ARC: ABI Implementation

This code deals with the ARC ABI.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

sysdeps/arc/machine-gmon.h

@@ -0,0 +1,35 @@
+/* Machine-dependent definitions for profiling support.  ARC version.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+#define _MCOUNT_DECL(frompc, selfpc)					\
+static void								\
+__mcount_internal (unsigned long int frompc, unsigned long int selfpc)
+
+/* This is very simple as gcc does all the heavy lifting at _mcount call site
+    - sets up caller's blink in r0, so frompc is setup correctly
+    - preserve argument registers for original call.  */
+
+#define MCOUNT								\
+void									\
+_mcount (void *frompc)							\
+{									\
+  __mcount_internal ((unsigned long int) frompc,			\
+		     (unsigned long int) __builtin_return_address (0));	\
+}