xref: /qemu/target/s390x/tcg/vec_fpu_helper.c (revision 860b707bbb1957d710d3469dbdc3b9f72576a7ef)
1 /*
2  * QEMU TCG support -- s390x vector floating point instruction support
3  *
4  * Copyright (C) 2019 Red Hat Inc
5  *
6  * Authors:
7  *   David Hildenbrand <david@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 #include "qemu/osdep.h"
13 #include "qemu-common.h"
14 #include "cpu.h"
15 #include "internal.h"
16 #include "vec.h"
17 #include "tcg_s390x.h"
18 #include "tcg/tcg-gvec-desc.h"
19 #include "exec/exec-all.h"
20 #include "exec/helper-proto.h"
21 #include "fpu/softfloat.h"
22 
23 #define VIC_INVALID         0x1
24 #define VIC_DIVBYZERO       0x2
25 #define VIC_OVERFLOW        0x3
26 #define VIC_UNDERFLOW       0x4
27 #define VIC_INEXACT         0x5
28 
29 /* returns the VEX. If the VEX is 0, there is no trap */
30 static uint8_t check_ieee_exc(CPUS390XState *env, uint8_t enr, bool XxC,
31                               uint8_t *vec_exc)
32 {
33     uint8_t vece_exc = 0, trap_exc;
34     unsigned qemu_exc;
35 
36     /* Retrieve and clear the softfloat exceptions */
37     qemu_exc = env->fpu_status.float_exception_flags;
38     if (qemu_exc == 0) {
39         return 0;
40     }
41     env->fpu_status.float_exception_flags = 0;
42 
43     vece_exc = s390_softfloat_exc_to_ieee(qemu_exc);
44 
45     /* Add them to the vector-wide s390x exception bits */
46     *vec_exc |= vece_exc;
47 
48     /* Check for traps and construct the VXC */
49     trap_exc = vece_exc & env->fpc >> 24;
50     if (trap_exc) {
51         if (trap_exc & S390_IEEE_MASK_INVALID) {
52             return enr << 4 | VIC_INVALID;
53         } else if (trap_exc & S390_IEEE_MASK_DIVBYZERO) {
54             return enr << 4 | VIC_DIVBYZERO;
55         } else if (trap_exc & S390_IEEE_MASK_OVERFLOW) {
56             return enr << 4 | VIC_OVERFLOW;
57         } else if (trap_exc & S390_IEEE_MASK_UNDERFLOW) {
58             return enr << 4 | VIC_UNDERFLOW;
59         } else if (!XxC) {
60             g_assert(trap_exc & S390_IEEE_MASK_INEXACT);
61             /* inexact has lowest priority on traps */
62             return enr << 4 | VIC_INEXACT;
63         }
64     }
65     return 0;
66 }
67 
68 static void handle_ieee_exc(CPUS390XState *env, uint8_t vxc, uint8_t vec_exc,
69                             uintptr_t retaddr)
70 {
71     if (vxc) {
72         /* on traps, the fpc flags are not updated, instruction is suppressed */
73         tcg_s390_vector_exception(env, vxc, retaddr);
74     }
75     if (vec_exc) {
76         /* indicate exceptions for all elements combined */
77         env->fpc |= vec_exc << 16;
78     }
79 }
80 
81 static float64 s390_vec_read_float64(const S390Vector *v, uint8_t enr)
82 {
83     return make_float64(s390_vec_read_element64(v, enr));
84 }
85 
86 static void s390_vec_write_float64(S390Vector *v, uint8_t enr, float64 data)
87 {
88     return s390_vec_write_element64(v, enr, data);
89 }
90 
91 typedef float64 (*vop64_2_fn)(float64 a, float_status *s);
92 static void vop64_2(S390Vector *v1, const S390Vector *v2, CPUS390XState *env,
93                     bool s, bool XxC, uint8_t erm, vop64_2_fn fn,
94                     uintptr_t retaddr)
95 {
96     uint8_t vxc, vec_exc = 0;
97     S390Vector tmp = {};
98     int i, old_mode;
99 
100     old_mode = s390_swap_bfp_rounding_mode(env, erm);
101     for (i = 0; i < 2; i++) {
102         const float64 a = s390_vec_read_float64(v2, i);
103 
104         s390_vec_write_float64(&tmp, i, fn(a, &env->fpu_status));
105         vxc = check_ieee_exc(env, i, XxC, &vec_exc);
106         if (s || vxc) {
107             break;
108         }
109     }
110     s390_restore_bfp_rounding_mode(env, old_mode);
111     handle_ieee_exc(env, vxc, vec_exc, retaddr);
112     *v1 = tmp;
113 }
114 
115 static float64 vcdg64(float64 a, float_status *s)
116 {
117     return int64_to_float64(a, s);
118 }
119 
120 static float64 vcdlg64(float64 a, float_status *s)
121 {
