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[qemu.git] / target / arm / vfp_helper.c
blob24e3d820a5b9d415ba547357fdcf84319ff5ac3d
1 /*
2 * ARM VFP floating-point operations
4 * Copyright (c) 2003 Fabrice Bellard
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.
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.
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/>.
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
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. */
33 #ifdef CONFIG_TCG
35 /* Convert host exception flags to vfp form. */
36 static inline int vfp_exceptbits_from_host(int host_bits)
38 int target_bits = 0;
40 if (host_bits & float_flag_invalid) {
41 target_bits |= 1;
43 if (host_bits & float_flag_divbyzero) {
44 target_bits |= 2;
46 if (host_bits & float_flag_overflow) {
47 target_bits |= 4;
49 if (host_bits & (float_flag_underflow | float_flag_output_denormal)) {
50 target_bits |= 8;
52 if (host_bits & float_flag_inexact) {
53 target_bits |= 0x10;
55 if (host_bits & float_flag_input_denormal) {
56 target_bits |= 0x80;
58 return target_bits;
61 /* Convert vfp exception flags to target form. */
62 static inline int vfp_exceptbits_to_host(int target_bits)
64 int host_bits = 0;
66 if (target_bits & 1) {
67 host_bits |= float_flag_invalid;
69 if (target_bits & 2) {
70 host_bits |= float_flag_divbyzero;
72 if (target_bits & 4) {
73 host_bits |= float_flag_overflow;
75 if (target_bits & 8) {
76 host_bits |= float_flag_underflow;
78 if (target_bits & 0x10) {
79 host_bits |= float_flag_inexact;
81 if (target_bits & 0x80) {
82 host_bits |= float_flag_input_denormal;
84 return host_bits;
87 static uint32_t vfp_get_fpscr_from_host(CPUARMState *env)
89 uint32_t i;
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);
101 static void vfp_set_fpscr_to_host(CPUARMState *env, uint32_t val)
103 int i;
104 uint32_t changed = env->vfp.xregs[ARM_VFP_FPSCR];
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;
123 set_float_rounding_mode(i, &env->vfp.fp_status);
124 set_float_rounding_mode(i, &env->vfp.fp_status_f16);
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);
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);
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);
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.
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);
156 #else
158 static uint32_t vfp_get_fpscr_from_host(CPUARMState *env)
160 return 0;
163 static void vfp_set_fpscr_to_host(CPUARMState *env, uint32_t val)
167 #endif
169 uint32_t HELPER(vfp_get_fpscr)(CPUARMState *env)
171 uint32_t i, fpscr;
173 fpscr = env->vfp.xregs[ARM_VFP_FPSCR]
174 | (env->vfp.vec_len << 16)
175 | (env->vfp.vec_stride << 20);
178 * M-profile LTPSIZE overlaps A-profile Stride; whichever of the
179 * two is not applicable to this CPU will always be zero.
181 fpscr |= env->v7m.ltpsize << 16;
183 fpscr |= vfp_get_fpscr_from_host(env);
185 i = env->vfp.qc[0] | env->vfp.qc[1] | env->vfp.qc[2] | env->vfp.qc[3];
186 fpscr |= i ? FPCR_QC : 0;
188 return fpscr;
191 uint32_t vfp_get_fpscr(CPUARMState *env)
193 return HELPER(vfp_get_fpscr)(env);
196 void HELPER(vfp_set_fpscr)(CPUARMState *env, uint32_t val)
198 ARMCPU *cpu = env_archcpu(env);
200 /* When ARMv8.2-FP16 is not supported, FZ16 is RES0. */
201 if (!cpu_isar_feature(any_fp16, cpu)) {
202 val &= ~FPCR_FZ16;
205 vfp_set_fpscr_to_host(env, val);
207 if (!arm_feature(env, ARM_FEATURE_M)) {
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.
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);
223 if (arm_feature(env, ARM_FEATURE_NEON) ||
224 cpu_isar_feature(aa32_mve, cpu)) {
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.
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;
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!)
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].
