1/* mpfr_add1sp1 -- internal function to perform a "real" addition on one limb
2   This code was extracted by Kremlin from a formal proof in F*
3   done by Jianyang Pan in April-August 2018: do not modify it!
4
5Source: https://github.com/project-everest/hacl-star/tree/dev_mpfr/code/mpfr
6
7Copyright 2004-2023 Free Software Foundation, Inc.
8Contributed by the AriC and Caramba projects, INRIA.
9
10This file is part of the GNU MPFR Library.
11
12The GNU MPFR Library is free software; you can redistribute it and/or modify
13it under the terms of the GNU Lesser General Public License as published by
14the Free Software Foundation; either version 3 of the License, or (at your
15option) any later version.
16
17The GNU MPFR Library is distributed in the hope that it will be useful, but
18WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
19or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
20License for more details.
21
22You should have received a copy of the GNU Lesser General Public License
23along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
24https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
2551 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
26
27#define int64_t long
28#define uint32_t unsigned int
29#define uint64_t mp_limb_t
30
31typedef struct MPFR_Add1sp1_state_s
32{
33  int64_t sh;
34  int64_t bx;
35  uint64_t rb;
36  uint64_t sb;
37}
38MPFR_Add1sp1_state;
39
40static MPFR_Add1sp1_state
41MPFR_Add1sp1_mk_state(int64_t sh, int64_t bx, uint64_t rb, uint64_t sb)
42{
43  return ((MPFR_Add1sp1_state){ .sh = sh, .bx = bx, .rb = rb, .sb = sb });
44}
45
46typedef struct K___uint64_t_int64_t_s
47{
48  uint64_t fst;
49  int64_t snd;
50}
51K___uint64_t_int64_t;
52
53typedef struct K___uint64_t_uint64_t_int64_t_s
54{
55  uint64_t fst;
56  uint64_t snd;
57  int64_t thd;
58}
59K___uint64_t_uint64_t_int64_t;
60
61#define MPFR_Lib_mpfr_struct __mpfr_struct
62#define MPFR_Lib_mpfr_RET(I) ((I) != 0 ? ((__gmpfr_flags |= MPFR_FLAGS_INEXACT), (I)) : 0)
63#define MPFR_Exceptions_mpfr_overflow mpfr_overflow
64#define mpfr_prec _mpfr_prec
65#define mpfr_exp _mpfr_exp
66#define mpfr_d _mpfr_d
67#define mpfr_sign _mpfr_sign
68#define MPFR_Lib_gmp_NUMB_BITS GMP_NUMB_BITS
69#define MPFR_Lib_mpfr_EMAX __gmpfr_emax
70
71#define MPFR_RoundingMode_uu___is_MPFR_RNDN(rnd_mode) (rnd_mode == MPFR_RNDN)
72#define MPFR_RoundingMode_mpfr_IS_LIKE_RNDZ MPFR_IS_LIKE_RNDZ
73
74/* same as mpfr_add1sp, but for p < GMP_NUMB_BITS */
75static int
76mpfr_add1sp1 (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode,
77              mpfr_prec_t p)
78{
79  MPFR_Lib_mpfr_struct a0 = a[0U];
80  MPFR_Lib_mpfr_struct b0 = b[0U];
81  MPFR_Lib_mpfr_struct c0 = c[0U];
82  int64_t bx = b0.mpfr_exp;
83  int64_t cx = c0.mpfr_exp;
84  int64_t sh = MPFR_Lib_gmp_NUMB_BITS - p;
85  MPFR_Add1sp1_state st;
86  if (bx == cx)
87  {
88    uint64_t *ap = a0.mpfr_d;
89    uint64_t *bp = b0.mpfr_d;
90    uint64_t *cp = c0.mpfr_d;
91    uint64_t a01 = (bp[0U] >> (uint32_t)1U) + (cp[0U] >> (uint32_t)1U);
92    int64_t bx1 = b0.mpfr_exp + (int64_t)1;
93    uint64_t rb = a01 & (uint64_t)1U << (uint32_t)(sh - (int64_t)1);
