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;
+}