245 env->vfp.xregs[ARM_VFP_FPSCR] = val & 0xf7c80000;
248 void vfp_set_fpscr(CPUARMState *env, uint32_t val)
250 HELPER(vfp_set_fpscr)(env, val);
253 #ifdef CONFIG_TCG
255 #define VFP_HELPER(name, p) HELPER(glue(glue(vfp_,name),p))
257 #define VFP_BINOP(name) \
258 dh_ctype_f16 VFP_HELPER(name, h)(dh_ctype_f16 a, dh_ctype_f16 b, void *fpstp) \
260 float_status *fpst = fpstp; \
261 return float16_ ## name(a, b, fpst); \
263 float32 VFP_HELPER(name, s)(float32 a, float32 b, void *fpstp) \
265 float_status *fpst = fpstp; \
266 return float32_ ## name(a, b, fpst); \
268 float64 VFP_HELPER(name, d)(float64 a, float64 b, void *fpstp) \
270 float_status *fpst = fpstp; \
271 return float64_ ## name(a, b, fpst); \
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
283 dh_ctype_f16 VFP_HELPER(neg, h)(dh_ctype_f16 a)
285 return float16_chs(a);
288 float32 VFP_HELPER(neg, s)(float32 a)
290 return float32_chs(a);
293 float64 VFP_HELPER(neg, d)(float64 a)
295 return float64_chs(a);
298 dh_ctype_f16 VFP_HELPER(abs, h)(dh_ctype_f16 a)
300 return float16_abs(a);
303 float32 VFP_HELPER(abs, s)(float32 a)
305 return float32_abs(a);
308 float64 VFP_HELPER(abs, d)(float64 a)
310 return float64_abs(a);
313 dh_ctype_f16 VFP_HELPER(sqrt, h)(dh_ctype_f16 a, CPUARMState *env)
315 return float16_sqrt(a, &env->vfp.fp_status_f16);
318 float32 VFP_HELPER(sqrt, s)(float32 a, CPUARMState *env)
320 return float32_sqrt(a, &env->vfp.fp_status);
323 float64 VFP_HELPER(sqrt, d)(float64 a, CPUARMState *env)
325 return float64_sqrt(a, &env->vfp.fp_status);
328 static void softfloat_to_vfp_compare(CPUARMState *env, FloatRelation cmp)
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();
347 env->vfp.xregs[ARM_VFP_FPSCR] =
348 deposit32(env->vfp.xregs[ARM_VFP_FPSCR], 28, 4, flags);
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) \
355 softfloat_to_vfp_compare(env, \
356 FLOATTYPE ## _compare_quiet(a, b, &env->vfp.FPST)); \
358 void VFP_HELPER(cmpe, P)(ARGTYPE a, ARGTYPE b, CPUARMState *env) \
360 softfloat_to_vfp_compare(env, \
361 FLOATTYPE ## _compare(a, b, &env->vfp.FPST)); \
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
368 /* Integer to float and float to integer conversions */
370 #define CONV_ITOF(name, ftype, fsz, sign) \
371 ftype HELPER(name)(uint32_t x, void *fpstp) \
373 float_status *fpst = fpstp; \
374 return sign##int32_to_##float##fsz((sign##int32_t)x, fpst); \
377 #define CONV_FTOI(name, ftype, fsz, sign, round) \
378 sign##int32_t HELPER(name)(ftype x, void *fpstp) \
380 float_status *fpst = fpstp; \
381 if (float##fsz##_is_any_nan(x)) { \
382 float_raise(float_flag_invalid, fpst); \
383 return 0; \
385 return float##fsz##_to_##sign##int32##round(x, fpst); \
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)
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)
400 #undef CONV_ITOF
401 #undef CONV_FTOI
402 #undef FLOAT_CONVS
404 /* floating point conversion */
405 float64 VFP_HELPER(fcvtd, s)(float32 x, CPUARMState *env)
407 return float32_to_float64(x, &env->vfp.fp_status);
410 float32 VFP_HELPER(fcvts, d)(float64 x, CPUARMState *env)
412 return float64_to_float32(x, &env->vfp.fp_status);
415 uint32_t HELPER(bfcvt)(float32 x, void *status)
417 return float32_to_bfloat16(x, status);
420 uint32_t HELPER(bfcvt_pair)(uint64_t pair, void *status)
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);
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.
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); }
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) \
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; \
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) \
457 if (unlikely(float##fsz##_is_any_nan(x))) { \
458 float_raise(float_flag_invalid, fpst); \
459 return 0; \
461 return float##fsz##_to_##itype##_scalbn(x, ROUND, shift, fpst); \
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), )
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), )
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)
496 #undef VFP_CONV_FIX
497 #undef VFP_CONV_FIX_FLOAT
498 #undef VFP_CONV_FLOAT_FIX_ROUND
499 #undef VFP_CONV_FIX_A64
501 /* Set the current fp rounding mode and return the old one.
502 * The argument is a softfloat float_round_ value.
