xref: /qemu/target/arm/vfp_helper.c (revision 05e391ae)
1 /*
2  * ARM VFP floating-point operations
3  *
4  *  Copyright (c) 2003 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/helper-proto.h"
23 #include "internals.h"
24 #ifdef CONFIG_TCG
25 #include "qemu/log.h"
26 #include "fpu/softfloat.h"
27 #endif
28 
29 /* VFP support.  We follow the convention used for VFP instructions:
30    Single precision routines have a "s" suffix, double precision a
31    "d" suffix.  */
32 
33 #ifdef CONFIG_TCG
34 
35 /* Convert host exception flags to vfp form.  */
36 static inline int vfp_exceptbits_from_host(int host_bits)
37 {
38     int target_bits = 0;
39 
40     if (host_bits & float_flag_invalid) {
41         target_bits |= 1;
42     }
43     if (host_bits & float_flag_divbyzero) {
44         target_bits |= 2;
45     }
46     if (host_bits & float_flag_overflow) {
47         target_bits |= 4;
48     }
49     if (host_bits & (float_flag_underflow | float_flag_output_denormal)) {
50         target_bits |= 8;
51     }
52     if (host_bits & float_flag_inexact) {
53         target_bits |= 0x10;
54     }
55     if (host_bits & float_flag_input_denormal) {
56         target_bits |= 0x80;
57     }
58     return target_bits;
59 }
60 
61 /* Convert vfp exception flags to target form.  */
62 static inline int vfp_exceptbits_to_host(int target_bits)
63 {
64     int host_bits = 0;
65 
66     if (target_bits & 1) {
67         host_bits |= float_flag_invalid;
68     }
69     if (target_bits & 2) {
70         host_bits |= float_flag_divbyzero;
71     }
72     if (target_bits & 4) {
73         host_bits |= float_flag_overflow;
74     }
75     if (target_bits & 8) {
76         host_bits |= float_flag_underflow;
77     }
78     if (target_bits & 0x10) {
79         host_bits |= float_flag_inexact;
80     }
81     if (target_bits & 0x80) {
82         host_bits |= float_flag_input_denormal;
83     }
84     return host_bits;
85 }
86 
87 static uint32_t vfp_get_fpscr_from_host(CPUARMState *env)
88 {
89     uint32_t i;
90 
91     i = get_float_exception_flags(&env->vfp.fp_status);
92     i |= get_float_exception_flags(&env->vfp.standard_fp_status);
93     /* FZ16 does not generate an input denormal exception.  */
94     i |= (get_float_exception_flags(&env->vfp.fp_status_f16)
95           & ~float_flag_input_denormal);
96     i |= (get_float_exception_flags(&env->vfp.standard_fp_status_f16)
97           & ~float_flag_input_denormal);
98     return vfp_exceptbits_from_host(i);
99 }
100 
101 static void vfp_set_fpscr_to_host(CPUARMState *env, uint32_t val)
102 {
103     int i;
104     uint32_t changed = env->vfp.xregs[ARM_VFP_FPSCR];
105 
106     changed ^= val;
107     if (changed & (3 << 22)) {
108         i = (val >> 22) & 3;
109         switch (i) {
110         case FPROUNDING_TIEEVEN:
111             i = float_round_nearest_even;
112             break;
113         case FPROUNDING_POSINF:
114             i = float_round_up;
115             break;
116         case FPROUNDING_NEGINF:
117             i = float_round_down;
118             break;
119         case FPROUNDING_ZERO:
120             i = float_round_to_zero;
121             break;
122         }
123         set_float_rounding_mode(i, &env->vfp.fp_status);
124         set_float_rounding_mode(i, &env->vfp.fp_status_f16);
125     }
126     if (changed & FPCR_FZ16) {
127         bool ftz_enabled = val & FPCR_FZ16;
128         set_flush_to_zero(ftz_enabled, &env->vfp.fp_status_f16);
129         set_flush_to_zero(ftz_enabled, &env->vfp.standard_fp_status_f16);
130         set_flush_inputs_to_zero(ftz_enabled, &env->vfp.fp_status_f16);
131         set_flush_inputs_to_zero(ftz_enabled, &env->vfp.standard_fp_status_f16);
132     }
133     if (changed & FPCR_FZ) {
134         bool ftz_enabled = val & FPCR_FZ;
135         set_flush_to_zero(ftz_enabled, &env->vfp.fp_status);
136         set_flush_inputs_to_zero(ftz_enabled, &env->vfp.fp_status);
137     }
138     if (changed & FPCR_DN) {
139         bool dnan_enabled = val & FPCR_DN;
140         set_default_nan_mode(dnan_enabled, &env->vfp.fp_status);
141         set_default_nan_mode(dnan_enabled, &env->vfp.fp_status_f16);
142     }
143 
144     /*
145      * The exception flags are ORed together when we read fpscr so we
146      * only need to preserve the current state in one of our
147      * float_status values.
148      */
149     i = vfp_exceptbits_to_host(val);
150     set_float_exception_flags(i, &env->vfp.fp_status);
151     set_float_exception_flags(0, &env->vfp.fp_status_f16);
152     set_float_exception_flags(0, &env->vfp.standard_fp_status);
153     set_float_exception_flags(0, &env->vfp.standard_fp_status_f16);
154 }
155 
156 #else
157 
158 static uint32_t vfp_get_fpscr_from_host(CPUARMState *env)
159 {
160     return 0;
161 }
162 
163 static void vfp_set_fpscr_to_host(CPUARMState *env, uint32_t val)
164 {
165 }
166 
167 #endif
168 
169 uint32_t HELPER(vfp_get_fpscr)(CPUARMState *env)
170 {
171     uint32_t i, fpscr;
172 
173     fpscr = env->vfp.xregs[ARM_VFP_FPSCR]
174             | (env->vfp.vec_len << 16)
175             | (env->vfp.vec_stride << 20);
176 
177     /*
178      * M-profile LTPSIZE overlaps A-profile Stride; whichever of the
179      * two is not applicable to this CPU will always be zero.
180      */
181     fpscr |= env->v7m.ltpsize << 16;
182 
183     fpscr |= vfp_get_fpscr_from_host(env);
184 
185     i = env->vfp.qc[0] | env->vfp.qc[1] | env->vfp.qc[2] | env->vfp.qc[3];
186     fpscr |= i ? FPCR_QC : 0;
187 
188     return fpscr;
189 }
190 
191 uint32_t vfp_get_fpscr(CPUARMState *env)
192 {
193     return HELPER(vfp_get_fpscr)(env);
194 }
195 
196 void HELPER(vfp_set_fpscr)(CPUARMState *env, uint32_t val)
197 {
198     ARMCPU *cpu = env_archcpu(env);
199 
200     /* When ARMv8.2-FP16 is not supported, FZ16 is RES0.  */
201     if (!cpu_isar_feature(any_fp16, cpu)) {
202         val &= ~FPCR_FZ16;
203     }
204 
205     vfp_set_fpscr_to_host(env, val);
206 
207     if (!arm_feature(env, ARM_FEATURE_M)) {
208         /*
209          * Short-vector length and stride; on M-profile these bits
210          * are used for different purposes.
