PR debug/39474

[pf3gnuchains/gcc-fork.git] / gcc / loop-iv.c

diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c
index 2523963..e02f164 100644 (file)
--- a/gcc/loop-iv.c
+++ b/gcc/loop-iv.c
@@ -1,5 +1,6 @@
 /* Rtl-level induction variable analysis.
-   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
+   Free Software Foundation, Inc.
    
 This file is part of GCC.
    
@@ -1337,13 +1338,26 @@ simple_rhs_p (rtx rhs)
     case MINUS:
       op0 = XEXP (rhs, 0);
       op1 = XEXP (rhs, 1);
-      /* Allow reg + const sets only.  */
-      if (REG_P (op0) && !HARD_REGISTER_P (op0) && CONSTANT_P (op1))
-       return true;
-      if (REG_P (op1) && !HARD_REGISTER_P (op1) && CONSTANT_P (op0))
-       return true;
+      /* Allow reg + const and reg + reg.  */
+      if (!(REG_P (op0) && !HARD_REGISTER_P (op0))
+         && !CONSTANT_P (op0))
+       return false;
+      if (!(REG_P (op1) && !HARD_REGISTER_P (op1))
+         && !CONSTANT_P (op1))
+       return false;
 
-      return false;
+      return true;
+
+    case ASHIFT:
+      op0 = XEXP (rhs, 0);
+      op1 = XEXP (rhs, 1);
+      /* Allow reg << const.  */
+      if (!(REG_P (op0) && !HARD_REGISTER_P (op0)))
+       return false;
+      if (!CONSTANT_P (op1))
+       return false;
+
+      return true;
 
     default:
       return false;
@@ -1543,7 +1557,8 @@ implies_p (rtx a, rtx b)
       && ((GET_CODE (a) == GT && op1 == constm1_rtx)
          || INTVAL (op1) >= 0)
       && GET_CODE (b) == LTU
-      && GET_CODE (opb1) == CONST_INT)
+      && GET_CODE (opb1) == CONST_INT
+      && rtx_equal_p (op0, opb0))
     return INTVAL (opb1) < 0;
 
   return false;
@@ -2786,7 +2801,9 @@ get_simple_loop_desc (struct loop *loop)
   if (desc)
     return desc;
 
-  desc = XNEW (struct niter_desc);
+  /* At least desc->infinite is not always initialized by
+     find_simple_loop_exit.  */
+  desc = XCNEW (struct niter_desc);
   iv_analysis_loop_init (loop);
   find_simple_exit (loop, desc);
   loop->aux = desc;