1 files changed, 59 insertions, 0 deletions
diff --git a/sysdeps/ieee754/soft-fp/s_dsubl.c b/sysdeps/ieee754/soft-fp/s_dsubl.c
new file mode 100644
index 0000000000..52f489c6ed
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_dsubl.c
@@ -0,0 +1,59 @@
+/* Subtract long double (ldbl-128) values, narrowing the result to
+   double, using soft-fp.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32xsubf64x __hide_f32xsubf64x
+#define f32xsubf128 __hide_f32xsubf128
+#define f64subf64x __hide_f64subf64x
+#define f64subf128 __hide_f64subf128
+#include <math.h>
+#undef f32xsubf64x
+#undef f32xsubf128
+#undef f64subf64x
+#undef f64subf128
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <double.h>
+#include <quad.h>
+
+double
+__dsubl (_Float128 x, _Float128 y)
+{
+  FP_DECL_EX;
+  FP_DECL_Q (X);
+  FP_DECL_Q (Y);
+  FP_DECL_Q (R);
+  FP_DECL_D (RN);
+  double ret;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_SEMIRAW_Q (X, x);
+  FP_UNPACK_SEMIRAW_Q (Y, y);
+  FP_SUB_Q (R, X, Y);
+#if (2 * _FP_W_TYPE_SIZE) < _FP_FRACBITS_Q
+  FP_TRUNC (D, Q, 2, 4, RN, R);
+#else
+  FP_TRUNC (D, Q, 1, 2, RN, R);
+#endif
+  FP_PACK_SEMIRAW_D (ret, RN);
+  FP_HANDLE_EXCEPTIONS;
+  CHECK_NARROW_SUB (ret, x, y);
+  return ret;
+}
+libm_alias_double_ldouble (sub)