122     return uint64_to_float64(a, s);
123 }
124 
125 static float64 vcgd64(float64 a, float_status *s)
126 {
127     const float64 tmp = float64_to_int64(a, s);
128 
129     return float64_is_any_nan(a) ? INT64_MIN : tmp;
130 }
131 
132 static float64 vclgd64(float64 a, float_status *s)
133 {
134     const float64 tmp = float64_to_uint64(a, s);
135 
136     return float64_is_any_nan(a) ? 0 : tmp;
137 }
138 
139 #define DEF_GVEC_VOP2_FN(NAME, FN, BITS)                                       \
140 void HELPER(gvec_##NAME##BITS)(void *v1, const void *v2, CPUS390XState *env,   \
141                                uint32_t desc)                                  \
142 {                                                                              \
143     const uint8_t erm = extract32(simd_data(desc), 4, 4);                      \
144     const bool se = extract32(simd_data(desc), 3, 1);                          \
145     const bool XxC = extract32(simd_data(desc), 2, 1);                         \
146                                                                                \
147     vop##BITS##_2(v1, v2, env, se, XxC, erm, FN, GETPC());                     \
148 }
149 
150 #define DEF_GVEC_VOP2_64(NAME)                                                 \
151 DEF_GVEC_VOP2_FN(NAME, NAME##64, 64)
152 
153 #define DEF_GVEC_VOP2(NAME, OP)                                                \
154 DEF_GVEC_VOP2_FN(NAME, float64_##OP, 64)
155 
156 DEF_GVEC_VOP2_64(vcdg)
157 DEF_GVEC_VOP2_64(vcdlg)
158 DEF_GVEC_VOP2_64(vcgd)
159 DEF_GVEC_VOP2_64(vclgd)
160 DEF_GVEC_VOP2(vfi, round_to_int)
161 DEF_GVEC_VOP2(vfsq, sqrt)
162 
163 typedef float64 (*vop64_3_fn)(float64 a, float64 b, float_status *s);
164 static void vop64_3(S390Vector *v1, const S390Vector *v2, const S390Vector *v3,
165                     CPUS390XState *env, bool s, vop64_3_fn fn,
166                     uintptr_t retaddr)
167 {
168     uint8_t vxc, vec_exc = 0;
169     S390Vector tmp = {};
170     int i;
171 
172     for (i = 0; i < 2; i++) {
173         const float64 a = s390_vec_read_float64(v2, i);
174         const float64 b = s390_vec_read_float64(v3, i);
175 
176         s390_vec_write_float64(&tmp, i, fn(a, b, &env->fpu_status));
177         vxc = check_ieee_exc(env, i, false, &vec_exc);
178         if (s || vxc) {
179             break;
180         }
181     }
182     handle_ieee_exc(env, vxc, vec_exc, retaddr);
183     *v1 = tmp;
184 }
185 
186 #define DEF_GVEC_VOP3(NAME, OP)                                                \
187 void HELPER(gvec_##NAME##64)(void *v1, const void *v2, const void *v3,         \
188                              CPUS390XState *env, uint32_t desc)                \
189 {                                                                              \
190     const bool se = extract32(simd_data(desc), 3, 1);                          \
191                                                                                \
192     vop64_3(v1, v2, v3, env, se, float64_##OP, GETPC());                       \
193 }
194 
195 DEF_GVEC_VOP3(vfa, add)
196 DEF_GVEC_VOP3(vfs, sub)
197 DEF_GVEC_VOP3(vfd, div)
198 DEF_GVEC_VOP3(vfm, mul)
199 
200 static int wfc64(const S390Vector *v1, const S390Vector *v2,
201                  CPUS390XState *env, bool signal, uintptr_t retaddr)
202 {
203     /* only the zero-indexed elements are compared */
204     const float64 a = s390_vec_read_element64(v1, 0);
205     const float64 b = s390_vec_read_element64(v2, 0);
206     uint8_t vxc, vec_exc = 0;
207     int cmp;
208 
209     if (signal) {
210         cmp = float64_compare(a, b, &env->fpu_status);
211     } else {
212         cmp = float64_compare_quiet(a, b, &env->fpu_status);
213     }
214     vxc = check_ieee_exc(env, 0, false, &vec_exc);
215     handle_ieee_exc(env, vxc, vec_exc, retaddr);
216 
217     return float_comp_to_cc(env, cmp);
218 }
219 
220 void HELPER(gvec_wfc64)(const void *v1, const void *v2, CPUS390XState *env,
221                         uint32_t desc)
