1 /* Private floating point rounding and exceptions handling. PowerPC version.
2 Copyright (C) 2013-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #ifndef POWERPC_FENV_PRIVATE_H
20 #define POWERPC_FENV_PRIVATE_H 1
21
22 #include <fenv.h>
23 #include <fenv_libc.h>
24 #include <fpu_control.h>
25
26 #ifdef _ARCH_PWR8
27 /* There is no performance advantage to non-stop mode. */
28 /* The odd syntax here is to innocuously reference the given variables
29 to prevent warnings about unused variables. */
30 #define __TEST_AND_BEGIN_NON_STOP(old, new) do {} while ((old) * (new) * 0 != 0)
31 #define __TEST_AND_END_NON_STOP(old, new) do {} while ((old) * (new) * 0 != 0)
32 #else
33 #define __TEST_AND_BEGIN_NON_STOP __TEST_AND_ENTER_NON_STOP
34 #define __TEST_AND_END_NON_STOP __TEST_AND_EXIT_NON_STOP
35 #endif
36
37 static __always_inline void
38 libc_feholdexcept_setround_ppc (fenv_t *envp, int r)
39 {
40 fenv_union_t old, new;
41
42 old.fenv = *envp = fegetenv_register ();
43
44 __TEST_AND_BEGIN_NON_STOP (old.l, 0ULL);
45
46 /* Clear everything and set the rounding mode. */
47 new.l = r;
48 fesetenv_register (new.fenv);
49 }
50
51 static __always_inline unsigned long long
52 __libc_femergeenv_ppc (const fenv_t *envp, unsigned long long old_mask,
53 unsigned long long new_mask)
54 {
55 fenv_union_t old, new;
56
57 new.fenv = *envp;
58 old.fenv = fegetenv_register ();
59
60 /* Merge bits while masking unwanted bits from new and old env. */
61 new.l = (old.l & old_mask) | (new.l & new_mask);
62
63 __TEST_AND_END_NON_STOP (old.l, new.l);
64 __TEST_AND_BEGIN_NON_STOP (old.l, new.l);
65
66 /* If requesting to keep status, replace control, and merge exceptions,
67 and exceptions haven't changed, we can just set new control instead
68 of the whole FPSCR. */
69 if ((old_mask & (FPSCR_CONTROL_MASK|FPSCR_STATUS_MASK|FPSCR_EXCEPTIONS_MASK))
70 == (FPSCR_STATUS_MASK|FPSCR_EXCEPTIONS_MASK) &&
71 (new_mask & (FPSCR_CONTROL_MASK|FPSCR_STATUS_MASK|FPSCR_EXCEPTIONS_MASK))
72 == (FPSCR_CONTROL_MASK|FPSCR_EXCEPTIONS_MASK) &&
73 (old.l & FPSCR_EXCEPTIONS_MASK) == (new.l & FPSCR_EXCEPTIONS_MASK))
74 {
75 fesetenv_control (new.fenv);
76 }
77 else
78 /* Atomically enable and raise (if appropriate) exceptions set in `new'. */
79 fesetenv_register (new.fenv);
80
81 return old.l;
82 }
83
84 static __always_inline void
85 libc_fesetenv_ppc (const fenv_t *envp)
86 {
87 /* Replace the entire environment. */
88 __libc_femergeenv_ppc (envp, 0LL, -1LL);
89 }
90
91 static __always_inline void
92 libc_feresetround_ppc (fenv_t *envp)
93 {
94 fenv_union_t new = { .fenv = *envp };
95 fegetenv_and_set_rn (new.l & FPSCR_RN_MASK);
96 }
97
98 static __always_inline int
99 libc_feupdateenv_test_ppc (fenv_t *envp, int ex)
100 {
101 return __libc_femergeenv_ppc (envp, ~FPSCR_CONTROL_MASK,
102 ~FPSCR_STATUS_MASK) & ex;
103 }
104
105 static __always_inline void
106 libc_feupdateenv_ppc (fenv_t *e)
107 {
108 libc_feupdateenv_test_ppc (e, 0);
109 }
110
111 #define libc_feholdexceptf libc_feholdexcept_ppc
112 #define libc_feholdexcept libc_feholdexcept_ppc
113 #define libc_feholdexcept_setroundf libc_feholdexcept_setround_ppc
