diff options
Diffstat (limited to 'pl/math/math_err.c')
-rw-r--r-- | pl/math/math_err.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/pl/math/math_err.c b/pl/math/math_err.c new file mode 100644 index 0000000..d246a89 --- /dev/null +++ b/pl/math/math_err.c @@ -0,0 +1,78 @@ +/* + * Double-precision math error handling. + * + * Copyright (c) 2018-2023, Arm Limited. + * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + */ + +#include "math_config.h" + +#if WANT_ERRNO +#include <errno.h> +/* NOINLINE reduces code size and avoids making math functions non-leaf + when the error handling is inlined. */ +NOINLINE static double +with_errno (double y, int e) +{ + errno = e; + return y; +} +#else +#define with_errno(x, e) (x) +#endif + +/* NOINLINE reduces code size. */ +NOINLINE static double +xflow (uint32_t sign, double y) +{ + y = eval_as_double (opt_barrier_double (sign ? -y : y) * y); + return with_errno (y, ERANGE); +} + +HIDDEN double +__math_uflow (uint32_t sign) +{ + return xflow (sign, 0x1p-767); +} + +/* Underflows to zero in some non-nearest rounding mode, setting errno + is valid even if the result is non-zero, but in the subnormal range. */ +HIDDEN double +__math_may_uflow (uint32_t sign) +{ + return xflow (sign, 0x1.8p-538); +} + +HIDDEN double +__math_oflow (uint32_t sign) +{ + return xflow (sign, 0x1p769); +} + +HIDDEN double +__math_divzero (uint32_t sign) +{ + double y = opt_barrier_double (sign ? -1.0 : 1.0) / 0.0; + return with_errno (y, ERANGE); +} + +HIDDEN double +__math_invalid (double x) +{ + double y = (x - x) / (x - x); + return isnan (x) ? y : with_errno (y, EDOM); +} + +/* Check result and set errno if necessary. */ + +HIDDEN double +__math_check_uflow (double y) +{ + return y == 0.0 ? with_errno (y, ERANGE) : y; +} + +HIDDEN double +__math_check_oflow (double y) +{ + return isinf (y) ? with_errno (y, ERANGE) : y; +} |