222 {
223     env->cc_op = wfc64(v1, v2, env, false, GETPC());
224 }
225 
226 void HELPER(gvec_wfk64)(const void *v1, const void *v2, CPUS390XState *env,
227                         uint32_t desc)
228 {
229     env->cc_op = wfc64(v1, v2, env, true, GETPC());
230 }
231 
232 typedef bool (*vfc64_fn)(float64 a, float64 b, float_status *status);
233 static int vfc64(S390Vector *v1, const S390Vector *v2, const S390Vector *v3,
234                  CPUS390XState *env, bool s, vfc64_fn fn, uintptr_t retaddr)
235 {
236     uint8_t vxc, vec_exc = 0;
237     S390Vector tmp = {};
238     int match = 0;
239     int i;
240 
241     for (i = 0; i < 2; i++) {
242         const float64 a = s390_vec_read_float64(v2, i);
243         const float64 b = s390_vec_read_float64(v3, i);
244 
245         /* swap the order of the parameters, so we can use existing functions */
246         if (fn(b, a, &env->fpu_status)) {
247             match++;
248             s390_vec_write_element64(&tmp, i, -1ull);
249         }
250         vxc = check_ieee_exc(env, i, false, &vec_exc);
251         if (s || vxc) {
252             break;
253         }
254     }
255 
256     handle_ieee_exc(env, vxc, vec_exc, retaddr);
257     *v1 = tmp;
258     if (match) {
259         return s || match == 2 ? 0 : 1;
260     }
261     return 3;
262 }
263 
264 #define DEF_GVEC_VFC_B(NAME, OP, BITS)                                         \
265 void HELPER(gvec_##NAME##BITS)(void *v1, const void *v2, const void *v3,       \
266                                CPUS390XState *env, uint32_t desc)              \
267 {                                                                              \
268     const bool se = extract32(simd_data(desc), 3, 1);                          \
269     vfc##BITS##_fn fn = float##BITS##_##OP##_quiet;                            \
270                                                                                \
271     vfc##BITS(v1, v2, v3, env, se, fn, GETPC());                               \
272 }                                                                              \
273                                                                                \
274 void HELPER(gvec_##NAME##BITS##_cc)(void *v1, const void *v2, const void *v3,  \
275                                     CPUS390XState *env, uint32_t desc)         \
276 {                                                                              \
277     const bool se = extract32(simd_data(desc), 3, 1);                          \
278     vfc##BITS##_fn fn = float##BITS##_##OP##_quiet;                            \
279                                                                                \
280     env->cc_op = vfc##BITS(v1, v2, v3, env, se, fn, GETPC());                  \
281 }
282 
283 #define DEF_GVEC_VFC(NAME, OP)                                                 \
284 DEF_GVEC_VFC_B(NAME, OP, 64)
285 
286 DEF_GVEC_VFC(vfce, eq)
287 DEF_GVEC_VFC(vfch, lt)
288 DEF_GVEC_VFC(vfche, le)
289 
290 void HELPER(gvec_vfll32)(void *v1, const void *v2, CPUS390XState *env,
291                          uint32_t desc)
292 {
293     const bool s = extract32(simd_data(desc), 3, 1);
294     uint8_t vxc, vec_exc = 0;
295     S390Vector tmp = {};
296     int i;
297 
298     for (i = 0; i < 2; i++) {
299         /* load from even element */
300         const float32 a = s390_vec_read_element32(v2, i * 2);
301         const uint64_t ret = float32_to_float64(a, &env->fpu_status);
302 
303         s390_vec_write_element64(&tmp, i, ret);
304         /* indicate the source element */
305         vxc = check_ieee_exc(env, i * 2, false, &vec_exc);
306         if (s || vxc) {
307             break;
308         }
309     }
310     handle_ieee_exc(env, vxc, vec_exc, GETPC());
311     *(S390Vector *)v1 = tmp;
312 }
313 
314 static void vflr64(S390Vector *v1, const S390Vector *v2, CPUS390XState *env,
315                    bool s, bool XxC, uint8_t erm, uintptr_t retaddr)
316 {
