[PowerPC/23070] CALL_V4_CLEAR_FP_ARGS flag not properly set

[Alan Modra]

The changelog says it all.  Bootstrapped and reg tested powerpc-linux.
This isn't a regression since abi_v4 has this bug as far back as I
could find, but I'd like to apply this to the 4.0 and 3.4 branches too.
I think it ought to qualify as an obvious bugfix.  OK to apply?

:ADDPATCH target(powerpc):

	PR target/23070
	* config/rs6000/rs6000.c (function_arg): For ABI_V4 calls to
	stdarg functions, set/clear the fp marker even when no variable
	args are passed.
	* config/rs6000/sysv4.opt (mprototype): Describe.

Index: gcc/config/rs6000/rs6000.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
retrieving revision 1.860
diff -u -p -r1.860 rs6000.c
--- gcc/config/rs6000/rs6000.c	11 Aug 2005 21:18:11 -0000	1.860
+++ gcc/config/rs6000/rs6000.c	19 Aug 2005 13:52:42 -0000
@@ -4997,9 +4997,10 @@ function_arg (CUMULATIVE_ARGS *cum, enum
   if (mode == VOIDmode)
     {
       if (abi == ABI_V4
-	  && cum->nargs_prototype < 0
 	  && (cum->call_cookie & CALL_LIBCALL) == 0
-	  && (cum->prototype || TARGET_NO_PROTOTYPE))
+	  && (cum->stdarg
+	      || (cum->nargs_prototype < 0
+		  && (cum->prototype || TARGET_NO_PROTOTYPE))))
 	{
 	  /* For the SPE, we need to crxor CR6 always.  */
 	  if (TARGET_SPE_ABI)
Index: gcc/config/rs6000/sysv4.opt
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/sysv4.opt,v
retrieving revision 1.5
diff -u -p -r1.5 sysv4.opt
--- gcc/config/rs6000/sysv4.opt	25 Jun 2005 01:22:18 -0000	1.5
+++ gcc/config/rs6000/sysv4.opt	19 Aug 2005 14:00:35 -0000
@@ -76,7 +76,7 @@ no description yet
 
 mprototype
 Target Mask(PROTOTYPE)
-no description yet
+Assume all variable arg functions are prototyped
 
 ;; FIXME: Does nothing.
 mno-traceback

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre