On 10/11/19 10:42 AM, Richard Sandiford wrote:
The range-tracking code has a pretty hard-coded assumption that
is_gimple_min_invariant is equivalent to "INTEGER_CST or invariant
ADDR_EXPR".  It seems better to add a predicate specifically for
that rather than contiually fight cases in which it can't handle
other invariants.

I was going to suggest we normalize ranges to numerics completely before folding. That is, replacing normalize_addresses() here:

  *vr = op->fold_range (expr_type,
                        vr0.normalize_addresses (),
                        vr1.normalize_addresses ());

...into normalize_symbolics(). But I suppose getting the gate correct is even better. Thanks for taking the care of this extensive and manual change.

The patch looks good to me. However, I do wonder if VRP and subsidiaries can't handle non-integer invariants, if we shouldn't disallow them from the setters as well:

void
value_range_base::set (tree val)
{
gcc_assert (TREE_CODE (val) == SSA_NAME || is_gimple_min_invariant (val));
  if (TREE_OVERFLOW_P (val))
    val = drop_tree_overflow (val);
  set (VR_RANGE, val, val);
}

void
value_range::set (tree val)
{
gcc_assert (TREE_CODE (val) == SSA_NAME || is_gimple_min_invariant (val));
  if (TREE_OVERFLOW_P (val))
    val = drop_tree_overflow (val);
  set (VR_RANGE, val, val, NULL);
}

This would still allow setting of VARYING and UNDEFINED, but disallow poly-ints, etc from a range.

Was this a small oversight, or was there a reason you left those in?

Aldy


Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?

Richard


2019-10-11  Richard Sandiford  <richard.sandif...@arm.com>

gcc/
        PR tree-optimization/92033
        * tree-vrp.h (constant_range_value_p): Declare.
        * tree-vrp.c (constant_range_value_p): New function.
        (value_range_base::symbolic_p, value_range_base::singleton_p)
        (get_single_symbol, compare_values_warnv, intersect_ranges)
        (value_range_base::normalize_symbolics): Use it instead of
        is_gimple_min_invariant.
        (simplify_stmt_for_jump_threading): Likewise.
        * vr-values.c (symbolic_range_based_on_p, valid_value_p): Likewise.
        (vr_values::op_with_constant_singleton_value_range): Likewise.
        (vr_values::extract_range_from_binary_expr): Likewise.
        (vr_values::extract_range_from_unary_expr): Likewise.
        (vr_values::extract_range_from_cond_expr): Likewise.
        (vr_values::extract_range_from_comparison): Likewise.
        (vr_values::extract_range_from_assignment): Likewise.
        (vr_values::adjust_range_with_scev, vrp_valueize): Likewise.
        (vr_values::vrp_visit_assignment_or_call): Likewise.
        (vr_values::vrp_evaluate_conditional): Likewise.
        (vr_values::simplify_bit_ops_using_ranges): Likewise.
        (test_for_singularity): Likewise.
        (vr_values::simplify_cond_using_ranges_1): Likewise.

