RISC-V: Generic <math.h> and soft-fp Routines

This patch contains the miscellaneous math routines and headers we have
implemented for RISC-V.  This includes things from <math.h> that aren't
completely ISA-generic, floating-point bit manipulation, and soft-fp
hooks.

2018-01-29  Palmer Dabbelt  <palmer@sifive.com>

        * sysdeps/riscv/bits/fenv.h: New file.
        * sysdeps/riscv/e_sqrtl.c: Likewise.
        * sysdeps/riscv/fpu_control.h: Likewise.
        * sysdeps/riscv/math-tests.h: Likewise.
        * sysdeps/riscv/nofpu/Implies: Likewise.
        * sysdeps/riscv/sfp-machine.h: Likewise.
        * sysdeps/riscv/tininess.h: Likewise.

1 files changed, 37 insertions, 0 deletions

diff --git a/sysdeps/riscv/e_sqrtl.c b/sysdeps/riscv/e_sqrtl.c
new file mode 100644
index 0000000000..55a875d9fb
--- /dev/null
+++ b/sysdeps/riscv/e_sqrtl.c
@@ -0,0 +1,37 @@
+/* long double square root in software floating-point emulation.
+   Copyright (C) 1997-2018 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/>.  */
+
+#include <stdlib.h>
+#include <soft-fp/soft-fp.h>
+#include <soft-fp/quad.h>
+
+long double
+__ieee754_sqrtl (const long double a)
+{
+  FP_DECL_EX;
+  FP_DECL_Q (A); FP_DECL_Q (C);
+  long double c;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_Q (A, a);
+  FP_SQRT_Q (C, A);
+  FP_PACK_Q (c, C);
+  FP_HANDLE_EXCEPTIONS;
+  return c;
+}
+strong_alias (__ieee754_sqrtl, __sqrtl_finite)