS
;
166 rmode
= ROUNDING_TO_ZERO
;
169 T128
= round_const_table_128
[rmode
][extra_digits
];
170 __add_carry_out (CX
.w
[0], carry
, T128
.w
[0], CX
.w
[0]);
171 CX
.w
[1] = CX
.w
[1] + T128
.w
[1] + carry
;
173 TP128
= reciprocals10_128
[extra_digits
];
174 __mul_128x128_full (Qh
, Ql
, CX
, TP128
);
175 amount
= recip_scale
[extra_digits
];
178 CX
.w
[0] = Qh
.w
[1] >> (amount
- 64);
181 __shr_128 (CX
, Qh
, amount
);
184 #ifndef IEEE_ROUND_NEAREST_TIES_AWAY
185 #ifndef IEEE_ROUND_NEAREST
189 // check whether fractional part of initial_P/10^ed1 is exactly .5
192 __shl_128_long (Qh1
, Qh
, (128 - amount
));
194 if (!Qh1
.w
[1] && !Qh1
.w
[0]
195 && (Ql
.w
[1] < reciprocals10_128
[extra_digits
].w
[1]
196 || (Ql
.w
[1] == reciprocals10_128
[extra_digits
].w
[1]
197 && Ql
.w
[0] < reciprocals10_128
[extra_digits
].w
[0]))) {
204 status
= INEXACT_EXCEPTION
;
206 __shl_128_long (Qh1
, Qh
, (128 - amount
));
209 case ROUNDING_TO_NEAREST
:
210 case ROUNDING_TIES_AWAY
:
211 // test whether fractional part is 0
212 if (Qh1
.w
[1] == 0x8000000000000000ull
&& (!Qh1
.w
[0])
213 && (Ql
.w
[1] < reciprocals10_128
[extra_digits
].w
[1]
214 || (Ql
.w
[1] == reciprocals10_128
[extra_digits
].w
[1]
215 && Ql
.w
[0] < reciprocals10_128
[extra_digits
].w
[0])))
216 status
= EXACT_STATUS
;
219 case ROUNDING_TO_ZERO
:
220 if ((!Qh1
.w
[1]) && (!Qh1
.w
[0])
221 && (Ql
.w
[1] < reciprocals10_128
[extra_digits
].w
[1]
222 || (Ql
.w
[1] == reciprocals10_128
[extra_digits
].w
[1]
223 && Ql
.w
[0] < reciprocals10_128
[extra_digits
].w
[0])))
224 status
= EXACT_STATUS
;
228 __add_carry_out (Stemp
.w
[0], cy
, Ql
.w
[0],
229 reciprocals10_128
[extra_digits
].w
[0]);
230 __add_carry_in_out (Stemp
.w
[1], carry
, Ql
.w
[1],
231 reciprocals10_128
[extra_digits
].w
[1], cy
);
232 __shr_128_long (Qh
, Qh1
, (128 - amount
));
235 __shl_128_long (Tmp1
, Tmp
, amount
);
239 if (__unsigned_compare_ge_128 (Qh
, Tmp1
))
240 status
= EXACT_STATUS
;
243 if (status
!= EXACT_STATUS
) {
245 status
|= UNDERFLOW_EXCEPTION
;
246 #ifdef SET_STATUS_FLAGS
247 __set_status_flags (pfpsf
, status
);
258 exponent_x
- DECIMAL_EXPONENT_BIAS_128
+
259 DECIMAL_EXPONENT_BIAS
, CX
.w
[0], rnd_mode
, pfpsf
);
260 BID_RETURN_VAL (res
);