PR tree-optimization/52563, tree-optimization/62173

commit 5fe66b3cf99994fd9c8c68cea43aa1cf42eaa76d
Author: amker <amker@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Tue Jun 2 03:33:35 2015 +0000

        PR tree-optimization/52563
        PR tree-optimization/62173
        * tree-ssa-loop-ivopts.c (struct iv): New field.  Reorder fields.
        (alloc_iv, set_iv): New parameter.
        (determine_biv_step): Delete.
        (find_bivs): Inline original determine_biv_step.  Pass new
        argument to set_iv.
        (idx_find_step): Use no_overflow information for conversion.
        * tree-scalar-evolution.c (analyze_scalar_evolution_in_loop): Let
        resolve_mixers handle folded_casts.
        (instantiate_scev_name): Change bool parameter to bool pointer.
        (instantiate_scev_poly, instantiate_scev_binary): Ditto.
        (instantiate_array_ref, instantiate_scev_not): Ditto.
        (instantiate_scev_3, instantiate_scev_2): Ditto.
        (instantiate_scev_1, instantiate_scev_r): Ditto.
        (instantiate_scev_convert, ): Change parameter.  Pass argument
        to chrec_convert_aggressive.
        (instantiate_scev): Change argument.
        (resolve_mixers): New parameter and set it.
        (scev_const_prop): New argument.
        * tree-scalar-evolution.h (resolve_mixers): New parameter.
        * tree-chrec.c (convert_affine_scev): Call chrec_convert instead
        of chrec_conert_1.
        (chrec_convert): New parameter.  Move definition below.
        (chrec_convert_aggressive): New parameter and set it.  Call
        convert_affine_scev.
        * tree-chrec.h (chrec_convert): New parameter.
        (chrec_convert_aggressive): Ditto.

        gcc/testsuite/ChangeLog
        PR tree-optimization/52563
        PR tree-optimization/62173
        * gcc.dg/tree-ssa/scev-3.c: Remove xfail.
        * gcc.dg/tree-ssa/scev-4.c: Ditto.

    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@224009 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 76 insertions, 62 deletions

diff --git a/gcc-4.9/gcc/tree-scalar-evolution.c b/gcc-4.9/gcc/tree-scalar-evolution.c
index f1ddc24b1..218baa406 100644
--- a/gcc-4.9/gcc/tree-scalar-evolution.c
+++ b/gcc-4.9/gcc/tree-scalar-evolution.c
@@ -2116,7 +2116,7 @@ analyze_scalar_evolution_in_loop (struct loop *wrto_loop, struct loop *use_loop,
   /* We cannot just do
 
      tmp = analyze_scalar_evolution (use_loop, version);
-     ev = resolve_mixers (wrto_loop, tmp);
+     ev = resolve_mixers (wrto_loop, tmp, folded_casts);
 
      as resolve_mixers would query the scalar evolution with respect to
      wrto_loop.  For example, in the situation described in the function
@@ -2125,9 +2125,9 @@ analyze_scalar_evolution_in_loop (struct loop *wrto_loop, struct loop *use_loop,
 
      analyze_scalar_evolution (use_loop, version) = k2
 
-     and resolve_mixers (loop1, k2) finds that the value of k2 in loop 1
-     is 100, which is a wrong result, since we are interested in the
-     value in loop 3.
+     and resolve_mixers (loop1, k2, folded_casts) finds that the value of
+     k2 in loop 1 is 100, which is a wrong result, since we are interested
+     in the value in loop 3.
 