504 uint32_t HELPER(set_rmode)(uint32_t rmode, void *fpstp)
506 float_status *fp_status = fpstp;
508 uint32_t prev_rmode = get_float_rounding_mode(fp_status);
509 set_float_rounding_mode(rmode, fp_status);
511 return prev_rmode;
514 /* Half precision conversions. */
515 float32 HELPER(vfp_fcvt_f16_to_f32)(uint32_t a, void *fpstp, uint32_t ahp_mode)
517 /* Squash FZ16 to 0 for the duration of conversion. In this case,
518 * it would affect flushing input denormals.
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;
528 uint32_t HELPER(vfp_fcvt_f32_to_f16)(float32 a, void *fpstp, uint32_t ahp_mode)
530 /* Squash FZ16 to 0 for the duration of conversion. In this case,
531 * it would affect flushing output denormals.
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;
541 float64 HELPER(vfp_fcvt_f16_to_f64)(uint32_t a, void *fpstp, uint32_t ahp_mode)
543 /* Squash FZ16 to 0 for the duration of conversion. In this case,
544 * it would affect flushing input denormals.
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;
554 uint32_t HELPER(vfp_fcvt_f64_to_f16)(float64 a, void *fpstp, uint32_t ahp_mode)
556 /* Squash FZ16 to 0 for the duration of conversion. In this case,
557 * it would affect flushing output denormals.
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;
567 /* NEON helpers. */
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)
577 /* Reciprocal functions
579 * The algorithm that must be used to calculate the estimate
580 * is specified by the ARM ARM, see FPRecipEstimate()/RecipEstimate
583 /* See RecipEstimate()
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.
590 static int recip_estimate(int input)
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;
602 * Common wrapper to call recip_estimate
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.
610 static uint64_t call_recip_estimate(int *exp, int exp_off, uint64_t frac)
612 uint32_t scaled, estimate;
613 uint64_t result_frac;
614 int result_exp;
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;
626 /* scaled = UInt('1':fraction<51:44>) */
627 scaled = deposit32(1 << 8, 0, 8, extract64(frac, 44, 8));
628 estimate = recip_estimate(scaled);
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;
639 *exp = result_exp;
641 return result_frac;
644 static bool round_to_inf(float_status *fpst, bool sign_bit)
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();
660 uint32_t HELPER(recpe_f16)(uint32_t input, void *fpstp)
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;
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 if (!fpst->default_nan_mode) {
675 nan = float16_silence_nan(f16, fpst);
678 if (fpst->default_nan_mode) {
679 nan = float16_default_nan(fpst);
681 return nan;
682 } else if (float16_is_infinity(f16)) {
683 return float16_set_sign(float16_zero, float16_is_neg(f16));
684 } else if (float16_is_zero(f16)) {
685 float_raise(float_flag_divbyzero, fpst);
686 return float16_set_sign(float16_infinity, float16_is_neg(f16));
687 } else if (float16_abs(f16) < (1 << 8)) {
688 /* Abs(value) < 2.0^-16 */
689 float_raise(float_flag_overflow | float_flag_inexact, fpst);
690 if (round_to_inf(fpst, f16_sign)) {
691 return float16_set_sign(float16_infinity, f16_sign);
692 } else {
693 return float16_set_sign(float16_maxnorm, f16_sign);
695 } else if (f16_exp >= 29 && fpst->flush_to_zero) {
696 float_raise(float_flag_underflow, fpst);
697 return float16_set_sign(float16_zero, float16_is_neg(f16));
700 f64_frac = call_recip_estimate(&f16_exp, 29,
701 ((uint64_t) f16_frac) << (52 - 10));
703 /* result = sign : result_exp<4:0> : fraction<51:42> */
704 f16_val = deposit32(0, 15, 1, f16_sign);
705 f16_val = deposit32(f16_val, 10, 5, f16_exp);
