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      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