      Instead, we need to proceed from use_loop to wrto_loop loop by loop,
      each time checking that there is no evolution in the inner loop.  */
@@ -2137,10 +2137,7 @@ analyze_scalar_evolution_in_loop (struct loop *wrto_loop, struct loop *use_loop,
   while (1)
     {
       tmp = analyze_scalar_evolution (use_loop, ev);
-      ev = resolve_mixers (use_loop, tmp);
-
-      if (folded_casts && tmp != ev)
-	*folded_casts = true;
+      ev = resolve_mixers (use_loop, tmp, folded_casts);
 
       if (use_loop == wrto_loop)
 	return ev;
@@ -2262,7 +2259,7 @@ loop_closed_phi_def (tree var)
 }
 
 static tree instantiate_scev_r (basic_block, struct loop *, struct loop *,
-				tree, bool, int);
+				tree, bool *, int);
 
 /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
    and EVOLUTION_LOOP, that were left under a symbolic form.
@@ -2271,9 +2268,10 @@ static tree instantiate_scev_r (basic_block, struct loop *, struct loop *,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2282,7 +2280,7 @@ static tree
 instantiate_scev_name (basic_block instantiate_below,
 		       struct loop *evolution_loop, struct loop *inner_loop,
 		       tree chrec,
-		       bool fold_conversions,
+		       bool *fold_conversions,
 		       int size_expr)
 {
   tree res;
@@ -2376,9 +2374,10 @@ instantiate_scev_name (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2386,7 +2385,7 @@ instantiate_scev_name (basic_block instantiate_below,
 static tree
 instantiate_scev_poly (basic_block instantiate_below,
 		       struct loop *evolution_loop, struct loop *,
-		       tree chrec, bool fold_conversions, int size_expr)
+		       tree chrec, bool *fold_conversions, int size_expr)
 {
   tree op1;
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
@@ -2420,9 +2419,10 @@ instantiate_scev_poly (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2432,7 +2432,7 @@ instantiate_scev_binary (basic_block instantiate_below,
 			 struct loop *evolution_loop, struct loop *inner_loop,
 			 tree chrec, enum tree_code code,
 			 tree type, tree c0, tree c1,
-			 bool fold_conversions, int size_expr)
+			 bool *fold_conversions, int size_expr)
 {
   tree op1;
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop,
@@ -2478,9 +2478,10 @@ instantiate_scev_binary (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2488,7 +2489,7 @@ instantiate_scev_binary (basic_block instantiate_below,
 static tree
 instantiate_array_ref (basic_block instantiate_below,
 		       struct loop *evolution_loop, struct loop *inner_loop,
-		       tree chrec, bool fold_conversions, int size_expr)
+		       tree chrec, bool *fold_conversions, int size_expr)
 {
   tree res;
   tree index = TREE_OPERAND (chrec, 1);
@@ -2515,9 +2516,10 @@ instantiate_array_ref (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2526,7 +2528,7 @@ static tree
 instantiate_scev_convert (basic_block instantiate_below,
 			  struct loop *evolution_loop, struct loop *inner_loop,
 			  tree chrec, tree type, tree op,
-			  bool fold_conversions, int size_expr)
+			  bool *fold_conversions, int size_expr)
 {
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
 				 inner_loop, op,
@@ -2537,19 +2539,21 @@ instantiate_scev_convert (basic_block instantiate_below,
 
   if (fold_conversions)
     {
-      tree tmp = chrec_convert_aggressive (type, op0);
+      tree tmp = chrec_convert_aggressive (type, op0, fold_conversions);
       if (tmp)
 	return tmp;
-    }
 
-  if (chrec && op0 == op)
-    return chrec;
+      /* If we used chrec_convert_aggressive, we can no longer assume that
+	 signed chrecs do not overflow, as chrec_convert does, so avoid
+	 calling it in that case.  */
+      if (*fold_conversions)
+	{
+	  if (chrec && op0 == op)
+	    return chrec;
 
-  /* If we used chrec_convert_aggressive, we can no longer assume that
-     signed chrecs do not overflow, as chrec_convert does, so avoid
-     calling it in that case.  */
-  if (fold_conversions)
-    return fold_convert (type, op0);
+	  return fold_convert (type, op0);
+	}
+    }
 
