soft-fp: Add __extendhfsf2/__extendhfdf2, __truncsfhf2/__truncdfhf2, __eqhf2/__nehf2

1. Add __extendhfdf2/__extendhfsf2 to return an IEEE half converted to IEEE double/single.
2. Add __truncdfhf2/__extendsfhf2 to truncate IEEE double/single into IEEE half.
3. Add __eqhf2/__nehf2 to return 0 if a == b and a,b are not NAN, otherwise return 1.

These are needed by x86 _Float16:

https://software.intel.com/content/www/us/en/develop/download/intel-avx512-fp16-architecture-specification.html

support in GCC.

1 files changed, 49 insertions, 0 deletions

diff --git a/soft-fp/eqhf2.c b/soft-fp/eqhf2.c
new file mode 100644
index 0000000..6d6634e
--- /dev/null
+++ b/soft-fp/eqhf2.c
@@ -0,0 +1,49 @@
+/* Software floating-point emulation.
+   Return 0 iff a == b, 1 otherwise
+   Copyright (C) 2021 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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file into
+   combinations with other programs, and to distribute those
+   combinations without any restriction coming from the use of this
+   file.  (The Lesser General Public License restrictions do apply in
+   other respects; for example, they cover modification of the file,
+   and distribution when not linked into a combine executable.)
+
+   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 "soft-fp.h"
+#include "half.h"
+
+CMPtype
+__eqhf2 (HFtype a, HFtype b)
+{
+  FP_DECL_EX;
+  FP_DECL_H (A);
+  FP_DECL_H (B);
+  CMPtype r;
+
+  FP_INIT_EXCEPTIONS;
+  FP_UNPACK_RAW_H (A, a);
+  FP_UNPACK_RAW_H (B, b);
+  FP_CMP_EQ_H (r, A, B, 1);
+  FP_HANDLE_EXCEPTIONS;
+
+  return r;
+}
+
+strong_alias (__eqhf2, __nehf2);