s390.c (s390_emit_epilogue): Change epilogue code to not restoring global registers.

      * config/s390/s390.c (s390_emit_epilogue): Change epilogue
        code to not restoring global registers.

From-SVN: r51374

gcc/ChangeLog

+2002-03-26  Hartmut Penner  <hpenner@de.ibm.com>
+
+	* config/s390/s390.c (s390_emit_epilogue): Change epilogue
+	code to not restoring global registers. 
+
 2002-03-26  Neil Booth  <neil@daikokuya.demon.co.uk>
 
 	* Makefile.in (ggc-common.o): Update.

gcc/config/s390/s390.c

@@ -3177,15 +3177,15 @@ s390_emit_epilogue ()
 
       if (frame.save_fprs_p)
 	for (i = 24; i < 32; i++)
-	  if (regs_ever_live[i])
+	  if (regs_ever_live[i] && !global_regs[i])
 	    restore_fpr (frame_pointer, 
 			 offset - 64 + (i-24) * 8, i);
     }
   else
     {
-      if (regs_ever_live[18])
+      if (regs_ever_live[18] && !global_regs[18])
 	restore_fpr (frame_pointer, offset + STACK_POINTER_OFFSET - 16, 18);
-      if (regs_ever_live[19]) 
+      if (regs_ever_live[19] && !global_regs[19])
 	restore_fpr (frame_pointer, offset + STACK_POINTER_OFFSET - 8, 19);
     }
 
@@ -3198,6 +3198,24 @@ s390_emit_epilogue ()
   if (frame.first_restore_gpr != -1)
     {
       rtx addr;
+      int i;
+
+      /* Check for global register and save them 
+	 to stack location from where they get restored.  */
+
+      for (i = frame.first_restore_gpr; 
+	   i <= frame.last_save_gpr;
+	   i++)
+	{
+	  if (global_regs[i])
+	    {
+	      addr = plus_constant (frame_pointer, 
+		     offset + i * UNITS_PER_WORD);
+	      addr = gen_rtx_MEM (Pmode, addr);
+	      set_mem_alias_set (addr, s390_sr_alias_set);
+	      emit_move_insn (addr, gen_rtx_REG (Pmode, i));
+	    }  
+	}
 
       /* Fetch return address from stack before load multiple,
 	 this will do good for scheduling.  */