211          * We can't make this conditional be "if MVFR0.FPShVec != 0",
212          * because in v7A no-short-vector-support cores still had to
213          * allow Stride/Len to be written with the only effect that
214          * some insns are required to UNDEF if the guest sets them.
215          */
216         env->vfp.vec_len = extract32(val, 16, 3);
217         env->vfp.vec_stride = extract32(val, 20, 2);
218     } else if (cpu_isar_feature(aa32_mve, cpu)) {
219         env->v7m.ltpsize = extract32(val, FPCR_LTPSIZE_SHIFT,
220                                      FPCR_LTPSIZE_LENGTH);
221     }
222 
223     if (arm_feature(env, ARM_FEATURE_NEON) ||
224         cpu_isar_feature(aa32_mve, cpu)) {
225         /*
226          * The bit we set within fpscr_q is arbitrary; the register as a
227          * whole being zero/non-zero is what counts.
228          * TODO: M-profile MVE also has a QC bit.
229          */
230         env->vfp.qc[0] = val & FPCR_QC;
231         env->vfp.qc[1] = 0;
232         env->vfp.qc[2] = 0;
233         env->vfp.qc[3] = 0;
234     }
235 
236     /*
237      * We don't implement trapped exception handling, so the
238      * trap enable bits, IDE|IXE|UFE|OFE|DZE|IOE are all RAZ/WI (not RES0!)
239      *
240      * The exception flags IOC|DZC|OFC|UFC|IXC|IDC are stored in
241      * fp_status; QC, Len and Stride are stored separately earlier.
242      * Clear out all of those and the RES0 bits: only NZCV, AHP, DN,
243      * FZ, RMode and FZ16 are kept in vfp.xregs[FPSCR].
244      */
245     env->vfp.xregs[ARM_VFP_FPSCR] = val & 0xf7c80000;
246 }
247 
248 void vfp_set_fpscr(CPUARMState *env, uint32_t val)
249 {
250     HELPER(vfp_set_fpscr)(env, val);
251 }
252 
253 #ifdef CONFIG_TCG
254 
255 #define VFP_HELPER(name, p) HELPER(glue(glue(vfp_,name),p))
256 
257 #define VFP_BINOP(name) \
258 dh_ctype_f16 VFP_HELPER(name, h)(dh_ctype_f16 a, dh_ctype_f16 b, void *fpstp) \
259 { \
260     float_status *fpst = fpstp; \
261     return float16_ ## name(a, b, fpst); \
262 } \
263 float32 VFP_HELPER(name, s)(float32 a, float32 b, void *fpstp) \
264 { \
265     float_status *fpst = fpstp; \
266     return float32_ ## name(a, b, fpst); \
267 } \
268 float64 VFP_HELPER(name, d)(float64 a, float64 b, void *fpstp) \
269 { \
270     float_status *fpst = fpstp; \
271     return float64_ ## name(a, b, fpst); \
272 }
273 VFP_BINOP(add)
274 VFP_BINOP(sub)
275 VFP_BINOP(mul)
276 VFP_BINOP(div)
277 VFP_BINOP(min)
278 VFP_BINOP(max)
279 VFP_BINOP(minnum)
280 VFP_BINOP(maxnum)
281 #undef VFP_BINOP
282 
283 dh_ctype_f16 VFP_HELPER(neg, h)(dh_ctype_f16 a)
284 {
285     return float16_chs(a);
286 }
287 
288 float32 VFP_HELPER(neg, s)(float32 a)
289 {
290     return float32_chs(a);
291 }
292 
293 float64 VFP_HELPER(neg, d)(float64 a)
294 {
295     return float64_chs(a);
296 }
297 
298 dh_ctype_f16 VFP_HELPER(abs, h)(dh_ctype_f16 a)
299 {
300     return float16_abs(a);
301 }
302 
303 float32 VFP_HELPER(abs, s)(float32 a)
304 {
305     return float32_abs(a);
306 }
307 
308 float64 VFP_HELPER(abs, d)(float64 a)
309 {
310     return float64_abs(a);
311 }
312 
313 dh_ctype_f16 VFP_HELPER(sqrt, h)(dh_ctype_f16 a, CPUARMState *env)
314 {
315     return float16_sqrt(a, &env->vfp.fp_status_f16);
316 }
317 
318 float32 VFP_HELPER(sqrt, s)(float32 a, CPUARMState *env)
319 {
320     return float32_sqrt(a, &env->vfp.fp_status);
321 }
322 
323 float64 VFP_HELPER(sqrt, d)(float64 a, CPUARMState *env)
324 {
325     return float64_sqrt(a, &env->vfp.fp_status);
326 }
327 
328 static void softfloat_to_vfp_compare(CPUARMState *env, FloatRelation cmp)
329 {
330     uint32_t flags;
331     switch (cmp) {
332     case float_relation_equal:
333         flags = 0x6;
334         break;
335     case float_relation_less:
336         flags = 0x8;
337         break;
338     case float_relation_greater:
339         flags = 0x2;
340         break;
341     case float_relation_unordered:
342         flags = 0x3;
343         break;
344     default:
345         g_assert_not_reached();
346     }
347     env->vfp.xregs[ARM_VFP_FPSCR] =
348         deposit32(env->vfp.xregs[ARM_VFP_FPSCR], 28, 4, flags);
349 }
350 
351 /* XXX: check quiet/signaling case */
352 #define DO_VFP_cmp(P, FLOATTYPE, ARGTYPE, FPST) \
353 void VFP_HELPER(cmp, P)(ARGTYPE a, ARGTYPE b, CPUARMState *env)  \
354 { \
355     softfloat_to_vfp_compare(env, \
356         FLOATTYPE ## _compare_quiet(a, b, &env->vfp.FPST)); \
357 } \
358 void VFP_HELPER(cmpe, P)(ARGTYPE a, ARGTYPE b, CPUARMState *env) \
359 { \
360     softfloat_to_vfp_compare(env, \
361         FLOATTYPE ## _compare(a, b, &env->vfp.FPST)); \
362 }
363 DO_VFP_cmp(h, float16, dh_ctype_f16, fp_status_f16)
364 DO_VFP_cmp(s, float32, float32, fp_status)
365 DO_VFP_cmp(d, float64, float64, fp_status)
366 #undef DO_VFP_cmp
367 
368 /* Integer to float and float to integer conversions */
369 
370 #define CONV_ITOF(name, ftype, fsz, sign)                           \
371 ftype HELPER(name)(uint32_t x, void *fpstp)                         \
372 {                                                                   \
373     float_status *fpst = fpstp;                                     \
374     return sign##int32_to_##float##fsz((sign##int32_t)x, fpst);     \
375 }
376 
377 #define CONV_FTOI(name, ftype, fsz, sign, round)                \
378 sign##int32_t HELPER(name)(ftype x, void *fpstp)                \
379 {                                                               \
380     float_status *fpst = fpstp;                                 \
381     if (float##fsz##_is_any_nan(x)) {                           \
382         float_raise(float_flag_invalid, fpst);                  \