706 f16_val = deposit32(f16_val, 0, 10, extract64(f64_frac, 52 - 10, 10));
707 return make_float16(f16_val);
710 float32 HELPER(recpe_f32)(float32 input, void *fpstp)
712 float_status *fpst = fpstp;
713 float32 f32 = float32_squash_input_denormal(input, fpst);
714 uint32_t f32_val = float32_val(f32);
715 bool f32_sign = float32_is_neg(f32);
716 int f32_exp = extract32(f32_val, 23, 8);
717 uint32_t f32_frac = extract32(f32_val, 0, 23);
718 uint64_t f64_frac;
720 if (float32_is_any_nan(f32)) {
721 float32 nan = f32;
722 if (float32_is_signaling_nan(f32, fpst)) {
723 float_raise(float_flag_invalid, fpst);
724 if (!fpst->default_nan_mode) {
725 nan = float32_silence_nan(f32, fpst);
728 if (fpst->default_nan_mode) {
729 nan = float32_default_nan(fpst);
731 return nan;
732 } else if (float32_is_infinity(f32)) {
733 return float32_set_sign(float32_zero, float32_is_neg(f32));
734 } else if (float32_is_zero(f32)) {
735 float_raise(float_flag_divbyzero, fpst);
736 return float32_set_sign(float32_infinity, float32_is_neg(f32));
737 } else if (float32_abs(f32) < (1ULL << 21)) {
738 /* Abs(value) < 2.0^-128 */
739 float_raise(float_flag_overflow | float_flag_inexact, fpst);
740 if (round_to_inf(fpst, f32_sign)) {
741 return float32_set_sign(float32_infinity, f32_sign);
742 } else {
743 return float32_set_sign(float32_maxnorm, f32_sign);
745 } else if (f32_exp >= 253 && fpst->flush_to_zero) {
746 float_raise(float_flag_underflow, fpst);
747 return float32_set_sign(float32_zero, float32_is_neg(f32));
750 f64_frac = call_recip_estimate(&f32_exp, 253,
751 ((uint64_t) f32_frac) << (52 - 23));
753 /* result = sign : result_exp<7:0> : fraction<51:29> */
754 f32_val = deposit32(0, 31, 1, f32_sign);
755 f32_val = deposit32(f32_val, 23, 8, f32_exp);
756 f32_val = deposit32(f32_val, 0, 23, extract64(f64_frac, 52 - 23, 23));
757 return make_float32(f32_val);
760 float64 HELPER(recpe_f64)(float64 input, void *fpstp)
762 float_status *fpst = fpstp;
763 float64 f64 = float64_squash_input_denormal(input, fpst);
764 uint64_t f64_val = float64_val(f64);
765 bool f64_sign = float64_is_neg(f64);
766 int f64_exp = extract64(f64_val, 52, 11);
767 uint64_t f64_frac = extract64(f64_val, 0, 52);
769 /* Deal with any special cases */
770 if (float64_is_any_nan(f64)) {
771 float64 nan = f64;
772 if (float64_is_signaling_nan(f64, fpst)) {
773 float_raise(float_flag_invalid, fpst);
774 if (!fpst->default_nan_mode) {
775 nan = float64_silence_nan(f64, fpst);
778 if (fpst->default_nan_mode) {
779 nan = float64_default_nan(fpst);
781 return nan;
782 } else if (float64_is_infinity(f64)) {
783 return float64_set_sign(float64_zero, float64_is_neg(f64));
784 } else if (float64_is_zero(f64)) {
785 float_raise(float_flag_divbyzero, fpst);
786 return float64_set_sign(float64_infinity, float64_is_neg(f64));
787 } else if ((f64_val & ~(1ULL << 63)) < (1ULL << 50)) {
788 /* Abs(value) < 2.0^-1024 */
789 float_raise(float_flag_overflow | float_flag_inexact, fpst);
790 if (round_to_inf(fpst, f64_sign)) {
791 return float64_set_sign(float64_infinity, f64_sign);
792 } else {
793 return float64_set_sign(float64_maxnorm, f64_sign);
795 } else if (f64_exp >= 2045 && fpst->flush_to_zero) {
796 float_raise(float_flag_underflow, fpst);
797 return float64_set_sign(float64_zero, float64_is_neg(f64));
800 f64_frac = call_recip_estimate(&f64_exp, 2045, f64_frac);
802 /* result = sign : result_exp<10:0> : fraction<51:0>; */
803 f64_val = deposit64(0, 63, 1, f64_sign);
804 f64_val = deposit64(f64_val, 52, 11, f64_exp);
805 f64_val = deposit64(f64_val, 0, 52, f64_frac);
806 return make_float64(f64_val);
809 /* The algorithm that must be used to calculate the estimate
810 * is specified by the ARM ARM.
