1 /*
2  * Single-precision math error handling.
3  *
4  * Copyright (c) 2017-2018, Arm Limited.
5  * SPDX-License-Identifier: MIT
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
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
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
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
42 __math_may_uflowf (uint32_t sign)
43 {
44   return xflowf (sign, 0x1.4p-75f);
45 }
46 #endif
47 
48 HIDDEN float
49 __math_oflowf (uint32_t sign)
50 {
51   return xflowf (sign, 0x1p97f);
52 }
53 
54 HIDDEN float
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
62 __math_invalidf (float x)
63 {
64   float y = (x - x) / (x - x);
65   return isnan (x) ? y : with_errnof (y, EDOM);
66 }
67