383         return 0;                                               \
384     }                                                           \
385     return float##fsz##_to_##sign##int32##round(x, fpst);       \
386 }
387 
388 #define FLOAT_CONVS(name, p, ftype, fsz, sign)            \
389     CONV_ITOF(vfp_##name##to##p, ftype, fsz, sign)        \
390     CONV_FTOI(vfp_to##name##p, ftype, fsz, sign, )        \
391     CONV_FTOI(vfp_to##name##z##p, ftype, fsz, sign, _round_to_zero)
392 
393 FLOAT_CONVS(si, h, uint32_t, 16, )
394 FLOAT_CONVS(si, s, float32, 32, )
395 FLOAT_CONVS(si, d, float64, 64, )
396 FLOAT_CONVS(ui, h, uint32_t, 16, u)
397 FLOAT_CONVS(ui, s, float32, 32, u)
398 FLOAT_CONVS(ui, d, float64, 64, u)
399 
400 #undef CONV_ITOF
401 #undef CONV_FTOI
402 #undef FLOAT_CONVS
403 
404 /* floating point conversion */
405 float64 VFP_HELPER(fcvtd, s)(float32 x, CPUARMState *env)
406 {
407     return float32_to_float64(x, &env->vfp.fp_status);
408 }
409 
410 float32 VFP_HELPER(fcvts, d)(float64 x, CPUARMState *env)
411 {
412     return float64_to_float32(x, &env->vfp.fp_status);
413 }
414 
415 uint32_t HELPER(bfcvt)(float32 x, void *status)
416 {
417     return float32_to_bfloat16(x, status);
418 }
419 
420 uint32_t HELPER(bfcvt_pair)(uint64_t pair, void *status)
421 {
422     bfloat16 lo = float32_to_bfloat16(extract64(pair, 0, 32), status);
423     bfloat16 hi = float32_to_bfloat16(extract64(pair, 32, 32), status);
424     return deposit32(lo, 16, 16, hi);
425 }
426 
427 /*
428  * VFP3 fixed point conversion. The AArch32 versions of fix-to-float
429  * must always round-to-nearest; the AArch64 ones honour the FPSCR
430  * rounding mode. (For AArch32 Neon the standard-FPSCR is set to
431  * round-to-nearest so either helper will work.) AArch32 float-to-fix
432  * must round-to-zero.
433  */
434 #define VFP_CONV_FIX_FLOAT(name, p, fsz, ftype, isz, itype)            \
435 ftype HELPER(vfp_##name##to##p)(uint##isz##_t  x, uint32_t shift,      \
436                                      void *fpstp) \
437 { return itype##_to_##float##fsz##_scalbn(x, -shift, fpstp); }
438 
439 #define VFP_CONV_FIX_FLOAT_ROUND(name, p, fsz, ftype, isz, itype)      \
440     ftype HELPER(vfp_##name##to##p##_round_to_nearest)(uint##isz##_t  x, \
441                                                      uint32_t shift,   \
442                                                      void *fpstp)      \
443     {                                                                  \
444         ftype ret;                                                     \
445         float_status *fpst = fpstp;                                    \
446         FloatRoundMode oldmode = fpst->float_rounding_mode;            \
447         fpst->float_rounding_mode = float_round_nearest_even;          \
448         ret = itype##_to_##float##fsz##_scalbn(x, -shift, fpstp);      \
449         fpst->float_rounding_mode = oldmode;                           \
450         return ret;                                                    \
451     }
452 
453 #define VFP_CONV_FLOAT_FIX_ROUND(name, p, fsz, ftype, isz, itype, ROUND, suff) \
454 uint##isz##_t HELPER(vfp_to##name##p##suff)(ftype x, uint32_t shift,      \
455                                             void *fpst)                   \
456 {                                                                         \
457     if (unlikely(float##fsz##_is_any_nan(x))) {                           \
458         float_raise(float_flag_invalid, fpst);                            \
459         return 0;                                                         \
460     }                                                                     \
461     return float##fsz##_to_##itype##_scalbn(x, ROUND, shift, fpst);       \
462 }
463 
464 #define VFP_CONV_FIX(name, p, fsz, ftype, isz, itype)            \
465 VFP_CONV_FIX_FLOAT(name, p, fsz, ftype, isz, itype)              \
466 VFP_CONV_FIX_FLOAT_ROUND(name, p, fsz, ftype, isz, itype)        \
467 VFP_CONV_FLOAT_FIX_ROUND(name, p, fsz, ftype, isz, itype,        \
468                          float_round_to_zero, _round_to_zero)    \
469 VFP_CONV_FLOAT_FIX_ROUND(name, p, fsz, ftype, isz, itype,        \
470                          get_float_rounding_mode(fpst), )
471 
472 #define VFP_CONV_FIX_A64(name, p, fsz, ftype, isz, itype)        \
473 VFP_CONV_FIX_FLOAT(name, p, fsz, ftype, isz, itype)              \
474 VFP_CONV_FLOAT_FIX_ROUND(name, p, fsz, ftype, isz, itype,        \
475                          get_float_rounding_mode(fpst), )
476 
477 VFP_CONV_FIX(sh, d, 64, float64, 64, int16)
478 VFP_CONV_FIX(sl, d, 64, float64, 64, int32)
479 VFP_CONV_FIX_A64(sq, d, 64, float64, 64, int64)
480 VFP_CONV_FIX(uh, d, 64, float64, 64, uint16)
481 VFP_CONV_FIX(ul, d, 64, float64, 64, uint32)
482 VFP_CONV_FIX_A64(uq, d, 64, float64, 64, uint64)
483 VFP_CONV_FIX(sh, s, 32, float32, 32, int16)
484 VFP_CONV_FIX(sl, s, 32, float32, 32, int32)
485 VFP_CONV_FIX_A64(sq, s, 32, float32, 64, int64)
486 VFP_CONV_FIX(uh, s, 32, float32, 32, uint16)
487 VFP_CONV_FIX(ul, s, 32, float32, 32, uint32)
488 VFP_CONV_FIX_A64(uq, s, 32, float32, 64, uint64)
489 VFP_CONV_FIX(sh, h, 16, dh_ctype_f16, 32, int16)
490 VFP_CONV_FIX(sl, h, 16, dh_ctype_f16, 32, int32)
491 VFP_CONV_FIX_A64(sq, h, 16, dh_ctype_f16, 64, int64)
492 VFP_CONV_FIX(uh, h, 16, dh_ctype_f16, 32, uint16)
493 VFP_CONV_FIX(ul, h, 16, dh_ctype_f16, 32, uint32)
494 VFP_CONV_FIX_A64(uq, h, 16, dh_ctype_f16, 64, uint64)
495 
496 #undef VFP_CONV_FIX
497 #undef VFP_CONV_FIX_FLOAT
498 #undef VFP_CONV_FLOAT_FIX_ROUND
499 #undef VFP_CONV_FIX_A64
500 
501 /* Set the current fp rounding mode and return the old one.
