--- gcc/lambda-code.c.jj	2010-08-20 16:05:41.000000000 +0200
+++ gcc/lambda-code.c	2010-12-17 17:57:32.000000000 +0100
@@ -1289,7 +1289,7 @@ gcc_loop_to_lambda_loop (struct loop *lo
   if (gimple_code (phi) != GIMPLE_PHI)
     {
       tree op = SINGLE_SSA_TREE_OPERAND (phi, SSA_OP_USE);
-      if (!op)
+      if (!op || !is_gimple_assign (phi))
 	{
 
 	  if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1332,7 +1332,9 @@ gcc_loop_to_lambda_loop (struct loop *lo
 
       return NULL;
     }
-  if (TREE_CODE (step) != INTEGER_CST)
+  if (!host_integerp (step, 0)
+      || (HOST_WIDE_INT) TREE_INT_CST_LOW (step)
+	  != (int) TREE_INT_CST_LOW (step))
     {
 
       if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1366,6 +1368,32 @@ gcc_loop_to_lambda_loop (struct loop *lo
       return NULL;
     }
 
+  if (SSA_NAME_DEF_STMT (inductionvar) != phi)
+    {
+      gimple stmt = SSA_NAME_DEF_STMT (inductionvar);
+      tree rhs2;
+      int stepintval = stepint;
+      switch (gimple_assign_rhs_code (stmt))
+	{
+	case MINUS_EXPR:
+	  stepintval = -stepint;
+	  /* FALLTHRU */
+	case PLUS_EXPR:
+	case POINTER_PLUS_EXPR:
+	  rhs2 = gimple_assign_rhs2 (stmt);
+	  if (TREE_CODE (rhs2) == INTEGER_CST
+	      && (HOST_WIDE_INT) TREE_INT_CST_LOW (rhs2) == stepintval
+	      && TREE_INT_CST_HIGH (rhs2) == (stepintval >= 0 ? 0 : -1))
+	    break;
+	  /* FALLTHRU */
+	default:
+	  if (dump_file && (dump_flags & TDF_DETAILS))
+	    fprintf (dump_file,
+		     "Unable to convert loop: Cannot find PHI node for induction variable\n");
+	  return NULL;
+	}
+    }
+
   if (flow_bb_inside_loop_p (loop, gimple_phi_arg_edge (phi, 0)->src))
     {
       lboundvar = PHI_ARG_DEF (phi, 1);
@@ -1417,14 +1445,24 @@ gcc_loop_to_lambda_loop (struct loop *lo
 
 
   /* We might have some leftover.  */
-  if (gimple_cond_code (exit_cond) == LT_EXPR)
-    extra = -1 * stepint;
-  else if (gimple_cond_code (exit_cond) == NE_EXPR)
-    extra = -1 * stepint;
-  else if (gimple_cond_code (exit_cond) == GT_EXPR)
-    extra = -1 * stepint;
-  else if (gimple_cond_code (exit_cond) == EQ_EXPR)
-    extra = 1 * stepint;
+  if (SSA_NAME_DEF_STMT (inductionvar) != phi)
+    {
+      if (gimple_cond_code (exit_cond) == LT_EXPR)
+	extra = -1 * stepint;
+      else if (gimple_cond_code (exit_cond) == NE_EXPR)
+	extra = -1 * stepint;
+      else if (gimple_cond_code (exit_cond) == GT_EXPR)
+	extra = -1 * stepint;
+      else if (gimple_cond_code (exit_cond) == EQ_EXPR)
+	extra = 1 * stepint;
+    }
+  else
+    {
+      if (gimple_cond_code (exit_cond) == LE_EXPR)
+	extra = 1 * stepint;
+      else if (gimple_cond_code (exit_cond) == GE_EXPR)
+	extra = 1 * stepint;
+    }
 
   ubound = gcc_tree_to_linear_expression (depth, uboundvar,
 					  outerinductionvars,
--- gcc/testsuite/gcc.dg/pr46970-1.c.jj	2010-12-17 16:08:01.000000000 +0100
+++ gcc/testsuite/gcc.dg/pr46970-1.c	2010-12-17 16:07:46.000000000 +0100
@@ -0,0 +1,27 @@
+/* PR tree-optimization/46970 */
+/* { dg-do run } */
+/* { dg-options "-Os -ftree-loop-linear" } */
+
+int
+foo (int n, int *a)
+{
+  int i, j;
+
+  for (i = 0; i < n; i++)
+    for (j = 0; j < n; j++)
+      a[j] = i + n;
+
+  for (j = 0; j < n; j++)
+    if (a[j] != i + n - 1)
+      __builtin_abort ();
+
+  return 0;
+}
+
+int
+main ()
+{
+  int a[16];
+  foo (16, a);
+  return 0;
+}
--- gcc/testsuite/gcc.dg/pr46970-2.c.jj	2010-12-17 18:01:05.000000000 +0100
+++ gcc/testsuite/gcc.dg/pr46970-2.c	2010-12-17 16:43:46.000000000 +0100
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -ftree-loop-linear" } */
+/* { dg-require-effective-target size32plus } */
+
+double u[1782225];
+
+__attribute__((noinline, noclone)) int
+foo (int N, int *res)
+{
+  unsigned int i, j;
+  double sum = 0;
+  for (i = 0; i < N; i++)
+    for (j = 0; j < N; j++)
+      sum = sum + u[i + 1335 * j];
+  *res = sum + N;
+}
+
+int
+main (void)
+{
+  int i;
+  for (i = 0; i < 1782225; i++)
+    u[i] = 1.0;
+  foo (64, &i);
+  if (i != 4160)
+    __builtin_abort ();
+  return 0;
+}