Index: calls.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/calls.c,v
retrieving revision 1.231.4.5
diff -w -u -p -r1.231.4.5 calls.c
--- calls.c	20 Sep 2002 01:29:06 -0000	1.231.4.5
+++ calls.c	28 Sep 2002 05:00:02 -0000
@@ -36,10 +36,6 @@ Software Foundation, 59 Temple Place - S
 #include "langhooks.h"
 #include "target.h"
 
-#if !defined FUNCTION_OK_FOR_SIBCALL
-#define FUNCTION_OK_FOR_SIBCALL(DECL) 1
-#endif
-
 /* Decide whether a function's arguments should be processed
    from first to last or from last to first.
 
@@ -2443,17 +2439,12 @@ expand_call (exp, target, ignore)
 	 It does not seem worth the effort since few optimizable
 	 sibling calls will return a structure.  */
       || structure_value_addr != NULL_RTX
-      /* If the register holding the address is a callee saved
-	 register, then we lose.  We have no way to prevent that,
-	 so we only allow calls to named functions.  */
-      /* ??? This could be done by having the insn constraints
-	 use a register class that is all call-clobbered.  Any
-	 reload insns generated to fix things up would appear
-	 before the sibcall_epilogue.  */
-      || fndecl == NULL_TREE
+      /* Check whether the target is able to optimize the call
+	 into a sibcall.  */
+      || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
       || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP))
-      || TREE_THIS_VOLATILE (fndecl)
-      || !FUNCTION_OK_FOR_SIBCALL (fndecl)
+      /* Functions that do not return may not be sibcall optimized.  */
+      || TYPE_VOLATILE (TREE_TYPE (TREE_OPERAND (exp, 0)))
       /* If this function requires more stack slots than the current
 	 function, we cannot change it into a sibling call.  */
       || args_size.constant > current_function_args_size
Index: hooks.h
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/hooks.h,v
retrieving revision 1.5
diff -w -u -p -r1.5 hooks.h
--- hooks.h	21 Aug 2002 02:41:44 -0000	1.5
+++ hooks.h	28 Sep 2002 05:00:03 -0000
@@ -27,5 +27,5 @@ bool hook_tree_bool_false PARAMS ((tree)
 void hook_tree_int_void PARAMS ((tree, int));
 void hook_void_void PARAMS ((void));
 void hook_FILEptr_constcharptr_void PARAMS ((FILE *, const char *));
-
+bool hook_tree_tree_bool_false PARAMS ((tree, tree));
 #endif
Index: hooks.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/hooks.c,v
retrieving revision 1.5
diff -w -u -p -r1.5 hooks.c
--- hooks.c	21 Aug 2002 02:41:44 -0000	1.5
+++ hooks.c	28 Sep 2002 05:00:03 -0000
@@ -62,3 +62,12 @@ hook_FILEptr_constcharptr_void (a, b)
      const char *b ATTRIBUTE_UNUSED;
 {
 }
+
+/* Hook that takes two trees and returns false.  */
+bool
+hook_tree_tree_bool_false (a, b)
+     tree a ATTRIBUTE_UNUSED;
+     tree b ATTRIBUTE_UNUSED;
+{
+  return false;
+}
Index: target.h
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/target.h,v
retrieving revision 1.33.2.3
diff -w -u -p -r1.33.2.3 target.h
--- target.h	17 Sep 2002 22:58:47 -0000	1.33.2.3
+++ target.h	28 Sep 2002 05:00:04 -0000
@@ -244,6 +244,11 @@ struct gcc_target
      not, at the current point in the compilation.  */
   bool (* cannot_modify_jumps_p) PARAMS ((void));
 
+  /* True if it is OK to do sibling call optimization for the specified
+     call expression EXP.  DECL will be the called function, or NULL if
+     this is an indirect call.  */
+  bool (*function_ok_for_sibcall) PARAMS ((tree decl, tree exp));
+  
   /* True if EXP should be placed in a "small data" section.  */
   bool (* in_small_data_p) PARAMS ((tree));
 
Index: target-def.h
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/target-def.h,v
retrieving revision 1.30.2.3
diff -w -u -p -r1.30.2.3 target-def.h
--- target-def.h	17 Sep 2002 22:58:47 -0000	1.30.2.3
+++ target-def.h	28 Sep 2002 05:00:05 -0000
@@ -245,6 +245,7 @@ Foundation, 59 Temple Place - Suite 330,
 
 /* In hook.c.  */
 #define TARGET_CANNOT_MODIFY_JUMPS_P hook_void_bool_false
+#define TARGET_FUNCTION_OK_FOR_SIBCALL hook_tree_tree_bool_false
 
 #ifndef TARGET_IN_SMALL_DATA_P
 #define TARGET_IN_SMALL_DATA_P hook_tree_bool_false
@@ -271,6 +272,7 @@ Foundation, 59 Temple Place - Suite 330,
   TARGET_EXPAND_BUILTIN,			\
   TARGET_SECTION_TYPE_FLAGS,			\
   TARGET_CANNOT_MODIFY_JUMPS_P,			\
+  TARGET_FUNCTION_OK_FOR_SIBCALL,		\
   TARGET_IN_SMALL_DATA_P,			\
   TARGET_BINDS_LOCAL_P,				\
   TARGET_ENCODE_SECTION_INFO,			\