reload.c (combine_reloads): Don't combine an output reload if there are other…

reload.c (combine_reloads): Don't combine an output reload if there are other reloads around for part of...

	* reload.c (combine_reloads): Don't combine an output reload if there
	are other reloads around for part of the output.

From-SVN: r46734

gcc/ChangeLog

 Sat Nov  3 10:37:56 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
+	* reload.c (combine_reloads): Don't combine an output reload if there
+	are other reloads around for part of the output.
+
+	* emit-rtl.c (set_mem_attributes): Set RTX_UNCHANGINGP_P if T is a
+	constant expression.
+	(set_mem_decl): New function.
+	* expr.h (set_mem_decl): New declaration.
+	* final.c (get_decl_from_op): Don't use ORIGINAL_REGNO if not pseudo.
+	(output_asm_operand_names): Add tab.
+	* reload1.c (alter_reg): Set decl of MEM from REG_DECL.
+
 	* builtins.c (get_memory_rtx): Properly set MEM alias set and
 	attributes.
 

gcc/reload.c

@@ -1641,6 +1641,16 @@ combine_reloads ()
   if (earlyclobber_operand_p (rld[output_reload].out))
     return;
 
+  /* If there is a reload for part of the address of this operand, we would
+     need to chnage it to RELOAD_FOR_OTHER_ADDRESS.  But that would extend
+     its life to the point where doing this combine would not lower the
+     number of spill registers needed.  */
+  for (i = 0; i < n_reloads; i++)
+    if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
+	 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
+	&& rld[i].opnum == rld[output_reload].opnum)
+      return;
+
   /* Check each input reload; can we combine it?  */
 
   for (i = 0; i < n_reloads; i++)