Index: gcc/tree-vrp.h
===================================================================
--- gcc/tree-vrp.h      2019-10-08 09:23:31.282533990 +0100
+++ gcc/tree-vrp.h      2019-10-11 15:41:20.380576059 +0100
@@ -284,6 +284,7 @@ value_range_base::supports_type_p (tree
    return false;
  }
+extern bool constant_range_value_p (const_tree);
  extern void register_edge_assert_for (tree, edge, enum tree_code,
                                      tree, tree, vec<assert_info> &);
  extern bool stmt_interesting_for_vrp (gimple *);
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c      2019-10-08 09:23:31.282533990 +0100
+++ gcc/tree-vrp.c      2019-10-11 15:41:20.380576059 +0100
@@ -78,6 +78,18 @@ ranges_from_anti_range (const value_rang
     for still active basic-blocks.  */
  static sbitmap *live;
+/* Return true if VALUE is considered constant for range tracking.
+   This is stricter than is_gimple_min_invariant and should be
+   used instead of it in range-related code.  */
+
+bool
+constant_range_value_p (const_tree value)
+{
+  return (TREE_CODE (value) == INTEGER_CST
+         || (TREE_CODE (value) == ADDR_EXPR
+             && is_gimple_invariant_address (value)));
+}
+
  void
  value_range::set_equiv (bitmap equiv)
  {
@@ -273,8 +285,8 @@ value_range_base::symbolic_p () const
  {
    return (!varying_p ()
          && !undefined_p ()
-         && (!is_gimple_min_invariant (m_min)
-             || !is_gimple_min_invariant (m_max)));
+         && (!constant_range_value_p (m_min)
+             || !constant_range_value_p (m_max)));
  }
/* NOTE: This is not the inverse of symbolic_p because the range
@@ -388,7 +400,7 @@ value_range_base::singleton_p (tree *res
      }
    if (m_kind == VR_RANGE
        && vrp_operand_equal_p (min (), max ())
-      && is_gimple_min_invariant (min ()))
+      && constant_range_value_p (min ()))
      {
        if (result)
          *result = min ();
@@ -953,13 +965,13 @@ get_single_symbol (tree t, bool *neg, tr
        || TREE_CODE (t) == POINTER_PLUS_EXPR
        || TREE_CODE (t) == MINUS_EXPR)
      {
-      if (is_gimple_min_invariant (TREE_OPERAND (t, 0)))
+      if (constant_range_value_p (TREE_OPERAND (t, 0)))
        {
          neg_ = (TREE_CODE (t) == MINUS_EXPR);
          inv_ = TREE_OPERAND (t, 0);
          t = TREE_OPERAND (t, 1);
        }
-      else if (is_gimple_min_invariant (TREE_OPERAND (t, 1)))
+      else if (constant_range_value_p (TREE_OPERAND (t, 1)))
        {
          neg_ = false;
          inv_ = TREE_OPERAND (t, 1);
@@ -1106,8 +1118,8 @@ compare_values_warnv (tree val1, tree va
                      TYPE_SIGN (TREE_TYPE (val1)));
      }
- const bool cst1 = is_gimple_min_invariant (val1);
-  const bool cst2 = is_gimple_min_invariant (val2);
+  const bool cst1 = constant_range_value_p (val1);
+  const bool cst2 = constant_range_value_p (val2);
/* If one is of the form '[-]NAME + CST' and the other is constant, then
       it might be possible to say something depending on the constants.  */
@@ -5785,7 +5797,7 @@ intersect_ranges (enum value_range_kind
       correct estimate unless VR1 is a constant singleton range
       in which case we choose that.  */
    if (vr1type == VR_RANGE
-      && is_gimple_min_invariant (vr1min)
+      && constant_range_value_p (vr1min)
        && vrp_operand_equal_p (vr1min, vr1max))
      {
        *vr0type = vr1type;
@@ -6045,8 +6057,8 @@ value_range_base::normalize_symbolics ()
    if (varying_p () || undefined_p ())
      return *this;
    tree ttype = type ();
-  bool min_symbolic = !is_gimple_min_invariant (min ());
-  bool max_symbolic = !is_gimple_min_invariant (max ());
+  bool min_symbolic = !constant_range_value_p (min ());
+  bool max_symbolic = !constant_range_value_p (max ());
    if (!min_symbolic && !max_symbolic)
      return normalize_addresses ();
@@ -6432,7 +6444,7 @@ simplify_stmt_for_jump_threading (gimple
  {
    /* First see if the conditional is in the hash table.  */
    tree cached_lhs = avail_exprs_stack->lookup_avail_expr (stmt, false, true);
-  if (cached_lhs && is_gimple_min_invariant (cached_lhs))
+  if (cached_lhs && constant_range_value_p (cached_lhs))
      return cached_lhs;
vr_values *vr_values = x_vr_values;
Index: gcc/vr-values.c
===================================================================