94    ap[0U] = a01 ^ rb;
95    uint64_t sb = (uint64_t)0U;
96    st = MPFR_Add1sp1_mk_state(sh, bx1, rb, sb);
97  }
98  else
99  {
100    MPFR_Add1sp1_state ite0;
101    if (bx > cx)
102    {
103      int64_t bx1 = b0.mpfr_exp;
104      int64_t cx1 = c0.mpfr_exp;
105      int64_t d = bx1 - cx1;
106      uint64_t mask = ((uint64_t)1U << (uint32_t)sh) - (uint64_t)1U;
107      MPFR_Add1sp1_state ite1;
108      if (d < sh)
109      {
110        uint64_t *ap = a0.mpfr_d;
111        uint64_t *bp = b0.mpfr_d;
112        uint64_t *cp = c0.mpfr_d;
113        int64_t bx2 = b0.mpfr_exp;
114        uint64_t a01 = bp[0U] + (cp[0U] >> (uint32_t)d);
115        K___uint64_t_int64_t scrut;
116        if (a01 < bp[0U])
117          scrut =
118            (
119              (K___uint64_t_int64_t){
120                .fst = (uint64_t)0x8000000000000000U | a01 >> (uint32_t)1U,
121                .snd = bx2 + (int64_t)1
122              }
123            );
124        else
125          scrut = ((K___uint64_t_int64_t){ .fst = a01, .snd = bx2 });
126        uint64_t a02 = scrut.fst;
127        int64_t bx3 = scrut.snd;
128        uint64_t rb = a02 & (uint64_t)1U << (uint32_t)(sh - (int64_t)1);
129        uint64_t sb = (a02 & mask) ^ rb;
130        ap[0U] = a02 & ~mask;
131        ite1 = MPFR_Add1sp1_mk_state(sh, bx3, rb, sb);
132      }
133      else
134      {
135        MPFR_Add1sp1_state ite;
136        if (d < MPFR_Lib_gmp_NUMB_BITS)
137        {
138          uint64_t *ap = a0.mpfr_d;
139          uint64_t *bp = b0.mpfr_d;
140          uint64_t *cp = c0.mpfr_d;
141          int64_t bx2 = b0.mpfr_exp;
142          uint64_t sb = cp[0U] << (uint32_t)(MPFR_Lib_gmp_NUMB_BITS - d);
143          uint64_t a01 = bp[0U] + (cp[0U] >> (uint32_t)d);
144          K___uint64_t_uint64_t_int64_t scrut;
145          if (a01 < bp[0U])
146            scrut =
147              (
148                (K___uint64_t_uint64_t_int64_t){
149                  .fst = sb | (a01 & (uint64_t)1U),
150                  .snd = (uint64_t)0x8000000000000000U | a01 >> (uint32_t)1U,
151                  .thd = bx2 + (int64_t)1
152                }
153              );
154          else
155            scrut = ((K___uint64_t_uint64_t_int64_t){ .fst = sb, .snd = a01, .thd = bx2 });
156          uint64_t sb1 = scrut.fst;
157          uint64_t a02 = scrut.snd;
158          int64_t bx3 = scrut.thd;
159          uint64_t rb = a02 & (uint64_t)1U << (uint32_t)(sh - (int64_t)1);
160          uint64_t sb2 = sb1 | ((a02 & mask) ^ rb);
161          ap[0U] = a02 & ~mask;
162          ite = MPFR_Add1sp1_mk_state(sh, bx3, rb, sb2);
163        }
164        else
165        {
166          uint64_t *ap = a0.mpfr_d;
167          uint64_t *bp = b0.mpfr_d;
168          int64_t bx2 = b0.mpfr_exp;
169          ap[0U] = bp[0U];
170          uint64_t rb = (uint64_t)0U;
171          uint64_t sb = (uint64_t)1U;
172          ite = MPFR_Add1sp1_mk_state(sh, bx2, rb, sb);
173        }
174        ite1 = ite;
175      }
176      ite0 = ite1;
177    }
178    else
179    {
180      int64_t bx1 = c0.mpfr_exp;