502  * The argument is a softfloat float_round_ value.
503  */
504 uint32_t HELPER(set_rmode)(uint32_t rmode, void *fpstp)
505 {
506     float_status *fp_status = fpstp;
507 
508     uint32_t prev_rmode = get_float_rounding_mode(fp_status);
509     set_float_rounding_mode(rmode, fp_status);
510 
511     return prev_rmode;
512 }
513 
514 /* Half precision conversions.  */
515 float32 HELPER(vfp_fcvt_f16_to_f32)(uint32_t a, void *fpstp, uint32_t ahp_mode)
516 {
517     /* Squash FZ16 to 0 for the duration of conversion.  In this case,
518      * it would affect flushing input denormals.
519      */
520     float_status *fpst = fpstp;
521     bool save = get_flush_inputs_to_zero(fpst);
522     set_flush_inputs_to_zero(false, fpst);
523     float32 r = float16_to_float32(a, !ahp_mode, fpst);
524     set_flush_inputs_to_zero(save, fpst);
525     return r;
526 }
527 
528 uint32_t HELPER(vfp_fcvt_f32_to_f16)(float32 a, void *fpstp, uint32_t ahp_mode)
529 {
530     /* Squash FZ16 to 0 for the duration of conversion.  In this case,
531      * it would affect flushing output denormals.
532      */
533     float_status *fpst = fpstp;
534     bool save = get_flush_to_zero(fpst);
535     set_flush_to_zero(false, fpst);
536     float16 r = float32_to_float16(a, !ahp_mode, fpst);
537     set_flush_to_zero(save, fpst);
538     return r;
539 }
540 
541 float64 HELPER(vfp_fcvt_f16_to_f64)(uint32_t a, void *fpstp, uint32_t ahp_mode)
542 {
543     /* Squash FZ16 to 0 for the duration of conversion.  In this case,
544      * it would affect flushing input denormals.
545      */
546     float_status *fpst = fpstp;
547     bool save = get_flush_inputs_to_zero(fpst);
548     set_flush_inputs_to_zero(false, fpst);
549     float64 r = float16_to_float64(a, !ahp_mode, fpst);
550     set_flush_inputs_to_zero(save, fpst);
551     return r;
552 }
553 
554 uint32_t HELPER(vfp_fcvt_f64_to_f16)(float64 a, void *fpstp, uint32_t ahp_mode)
555 {
556     /* Squash FZ16 to 0 for the duration of conversion.  In this case,
557      * it would affect flushing output denormals.
558      */
559     float_status *fpst = fpstp;
560     bool save = get_flush_to_zero(fpst);
561     set_flush_to_zero(false, fpst);
562     float16 r = float64_to_float16(a, !ahp_mode, fpst);
563     set_flush_to_zero(save, fpst);
564     return r;
565 }
566 
567 /* NEON helpers.  */
568 
569 /* Constants 256 and 512 are used in some helpers; we avoid relying on
570  * int->float conversions at run-time.  */
571 #define float64_256 make_float64(0x4070000000000000LL)
572 #define float64_512 make_float64(0x4080000000000000LL)
573 #define float16_maxnorm make_float16(0x7bff)
574 #define float32_maxnorm make_float32(0x7f7fffff)
575 #define float64_maxnorm make_float64(0x7fefffffffffffffLL)
576 
577 /* Reciprocal functions
578  *
579  * The algorithm that must be used to calculate the estimate
580  * is specified by the ARM ARM, see FPRecipEstimate()/RecipEstimate
581  */
582 
583 /* See RecipEstimate()
584  *
585  * input is a 9 bit fixed point number
586  * input range 256 .. 511 for a number from 0.5 <= x < 1.0.
587  * result range 256 .. 511 for a number from 1.0 to 511/256.
588  */
589 
590 static int recip_estimate(int input)
591 {
592     int a, b, r;
593     assert(256 <= input && input < 512);
594     a = (input * 2) + 1;
595     b = (1 << 19) / a;
596     r = (b + 1) >> 1;
597     assert(256 <= r && r < 512);
598     return r;
599 }
600 
601 /*
602  * Common wrapper to call recip_estimate
603  *
604  * The parameters are exponent and 64 bit fraction (without implicit
605  * bit) where the binary point is nominally at bit 52. Returns a
606  * float64 which can then be rounded to the appropriate size by the
607  * callee.