--- gcc/vr-values.c     2019-10-03 14:04:54.161520173 +0100
+++ gcc/vr-values.c     2019-10-11 15:41:20.380576059 +0100
@@ -263,14 +263,14 @@ symbolic_range_based_on_p (value_range_b
    bool neg, min_has_symbol, max_has_symbol;
    tree inv;
- if (is_gimple_min_invariant (vr->min ()))
+  if (constant_range_value_p (vr->min ()))
      min_has_symbol = false;
    else if (get_single_symbol (vr->min (), &neg, &inv) == sym)
      min_has_symbol = true;
    else
      return false;
- if (is_gimple_min_invariant (vr->max ()))
+  if (constant_range_value_p (vr->max ()))
      max_has_symbol = false;
    else if (get_single_symbol (vr->max (), &neg, &inv) == sym)
      max_has_symbol = true;
@@ -409,7 +409,7 @@ valid_value_p (tree expr)
      return (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME
            && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST);
- return is_gimple_min_invariant (expr);
+  return constant_range_value_p (expr);
  }
/* If OP has a value range with a single constant value return that,
@@ -419,7 +419,7 @@ valid_value_p (tree expr)
  tree
  vr_values::op_with_constant_singleton_value_range (tree op)
  {
-  if (is_gimple_min_invariant (op))
+  if (constant_range_value_p (op))
      return op;
if (TREE_CODE (op) != SSA_NAME)
@@ -778,14 +778,14 @@ vr_values::extract_range_from_binary_exp
    value_range_base vr0, vr1;
    if (TREE_CODE (op0) == SSA_NAME)
      vr0 = *(get_value_range (op0));
-  else if (is_gimple_min_invariant (op0))
+  else if (constant_range_value_p (op0))
      vr0.set (op0);
    else
      vr0.set_varying (TREE_TYPE (op0));
if (TREE_CODE (op1) == SSA_NAME)
      vr1 = *(get_value_range (op1));
-  else if (is_gimple_min_invariant (op1))
+  else if (constant_range_value_p (op1))
      vr1.set (op1);
    else
      vr1.set_varying (TREE_TYPE (op1));
@@ -855,11 +855,11 @@ vr_values::extract_range_from_binary_exp
        value_range n_vr1;
/* Try with VR0 and [-INF, OP1]. */
-      if (is_gimple_min_invariant (minus_p ? vr0.max () : vr0.min ()))
+      if (constant_range_value_p (minus_p ? vr0.max () : vr0.min ()))
        n_vr1.set (VR_RANGE, vrp_val_min (expr_type), op1);
/* Try with VR0 and [OP1, +INF]. */
-      else if (is_gimple_min_invariant (minus_p ? vr0.min () : vr0.max ()))
+      else if (constant_range_value_p (minus_p ? vr0.min () : vr0.max ()))
        n_vr1.set (VR_RANGE, op1, vrp_val_max (expr_type));
/* Try with VR0 and [OP1, OP1]. */
@@ -879,11 +879,11 @@ vr_values::extract_range_from_binary_exp
        value_range n_vr0;
/* Try with [-INF, OP0] and VR1. */
-      if (is_gimple_min_invariant (minus_p ? vr1.max () : vr1.min ()))
+      if (constant_range_value_p (minus_p ? vr1.max () : vr1.min ()))
        n_vr0.set (VR_RANGE, vrp_val_min (expr_type), op0);
/* Try with [OP0, +INF] and VR1. */
-      else if (is_gimple_min_invariant (minus_p ? vr1.min (): vr1.max ()))
+      else if (constant_range_value_p (minus_p ? vr1.min (): vr1.max ()))
        n_vr0.set (VR_RANGE, op0, vrp_val_max (expr_type));
/* Try with [OP0, OP0] and VR1. */
@@ -926,7 +926,7 @@ vr_values::extract_range_from_unary_expr
       a new value range with the operand to simplify processing.  */
    if (TREE_CODE (op0) == SSA_NAME)
      vr0 = *(get_value_range (op0));
-  else if (is_gimple_min_invariant (op0))
+  else if (constant_range_value_p (op0))
      vr0.set (op0);
    else
      vr0.set_varying (type);
@@ -948,7 +948,7 @@ vr_values::extract_range_from_cond_expr
    const value_range *vr0 = &tem0;
    if (TREE_CODE (op0) == SSA_NAME)
      vr0 = get_value_range (op0);
-  else if (is_gimple_min_invariant (op0))
+  else if (constant_range_value_p (op0))
      tem0.set (op0);
    else
      tem0.set_varying (TREE_TYPE (op0));
@@ -958,7 +958,7 @@ vr_values::extract_range_from_cond_expr
    const value_range *vr1 = &tem1;
    if (TREE_CODE (op1) == SSA_NAME)
      vr1 = get_value_range (op1);
-  else if (is_gimple_min_invariant (op1))
+  else if (constant_range_value_p (op1))
      tem1.set (op1);
    else
      tem1.set_varying (TREE_TYPE (op1));
@@ -987,7 +987,7 @@ vr_values::extract_range_from_comparison
         its type may be different from _Bool.  Convert VAL to EXPR's
         type.  */
        val = fold_convert (type, val);
-      if (is_gimple_min_invariant (val))