181      int64_t cx1 = b0.mpfr_exp;
182      int64_t d = bx1 - cx1;
183      uint64_t mask = ((uint64_t)1U << (uint32_t)sh) - (uint64_t)1U;
184      MPFR_Add1sp1_state ite1;
185      if (d < sh)
186      {
187        uint64_t *ap = a0.mpfr_d;
188        uint64_t *bp = c0.mpfr_d;
189        uint64_t *cp = b0.mpfr_d;
190        int64_t bx2 = c0.mpfr_exp;
191        uint64_t a01 = bp[0U] + (cp[0U] >> (uint32_t)d);
192        K___uint64_t_int64_t scrut;
193        if (a01 < bp[0U])
194          scrut =
195            (
196              (K___uint64_t_int64_t){
197                .fst = (uint64_t)0x8000000000000000U | a01 >> (uint32_t)1U,
198                .snd = bx2 + (int64_t)1
199              }
200            );
201        else
202          scrut = ((K___uint64_t_int64_t){ .fst = a01, .snd = bx2 });
203        uint64_t a02 = scrut.fst;
204        int64_t bx3 = scrut.snd;
205        uint64_t rb = a02 & (uint64_t)1U << (uint32_t)(sh - (int64_t)1);
206        uint64_t sb = (a02 & mask) ^ rb;
207        ap[0U] = a02 & ~mask;
208        ite1 = MPFR_Add1sp1_mk_state(sh, bx3, rb, sb);
209      }
210      else
211      {
212        MPFR_Add1sp1_state ite;
213        if (d < MPFR_Lib_gmp_NUMB_BITS)
214        {
215          uint64_t *ap = a0.mpfr_d;
216          uint64_t *bp = c0.mpfr_d;
217          uint64_t *cp = b0.mpfr_d;
218          int64_t bx2 = c0.mpfr_exp;
219          uint64_t sb = cp[0U] << (uint32_t)(MPFR_Lib_gmp_NUMB_BITS - d);
220          uint64_t a01 = bp[0U] + (cp[0U] >> (uint32_t)d);
221          K___uint64_t_uint64_t_int64_t scrut;
222          if (a01 < bp[0U])
223            scrut =
224              (
225                (K___uint64_t_uint64_t_int64_t){
226                  .fst = sb | (a01 & (uint64_t)1U),
227                  .snd = (uint64_t)0x8000000000000000U | a01 >> (uint32_t)1U,
228                  .thd = bx2 + (int64_t)1
229                }
230              );
231          else
232            scrut = ((K___uint64_t_uint64_t_int64_t){ .fst = sb, .snd = a01, .thd = bx2 });
233          uint64_t sb1 = scrut.fst;
234          uint64_t a02 = scrut.snd;
235          int64_t bx3 = scrut.thd;
236          uint64_t rb = a02 & (uint64_t)1U << (uint32_t)(sh - (int64_t)1);
237          uint64_t sb2 = sb1 | ((a02 & mask) ^ rb);
238          ap[0U] = a02 & ~mask;
239          ite = MPFR_Add1sp1_mk_state(sh, bx3, rb, sb2);
240        }
241        else
242        {
243          uint64_t *ap = a0.mpfr_d;
244          uint64_t *bp = c0.mpfr_d;
245          int64_t bx2 = c0.mpfr_exp;
246          ap[0U] = bp[0U];
247          uint64_t rb = (uint64_t)0U;
248          uint64_t sb = (uint64_t)1U;
249          ite = MPFR_Add1sp1_mk_state(sh, bx2, rb, sb);
250        }
251        ite1 = ite;
252      }
253      ite0 = ite1;
254    }
255    st = ite0;
256  }
257  if (st.bx > MPFR_Lib_mpfr_EMAX)
258  {
259    int32_t t = MPFR_Exceptions_mpfr_overflow(a, rnd_mode, a->mpfr_sign);
260    return t;
261  }
262  else
263  {
264    uint64_t *ap = a->mpfr_d;
265    uint64_t a01 = ap[0U];
266    MPFR_Lib_mpfr_struct uu___72_3478 = a[0U];
267    a[0U] =
268      (
269        (MPFR_Lib_mpfr_struct){