813 static int do_recip_sqrt_estimate(int a)
815 int b, estimate;
817 assert(128 <= a && a < 512);
818 if (a < 256) {
819 a = a * 2 + 1;
820 } else {
821 a = (a >> 1) << 1;
822 a = (a + 1) * 2;
824 b = 512;
825 while (a * (b + 1) * (b + 1) < (1 << 28)) {
826 b += 1;
828 estimate = (b + 1) / 2;
829 assert(256 <= estimate && estimate < 512);
831 return estimate;
835 static uint64_t recip_sqrt_estimate(int *exp , int exp_off, uint64_t frac)
837 int estimate;
838 uint32_t scaled;
840 if (*exp == 0) {
841 while (extract64(frac, 51, 1) == 0) {
842 frac = frac << 1;
843 *exp -= 1;
845 frac = extract64(frac, 0, 51) << 1;
848 if (*exp & 1) {
849 /* scaled = UInt('01':fraction<51:45>) */
850 scaled = deposit32(1 << 7, 0, 7, extract64(frac, 45, 7));
851 } else {
852 /* scaled = UInt('1':fraction<51:44>) */
853 scaled = deposit32(1 << 8, 0, 8, extract64(frac, 44, 8));
855 estimate = do_recip_sqrt_estimate(scaled);
857 *exp = (exp_off - *exp) / 2;
858 return extract64(estimate, 0, 8) << 44;
861 uint32_t HELPER(rsqrte_f16)(uint32_t input, void *fpstp)
863 float_status *s = fpstp;
864 float16 f16 = float16_squash_input_denormal(input, s);
865 uint16_t val = float16_val(f16);
866 bool f16_sign = float16_is_neg(f16);
867 int f16_exp = extract32(val, 10, 5);
868 uint16_t f16_frac = extract32(val, 0, 10);
869 uint64_t f64_frac;
871 if (float16_is_any_nan(f16)) {
872 float16 nan = f16;
873 if (float16_is_signaling_nan(f16, s)) {
874 float_raise(float_flag_invalid, s);
875 if (!s->default_nan_mode) {
876 nan = float16_silence_nan(f16, fpstp);
879 if (s->default_nan_mode) {
880 nan = float16_default_nan(s);
882 return nan;
883 } else if (float16_is_zero(f16)) {
884 float_raise(float_flag_divbyzero, s);
885 return float16_set_sign(float16_infinity, f16_sign);
886 } else if (f16_sign) {
887 float_raise(float_flag_invalid, s);
888 return float16_default_nan(s);
889 } else if (float16_is_infinity(f16)) {
890 return float16_zero;
893 /* Scale and normalize to a double-precision value between 0.25 and 1.0,
894 * preserving the parity of the exponent. */
896 f64_frac = ((uint64_t) f16_frac) << (52 - 10);
898 f64_frac = recip_sqrt_estimate(&f16_exp, 44, f64_frac);
900 /* result = sign : result_exp<4:0> : estimate<7:0> : Zeros(2) */
901 val = deposit32(0, 15, 1, f16_sign);
902 val = deposit32(val, 10, 5, f16_exp);
903 val = deposit32(val, 2, 8, extract64(f64_frac, 52 - 8, 8));
904 return make_float16(val);
907 float32 HELPER(rsqrte_f32)(float32 input, void *fpstp)
909 float_status *s = fpstp;
910 float32 f32 = float32_squash_input_denormal(input, s);
911 uint32_t val = float32_val(f32);
912 uint32_t f32_sign = float32_is_neg(f32);
913 int f32_exp = extract32(val, 23, 8);
914 uint32_t f32_frac = extract32(val, 0, 23);
915 uint64_t f64_frac;
917 if (float32_is_any_nan(f32)) {
918 float32 nan = f32;
919 if (float32_is_signaling_nan(f32, s)) {
920 float_raise(float_flag_invalid, s);
921 if (!s->default_nan_mode) {
922 nan = float32_silence_nan(f32, fpstp);
925 if (s->default_nan_mode) {
926 nan = float32_default_nan(s);
928 return nan;
929 } else if (float32_is_zero(f32)) {
930 float_raise(float_flag_divbyzero, s);
931 return float32_set_sign(float32_infinity, float32_is_neg(f32));
932 } else if (float32_is_neg(f32)) {
933 float_raise(float_flag_invalid, s);
934 return float32_default_nan(s);
935 } else if (float32_is_infinity(f32)) {
936 return float32_zero;
939 /* Scale and normalize to a double-precision value between 0.25 and 1.0,
940 * preserving the parity of the exponent. */