608  */
609 
610 static uint64_t call_recip_estimate(int *exp, int exp_off, uint64_t frac)
611 {
612     uint32_t scaled, estimate;
613     uint64_t result_frac;
614     int result_exp;
615 
616     /* Handle sub-normals */
617     if (*exp == 0) {
618         if (extract64(frac, 51, 1) == 0) {
619             *exp = -1;
620             frac <<= 2;
621         } else {
622             frac <<= 1;
623         }
624     }
625 
626     /* scaled = UInt('1':fraction<51:44>) */
627     scaled = deposit32(1 << 8, 0, 8, extract64(frac, 44, 8));
628     estimate = recip_estimate(scaled);
629 
630     result_exp = exp_off - *exp;
631     result_frac = deposit64(0, 44, 8, estimate);
632     if (result_exp == 0) {
633         result_frac = deposit64(result_frac >> 1, 51, 1, 1);
634     } else if (result_exp == -1) {
635         result_frac = deposit64(result_frac >> 2, 50, 2, 1);
636         result_exp = 0;
637     }
638 
639     *exp = result_exp;
640 
641     return result_frac;
642 }
643 
644 static bool round_to_inf(float_status *fpst, bool sign_bit)
645 {
646     switch (fpst->float_rounding_mode) {
647     case float_round_nearest_even: /* Round to Nearest */
648         return true;
649     case float_round_up: /* Round to +Inf */
650         return !sign_bit;
651     case float_round_down: /* Round to -Inf */
652         return sign_bit;
653     case float_round_to_zero: /* Round to Zero */
654         return false;
655     default:
656         g_assert_not_reached();
657     }
658 }
659 
660 uint32_t HELPER(recpe_f16)(uint32_t input, void *fpstp)
661 {
662     float_status *fpst = fpstp;
663     float16 f16 = float16_squash_input_denormal(input, fpst);
664     uint32_t f16_val = float16_val(f16);
665     uint32_t f16_sign = float16_is_neg(f16);
666     int f16_exp = extract32(f16_val, 10, 5);
667     uint32_t f16_frac = extract32(f16_val, 0, 10);
668     uint64_t f64_frac;
669 
670     if (float16_is_any_nan(f16)) {
671         float16 nan = f16;
672         if (float16_is_signaling_nan(f16, fpst)) {
673             float_raise(float_flag_invalid, fpst);
674             nan = float16_silence_nan(f16, fpst);
675         }
676         if (fpst->default_nan_mode) {
677             nan =  float16_default_nan(fpst);
678         }
679         return nan;
680     } else if (float16_is_infinity(f16)) {
681         return float16_set_sign(float16_zero, float16_is_neg(f16));
682     } else if (float16_is_zero(f16)) {
683         float_raise(float_flag_divbyzero, fpst);
684         return float16_set_sign(float16_infinity, float16_is_neg(f16));
685     } else if (float16_abs(f16) < (1 << 8)) {
686         /* Abs(value) < 2.0^-16 */
687         float_raise(float_flag_overflow | float_flag_inexact, fpst);
688         if (round_to_inf(fpst, f16_sign)) {
689             return float16_set_sign(float16_infinity, f16_sign);
690         } else {
691             return float16_set_sign(float16_maxnorm, f16_sign);
692         }
693     } else if (f16_exp >= 29 && fpst->flush_to_zero) {
694         float_raise(float_flag_underflow, fpst);
695         return float16_set_sign(float16_zero, float16_is_neg(f16));
696     }
697 
698     f64_frac = call_recip_estimate(&f16_exp, 29,
699                                    ((uint64_t) f16_frac) << (52 - 10));
700 
701     /* result = sign : result_exp<4:0> : fraction<51:42> */
702     f16_val = deposit32(0, 15, 1, f16_sign);
703     f16_val = deposit32(f16_val, 10, 5, f16_exp);
704     f16_val = deposit32(f16_val, 0, 10, extract64(f64_frac, 52 - 10, 10));
705     return make_float16(f16_val);
706 }
707 
708 float32 HELPER(recpe_f32)(float32 input, void *fpstp)
709 {
710     float_status *fpst = fpstp;
711     float32 f32 = float32_squash_input_denormal(input, fpst);
712     uint32_t f32_val = float32_val(f32);
713     bool f32_sign = float32_is_neg(f32);
714     int f32_exp = extract32(f32_val, 23, 8);
715     uint32_t f32_frac = extract32(f32_val, 0, 23);
716     uint64_t f64_frac;
717 
718     if (float32_is_any_nan(f32)) {
719         float32 nan = f32;
720         if (float32_is_signaling_nan(f32, fpst)) {
721             float_raise(float_flag_invalid, fpst);
722             nan = float32_silence_nan(f32, fpst);
723         }
724         if (fpst->default_nan_mode) {
725             nan =  float32_default_nan(fpst);
726         }
727         return nan;
728     } else if (float32_is_infinity(f32)) {
729         return float32_set_sign(float32_zero, float32_is_neg(f32));
730     } else if (float32_is_zero(f32)) {
731         float_raise(float_flag_divbyzero, fpst);
732         return float32_set_sign(float32_infinity, float32_is_neg(f32));
733     } else if (float32_abs(f32) < (1ULL << 21)) {
734         /* Abs(value) < 2.0^-128 */
735         float_raise(float_flag_overflow | float_flag_inexact, fpst);
736         if (round_to_inf(fpst, f32_sign)) {
737             return float32_set_sign(float32_infinity, f32_sign);
738         } else {
739             return float32_set_sign(float32_maxnorm, f32_sign);
740         }
741     } else if (f32_exp >= 253 && fpst->flush_to_zero) {
742         float_raise(float_flag_underflow, fpst);
743         return float32_set_sign(float32_zero, float32_is_neg(f32));
744     }
745 
746     f64_frac = call_recip_estimate(&f32_exp, 253,
747                                    ((uint64_t) f32_frac) << (52 - 23));
748 
749     /* result = sign : result_exp<7:0> : fraction<51:29> */
750     f32_val = deposit32(0, 31, 1, f32_sign);
751     f32_val = deposit32(f32_val, 23, 8, f32_exp);
752     f32_val = deposit32(f32_val, 0, 23, extract64(f64_frac, 52 - 23, 23));
753     return make_float32(f32_val);
754 }
755 
756 float64 HELPER(recpe_f64)(float64 input, void *fpstp)
757 {
758     float_status *fpst = fpstp;
759     float64 f64 = float64_squash_input_denormal(input, fpst);
760     uint64_t f64_val = float64_val(f64);
761     bool f64_sign = float64_is_neg(f64);
762     int f64_exp = extract64(f64_val, 52, 11);
763     uint64_t f64_frac = extract64(f64_val, 0, 52);
764 
765     /* Deal with any special cases */
766     if (float64_is_any_nan(f64)) {
767         float64 nan = f64;
768         if (float64_is_signaling_nan(f64, fpst)) {
769             float_raise(float_flag_invalid, fpst);
770             nan = float64_silence_nan(f64, fpst);
771         }
772         if (fpst->default_nan_mode) {
773             nan =  float64_default_nan(fpst);
774         }
775         return nan;
776     } else if (float64_is_infinity(f64)) {
777         return float64_set_sign(float64_zero, float64_is_neg(f64));
778     } else if (float64_is_zero(f64)) {
779         float_raise(float_flag_divbyzero, fpst);
780         return float64_set_sign(float64_infinity, float64_is_neg(f64));
781     } else if ((f64_val & ~(1ULL << 63)) < (1ULL << 50)) {
782         /* Abs(value) < 2.0^-1024 */
783         float_raise(float_flag_overflow | float_flag_inexact, fpst);
784         if (round_to_inf(fpst, f64_sign)) {
785             return float64_set_sign(float64_infinity, f64_sign);
786         } else {
787             return float64_set_sign(float64_maxnorm, f64_sign);
788         }
789     } else if (f64_exp >= 2045 && fpst->flush_to_zero) {
790         float_raise(float_flag_underflow, fpst);
791         return float64_set_sign(float64_zero, float64_is_neg(f64));
792     }
793 
794     f64_frac = call_recip_estimate(&f64_exp, 2045, f64_frac);
795 
796     /* result = sign : result_exp<10:0> : fraction<51:0>; */
797     f64_val = deposit64(0, 63, 1, f64_sign);
798     f64_val = deposit64(f64_val, 52, 11, f64_exp);
799     f64_val = deposit64(f64_val, 0, 52, f64_frac);
800     return make_float64(f64_val);
801 }
802 
803 /* The algorithm that must be used to calculate the estimate
804  * is specified by the ARM ARM.
