xref: /openbmc/qemu/target/riscv/internals.h (revision 5e689840)
1 /*
2  * QEMU RISC-V CPU -- internal functions and types
3  *
4  * Copyright (c) 2020 T-Head Semiconductor Co., Ltd. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2 or later, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #ifndef RISCV_CPU_INTERNALS_H
20 #define RISCV_CPU_INTERNALS_H
21 
22 #include "hw/registerfields.h"
23 
24 /* share data between vector helpers and decode code */
25 FIELD(VDATA, VM, 0, 1)
26 FIELD(VDATA, LMUL, 1, 3)
27 FIELD(VDATA, VTA, 4, 1)
28 FIELD(VDATA, VTA_ALL_1S, 5, 1)
29 FIELD(VDATA, VMA, 6, 1)
30 FIELD(VDATA, NF, 7, 4)
31 FIELD(VDATA, WD, 7, 1)
32 
33 /* float point classify helpers */
34 target_ulong fclass_h(uint64_t frs1);
35 target_ulong fclass_s(uint64_t frs1);
36 target_ulong fclass_d(uint64_t frs1);
37 
38 #ifndef CONFIG_USER_ONLY
39 extern const VMStateDescription vmstate_riscv_cpu;
40 #endif
41 
42 enum {
43     RISCV_FRM_RNE = 0,  /* Round to Nearest, ties to Even */
44     RISCV_FRM_RTZ = 1,  /* Round towards Zero */
45     RISCV_FRM_RDN = 2,  /* Round Down */
46     RISCV_FRM_RUP = 3,  /* Round Up */
47     RISCV_FRM_RMM = 4,  /* Round to Nearest, ties to Max Magnitude */
48     RISCV_FRM_DYN = 7,  /* Dynamic rounding mode */
49     RISCV_FRM_ROD = 8,  /* Round to Odd */
50 };
51 
52 static inline uint64_t nanbox_s(CPURISCVState *env, float32 f)
53 {
54     /* the value is sign-extended instead of NaN-boxing for zfinx */
55     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
56         return (int32_t)f;
57     } else {
58         return f | MAKE_64BIT_MASK(32, 32);
59     }
60 }
61 
62 static inline float32 check_nanbox_s(CPURISCVState *env, uint64_t f)
63 {
64     /* Disable NaN-boxing check when enable zfinx */
65     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
66         return (uint32_t)f;
67     }
68 
69     uint64_t mask = MAKE_64BIT_MASK(32, 32);
70 
71     if (likely((f & mask) == mask)) {
72         return (uint32_t)f;
73     } else {
74         return 0x7fc00000u; /* default qnan */
75     }
76 }
77 
78 static inline uint64_t nanbox_h(CPURISCVState *env, float16 f)
79 {
80     /* the value is sign-extended instead of NaN-boxing for zfinx */
81     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
82         return (int16_t)f;
83     } else {
84         return f | MAKE_64BIT_MASK(16, 48);
85     }
86 }
87 
88 static inline float16 check_nanbox_h(CPURISCVState *env, uint64_t f)
89 {
90     /* Disable nanbox check when enable zfinx */
91     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
92         return (uint16_t)f;
93     }
94 
95     uint64_t mask = MAKE_64BIT_MASK(16, 48);
96 
97     if (likely((f & mask) == mask)) {
98         return (uint16_t)f;
99     } else {
100         return 0x7E00u; /* default qnan */
101     }
102 }
103 
104 #endif
105