xref: /openbmc/qemu/target/openrisc/fpu_helper.c (revision bf616ce4)
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/exec-all.h"
24 #include "exec/helper-proto.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 static G_NORETURN
49 void do_fpe(CPUOpenRISCState *env, uintptr_t pc)
50 {
51     CPUState *cs = env_cpu(env);
52 
53     cs->exception_index = EXCP_FPE;
54     cpu_loop_exit_restore(cs, pc);
55 }
56 
57 void HELPER(update_fpcsr)(CPUOpenRISCState *env)
58 {
59     int tmp = get_float_exception_flags(&env->fp_status);
60 
61     if (tmp) {
62         set_float_exception_flags(0, &env->fp_status);
63         tmp = ieee_ex_to_openrisc(tmp);
64         if (tmp) {
65             env->fpcsr |= tmp;
66             if (env->fpcsr & FPCSR_FPEE) {
67                 do_fpe(env, GETPC());
68             }
69         }
70     }
71 }
72 
73 void cpu_set_fpcsr(CPUOpenRISCState *env, uint32_t val)
74 {
75     static const int rm_to_sf[] = {
76         float_round_nearest_even,
77         float_round_to_zero,
78         float_round_up,
79         float_round_down
80     };
81 
82     env->fpcsr = val & 0xfff;
83     set_float_rounding_mode(rm_to_sf[extract32(val, 1, 2)], &env->fp_status);
84 }
85 
86 uint64_t HELPER(itofd)(CPUOpenRISCState *env, uint64_t val)
87 {
88     return int64_to_float64(val, &env->fp_status);
89 }
90 
91 uint32_t HELPER(itofs)(CPUOpenRISCState *env, uint32_t val)
92 {
93     return int32_to_float32(val, &env->fp_status);
94 }
95 
96 uint64_t HELPER(ftoid)(CPUOpenRISCState *env, uint64_t val)
97 {
98     return float64_to_int64_round_to_zero(val, &env->fp_status);
99 }
100 
101 uint32_t HELPER(ftois)(CPUOpenRISCState *env, uint32_t val)
102 {
103     return float32_to_int32_round_to_zero(val, &env->fp_status);
104 }
105 
106 uint64_t HELPER(stod)(CPUOpenRISCState *env, uint32_t val)
107 {
108     return float32_to_float64(val, &env->fp_status);
109 }
110 
111 uint32_t HELPER(dtos)(CPUOpenRISCState *env, uint64_t val)
112 {
113     return float64_to_float32(val, &env->fp_status);
114 }
115 
116 #define FLOAT_CALC(name)                                                  \
117 uint64_t helper_float_ ## name ## _d(CPUOpenRISCState *env,               \
118                                      uint64_t fdt0, uint64_t fdt1)        \
119 { return float64_ ## name(fdt0, fdt1, &env->fp_status); }                 \
120 uint32_t helper_float_ ## name ## _s(CPUOpenRISCState *env,               \
121                                      uint32_t fdt0, uint32_t fdt1)        \
122 { return float32_ ## name(fdt0, fdt1, &env->fp_status); }
123 
124 FLOAT_CALC(add)
125 FLOAT_CALC(sub)
126 FLOAT_CALC(mul)
127 FLOAT_CALC(div)
128 FLOAT_CALC(rem)
129 #undef FLOAT_CALC
130 
131 
132 uint64_t helper_float_madd_d(CPUOpenRISCState *env, uint64_t a,
133                              uint64_t b, uint64_t c)
134 {
135     /* Note that or1ksim doesn't use fused operation.  */
136     b = float64_mul(b, c, &env->fp_status);
137     return float64_add(a, b, &env->fp_status);
138 }
139 
140 uint32_t helper_float_madd_s(CPUOpenRISCState *env, uint32_t a,
141                              uint32_t b, uint32_t c)
142 {
143     /* Note that or1ksim doesn't use fused operation.  */
144     b = float32_mul(b, c, &env->fp_status);
145     return float32_add(a, b, &env->fp_status);
146 }
147 
148 
149 #define FLOAT_CMP(name, impl)                                             \
150 target_ulong helper_float_ ## name ## _d(CPUOpenRISCState *env,           \
151                                          uint64_t fdt0, uint64_t fdt1)    \
152 { return float64_ ## impl(fdt0, fdt1, &env->fp_status); }                 \
153 target_ulong helper_float_ ## name ## _s(CPUOpenRISCState *env,           \
154                                          uint32_t fdt0, uint32_t fdt1)    \
155 { return float32_ ## impl(fdt0, fdt1, &env->fp_status); }
156 
157 FLOAT_CMP(le, le)
158 FLOAT_CMP(lt, lt)
159 FLOAT_CMP(eq, eq_quiet)
160 FLOAT_CMP(un, unordered_quiet)
161 #undef FLOAT_CMP
162 
163 #define FLOAT_UCMP(name, expr) \
164 target_ulong helper_float_ ## name ## _d(CPUOpenRISCState *env,           \
165                                          uint64_t fdt0, uint64_t fdt1)    \
166 {                                                                         \
167     FloatRelation r = float64_compare_quiet(fdt0, fdt1, &env->fp_status); \
168     return expr;                                                          \
169 }                                                                         \
170 target_ulong helper_float_ ## name ## _s(CPUOpenRISCState *env,           \
171                                          uint32_t fdt0, uint32_t fdt1)    \
172 {                                                                         \
173     FloatRelation r = float32_compare_quiet(fdt0, fdt1, &env->fp_status); \
174     return expr;                                                          \
175 }
176 
177 FLOAT_UCMP(ueq, r == float_relation_equal || r == float_relation_unordered)
178 FLOAT_UCMP(ult, r == float_relation_less || r == float_relation_unordered)
179 FLOAT_UCMP(ule, r != float_relation_greater)
180 #undef FLOAT_UCMP
181