942 f64_frac = ((uint64_t) f32_frac) << 29;
944 f64_frac = recip_sqrt_estimate(&f32_exp, 380, f64_frac);
946 /* result = sign : result_exp<4:0> : estimate<7:0> : Zeros(15) */
947 val = deposit32(0, 31, 1, f32_sign);
948 val = deposit32(val, 23, 8, f32_exp);
949 val = deposit32(val, 15, 8, extract64(f64_frac, 52 - 8, 8));
950 return make_float32(val);
953 float64 HELPER(rsqrte_f64)(float64 input, void *fpstp)
955 float_status *s = fpstp;
956 float64 f64 = float64_squash_input_denormal(input, s);
957 uint64_t val = float64_val(f64);
958 bool f64_sign = float64_is_neg(f64);
959 int f64_exp = extract64(val, 52, 11);
960 uint64_t f64_frac = extract64(val, 0, 52);
962 if (float64_is_any_nan(f64)) {
963 float64 nan = f64;
964 if (float64_is_signaling_nan(f64, s)) {
965 float_raise(float_flag_invalid, s);
966 if (!s->default_nan_mode) {
967 nan = float64_silence_nan(f64, fpstp);
970 if (s->default_nan_mode) {
971 nan = float64_default_nan(s);
973 return nan;
974 } else if (float64_is_zero(f64)) {
975 float_raise(float_flag_divbyzero, s);
976 return float64_set_sign(float64_infinity, float64_is_neg(f64));
977 } else if (float64_is_neg(f64)) {
978 float_raise(float_flag_invalid, s);
979 return float64_default_nan(s);
980 } else if (float64_is_infinity(f64)) {
981 return float64_zero;
984 f64_frac = recip_sqrt_estimate(&f64_exp, 3068, f64_frac);
986 /* result = sign : result_exp<4:0> : estimate<7:0> : Zeros(44) */
987 val = deposit64(0, 61, 1, f64_sign);
988 val = deposit64(val, 52, 11, f64_exp);
989 val = deposit64(val, 44, 8, extract64(f64_frac, 52 - 8, 8));
990 return make_float64(val);
993 uint32_t HELPER(recpe_u32)(uint32_t a)
995 int input, estimate;
997 if ((a & 0x80000000) == 0) {
998 return 0xffffffff;
1001 input = extract32(a, 23, 9);
1002 estimate = recip_estimate(input);
1004 return deposit32(0, (32 - 9), 9, estimate);
1007 uint32_t HELPER(rsqrte_u32)(uint32_t a)
1009 int estimate;
1011 if ((a & 0xc0000000) == 0) {
1012 return 0xffffffff;
1015 estimate = do_recip_sqrt_estimate(extract32(a, 23, 9));
1017 return deposit32(0, 23, 9, estimate);
1020 /* VFPv4 fused multiply-accumulate */
1021 dh_ctype_f16 VFP_HELPER(muladd, h)(dh_ctype_f16 a, dh_ctype_f16 b,
1022 dh_ctype_f16 c, void *fpstp)
1024 float_status *fpst = fpstp;
1025 return float16_muladd(a, b, c, 0, fpst);
1028 float32 VFP_HELPER(muladd, s)(float32 a, float32 b, float32 c, void *fpstp)
1030 float_status *fpst = fpstp;
1031 return float32_muladd(a, b, c, 0, fpst);
1034 float64 VFP_HELPER(muladd, d)(float64 a, float64 b, float64 c, void *fpstp)
1036 float_status *fpst = fpstp;
1037 return float64_muladd(a, b, c, 0, fpst);
1040 /* ARMv8 round to integral */
1041 dh_ctype_f16 HELPER(rinth_exact)(dh_ctype_f16 x, void *fp_status)
1043 return float16_round_to_int(x, fp_status);
1046 float32 HELPER(rints_exact)(float32 x, void *fp_status)
1048 return float32_round_to_int(x, fp_status);
1051 float64 HELPER(rintd_exact)(float64 x, void *fp_status)
1053 return float64_round_to_int(x, fp_status);
1056 dh_ctype_f16 HELPER(rinth)(dh_ctype_f16 x, void *fp_status)
1058 int old_flags = get_float_exception_flags(fp_status), new_flags;
1059 float16 ret;
1061 ret = float16_round_to_int(x, fp_status);
1063 /* Suppress any inexact exceptions the conversion produced */
1064 if (!(old_flags & float_flag_inexact)) {
1065 new_flags = get_float_exception_flags(fp_status);
1066 set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
1069 return ret;
1072 float32 HELPER(rints)(float32 x, void *fp_status)