   return chrec_convert (type, op0, NULL);
 }
@@ -2563,9 +2567,10 @@ instantiate_scev_convert (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2575,7 +2580,7 @@ instantiate_scev_not (basic_block instantiate_below,
 		      struct loop *evolution_loop, struct loop *inner_loop,
 		      tree chrec,
 		      enum tree_code code, tree type, tree op,
-		      bool fold_conversions, int size_expr)
+		      bool *fold_conversions, int size_expr)
 {
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
 				 inner_loop, op,
@@ -2613,9 +2618,10 @@ instantiate_scev_not (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2624,7 +2630,7 @@ static tree
 instantiate_scev_3 (basic_block instantiate_below,
 		    struct loop *evolution_loop, struct loop *inner_loop,
 		    tree chrec,
-		    bool fold_conversions, int size_expr)
+		    bool *fold_conversions, int size_expr)
 {
   tree op1, op2;
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
@@ -2661,9 +2667,10 @@ instantiate_scev_3 (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2672,7 +2679,7 @@ static tree
 instantiate_scev_2 (basic_block instantiate_below,
 		    struct loop *evolution_loop, struct loop *inner_loop,
 		    tree chrec,
-		    bool fold_conversions, int size_expr)
+		    bool *fold_conversions, int size_expr)
 {
   tree op1;
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
@@ -2701,9 +2708,10 @@ instantiate_scev_2 (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2712,7 +2720,7 @@ static tree
 instantiate_scev_1 (basic_block instantiate_below,
 		    struct loop *evolution_loop, struct loop *inner_loop,
 		    tree chrec,
-		    bool fold_conversions, int size_expr)
+		    bool *fold_conversions, int size_expr)
 {
   tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
 				 inner_loop, TREE_OPERAND (chrec, 0),
@@ -2734,9 +2742,10 @@ instantiate_scev_1 (basic_block instantiate_below,
 
    CACHE is the cache of already instantiated values.
 
-   FOLD_CONVERSIONS should be set to true when the conversions that
-   may wrap in signed/pointer type are folded, as long as the value of
-   the chrec is preserved.
+   Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
+   conversions that may wrap in signed/pointer type are folded, as long
+   as the value of the chrec is preserved.  If FOLD_CONVERSIONS is NULL
+   then we don't do such fold.
 
    SIZE_EXPR is used for computing the size of the expression to be
    instantiated, and to stop if it exceeds some limit.  */
@@ -2745,7 +2754,7 @@ static tree
 instantiate_scev_r (basic_block instantiate_below,
 		    struct loop *evolution_loop, struct loop *inner_loop,
 		    tree chrec,
-		    bool fold_conversions, int size_expr)
+		    bool *fold_conversions, int size_expr)
 {
   /* Give up if the expression is larger than the MAX that we allow.  */
   if (size_expr++ > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
@@ -2870,7 +2879,7 @@ instantiate_scev (basic_block instantiate_below, struct loop *evolution_loop,
     }
 
   res = instantiate_scev_r (instantiate_below, evolution_loop,
-			    NULL, chrec, false, 0);
+			    NULL, chrec, NULL, 0);
 
   if (destr)
     {
@@ -2894,9 +2903,10 @@ instantiate_scev (basic_block instantiate_below, struct loop *evolution_loop,
    of an expression.  */
 
 tree
-resolve_mixers (struct loop *loop, tree chrec)
+resolve_mixers (struct loop *loop, tree chrec, bool *folded_casts)
 {
   bool destr = false;
+  bool fold_conversions = false;
   if (!global_cache)
     {
       global_cache = new instantiate_cache_type;
@@ -2904,7 +2914,10 @@ resolve_mixers (struct loop *loop, tree chrec)
     }
 
   tree ret = instantiate_scev_r (block_before_loop (loop), loop, NULL,
-				 chrec, true, 0);
+				 chrec, &fold_conversions, 0);
+
+  if (folded_casts && !*folded_casts)
+    *folded_casts = fold_conversions;
 
   if (destr)
     {
@@ -3369,7 +3382,8 @@ scev_const_prop (void)
 	      && !INTEGRAL_TYPE_P (type))
 	    continue;
 
-	  ev = resolve_mixers (loop, analyze_scalar_evolution (loop, name));
+	  ev = resolve_mixers (loop, analyze_scalar_evolution (loop, name),
+			       NULL);
 	  if (!is_gimple_min_invariant (ev)
 	      || !may_propagate_copy (name, ev))
 	    continue;