805  */
806 
807 static int do_recip_sqrt_estimate(int a)
808 {
809     int b, estimate;
810 
811     assert(128 <= a && a < 512);
812     if (a < 256) {
813         a = a * 2 + 1;
814     } else {
815         a = (a >> 1) << 1;
816         a = (a + 1) * 2;
817     }
818     b = 512;
819     while (a * (b + 1) * (b + 1) < (1 << 28)) {
820         b += 1;
821     }
822     estimate = (b + 1) / 2;
823     assert(256 <= estimate && estimate < 512);
824 
825     return estimate;
826 }
827 
828 
829 static uint64_t recip_sqrt_estimate(int *exp , int exp_off, uint64_t frac)
830 {
831     int estimate;
832     uint32_t scaled;
833 
834     if (*exp == 0) {
835         while (extract64(frac, 51, 1) == 0) {
836             frac = frac << 1;
837             *exp -= 1;
838         }
839         frac = extract64(frac, 0, 51) << 1;
840     }
841 
842     if (*exp & 1) {
843         /* scaled = UInt('01':fraction<51:45>) */
844         scaled = deposit32(1 << 7, 0, 7, extract64(frac, 45, 7));
845     } else {
846         /* scaled = UInt('1':fraction<51:44>) */
847         scaled = deposit32(1 << 8, 0, 8, extract64(frac, 44, 8));
848     }
849     estimate = do_recip_sqrt_estimate(scaled);
850 
851     *exp = (exp_off - *exp) / 2;
852     return extract64(estimate, 0, 8) << 44;
853 }
854 
855 uint32_t HELPER(rsqrte_f16)(uint32_t input, void *fpstp)
856 {
857     float_status *s = fpstp;
858     float16 f16 = float16_squash_input_denormal(input, s);
859     uint16_t val = float16_val(f16);
860     bool f16_sign = float16_is_neg(f16);
861     int f16_exp = extract32(val, 10, 5);
862     uint16_t f16_frac = extract32(val, 0, 10);
863     uint64_t f64_frac;
864 
865     if (float16_is_any_nan(f16)) {
866         float16 nan = f16;
867         if (float16_is_signaling_nan(f16, s)) {
868             float_raise(float_flag_invalid, s);
869             nan = float16_silence_nan(f16, s);
870         }
871         if (s->default_nan_mode) {
872             nan =  float16_default_nan(s);
873         }
874         return nan;
875     } else if (float16_is_zero(f16)) {
876         float_raise(float_flag_divbyzero, s);
877         return float16_set_sign(float16_infinity, f16_sign);
878     } else if (f16_sign) {
879         float_raise(float_flag_invalid, s);
880         return float16_default_nan(s);
881     } else if (float16_is_infinity(f16)) {
882         return float16_zero;
883     }
884 
885     /* Scale and normalize to a double-precision value between 0.25 and 1.0,
886      * preserving the parity of the exponent.  */
887 
888     f64_frac = ((uint64_t) f16_frac) << (52 - 10);
889 
890     f64_frac = recip_sqrt_estimate(&f16_exp, 44, f64_frac);
891 
892     /* result = sign : result_exp<4:0> : estimate<7:0> : Zeros(2) */
893     val = deposit32(0, 15, 1, f16_sign);
894     val = deposit32(val, 10, 5, f16_exp);
895     val = deposit32(val, 2, 8, extract64(f64_frac, 52 - 8, 8));
896     return make_float16(val);
897 }
898 
899 float32 HELPER(rsqrte_f32)(float32 input, void *fpstp)
900 {
901     float_status *s = fpstp;
902     float32 f32 = float32_squash_input_denormal(input, s);
903     uint32_t val = float32_val(f32);
904     uint32_t f32_sign = float32_is_neg(f32);
905     int f32_exp = extract32(val, 23, 8);
906     uint32_t f32_frac = extract32(val, 0, 23);
907     uint64_t f64_frac;
908 
909     if (float32_is_any_nan(f32)) {
910         float32 nan = f32;
911         if (float32_is_signaling_nan(f32, s)) {
912             float_raise(float_flag_invalid, s);
913             nan = float32_silence_nan(f32, s);
914         }
915         if (s->default_nan_mode) {
916             nan =  float32_default_nan(s);
917         }
918         return nan;
919     } else if (float32_is_zero(f32)) {
920         float_raise(float_flag_divbyzero, s);
921         return float32_set_sign(float32_infinity, float32_is_neg(f32));
922     } else if (float32_is_neg(f32)) {
923         float_raise(float_flag_invalid, s);
924         return float32_default_nan(s);
925     } else if (float32_is_infinity(f32)) {
926         return float32_zero;
927     }
928 
929     /* Scale and normalize to a double-precision value between 0.25 and 1.0,
930      * preserving the parity of the exponent.  */
931 
932     f64_frac = ((uint64_t) f32_frac) << 29;
933 
934     f64_frac = recip_sqrt_estimate(&f32_exp, 380, f64_frac);
935 
936     /* result = sign : result_exp<4:0> : estimate<7:0> : Zeros(15) */
937     val = deposit32(0, 31, 1, f32_sign);
938     val = deposit32(val, 23, 8, f32_exp);
939     val = deposit32(val, 15, 8, extract64(f64_frac, 52 - 8, 8));
940     return make_float32(val);
941 }
942 
943 float64 HELPER(rsqrte_f64)(float64 input, void *fpstp)
944 {
945     float_status *s = fpstp;
946     float64 f64 = float64_squash_input_denormal(input, s);
947     uint64_t val = float64_val(f64);
948     bool f64_sign = float64_is_neg(f64);
949     int f64_exp = extract64(val, 52, 11);
950     uint64_t f64_frac = extract64(val, 0, 52);
951 
952     if (float64_is_any_nan(f64)) {
953         float64 nan = f64;
954         if (float64_is_signaling_nan(f64, s)) {
955             float_raise(float_flag_invalid, s);
956             nan = float64_silence_nan(f64, s);
957         }
