[ARC] Reimplement exception handling support.

2016-06-09  Claudiu Zissulescu  <claziss@synopsys.com>
	    Andrew Burgess  <andrew.burgess@embecosm.com>

	* config/arc/arc-protos.h (arc_compute_frame_size): Delete
	declaration.
	(arc_return_slot_offset): Likewise.
	(arc_eh_return_address_location): New declaration.
	* config/arc/arc.c (TARGET_BUILTIN_SETJMP_FRAME_VALUE): Define.
	(MUST_SAVE_REGISTER): Add exception handler case.
	(MUST_SAVE_RETURN_ADDR): Likewise.
	(arc_frame_pointer_required): Likewise.
	(arc_frame_pointer_needed): New function.
	(arc_compute_frame_size): Changed.
	(arc_expand_prologue): Likewise.
	(arc_expand_epilogue): Likewise.
	(arc_initial_elimination_offset): Likewise.
	(arc_return_slot_offset): Delete.
	(arc_eh_return_address_location): New function.
	(arc_builtin_setjmp_frame_value): Likewise.
	* config/arc/arc.h (EH_RETURN_DATA_REGNO): Use 2 registers.
	(EH_RETURN_STACKADJ_RTX): Define.
	(EH_RETURN_HANDLER_RTX): Likewise.
	* config/arc/arc.md (eh_return): Delete.

Co-Authored-By: Andrew Burgess <andrew.burgess@embecosm.com>

From-SVN: r254997

gcc/ChangeLog

+2017-11-21  Claudiu Zissulescu  <claziss@synopsys.com>
+	    Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* config/arc/arc-protos.h (arc_compute_frame_size): Delete
+	declaration.
+	(arc_return_slot_offset): Likewise.
+	(arc_eh_return_address_location): New declaration.
+	* config/arc/arc.c (TARGET_BUILTIN_SETJMP_FRAME_VALUE): Define.
+	(MUST_SAVE_REGISTER): Add exception handler case.
+	(MUST_SAVE_RETURN_ADDR): Likewise.
+	(arc_frame_pointer_required): Likewise.
+	(arc_frame_pointer_needed): New function.
+	(arc_compute_frame_size): Changed.
+	(arc_expand_prologue): Likewise.
+	(arc_expand_epilogue): Likewise.
+	(arc_initial_elimination_offset): Likewise.
+	(arc_return_slot_offset): Delete.
+	(arc_eh_return_address_location): New function.
+	(arc_builtin_setjmp_frame_value): Likewise.
+	* config/arc/arc.h (EH_RETURN_DATA_REGNO): Use 2 registers.
+	(EH_RETURN_STACKADJ_RTX): Define.
+	(EH_RETURN_HANDLER_RTX): Likewise.
+	* config/arc/arc.md (eh_return): Delete.
+
 2017-11-21  Aldy Hernandez  <aldyh@redhat.com>
 
 	* print-tree.h (debug_vec_tree): Remove prototype.

gcc/config/arc/arc-protos.h

@@ -111,8 +111,8 @@ extern bool arc_epilogue_uses (int regno);
 extern bool arc_eh_uses (int regno);
 /* insn-attrtab.c doesn't include reload.h, which declares regno_clobbered_p. */
 extern int regno_clobbered_p (unsigned int, rtx_insn *, machine_mode, int);
-extern int arc_return_slot_offset (void);
 extern bool arc_legitimize_reload_address (rtx *, machine_mode, int, int);
 extern void arc_secondary_reload_conv (rtx, rtx, rtx, bool);
 extern void arc_cpu_cpp_builtins (cpp_reader *);
 extern bool arc_store_addr_hazard_p (rtx_insn *, rtx_insn *);
+extern rtx arc_eh_return_address_location (void);

gcc/config/arc/arc.h

@@ -1365,8 +1365,11 @@ do { \
 
 /* Frame info.  */
 
-#define EH_RETURN_DATA_REGNO(N)	\
-  ((N) < 4 ? (N) : INVALID_REGNUM)
+#define EH_RETURN_DATA_REGNO(N)  ((N) < 2 ? (N) : INVALID_REGNUM)
+
+#define EH_RETURN_STACKADJ_RTX   gen_rtx_REG (Pmode, 2)
+
+#define EH_RETURN_HANDLER_RTX    arc_eh_return_address_location ()
 
 /* Turn off splitting of long stabs.  */
 #define DBX_CONTIN_LENGTH 0

gcc/config/arc/arc.md

@@ -4935,39 +4935,6 @@
 	       (const_int 4)]
 	      (const_int 2)))])
 
-(define_insn_and_split "eh_return"
-  [(eh_return)
-   (use (match_operand:SI 0 "move_src_operand" "rC32,mCalCpc"))
-   (clobber (match_scratch:SI 1  "=X,r"))
-   (clobber (match_scratch:SI 2 "=&r,r"))]
-  ""
-  "#"
-  "reload_completed"
-  [(set (match_dup 2) (match_dup 0))]
-{
-  int offs = arc_return_slot_offset ();
-
-  if (offs < 0)
-    operands[2] = gen_rtx_REG (Pmode, RETURN_ADDR_REGNUM);
-  else
-    {
-      if (!register_operand (operands[0], Pmode)
-	  && !satisfies_constraint_C32 (operands[0]))
-	{
-	  emit_move_insn (operands[1], operands[0]);
-	  operands[0] = operands[1];
-	}
-      rtx addr = plus_constant (Pmode, stack_pointer_rtx, offs);
-      if (!strict_memory_address_p (Pmode, addr))
-	{
-	  emit_move_insn (operands[2], addr);
-	  addr = operands[2];
-	}
-      operands[2] = gen_frame_mem (Pmode, addr);
-    }
-}
-  [(set_attr "length" "12")])
-
 ;; ??? #ifdefs in function.c require the presence of this pattern, with a
 ;; non-constant predicate.
 (define_expand "return"