[AArch64] Fix preferred_reload_class for regclass STACK_REG.

From-SVN: r203778

gcc/ChangeLog

+2013-10-17  Marcus Shawcroft  <marcus.shawcroft@arm.com>
+
+	* config/aarch64/aarch64.c (aarch64_preferred_reload_class): Adjust
+	handling of STACK_REG.
+
 2013-10-17  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/58143

gcc/config/aarch64/aarch64.c

@@ -4219,9 +4219,18 @@ aarch64_class_max_nregs (reg_class_t regclass, enum machine_mode mode)
 static reg_class_t
 aarch64_preferred_reload_class (rtx x, reg_class_t regclass)
 {
-  if (regclass == POINTER_REGS || regclass == STACK_REG)
+  if (regclass == POINTER_REGS)
     return GENERAL_REGS;
 
+  if (regclass == STACK_REG)
+    {
+      if (REG_P(x)
+	  && reg_class_subset_p (REGNO_REG_CLASS (REGNO (x)), POINTER_REGS))
+	  return regclass;
+
+      return NO_REGS;
+    }
+
   /* If it's an integer immediate that MOVI can't handle, then
      FP_REGS is not an option, so we return NO_REGS instead.  */
   if (CONST_INT_P (x) && reg_class_subset_p (regclass, FP_REGS)