958         if (s->default_nan_mode) {
959             nan =  float64_default_nan(s);
960         }
961         return nan;
962     } else if (float64_is_zero(f64)) {
963         float_raise(float_flag_divbyzero, s);
964         return float64_set_sign(float64_infinity, float64_is_neg(f64));
965     } else if (float64_is_neg(f64)) {
966         float_raise(float_flag_invalid, s);
967         return float64_default_nan(s);
968     } else if (float64_is_infinity(f64)) {
969         return float64_zero;
970     }
971 
972     f64_frac = recip_sqrt_estimate(&f64_exp, 3068, f64_frac);
973 
974     /* result = sign : result_exp<4:0> : estimate<7:0> : Zeros(44) */
975     val = deposit64(0, 61, 1, f64_sign);
976     val = deposit64(val, 52, 11, f64_exp);
977     val = deposit64(val, 44, 8, extract64(f64_frac, 52 - 8, 8));
978     return make_float64(val);
979 }
980 
981 uint32_t HELPER(recpe_u32)(uint32_t a)
982 {
983     int input, estimate;
984 
985     if ((a & 0x80000000) == 0) {
986         return 0xffffffff;
987     }
988 
989     input = extract32(a, 23, 9);
990     estimate = recip_estimate(input);
991 
992     return deposit32(0, (32 - 9), 9, estimate);
993 }
994 
995 uint32_t HELPER(rsqrte_u32)(uint32_t a)
996 {
997     int estimate;
998 
999     if ((a & 0xc0000000) == 0) {
1000         return 0xffffffff;
1001     }
1002 
1003     estimate = do_recip_sqrt_estimate(extract32(a, 23, 9));
1004 
1005     return deposit32(0, 23, 9, estimate);
1006 }
1007 
1008 /* VFPv4 fused multiply-accumulate */
1009 dh_ctype_f16 VFP_HELPER(muladd, h)(dh_ctype_f16 a, dh_ctype_f16 b,
1010                                    dh_ctype_f16 c, void *fpstp)
1011 {
1012     float_status *fpst = fpstp;
1013     return float16_muladd(a, b, c, 0, fpst);
1014 }
1015 
1016 float32 VFP_HELPER(muladd, s)(float32 a, float32 b, float32 c, void *fpstp)
1017 {
1018     float_status *fpst = fpstp;
1019     return float32_muladd(a, b, c, 0, fpst);
1020 }
1021 
1022 float64 VFP_HELPER(muladd, d)(float64 a, float64 b, float64 c, void *fpstp)
1023 {
1024     float_status *fpst = fpstp;
1025     return float64_muladd(a, b, c, 0, fpst);
1026 }
1027 
1028 /* ARMv8 round to integral */
1029 dh_ctype_f16 HELPER(rinth_exact)(dh_ctype_f16 x, void *fp_status)
1030 {
1031     return float16_round_to_int(x, fp_status);
1032 }
1033 
1034 float32 HELPER(rints_exact)(float32 x, void *fp_status)
1035 {
1036     return float32_round_to_int(x, fp_status);
1037 }
1038 
1039 float64 HELPER(rintd_exact)(float64 x, void *fp_status)
1040 {
1041     return float64_round_to_int(x, fp_status);
1042 }
1043 
1044 dh_ctype_f16 HELPER(rinth)(dh_ctype_f16 x, void *fp_status)
1045 {
1046     int old_flags = get_float_exception_flags(fp_status), new_flags;
1047     float16 ret;
1048 
1049     ret = float16_round_to_int(x, fp_status);
1050 
1051     /* Suppress any inexact exceptions the conversion produced */
1052     if (!(old_flags & float_flag_inexact)) {
1053         new_flags = get_float_exception_flags(fp_status);
1054         set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
1055     }
1056 
1057     return ret;
1058 }
1059 
1060 float32 HELPER(rints)(float32 x, void *fp_status)
1061 {
1062     int old_flags = get_float_exception_flags(fp_status), new_flags;
1063     float32 ret;
1064 
1065     ret = float32_round_to_int(x, fp_status);
1066 
1067     /* Suppress any inexact exceptions the conversion produced */
1068     if (!(old_flags & float_flag_inexact)) {
1069         new_flags = get_float_exception_flags(fp_status);
1070         set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
1071     }
1072 
1073     return ret;
1074 }
1075 
1076 float64 HELPER(rintd)(float64 x, void *fp_status)
1077 {
1078     int old_flags = get_float_exception_flags(fp_status), new_flags;
1079     float64 ret;
1080 
1081     ret = float64_round_to_int(x, fp_status);
1082 
1083     new_flags = get_float_exception_flags(fp_status);
1084 
1085     /* Suppress any inexact exceptions the conversion produced */
1086     if (!(old_flags & float_flag_inexact)) {
1087         new_flags = get_float_exception_flags(fp_status);
1088         set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
1089     }
1090 
1091     return ret;
1092 }
1093 
1094 /* Convert ARM rounding mode to softfloat */
1095 int arm_rmode_to_sf(int rmode)
1096 {
1097     switch (rmode) {
1098     case FPROUNDING_TIEAWAY:
1099         rmode = float_round_ties_away;
1100         break;
1101     case FPROUNDING_ODD:
1102         /* FIXME: add support for TIEAWAY and ODD */
1103         qemu_log_mask(LOG_UNIMP, "arm: unimplemented rounding mode: %d\n",
1104                       rmode);
1105         /* fall through for now */
1106     case FPROUNDING_TIEEVEN:
1107     default:
1108         rmode = float_round_nearest_even;
1109         break;
1110     case FPROUNDING_POSINF:
1111         rmode = float_round_up;
1112         break;
1113     case FPROUNDING_NEGINF:
1114         rmode = float_round_down;
1115         break;
1116     case FPROUNDING_ZERO:
1117         rmode = float_round_to_zero;
1118         break;
1119     }
1120     return rmode;
1121 }
1122 
1123 /*
1124  * Implement float64 to int32_t conversion without saturation;
1125  * the result is supplied modulo 2^32.
