[ARC] Add support for profiling in glibc.

Use PROFILE_HOOK to add mcount library calls in each toolchain.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.h (FUNCTION_PROFILER): Redefine to empty.
	* config/arc/elf.h (PROFILE_HOOK): Define.
	* config/arc/linux.h (PROFILE_HOOK): Likewise.

From-SVN: r266068

gcc/ChangeLog

 2018-11-13  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* config/arc/arc.h (FUNCTION_PROFILER): Redefine to empty.
+	* config/arc/elf.h (PROFILE_HOOK): Define.
+	* config/arc/linux.h (PROFILE_HOOK): Likewise.
+
+2018-11-13  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* config/arc/arc.c (hwloop_optimize): Bailout when detecting a
 	jump table data in the text section.
 

gcc/config/arc/arc.h

@@ -811,15 +811,9 @@ extern int arc_initial_elimination_offset(int from, int to);
 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET)                    \
   (OFFSET) = arc_initial_elimination_offset ((FROM), (TO))
 
-/* Output assembler code to FILE to increment profiler label # LABELNO
-   for profiling a function entry.  */
-#define FUNCTION_PROFILER(FILE, LABELNO)			\
-  do {								\
-  if (flag_pic)							\
-    fprintf (FILE, "\tbl\t__mcount@plt\n");			\
-  else								\
-    fprintf (FILE, "\tbl\t__mcount\n");				\
-  } while (0)
+/* All the work done in PROFILE_HOOK, but still required.  */
+#undef FUNCTION_PROFILER
+#define FUNCTION_PROFILER(STREAM, LABELNO) do { } while (0)
 
 #define NO_PROFILE_COUNTERS  1
 

gcc/config/arc/elf.h

@@ -78,3 +78,12 @@ along with GCC; see the file COPYING3.  If not see
 #undef LINK_GCC_C_SEQUENCE_SPEC
 #define LINK_GCC_C_SEQUENCE_SPEC				\
   "--start-group %G %{!specs=*:%{!nolibc:-lc -lnosys}} --end-group"
+
+/* Emit rtl for profiling.  Output assembler code to FILE
+   to call "_mcount" for profiling a function entry.  */
+#define PROFILE_HOOK(LABEL)					\
+  {								\
+    rtx fun;							\
+    fun = gen_rtx_SYMBOL_REF (Pmode, "__mcount");		\
+    emit_library_call (fun, LCT_NORMAL, VOIDmode);		\
+  }

gcc/config/arc/linux.h

@@ -123,3 +123,13 @@ along with GCC; see the file COPYING3.  If not see
 		    : "=r" (_beg)					\
 		    : "0" (_beg), "r" (_end), "r" (_xtr), "r" (_scno));	\
 }
+
+/* Emit rtl for profiling.  Output assembler code to FILE
+   to call "_mcount" for profiling a function entry.  */
+#define PROFILE_HOOK(LABEL)					\
+  {								\
+   rtx fun, rt;							\
+   rt = get_hard_reg_initial_val (Pmode, RETURN_ADDR_REGNUM);	\
+   fun = gen_rtx_SYMBOL_REF (Pmode, "_mcount");			\
+   emit_library_call (fun, LCT_NORMAL, VOIDmode, rt, Pmode);	\
+  }