re PR tree-optimization/48052 (loop not vectorized if index is "unsigned int")

	PR tree-optimization/48052
	* cfgloop.h (struct control_iv): New.
	(struct loop): New field control_ivs.
	* tree-ssa-loop-niter.c : Include "stor-layout.h".
	(number_of_iterations_lt): Set no_overflow information.
	(number_of_iterations_exit): Init control iv in niter struct.
	(record_control_iv): New.
	(estimate_numbers_of_iterations_loop): Call record_control_iv.
	(loop_exits_before_overflow): New.  Interface factored out of
	scev_probably_wraps_p.
	(scev_probably_wraps_p): Factor loop niter related code into
	loop_exits_before_overflow.
	(free_numbers_of_iterations_estimates_loop): Free control ivs.
	* tree-ssa-loop-niter.h (free_loop_control_ivs): New.

	gcc/testsuite/ChangeLog
	PR tree-optimization/48052
	* gcc.dg/tree-ssa/scev-8.c: New.
	* gcc.dg/tree-ssa/scev-9.c: New.
	* gcc.dg/tree-ssa/scev-10.c: New.
	* gcc.dg/vect/pr48052.c: New.

From-SVN: r224020

gcc/ChangeLog

+2015-06-02  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/48052
+	* cfgloop.h (struct control_iv): New.
+	(struct loop): New field control_ivs.
+	* tree-ssa-loop-niter.c : Include "stor-layout.h".
+	(number_of_iterations_lt): Set no_overflow information.
+	(number_of_iterations_exit): Init control iv in niter struct.
+	(record_control_iv): New.
+	(estimate_numbers_of_iterations_loop): Call record_control_iv.
+	(loop_exits_before_overflow): New.  Interface factored out of
+	scev_probably_wraps_p.
+	(scev_probably_wraps_p): Factor loop niter related code into
+	loop_exits_before_overflow.
+	(free_numbers_of_iterations_estimates_loop): Free control ivs.
+	* tree-ssa-loop-niter.h (free_loop_control_ivs): New.
+
 2015-06-02  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gimplify.c (gimplify_modify_expr): Do not create a DECL_DEBUG_EXPR if

gcc/cfgloop.h

@@ -116,6 +116,14 @@ enum loop_estimation
   EST_LAST
 };
 
+/* The structure describing non-overflow control induction variable for
+   loop's exit edge.  */
+struct GTY ((chain_next ("%h.next"))) control_iv {
+  tree base;
+  tree step;
+  struct control_iv *next;
+};
+
 /* Structure to hold information for each natural loop.  */
 struct GTY ((chain_next ("%h.next"))) loop {
   /* Index into loops array.  */
@@ -203,6 +211,9 @@ struct GTY ((chain_next ("%h.next"))) loop {
   /* Upper bound on number of iterations of a loop.  */
   struct nb_iter_bound *bounds;
 
+  /* Non-overflow control ivs of a loop.  */
+  struct control_iv *control_ivs;
+
   /* Head of the cyclic list of the exits of the loop.  */
   struct loop_exit *exits;
 

gcc/testsuite/ChangeLog

+2015-06-02  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/48052
+	* gcc.dg/tree-ssa/scev-8.c: New.
+	* gcc.dg/tree-ssa/scev-9.c: New.
+	* gcc.dg/tree-ssa/scev-10.c: New.
+	* gcc.dg/vect/pr48052.c: New.
+
 2015-06-02  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc.dg/vect/vec-scal-opt.c: Adjust regexp.

gcc/testsuite/gcc.dg/tree-ssa/scev-10.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ivopts-details" } */
+
+int *a;
+
+int
+foo (signed char s, signed char l)
+{
+  signed char i;
+  int sum = 0;
+
+  for (i = s; i < l; i++)
+    {
+      sum += a[i];
+    }
+
+  return sum;
+}
+
+/* Address of array reference is scev.  */
+/* { dg-final { scan-tree-dump-times "use \[0-9\]\n  address" 1 "ivopts" } } */
+
+

gcc/testsuite/gcc.dg/tree-ssa/scev-8.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ivopts-details" } */
+
+int *a;
+
+int
+foo1 (long long s, long long l)
+{
+  long long i;
+
+  for (i = s; i < l; i++)
+    {
+      a[(short)i] = 0;
+    }
+  return 0;
+}
+
+int
+foo2 (unsigned char s, unsigned char l, unsigned char c)
+{
+  unsigned char i, step = 1;
+  int sum = 0;
+
+  for (i = s; i < l; i++)
+    {
+      sum += a[c];
+      c += step;
+    }
+
+  return sum;
+}
+
+int
+foo3 (unsigned char s, unsigned char l, unsigned char c)
+{
+  unsigned char i;
+  int sum = 0;
+
+  for (i = s; i != l; i += c)
+    {
+      sum += a[i];
+    }
+
+  return sum;
+}
+
+int
+foo4 (unsigned char s, unsigned char l)
+{
+  unsigned char i;
+  int sum = 0;
+
+  for (i = s; i != l; i++)
+    {
+      sum += a[i];
+    }
+
+  return sum;
+}
+
+/* Address of array references are not scevs.  */
+/* { dg-final { scan-tree-dump-not "use \[0-9\]\n  address" "ivopts" } } */

gcc/testsuite/gcc.dg/tree-ssa/scev-9.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ivopts-details" } */
+
+int *a;
+
+int
+foo (unsigned char s, unsigned char l)
+{
+  unsigned char i;
+  int sum = 0;
+
+  for (i = s; i < l; i += 1)
+    {
+      sum += a[i];
+    }
+
+  return sum;
+}
+
+/* Address of array reference is scev.  */
+/* { dg-final { scan-tree-dump-times "use \[0-9\]\n  address" 1 "ivopts" } } */
+

gcc/testsuite/gcc.dg/vect/pr48052.c

+/* { dg-do compile } */
+/* { dg-additional-options "-O3" } */
+
+int foo(int* A, int* B,  unsigned start, unsigned BS)
+{
+  int s;
+  for (unsigned k = start;  k < start + BS; k++)
+    {
+      s += A[k] * B[k];
+    }
+
+  return s;
+}
+
+int bar(int* A, int* B, unsigned BS)
+{
+  int s;
+  for (unsigned k = 0;  k < BS; k++)
+    {
+      s += A[k] * B[k];
+    }
+
+  return s;
+}
+
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" } } */

gcc/tree-ssa-loop-niter.h

@@ -41,6 +41,7 @@ extern void estimate_numbers_of_iterations (void);
 extern bool stmt_dominates_stmt_p (gimple, gimple);
 extern bool nowrap_type_p (tree);
 extern bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
+extern void free_loop_control_ivs (struct loop *);
 extern void free_numbers_of_iterations_estimates_loop (struct loop *);
 extern void free_numbers_of_iterations_estimates (void);
 extern void substitute_in_loop_info (struct loop *, tree, tree);