1126  */
1127 uint64_t HELPER(fjcvtzs)(float64 value, void *vstatus)
1128 {
1129     float_status *status = vstatus;
1130     uint32_t exp, sign;
1131     uint64_t frac;
1132     uint32_t inexact = 1; /* !Z */
1133 
1134     sign = extract64(value, 63, 1);
1135     exp = extract64(value, 52, 11);
1136     frac = extract64(value, 0, 52);
1137 
1138     if (exp == 0) {
1139         /* While not inexact for IEEE FP, -0.0 is inexact for JavaScript.  */
1140         inexact = sign;
1141         if (frac != 0) {
1142             if (status->flush_inputs_to_zero) {
1143                 float_raise(float_flag_input_denormal, status);
1144             } else {
1145                 float_raise(float_flag_inexact, status);
1146                 inexact = 1;
1147             }
1148         }
1149         frac = 0;
1150     } else if (exp == 0x7ff) {
1151         /* This operation raises Invalid for both NaN and overflow (Inf).  */
1152         float_raise(float_flag_invalid, status);
1153         frac = 0;
1154     } else {
1155         int true_exp = exp - 1023;
1156         int shift = true_exp - 52;
1157 
1158         /* Restore implicit bit.  */
1159         frac |= 1ull << 52;
1160 
1161         /* Shift the fraction into place.  */
1162         if (shift >= 0) {
1163             /* The number is so large we must shift the fraction left.  */
1164             if (shift >= 64) {
1165                 /* The fraction is shifted out entirely.  */
1166                 frac = 0;
1167             } else {
1168                 frac <<= shift;
1169             }
1170         } else if (shift > -64) {
1171             /* Normal case -- shift right and notice if bits shift out.  */
1172             inexact = (frac << (64 + shift)) != 0;
1173             frac >>= -shift;
1174         } else {
1175             /* The fraction is shifted out entirely.  */
1176             frac = 0;
1177         }
1178 
1179         /* Notice overflow or inexact exceptions.  */
1180         if (true_exp > 31 || frac > (sign ? 0x80000000ull : 0x7fffffff)) {
1181             /* Overflow, for which this operation raises invalid.  */
1182             float_raise(float_flag_invalid, status);
1183             inexact = 1;
1184         } else if (inexact) {
1185             float_raise(float_flag_inexact, status);
1186         }
1187 
1188         /* Honor the sign.  */
1189         if (sign) {
1190             frac = -frac;
1191         }
1192     }
1193 
1194     /* Pack the result and the env->ZF representation of Z together.  */
1195     return deposit64(frac, 32, 32, inexact);
1196 }
1197 
1198 uint32_t HELPER(vjcvt)(float64 value, CPUARMState *env)
1199 {
1200     uint64_t pair = HELPER(fjcvtzs)(value, &env->vfp.fp_status);
1201     uint32_t result = pair;
1202     uint32_t z = (pair >> 32) == 0;
1203 
1204     /* Store Z, clear NCV, in FPSCR.NZCV.  */
1205     env->vfp.xregs[ARM_VFP_FPSCR]
1206         = (env->vfp.xregs[ARM_VFP_FPSCR] & ~CPSR_NZCV) | (z * CPSR_Z);
1207 
1208     return result;
1209 }
1210 
1211 /* Round a float32 to an integer that fits in int32_t or int64_t.  */
1212 static float32 frint_s(float32 f, float_status *fpst, int intsize)
1213 {
1214     int old_flags = get_float_exception_flags(fpst);
1215     uint32_t exp = extract32(f, 23, 8);
1216 
1217     if (unlikely(exp == 0xff)) {
1218         /* NaN or Inf.  */
1219         goto overflow;
1220     }
1221 
1222     /* Round and re-extract the exponent.  */
1223     f = float32_round_to_int(f, fpst);
1224     exp = extract32(f, 23, 8);
1225 
1226     /* Validate the range of the result.  */
1227     if (exp < 126 + intsize) {
1228         /* abs(F) <= INT{N}_MAX */
1229         return f;
1230     }
1231     if (exp == 126 + intsize) {
1232         uint32_t sign = extract32(f, 31, 1);
1233         uint32_t frac = extract32(f, 0, 23);
1234         if (sign && frac == 0) {
1235             /* F == INT{N}_MIN */
1236             return f;
1237         }
1238     }
1239 
1240  overflow:
1241     /*
1242      * Raise Invalid and return INT{N}_MIN as a float.  Revert any
1243      * inexact exception float32_round_to_int may have raised.
1244      */
1245     set_float_exception_flags(old_flags | float_flag_invalid, fpst);
1246     return (0x100u + 126u + intsize) << 23;
1247 }
1248 
1249 float32 HELPER(frint32_s)(float32 f, void *fpst)
1250 {
1251     return frint_s(f, fpst, 32);
1252 }
1253 
1254 float32 HELPER(frint64_s)(float32 f, void *fpst)
1255 {
1256     return frint_s(f, fpst, 64);
1257 }
1258 
1259 /* Round a float64 to an integer that fits in int32_t or int64_t.  */
1260 static float64 frint_d(float64 f, float_status *fpst, int intsize)
1261 {
1262     int old_flags = get_float_exception_flags(fpst);
1263     uint32_t exp = extract64(f, 52, 11);
1264 
1265     if (unlikely(exp == 0x7ff)) {
1266         /* NaN or Inf.  */
1267         goto overflow;
1268     }
1269 
1270     /* Round and re-extract the exponent.  */
1271     f = float64_round_to_int(f, fpst);
1272     exp = extract64(f, 52, 11);
1273 
1274     /* Validate the range of the result.  */
1275     if (exp < 1022 + intsize) {
1276         /* abs(F) <= INT{N}_MAX */
1277         return f;
1278     }
1279     if (exp == 1022 + intsize) {
1280         uint64_t sign = extract64(f, 63, 1);
1281         uint64_t frac = extract64(f, 0, 52);
1282         if (sign && frac == 0) {
1283             /* F == INT{N}_MIN */
1284             return f;
1285         }
1286     }
1287 
1288  overflow:
1289     /*
1290      * Raise Invalid and return INT{N}_MIN as a float.  Revert any
1291      * inexact exception float64_round_to_int may have raised.
1292      */
1293     set_float_exception_flags(old_flags | float_flag_invalid, fpst);
1294     return (uint64_t)(0x800 + 1022 + intsize) << 52;
1295 }
1296 
1297 float64 HELPER(frint32_d)(float64 f, void *fpst)
1298 {
1299     return frint_d(f, fpst, 32);
1300 }
1301 
1302 float64 HELPER(frint64_d)(float64 f, void *fpst)
1303 {
1304     return frint_d(f, fpst, 64);
1305 }
1306 
1307 void HELPER(check_hcr_el2_trap)(CPUARMState *env, uint32_t rt, uint32_t reg)
1308 {
1309     uint32_t syndrome;
1310 
1311     switch (reg) {
1312     case ARM_VFP_MVFR0:
1313     case ARM_VFP_MVFR1:
1314     case ARM_VFP_MVFR2:
1315         if (!(arm_hcr_el2_eff(env) & HCR_TID3)) {
1316             return;
1317         }
1318         break;
1319     case ARM_VFP_FPSID:
1320         if (!(arm_hcr_el2_eff(env) & HCR_TID0)) {
1321             return;
1322         }
1323         break;
1324     default:
1325         g_assert_not_reached();
1326     }
1327 
1328     syndrome = ((EC_FPIDTRAP << ARM_EL_EC_SHIFT)
1329                 | ARM_EL_IL
1330                 | (1 << 24) | (0xe << 20) | (7 << 14)
1331                 | (reg << 10) | (rt << 5) | 1);
1332 
1333     raise_exception(env, EXCP_HYP_TRAP, syndrome, 2);
1334 }
1335 
1336 #endif
1337