1074 int old_flags = get_float_exception_flags(fp_status), new_flags;
1075 float32 ret;
1077 ret = float32_round_to_int(x, fp_status);
1079 /* Suppress any inexact exceptions the conversion produced */
1080 if (!(old_flags & float_flag_inexact)) {
1081 new_flags = get_float_exception_flags(fp_status);
1082 set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
1085 return ret;
1088 float64 HELPER(rintd)(float64 x, void *fp_status)
1090 int old_flags = get_float_exception_flags(fp_status), new_flags;
1091 float64 ret;
1093 ret = float64_round_to_int(x, fp_status);
1095 new_flags = get_float_exception_flags(fp_status);
1097 /* Suppress any inexact exceptions the conversion produced */
1098 if (!(old_flags & float_flag_inexact)) {
1099 new_flags = get_float_exception_flags(fp_status);
1100 set_float_exception_flags(new_flags & ~float_flag_inexact, fp_status);
1103 return ret;
1106 /* Convert ARM rounding mode to softfloat */
1107 int arm_rmode_to_sf(int rmode)
1109 switch (rmode) {
1110 case FPROUNDING_TIEAWAY:
1111 rmode = float_round_ties_away;
1112 break;
1113 case FPROUNDING_ODD:
1114 /* FIXME: add support for TIEAWAY and ODD */
1115 qemu_log_mask(LOG_UNIMP, "arm: unimplemented rounding mode: %d\n",
1116 rmode);
1117 /* fall through for now */
1118 case FPROUNDING_TIEEVEN:
1119 default:
1120 rmode = float_round_nearest_even;
1121 break;
1122 case FPROUNDING_POSINF:
1123 rmode = float_round_up;
1124 break;
1125 case FPROUNDING_NEGINF:
1126 rmode = float_round_down;
1127 break;
1128 case FPROUNDING_ZERO:
1129 rmode = float_round_to_zero;
1130 break;
1132 return rmode;
1136 * Implement float64 to int32_t conversion without saturation;
1137 * the result is supplied modulo 2^32.
1139 uint64_t HELPER(fjcvtzs)(float64 value, void *vstatus)
1141 float_status *status = vstatus;
1142 uint32_t exp, sign;
1143 uint64_t frac;
1144 uint32_t inexact = 1; /* !Z */
1146 sign = extract64(value, 63, 1);
1147 exp = extract64(value, 52, 11);
1148 frac = extract64(value, 0, 52);
1150 if (exp == 0) {
1151 /* While not inexact for IEEE FP, -0.0 is inexact for JavaScript. */
1152 inexact = sign;
1153 if (frac != 0) {
1154 if (status->flush_inputs_to_zero) {
1155 float_raise(float_flag_input_denormal, status);
1156 } else {
1157 float_raise(float_flag_inexact, status);
1158 inexact = 1;
1161 frac = 0;
1162 } else if (exp == 0x7ff) {
1163 /* This operation raises Invalid for both NaN and overflow (Inf). */
1164 float_raise(float_flag_invalid, status);
1165 frac = 0;
1166 } else {
1167 int true_exp = exp - 1023;
1168 int shift = true_exp - 52;
1170 /* Restore implicit bit. */
1171 frac |= 1ull << 52;
1173 /* Shift the fraction into place. */
1174 if (shift >= 0) {
1175 /* The number is so large we must shift the fraction left. */
1176 if (shift >= 64) {
1177 /* The fraction is shifted out entirely. */
1178 frac = 0;
1179 } else {
1180 frac <<= shift;
1182 } else if (shift > -64) {
1183 /* Normal case -- shift right and notice if bits shift out. */
1184 inexact = (frac << (64 + shift)) != 0;
1185 frac >>= -shift;
1186 } else {
1187 /* The fraction is shifted out entirely. */
1188 frac = 0;
1191 /* Notice overflow or inexact exceptions. */
1192 if (true_exp > 31 || frac > (sign ? 0x80000000ull : 0x7fffffff)) {
1193 /* Overflow, for which this operation raises invalid. */
1194 float_raise(float_flag_invalid, status);
1195 inexact = 1;
1196 } else if (inexact) {
1197 float_raise(float_flag_inexact, status);
1200 /* Honor the sign. */
1201 if (sign) {