114 #define libc_feholdexcept_setround libc_feholdexcept_setround_ppc
115 #define libc_fetestexceptf libc_fetestexcept_ppc
116 #define libc_fetestexcept libc_fetestexcept_ppc
117 #define libc_fesetroundf libc_fesetround_ppc
118 #define libc_fesetround libc_fesetround_ppc
119 #define libc_fesetenvf libc_fesetenv_ppc
120 #define libc_fesetenv libc_fesetenv_ppc
121 #define libc_feupdateenv_testf libc_feupdateenv_test_ppc
122 #define libc_feupdateenv_test libc_feupdateenv_test_ppc
123 #define libc_feupdateenvf libc_feupdateenv_ppc
124 #define libc_feupdateenv libc_feupdateenv_ppc
125 #define libc_feholdsetroundf libc_feholdsetround_ppc
126 #define libc_feholdsetround libc_feholdsetround_ppc
127 #define libc_feresetroundf libc_feresetround_ppc
128 #define libc_feresetround libc_feresetround_ppc
129
130
131 /* We have support for rounding mode context. */
132 #define HAVE_RM_CTX 1
133
134 static __always_inline void
135 libc_feholdsetround_ppc_ctx (struct rm_ctx *ctx, int r)
136 {
137 fenv_union_t old;
138
139 ctx->env = old.fenv = fegetenv_and_set_rn (r);
140 ctx->updated_status = (r != (old.l & FPSCR_RN_MASK));
141 }
142
143 static __always_inline void
144 libc_feholdsetround_noex_ppc_ctx (struct rm_ctx *ctx, int r)
145 {
146 fenv_union_t old, new;
147
148 old.fenv = fegetenv_register ();
149
150 new.l = (old.l & ~(FPSCR_ENABLES_MASK|FPSCR_RN_MASK)) | r;
151
152 ctx->env = old.fenv;
153 if (__glibc_unlikely (new.l != old.l))
154 {
155 __TEST_AND_BEGIN_NON_STOP (old.l, 0ULL);
156 fesetenv_control (new.fenv);
157 ctx->updated_status = true;
158 }
159 else
160 ctx->updated_status = false;
161 }
162
163 static __always_inline void
164 libc_fesetenv_ppc_ctx (struct rm_ctx *ctx)
165 {
166 libc_fesetenv_ppc (&ctx->env);
167 }
168
169 static __always_inline void
170 libc_feupdateenv_ppc_ctx (struct rm_ctx *ctx)
171 {
172 if (__glibc_unlikely (ctx->updated_status))
173 libc_feresetround_ppc (&ctx->env);
174 }
175
176 static __always_inline void
177 libc_feresetround_ppc_ctx (struct rm_ctx *ctx)
178 {
179 if (__glibc_unlikely (ctx->updated_status))
180 libc_feresetround_ppc (&ctx->env);
181 }
182
183 #define libc_fesetenv_ctx libc_fesetenv_ppc_ctx
184 #define libc_fesetenvf_ctx libc_fesetenv_ppc_ctx
185 #define libc_fesetenvl_ctx libc_fesetenv_ppc_ctx
186 #define libc_feholdsetround_ctx libc_feholdsetround_ppc_ctx
187 #define libc_feholdsetroundf_ctx libc_feholdsetround_ppc_ctx
188 #define libc_feholdsetroundl_ctx libc_feholdsetround_ppc_ctx
189 #define libc_feholdsetround_noex_ctx libc_feholdsetround_noex_ppc_ctx
190 #define libc_feholdsetround_noexf_ctx libc_feholdsetround_noex_ppc_ctx
191 #define libc_feholdsetround_noexl_ctx libc_feholdsetround_noex_ppc_ctx
192 #define libc_feresetround_ctx libc_feresetround_ppc_ctx
193 #define libc_feresetroundf_ctx libc_feresetround_ppc_ctx
194 #define libc_feresetroundl_ctx libc_feresetround_ppc_ctx
195 #define libc_feupdateenv_ctx libc_feupdateenv_ppc_ctx
196 #define libc_feupdateenvf_ctx libc_feupdateenv_ppc_ctx
197 #define libc_feupdateenvl_ctx libc_feupdateenv_ppc_ctx
198
199 #include_next <fenv_private.h>
200
201 #endif