xref: /openbmc/qemu/target/riscv/internals.h (revision f1eed927)
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, NF, 5, 4)
29 FIELD(VDATA, WD, 5, 1)
30 
31 /* float point classify helpers */
32 target_ulong fclass_h(uint64_t frs1);
33 target_ulong fclass_s(uint64_t frs1);
34 target_ulong fclass_d(uint64_t frs1);
35 
36 #ifndef CONFIG_USER_ONLY
37 extern const VMStateDescription vmstate_riscv_cpu;
38 #endif
39 
40 enum {
41     RISCV_FRM_RNE = 0,  /* Round to Nearest, ties to Even */
42     RISCV_FRM_RTZ = 1,  /* Round towards Zero */
43     RISCV_FRM_RDN = 2,  /* Round Down */
44     RISCV_FRM_RUP = 3,  /* Round Up */
45     RISCV_FRM_RMM = 4,  /* Round to Nearest, ties to Max Magnitude */
46     RISCV_FRM_DYN = 7,  /* Dynamic rounding mode */
47     RISCV_FRM_ROD = 8,  /* Round to Odd */
48 };
49 
50 static inline uint64_t nanbox_s(CPURISCVState *env, float32 f)
51 {
52     /* the value is sign-extended instead of NaN-boxing for zfinx */
53     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
54         return (int32_t)f;
55     } else {
56         return f | MAKE_64BIT_MASK(32, 32);
57     }
58 }
59 
60 static inline float32 check_nanbox_s(CPURISCVState *env, uint64_t f)
61 {
62     /* Disable NaN-boxing check when enable zfinx */
63     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
64         return (uint32_t)f;
65     }
66 
67     uint64_t mask = MAKE_64BIT_MASK(32, 32);
68 
69     if (likely((f & mask) == mask)) {
70         return (uint32_t)f;
71     } else {
72         return 0x7fc00000u; /* default qnan */
73     }
74 }
75 
76 static inline uint64_t nanbox_h(CPURISCVState *env, float16 f)
77 {
78     /* the value is sign-extended instead of NaN-boxing for zfinx */
79     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
80         return (int16_t)f;
81     } else {
82         return f | MAKE_64BIT_MASK(16, 48);
83     }
84 }
85 
86 static inline float16 check_nanbox_h(CPURISCVState *env, uint64_t f)
87 {
88     /* Disable nanbox check when enable zfinx */
89     if (RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
90         return (uint16_t)f;
91     }
92 
93     uint64_t mask = MAKE_64BIT_MASK(16, 48);
94 
95     if (likely((f & mask) == mask)) {
96         return (uint16_t)f;
97     } else {
98         return 0x7E00u; /* default qnan */
99     }
100 }
101 
102 #endif
103