re PR rtl-optimization/37514 (Wrong code generated for 20021120-1.c with -O3…

re PR rtl-optimization/37514 (Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4)

2008-12-01  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/37514
	* reload1.c (reload_as_needed): Invalidate reg_last_reload
	from previous insns.

From-SVN: r142328

gcc/ChangeLog

+2008-12-01  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR rtl-optimization/37514
+	* reload1.c (reload_as_needed): Invalidate reg_last_reload
+	from previous insns.
+
 2008-12-01  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/38348

gcc/reload1.c

@@ -4164,6 +4164,9 @@ reload_as_needed (int live_known)
       rtx prev = 0;
       rtx insn = chain->insn;
       rtx old_next = NEXT_INSN (insn);
+#ifdef AUTO_INC_DEC
+      rtx old_prev = PREV_INSN (insn);
+#endif
 
       /* If we pass a label, copy the offsets from the label information
 	 into the current offsets of each elimination.  */
@@ -4388,6 +4391,33 @@ reload_as_needed (int live_known)
 		      SET_REGNO_REG_SET (&reg_has_output_reload,
 					 REGNO (XEXP (in_reg, 0)));
 		    }
+		  else if ((code == PRE_INC || code == PRE_DEC
+			    || code == POST_INC || code == POST_DEC))
+		    {
+		      int in_hard_regno;
+		      int in_regno = REGNO (XEXP (in_reg, 0));
+
+		      if (reg_last_reload_reg[in_regno] != NULL_RTX)
+			{
+			  in_hard_regno = REGNO (reg_last_reload_reg[in_regno]);
+			  gcc_assert (TEST_HARD_REG_BIT (reg_reloaded_valid,
+							 in_hard_regno));
+			  for (x = old_prev ? NEXT_INSN (old_prev) : insn;
+			       x != old_next;
+			       x = NEXT_INSN (x))
+			    if (x == reg_reloaded_insn[in_hard_regno])
+			      break;
+			  /* If for some reasons, we didn't set up
+			     reg_last_reload_reg in this insn,
+			     invalidate inheritance from previous
+			     insns for the incremented/decremented
+			     register.  Such registers will be not in
+			     reg_has_output_reload.  */
+			  if (x == old_next)
+			    forget_old_reloads_1 (XEXP (in_reg, 0),
+						  NULL_RTX, NULL);
+			}
+		    }
 		}
 	    }
 	  /* If a pseudo that got a hard register is auto-incremented,