270          .mpfr_prec = uu___72_3478.mpfr_prec,
271          .mpfr_sign = uu___72_3478.mpfr_sign,
272          .mpfr_exp = st.bx,
273          .mpfr_d = uu___72_3478.mpfr_d
274        }
275      );
276    if (st.rb == (uint64_t)0U && st.sb == (uint64_t)0U)
277      return MPFR_Lib_mpfr_RET((int32_t)0);
278    else if (MPFR_RoundingMode_uu___is_MPFR_RNDN(rnd_mode))
279      if
280      (
281        st.rb
282        == (uint64_t)0U
283        || (st.sb == (uint64_t)0U && (a01 & (uint64_t)1U << (uint32_t)st.sh) == (uint64_t)0U)
284      )
285      {
286        int32_t ite;
287        if (a->mpfr_sign == (int32_t)1)
288          ite = (int32_t)-1;
289        else
290          ite = (int32_t)1;
291        return MPFR_Lib_mpfr_RET(ite);
292      }
293      else
294      {
295        uint64_t *ap1 = a->mpfr_d;
296        ap1[0U] = ap1[0U] + ((uint64_t)1U << (uint32_t)st.sh);
297        if (ap1[0U] == (uint64_t)0U)
298        {
299          ap1[0U] = (uint64_t)0x8000000000000000U;
300          if (st.bx + (int64_t)1 <= MPFR_Lib_mpfr_EMAX)
301          {
302            MPFR_Lib_mpfr_struct uu___72_3574 = a[0U];
303            a[0U] =
304              (
305                (MPFR_Lib_mpfr_struct){
306                  .mpfr_prec = uu___72_3574.mpfr_prec,
307                  .mpfr_sign = uu___72_3574.mpfr_sign,
308                  .mpfr_exp = st.bx + (int64_t)1,
309                  .mpfr_d = uu___72_3574.mpfr_d
310                }
311              );
312            return MPFR_Lib_mpfr_RET(a->mpfr_sign);
313          }
314          else
315          {
316            int32_t t = MPFR_Exceptions_mpfr_overflow(a, rnd_mode, a->mpfr_sign);
317            return MPFR_Lib_mpfr_RET(t);
318          }
319        }
320        else
321          return MPFR_Lib_mpfr_RET(a->mpfr_sign);
322      }
323    else if (MPFR_RoundingMode_mpfr_IS_LIKE_RNDZ(rnd_mode, a->mpfr_sign < (int32_t)0))
324    {
325      int32_t ite;
326      if (a->mpfr_sign == (int32_t)1)
327        ite = (int32_t)-1;
328      else
329        ite = (int32_t)1;
330      return MPFR_Lib_mpfr_RET(ite);
331    }
332    else
333    {
334      uint64_t *ap1 = a->mpfr_d;
335      ap1[0U] = ap1[0U] + ((uint64_t)1U << (uint32_t)st.sh);
336      if (ap1[0U] == (uint64_t)0U)
337      {
338        ap1[0U] = (uint64_t)0x8000000000000000U;
339        if (st.bx + (int64_t)1 <= MPFR_Lib_mpfr_EMAX)
340        {
341          MPFR_Lib_mpfr_struct uu___72_3781 = a[0U];
342          a[0U] =
343            (
344              (MPFR_Lib_mpfr_struct){
345                .mpfr_prec = uu___72_3781.mpfr_prec,
346                .mpfr_sign = uu___72_3781.mpfr_sign,
347                .mpfr_exp = st.bx + (int64_t)1,
348                .mpfr_d = uu___72_3781.mpfr_d
349              }
350            );
351          return MPFR_Lib_mpfr_RET(a->mpfr_sign);
352        }
353        else
354        {
355          int32_t t = MPFR_Exceptions_mpfr_overflow(a, rnd_mode, a->mpfr_sign);
356          return MPFR_Lib_mpfr_RET(t);
357        }
358      }
359      else
360        return MPFR_Lib_mpfr_RET(a->mpfr_sign);
361    }
362  }
363}
364