s390.c (override_options): Return error if -mbackchain, -mpacked-stack and -mhard-float are used together.

2005-01-11  Andreas Krebbel  <krebbel1@de.ibm.com>

	* config/s390/s390.c (override_options): Return error if
	-mbackchain, -mpacked-stack and -mhard-float are used together.
	(s390_va_start): Remove the backchain && packed-stack special case.
	(s390_gimplify_va_arg): Likewise.
	* doc/invoke.texi: Remove the ABI incompatibility note.

From-SVN: r93182

3 files changed, 24 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ece44ff..c10fefa 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
 2005-01-11  Andreas Krebbel  <krebbel1@de.ibm.com>
 
+	* config/s390/s390.c (override_options): Return error if
+	-mbackchain, -mpacked-stack and -mhard-float are used together.
+	(s390_va_start): Remove the backchain && packed-stack special case.
+	(s390_gimplify_va_arg): Likewise.
+	* doc/invoke.texi: Remove the ABI incompatibility note.
+
+2005-01-11  Andreas Krebbel  <krebbel1@de.ibm.com>
+
 	* config/s390/s390.c (struct s390_frame_layout): Remove 
 	save_backchain_p.
 	(s390_frame_info, s390_emit_prologue): Replace occurrences of
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index cd174c7..92ec196 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -1424,6 +1424,10 @@ override_options (void)
     s390_cost = &z900_cost;
 
 
+  if (TARGET_BACKCHAIN && TARGET_PACKED_STACK && TARGET_HARD_FLOAT)
+    error ("-mbackchain -mpacked-stack -mhard-float are not supported "
+	   "in combination.");
+
   if (s390_warn_framesize_string)
     {
       if (sscanf (s390_warn_framesize_string, HOST_WIDE_INT_PRINT_DEC,
@@ -7711,15 +7715,9 @@ s390_va_start (tree valist, rtx nextarg ATTRIBUTE_UNUSED)
 
   /* Find the register save area.  */
   t = make_tree (TREE_TYPE (sav), return_address_pointer_rtx);
-  if (TARGET_BACKCHAIN && TARGET_PACKED_STACK) /* kernel stack layout */
-    t = build (PLUS_EXPR, TREE_TYPE (sav), t,
-	       build_int_cst (NULL_TREE,
-			      -(RETURN_REGNUM - 2) * UNITS_PER_WORD
-			      - (TARGET_64BIT ? 4 : 2) * 8));
-  else
-    t = build (PLUS_EXPR, TREE_TYPE (sav), t,
-	       build_int_cst (NULL_TREE, -RETURN_REGNUM * UNITS_PER_WORD));
-
+  t = build (PLUS_EXPR, TREE_TYPE (sav), t,
+	     build_int_cst (NULL_TREE, -RETURN_REGNUM * UNITS_PER_WORD));
+  
   t = build (MODIFY_EXPR, TREE_TYPE (sav), sav, t);
   TREE_SIDE_EFFECTS (t) = 1;
   expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
@@ -7787,8 +7785,7 @@ s390_gimplify_va_arg (tree valist, tree type, tree *pre_p,
       /* kernel stack layout on 31 bit: It is assumed here that no padding
 	 will be added by s390_frame_info because for va_args always an even
 	 number of gprs has to be saved r15-r2 = 14 regs.  */
-      sav_ofs = ((TARGET_BACKCHAIN && TARGET_PACKED_STACK) ?
-		 (TARGET_64BIT ? 4 : 2) * 8 : 2 * UNITS_PER_WORD);
+      sav_ofs = 2 * UNITS_PER_WORD;
       sav_scale = UNITS_PER_WORD;
       size = UNITS_PER_WORD;
       max_reg = 4;
@@ -7805,8 +7802,7 @@ s390_gimplify_va_arg (tree valist, tree type, tree *pre_p,
       indirect_p = 0;
       reg = fpr;
       n_reg = 1;
-      sav_ofs = ((TARGET_BACKCHAIN && TARGET_PACKED_STACK) ?
-		 0 : 16 * UNITS_PER_WORD);
+      sav_ofs = 16 * UNITS_PER_WORD;
       sav_scale = 8;
       /* TARGET_64BIT has up to 4 parameter in fprs */
       max_reg = TARGET_64BIT ? 3 : 1;
@@ -7827,8 +7823,7 @@ s390_gimplify_va_arg (tree valist, tree type, tree *pre_p,
       /* kernel stack layout on 31 bit: It is assumed here that no padding
 	 will be added by s390_frame_info because for va_args always an even
 	 number of gprs has to be saved r15-r2 = 14 regs.  */
-      sav_ofs = ((TARGET_BACKCHAIN && TARGET_PACKED_STACK) ? 
-		 (TARGET_64BIT ? 4 : 2) * 8 : 2 * UNITS_PER_WORD);
+      sav_ofs = 2 * UNITS_PER_WORD;
 
       if (size < UNITS_PER_WORD)
 	sav_ofs += UNITS_PER_WORD - size;
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index bb8659a..9de9b84 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -10892,8 +10892,9 @@ save area.
 In general, code compiled with @option{-mbackchain} is call-compatible with
 code compiled with @option{-mmo-backchain}; however, use of the backchain
 for debugging purposes usually requires that the whole binary is built with
-@option{-mbackchain}.  Note that the combination of @option{-mbackchain} and
-@option{-mpacked-stack} generates code that is not ABI-compatible.
+@option{-mbackchain}.  Note that the combination of @option{-mbackchain},
+@option{-mpacked-stack} and @option{-mhard-float} is not supported.  In order
+to build a linux kernel use @option{-msoft-float}.
 
 The default is to not maintain the backchain.
 
@@ -10917,8 +10918,9 @@ As long as the stack frame backchain is not used, code generated with
 S/390 or zSeries generated code that uses the stack frame backchain at run
 time, not just for debugging purposes.  Such code is not call-compatible
 with code compiled with @option{-mpacked-stack}.  Also, note that the
-combination of @option{-mbackchain} and @option{-mpacked-stack} generates code
-that is not ABI-compatible.
+combination of @option{-mbackchain},
+@option{-mpacked-stack} and @option{-mhard-float} is not supported.  In order
+to build a linux kernel use @option{-msoft-float}.
 
 The default is to not use the packed stack layout.