317     uint8_t vxc, vec_exc = 0;
318     S390Vector tmp = {};
319     int i, old_mode;
320 
321     old_mode = s390_swap_bfp_rounding_mode(env, erm);
322     for (i = 0; i < 2; i++) {
323         float64 a = s390_vec_read_element64(v2, i);
324         uint32_t ret = float64_to_float32(a, &env->fpu_status);
325 
326         /* place at even element */
327         s390_vec_write_element32(&tmp, i * 2, ret);
328         /* indicate the source element */
329         vxc = check_ieee_exc(env, i, XxC, &vec_exc);
330         if (s || vxc) {
331             break;
332         }
333     }
334     s390_restore_bfp_rounding_mode(env, old_mode);
335     handle_ieee_exc(env, vxc, vec_exc, retaddr);
336     *v1 = tmp;
337 }
338 
339 void HELPER(gvec_vflr64)(void *v1, const void *v2, CPUS390XState *env,
340                          uint32_t desc)
341 {
342     const uint8_t erm = extract32(simd_data(desc), 4, 4);
343     const bool XxC = extract32(simd_data(desc), 2, 1);
344 
345     vflr64(v1, v2, env, false, XxC, erm, GETPC());
346 }
347 
348 void HELPER(gvec_vflr64s)(void *v1, const void *v2, CPUS390XState *env,
349                           uint32_t desc)
350 {
351     const uint8_t erm = extract32(simd_data(desc), 4, 4);
352     const bool XxC = extract32(simd_data(desc), 2, 1);
353 
354     vflr64(v1, v2, env, true, XxC, erm, GETPC());
355 }
356 
357 static void vfma64(S390Vector *v1, const S390Vector *v2, const S390Vector *v3,
358                    const S390Vector *v4, CPUS390XState *env, bool s, int flags,
359                    uintptr_t retaddr)
360 {
361     uint8_t vxc, vec_exc = 0;
362     S390Vector tmp = {};
363     int i;
364 
365     for (i = 0; i < 2; i++) {
366         const float64 a = s390_vec_read_float64(v2, i);
367         const float64 b = s390_vec_read_float64(v3, i);
368         const float64 c = s390_vec_read_float64(v4, i);
369         const float64 ret = float64_muladd(a, b, c, flags, &env->fpu_status);
370 
371         s390_vec_write_float64(&tmp, i, ret);
372         vxc = check_ieee_exc(env, i, false, &vec_exc);
373         if (s || vxc) {
374             break;
375         }
376     }
377     handle_ieee_exc(env, vxc, vec_exc, retaddr);
378     *v1 = tmp;
379 }
380 
381 #define DEF_GVEC_VFMA_B(NAME, FLAGS, BITS)                                     \
382 void HELPER(gvec_##NAME##BITS)(void *v1, const void *v2, const void *v3,       \
383                                const void *v4, CPUS390XState *env,             \
384                                uint32_t desc)                                  \
385 {                                                                              \
386     const bool se = extract32(simd_data(desc), 3, 1);                          \
387                                                                                \
388     vfma##BITS(v1, v2, v3, v4, env, se, FLAGS, GETPC());                       \
389 }
390 
391 #define DEF_GVEC_VFMA(NAME, FLAGS)                                             \
392     DEF_GVEC_VFMA_B(NAME, FLAGS, 64)
393 
394 DEF_GVEC_VFMA(vfma, 0)
395 DEF_GVEC_VFMA(vfms, float_muladd_negate_c)
396 
397 void HELPER(gvec_vftci64)(void *v1, const void *v2, CPUS390XState *env,
398                           uint32_t desc)
399 {
400     const uint16_t i3 = extract32(simd_data(desc), 4, 12);
401     const bool s = extract32(simd_data(desc), 3, 1);
402     int i, match = 0;
403 
404     for (i = 0; i < 2; i++) {
405         const float64 a = s390_vec_read_float64(v2, i);
406 
407         if (float64_dcmask(env, a) & i3) {
408             match++;
409             s390_vec_write_element64(v1, i, -1ull);
410         } else {
411             s390_vec_write_element64(v1, i, 0);
412         }
413         if (s) {
414             break;
415         }
416     }
417 
418     if (match == 2 || (s && match)) {
419         env->cc_op = 0;
420     } else if (match) {
421         env->cc_op = 1;
422     } else {
423         env->cc_op = 3;
424     }
425 }
426