1 /*
2 * Single-precision math error handling.
3 *
4 * Copyright (c) 2017-2020, Arm Limited.
5 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
6 */
7
8 #include "math_config.h"
9
10 #if WANT_ERRNO
11 #include <errno.h>
12 /* NOINLINE reduces code size and avoids making math functions non-leaf
13 when the error handling is inlined. */
14 NOINLINE static float
with_errnof(float y,int e)15 with_errnof (float y, int e)
16 {
17 errno = e;
18 return y;
19 }
20 #else
21 #define with_errnof(x, e) (x)
22 #endif
23
24 /* NOINLINE reduces code size. */
25 NOINLINE static float
xflowf(uint32_t sign,float y)26 xflowf (uint32_t sign, float y)
27 {
28 y = eval_as_float (opt_barrier_float (sign ? -y : y) * y);
29 return with_errnof (y, ERANGE);
30 }
31
32 HIDDEN float
__math_uflowf(uint32_t sign)33 __math_uflowf (uint32_t sign)
34 {
35 return xflowf (sign, 0x1p-95f);
36 }
37
38 #if WANT_ERRNO_UFLOW
39 /* Underflows to zero in some non-nearest rounding mode, setting errno
40 is valid even if the result is non-zero, but in the subnormal range. */
41 HIDDEN float
__math_may_uflowf(uint32_t sign)42 __math_may_uflowf (uint32_t sign)
43 {
44 return xflowf (sign, 0x1.4p-75f);
45 }
46 #endif
47
48 HIDDEN float
__math_oflowf(uint32_t sign)49 __math_oflowf (uint32_t sign)
50 {
51 return xflowf (sign, 0x1p97f);
52 }
53
54 HIDDEN float
__math_divzerof(uint32_t sign)55 __math_divzerof (uint32_t sign)
56 {
57 float y = opt_barrier_float (sign ? -1.0f : 1.0f) / 0.0f;
58 return with_errnof (y, ERANGE);
59 }
60
61 HIDDEN float
__math_invalidf(float x)62 __math_invalidf (float x)
63 {
64 float y = (x - x) / (x - x);
65 return isnan (x) ? y : with_errnof (y, EDOM);
66 }
67
68 /* Check result and set errno if necessary. */
69
70 HIDDEN float
__math_check_uflowf(float y)71 __math_check_uflowf (float y)
72 {
73 return y == 0.0f ? with_errnof (y, ERANGE) : y;
74 }
75
76 HIDDEN float
__math_check_oflowf(float y)77 __math_check_oflowf (float y)
78 {
79 return isinf (y) ? with_errnof (y, ERANGE) : y;
80 }
81