calls.c (expand_call): Disallow sibcalls to noreturn functions.

        * calls.c (expand_call): Disallow sibcalls to noreturn functions.
        * flow.c (make_edges): Revert last change.

        * config/alpha/alpha.h (FUNCTION_OK_FOR_SIBCALL): Don't test
        TREE_THIS_VOLATILE.
        * config/pa/pa.h (FUNCTION_OK_FOR_SIBCALL): Likewise.

From-SVN: r36781

gcc/ChangeLog

+2000-10-07  Richard Henderson  <rth@cygnus.com>
+
+	* calls.c (expand_call): Disallow sibcalls to noreturn functions.
+	* flow.c (make_edges): Revert last change.
+
+	* config/alpha/alpha.h (FUNCTION_OK_FOR_SIBCALL): Don't test
+	TREE_THIS_VOLATILE.
+	* config/pa/pa.h (FUNCTION_OK_FOR_SIBCALL): Likewise.
+
 2000-10-06  David O'Brien  <obrien@dragon.nuxi.com>
 
 	* config/alpha/elf.h: Standardize the formatting.

gcc/calls.c

@@ -2463,6 +2463,7 @@ expand_call (exp, target, ignore)
 	 before the sibcall_epilogue.  */
       || fndecl == NULL_TREE
       || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP))
+      || TREE_THIS_VOLATILE (fndecl)
       || !FUNCTION_OK_FOR_SIBCALL (fndecl)
       /* If this function requires more stack slots than the current
 	 function, we cannot change it into a sibling call.  */

gcc/config/alpha/alpha.h

@@ -1187,8 +1187,7 @@ extern int alpha_memory_latency;
 #define FUNCTION_OK_FOR_SIBCALL(DECL)			\
   (DECL							\
    && ((TREE_ASM_WRITTEN (DECL) && !flag_pic)		\
-       || ! TREE_PUBLIC (DECL)				\
-       || (0 && TREE_THIS_VOLATILE (DECL))))
+       || ! TREE_PUBLIC (DECL)))
 
 /* Try to output insns to set TARGET equal to the constant C if it can be
    done in less than N insns.  Do all computations in MODE.  Returns the place

gcc/config/pa/pa.h

@@ -2014,8 +2014,7 @@ while (0)
 #define FUNCTION_OK_FOR_SIBCALL(DECL) \
   (DECL \
    && ! TARGET_64BIT \
-   && (! TREE_PUBLIC (DECL) \
-       || TREE_THIS_VOLATILE (DECL)))
+   && ! TREE_PUBLIC (DECL))
 
 #define PREDICATE_CODES							\
   {"reg_or_0_operand", {SUBREG, REG, CONST_INT}},			\

gcc/flow.c

@@ -1152,12 +1152,8 @@ make_edges (label_value_list)
 	 wouldn't have created the sibling call in the first place.  */
 
       if (code == CALL_INSN && SIBLING_CALL_P (insn))
-	{
-	  if (! find_reg_note (insn, REG_NORETURN, NULL_RTX))
-	    make_edge (edge_cache, bb, EXIT_BLOCK_PTR,
-		       EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
-	}
-      else
+	make_edge (edge_cache, bb, EXIT_BLOCK_PTR,
+		   EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
 
       /* If this is a CALL_INSN, then mark it as reaching the active EH
 	 handler for this CALL_INSN.  If we're handling asynchronous
@@ -1165,7 +1161,7 @@ make_edges (label_value_list)
 
 	 Also mark the CALL_INSN as reaching any nonlocal goto handler.  */
 
-      if (code == CALL_INSN || asynchronous_exceptions)
+      else if (code == CALL_INSN || asynchronous_exceptions)
 	{
 	  /* Add any appropriate EH edges.  We do this unconditionally
 	     since there may be a REG_EH_REGION or REG_EH_RETHROW note