xref: /openbmc/qemu/target/openrisc/fpu_helper.c (revision 0b84b662)
1 /*
2  * OpenRISC float helper routines
3  *
4  * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
5  *                         Feng Gao <gf91597@gmail.com>
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "exec/helper-proto.h"
24 #include "exception.h"
25 #include "fpu/softfloat.h"
26 
27 static int ieee_ex_to_openrisc(int fexcp)
28 {
29     int ret = 0;
30     if (fexcp & float_flag_invalid) {
31         ret |= FPCSR_IVF;
32     }
33     if (fexcp & float_flag_overflow) {
34         ret |= FPCSR_OVF;
35     }
36     if (fexcp & float_flag_underflow) {
37         ret |= FPCSR_UNF;
38     }
39     if (fexcp & float_flag_divbyzero) {
40         ret |= FPCSR_DZF;
41     }
42     if (fexcp & float_flag_inexact) {
43         ret |= FPCSR_IXF;
44     }
45     return ret;
46 }
47 
48 void HELPER(update_fpcsr)(CPUOpenRISCState *env)
49 {
50     int tmp = get_float_exception_flags(&env->fp_status);
51 
52     if (tmp) {
53         set_float_exception_flags(0, &env->fp_status);
54         tmp = ieee_ex_to_openrisc(tmp);
55         if (tmp) {
56             env->fpcsr |= tmp;
57             if (env->fpcsr & FPCSR_FPEE) {
58                 helper_exception(env, EXCP_FPE);
59             }
60         }
61     }
62 }
63 
64 void cpu_set_fpcsr(CPUOpenRISCState *env, uint32_t val)
65 {
66     static const int rm_to_sf[] = {
67         float_round_nearest_even,
68         float_round_to_zero,
69         float_round_up,
70         float_round_down
71     };
72 
73     env->fpcsr = val & 0x7ff;
74     set_float_rounding_mode(rm_to_sf[extract32(val, 1, 2)], &env->fp_status);
75 }
76 
77 uint64_t HELPER(itofd)(CPUOpenRISCState *env, uint64_t val)
78 {
79     return int64_to_float64(val, &env->fp_status);
80 }
81 
82 uint32_t HELPER(itofs)(CPUOpenRISCState *env, uint32_t val)
83 {
84     return int32_to_float32(val, &env->fp_status);
85 }
86 
87 uint64_t HELPER(ftoid)(CPUOpenRISCState *env, uint64_t val)
88 {
89     return float64_to_int64_round_to_zero(val, &env->fp_status);
90 }
91 
92 uint32_t HELPER(ftois)(CPUOpenRISCState *env, uint32_t val)
93 {
94     return float32_to_int32_round_to_zero(val, &env->fp_status);
95 }
96 
97 uint64_t HELPER(stod)(CPUOpenRISCState *env, uint32_t val)
98 {
99     return float32_to_float64(val, &env->fp_status);
100 }
101 
102 uint32_t HELPER(dtos)(CPUOpenRISCState *env, uint64_t val)
103 {
104     return float64_to_float32(val, &env->fp_status);
105 }
106 
107 #define FLOAT_CALC(name)                                                  \
108 uint64_t helper_float_ ## name ## _d(CPUOpenRISCState *env,               \
109                                      uint64_t fdt0, uint64_t fdt1)        \
110 { return float64_ ## name(fdt0, fdt1, &env->fp_status); }                 \
111 uint32_t helper_float_ ## name ## _s(CPUOpenRISCState *env,               \
112                                      uint32_t fdt0, uint32_t fdt1)        \
113 { return float32_ ## name(fdt0, fdt1, &env->fp_status); }
114 
115 FLOAT_CALC(add)
116 FLOAT_CALC(sub)
117 FLOAT_CALC(mul)
118 FLOAT_CALC(div)
119 FLOAT_CALC(rem)
120 #undef FLOAT_CALC
121 
122 
123 uint64_t helper_float_madd_d(CPUOpenRISCState *env, uint64_t a,
124                              uint64_t b, uint64_t c)
125 {
126     /* Note that or1ksim doesn't use fused operation.  */
127     b = float64_mul(b, c, &env->fp_status);
128     return float64_add(a, b, &env->fp_status);
129 }
130 
131 uint32_t helper_float_madd_s(CPUOpenRISCState *env, uint32_t a,
132                              uint32_t b, uint32_t c)
133 {
134     /* Note that or1ksim doesn't use fused operation.  */
135     b = float32_mul(b, c, &env->fp_status);
136     return float32_add(a, b, &env->fp_status);
137 }
138 
139 
140 #define FLOAT_CMP(name, impl)                                             \
141 target_ulong helper_float_ ## name ## _d(CPUOpenRISCState *env,           \
142                                          uint64_t fdt0, uint64_t fdt1)    \
143 { return float64_ ## impl(fdt0, fdt1, &env->fp_status); }                 \
144 target_ulong helper_float_ ## name ## _s(CPUOpenRISCState *env,           \
145                                          uint32_t fdt0, uint32_t fdt1)    \
146 { return float32_ ## impl(fdt0, fdt1, &env->fp_status); }
147 
148 FLOAT_CMP(le, le)
149 FLOAT_CMP(lt, lt)
150 FLOAT_CMP(eq, eq_quiet)
151 FLOAT_CMP(un, unordered_quiet)
152 #undef FLOAT_CMP
153 
154 #define FLOAT_UCMP(name, expr) \
155 target_ulong helper_float_ ## name ## _d(CPUOpenRISCState *env,           \
156                                          uint64_t fdt0, uint64_t fdt1)    \
157 {                                                                         \
158     int r = float64_compare_quiet(fdt0, fdt1, &env->fp_status);           \
159     return expr;                                                          \
160 }                                                                         \
161 target_ulong helper_float_ ## name ## _s(CPUOpenRISCState *env,           \
162                                          uint32_t fdt0, uint32_t fdt1)    \
163 {                                                                         \
164     int r = float32_compare_quiet(fdt0, fdt1, &env->fp_status);           \
165     return expr;                                                          \
166 }
167 
168 FLOAT_UCMP(ueq, r == float_relation_equal || r == float_relation_unordered)
169 FLOAT_UCMP(ult, r == float_relation_less || r == float_relation_unordered)
170 FLOAT_UCMP(ule, r != float_relation_greater)
171 #undef FLOAT_UCMP
172