1202 frac = -frac;
1206 /* Pack the result and the env->ZF representation of Z together. */
1207 return deposit64(frac, 32, 32, inexact);
1210 uint32_t HELPER(vjcvt)(float64 value, CPUARMState *env)
1212 uint64_t pair = HELPER(fjcvtzs)(value, &env->vfp.fp_status);
1213 uint32_t result = pair;
1214 uint32_t z = (pair >> 32) == 0;
1216 /* Store Z, clear NCV, in FPSCR.NZCV. */
1217 env->vfp.xregs[ARM_VFP_FPSCR]
1218 = (env->vfp.xregs[ARM_VFP_FPSCR] & ~CPSR_NZCV) | (z * CPSR_Z);
1220 return result;
1223 /* Round a float32 to an integer that fits in int32_t or int64_t. */
1224 static float32 frint_s(float32 f, float_status *fpst, int intsize)
1226 int old_flags = get_float_exception_flags(fpst);
1227 uint32_t exp = extract32(f, 23, 8);
1229 if (unlikely(exp == 0xff)) {
1230 /* NaN or Inf. */
1231 goto overflow;
1234 /* Round and re-extract the exponent. */
1235 f = float32_round_to_int(f, fpst);
1236 exp = extract32(f, 23, 8);
1238 /* Validate the range of the result. */
1239 if (exp < 126 + intsize) {
1240 /* abs(F) <= INT{N}_MAX */
1241 return f;
1243 if (exp == 126 + intsize) {
1244 uint32_t sign = extract32(f, 31, 1);
1245 uint32_t frac = extract32(f, 0, 23);
1246 if (sign && frac == 0) {
1247 /* F == INT{N}_MIN */
1248 return f;
1252 overflow:
1254 * Raise Invalid and return INT{N}_MIN as a float. Revert any
1255 * inexact exception float32_round_to_int may have raised.
1257 set_float_exception_flags(old_flags | float_flag_invalid, fpst);
1258 return (0x100u + 126u + intsize) << 23;
1261 float32 HELPER(frint32_s)(float32 f, void *fpst)
1263 return frint_s(f, fpst, 32);
1266 float32 HELPER(frint64_s)(float32 f, void *fpst)
1268 return frint_s(f, fpst, 64);
1271 /* Round a float64 to an integer that fits in int32_t or int64_t. */
1272 static float64 frint_d(float64 f, float_status *fpst, int intsize)
1274 int old_flags = get_float_exception_flags(fpst);
1275 uint32_t exp = extract64(f, 52, 11);
1277 if (unlikely(exp == 0x7ff)) {
1278 /* NaN or Inf. */
1279 goto overflow;
1282 /* Round and re-extract the exponent. */
1283 f = float64_round_to_int(f, fpst);
1284 exp = extract64(f, 52, 11);
1286 /* Validate the range of the result. */
1287 if (exp < 1022 + intsize) {
1288 /* abs(F) <= INT{N}_MAX */
1289 return f;
1291 if (exp == 1022 + intsize) {
1292 uint64_t sign = extract64(f, 63, 1);
1293 uint64_t frac = extract64(f, 0, 52);
1294 if (sign && frac == 0) {
1295 /* F == INT{N}_MIN */
1296 return f;
1300 overflow:
1302 * Raise Invalid and return INT{N}_MIN as a float. Revert any
1303 * inexact exception float64_round_to_int may have raised.
1305 set_float_exception_flags(old_flags | float_flag_invalid, fpst);
1306 return (uint64_t)(0x800 + 1022 + intsize) << 52;
1309 float64 HELPER(frint32_d)(float64 f, void *fpst)
1311 return frint_d(f, fpst, 32);
1314 float64 HELPER(frint64_d)(float64 f, void *fpst)
1316 return frint_d(f, fpst, 64);
1319 void HELPER(check_hcr_el2_trap)(CPUARMState *env, uint32_t rt, uint32_t reg)
1321 uint32_t syndrome;
1323 switch (reg) {
1324 case ARM_VFP_MVFR0:
1325 case ARM_VFP_MVFR1:
1326 case ARM_VFP_MVFR2:
1327 if (!(arm_hcr_el2_eff(env) & HCR_TID3)) {
1328 return;
1330 break;
1331 case ARM_VFP_FPSID:
1332 if (!(arm_hcr_el2_eff(env) & HCR_TID0)) {
1333 return;
1335 break;
1336 default:
1337 g_assert_not_reached();
1340 syndrome = ((EC_FPIDTRAP << ARM_EL_EC_SHIFT)
1341 | ARM_EL_IL
1342 | (1 << 24) | (0xe << 20) | (7 << 14)
1343 | (reg << 10) | (rt << 5) | 1);
1345 raise_exception(env, EXCP_HYP_TRAP, syndrome, 2);
1348 #endif