function.c (keep_stack_depressed): Major rework.

	* function.c (keep_stack_depressed): Major rework.
	(handle_epilogue_set, emit_equiv_load): New functions.
	(thread_prologue_and_epilogue_insns): keep_stack_depressed now
	has return value.
	* jump.c (returnjump_p_1): Also return 1 if SET with SET_IS_RETURN_P.
	* rtl.h (SET_IS_RETURN_P): New macro.

From-SVN: r47250

gcc/ChangeLog

 Wed Nov 21 17:37:16 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
+	* function.c (keep_stack_depressed): Major rework.
+	(handle_epilogue_set, emit_equiv_load): New functions.
+	(thread_prologue_and_epilogue_insns): keep_stack_depressed now
+	has return value.
+	* jump.c (returnjump_p_1): Also return 1 if SET with SET_IS_RETURN_P.
+	* rtl.h (SET_IS_RETURN_P): New macro.
+
 	* expr.c (expand_expr, case VIEW_CONVERT_EXPR): Refine slightly
 	and also support TREE_ADDRESSABLE.
 	* tree.def (VIEW_CONVERT_EXPR): Document TREE_ADDRESSABLE.

gcc/jump.c

@@ -1244,7 +1244,9 @@ returnjump_p_1 (loc, data)
      void *data ATTRIBUTE_UNUSED;
 {
   rtx x = *loc;
-  return x && GET_CODE (x) == RETURN;
+
+  return x && (GET_CODE (x) == RETURN
+	       || (GET_CODE (x) == SET && SET_IS_RETURN_P (x)));
 }
 
 int

gcc/rtl.h

@@ -130,7 +130,8 @@ struct rtx_def
   /* 1 in an INSN if it can alter flow of control
      within this function.
      MEM_KEEP_ALIAS_SET_P in a MEM.
-     LINK_COST_ZERO in an INSN_LIST.  */
+     LINK_COST_ZERO in an INSN_LIST.
+     SET_IS_RETURN_P in a SET.  */
   unsigned int jump : 1;
   /* 1 in an INSN if it can call another function.
      LINK_COST_FREE in an INSN_LIST.  */
@@ -965,6 +966,7 @@ extern unsigned int subreg_regno 	PARAMS ((rtx));
    and SET_SRC is the value it is set to.  */
 #define SET_DEST(RTX) XC2EXP(RTX, 0, SET, CLOBBER)
 #define SET_SRC(RTX) XCEXP(RTX, 1, SET)
+#define SET_IS_RETURN_P(RTX) ((RTX)->jump)
 
 /* For a TRAP_IF rtx, TRAP_CONDITION is an expression.  */
 #define TRAP_CONDITION(RTX) XCEXP(RTX, 0, TRAP_IF)