+      if (constant_range_value_p (val))
        vr->set (val);
        else
        vr->update (VR_RANGE, val, val);
@@ -1479,7 +1479,7 @@ vr_values::extract_range_from_assignment
                                   gimple_assign_rhs1 (stmt),
                                   gimple_assign_rhs2 (stmt));
    else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
-          && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+          && constant_range_value_p (gimple_assign_rhs1 (stmt)))
      vr->set (gimple_assign_rhs1 (stmt));
    else
      vr->set_varying (TREE_TYPE (gimple_assign_lhs (stmt)));
@@ -1756,7 +1756,7 @@ vr_values::adjust_range_with_scev (value
    chrec = instantiate_parameters (loop, analyze_scalar_evolution (loop, var));
/* Like in PR19590, scev can return a constant function. */
-  if (is_gimple_min_invariant (chrec))
+  if (constant_range_value_p (chrec))
      {
        vr->set (chrec);
        return;
@@ -1779,7 +1779,7 @@ vr_values::adjust_range_with_scev (value
       a simple expression, compare_values and possibly other functions
       in tree-vrp won't be able to handle it.  */
    if (step == NULL_TREE
-      || !is_gimple_min_invariant (step)
+      || !constant_range_value_p (step)
        || !valid_value_p (init))
      return;
@@ -1841,7 +1841,7 @@ vr_values::adjust_range_with_scev (value if (TREE_CODE (init) == SSA_NAME)
                    initvr = *(get_value_range (init));
-                 else if (is_gimple_min_invariant (init))
+                 else if (constant_range_value_p (init))
                    initvr.set (init);
                  else
                    return;
@@ -1995,7 +1995,7 @@ vrp_valueize (tree name)
        const value_range *vr = x_vr_values->get_value_range (name);
        if (vr->kind () == VR_RANGE
          && (TREE_CODE (vr->min ()) == SSA_NAME
-             || is_gimple_min_invariant (vr->min ()))
+             || constant_range_value_p (vr->min ()))
          && vrp_operand_equal_p (vr->min (), vr->max ()))
        return vr->min ();
      }
@@ -2077,7 +2077,7 @@ vr_values::vrp_visit_assignment_or_call
              extract_range_from_ssa_name (vr, tem);
              return;
            }
-         else if (is_gimple_min_invariant (tem))
+         else if (constant_range_value_p (tem))
            {
              vr->set (tem);
              return;
@@ -2475,7 +2475,7 @@ vr_values::vrp_evaluate_conditional (tre
        enum warn_strict_overflow_code wc;
        const char* warnmsg;
- if (is_gimple_min_invariant (ret))
+      if (constant_range_value_p (ret))
        {
          wc = WARN_STRICT_OVERFLOW_CONDITIONAL;
          warnmsg = G_("assuming signed overflow does not occur when "
@@ -2517,7 +2517,7 @@ vr_values::vrp_evaluate_conditional (tre
          && INTEGRAL_TYPE_P (type)
          && vrp_val_is_min (vr0->min ())
          && vrp_val_is_max (vr0->max ())
-         && is_gimple_min_invariant (op1))
+         && constant_range_value_p (op1))
        {
          location_t location;
@@ -3361,14 +3361,14 @@ vr_values::simplify_bit_ops_using_ranges if (TREE_CODE (op0) == SSA_NAME)
      vr0 = *(get_value_range (op0));
-  else if (is_gimple_min_invariant (op0))
+  else if (constant_range_value_p (op0))
      vr0.set (op0);
    else
      return false;
if (TREE_CODE (op1) == SSA_NAME)
      vr1 = *(get_value_range (op1));
-  else if (is_gimple_min_invariant (op1))
+  else if (constant_range_value_p (op1))
      vr1.set (op1);
    else
      return false;
@@ -3481,7 +3481,7 @@ test_for_singularity (enum tree_code con
        /* If the new min/max values have converged to a single value,
         then there is only one value which can satisfy the condition,
         return that value.  */
-      if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min))
+      if (operand_equal_p (min, max, 0) && constant_range_value_p (min))
        return min;
      }
    return NULL;
@@ -3554,7 +3554,7 @@ vr_values::simplify_cond_using_ranges_1
        && cond_code != EQ_EXPR
        && TREE_CODE (op0) == SSA_NAME
        && INTEGRAL_TYPE_P (TREE_TYPE (op0))
-      && is_gimple_min_invariant (op1))
+      && constant_range_value_p (op1))
      {
        const value_range *vr = get_value_range (op0);

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