[gcc r13-2792] Convert CFN_BUILT_FFS and CFN_POPCOUNT to range-ops.

[Andrew Macleod <amacleod@gcc.gnu.org>]

https://gcc.gnu.org/g:5f730c650184d4c8bfad513a9e0e593f87a5bf0c

commit r13-2792-g5f730c650184d4c8bfad513a9e0e593f87a5bf0c
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Tue Sep 20 18:07:14 2022 -0400

    Convert CFN_BUILT_FFS and CFN_POPCOUNT to range-ops.
    
            * gimple-range-fold.cc (range_of_builtin_int_call): Remove case
            for CFN_FFS and CFN_POPCOUNT.
            * gimple-range-op.cc (class cfn_pocount): New.
            (gimple_range_op_handler::maybe_builtin_call): Set arguments.

Diff:
---
 gcc/gimple-range-fold.cc | 22 ----------------------
 gcc/gimple-range-op.cc   | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/gcc/gimple-range-fold.cc b/gcc/gimple-range-fold.cc
index af1f83f7409..ca531037e13 100644
--- a/gcc/gimple-range-fold.cc
+++ b/gcc/gimple-range-fold.cc
@@ -922,28 +922,6 @@ fold_using_range::range_of_builtin_int_call (irange &r, gcall *call,
 
   switch (func)
     {
-    CASE_CFN_FFS:
-    CASE_CFN_POPCOUNT:
-      // __builtin_ffs* and __builtin_popcount* return [0, prec].
-      arg = gimple_call_arg (call, 0);
-      prec = TYPE_PRECISION (TREE_TYPE (arg));
-      mini = 0;
-      maxi = prec;
-      src.get_operand (r, arg);
-      // If arg is non-zero, then ffs or popcount are non-zero.
-      if (!range_includes_zero_p (&r))
-	mini = 1;
-      // If some high bits are known to be zero, decrease the maximum.
-      if (!r.undefined_p ())
-	{
-	  if (TYPE_SIGN (r.type ()) == SIGNED)
-	    range_cast (r, unsigned_type_for (r.type ()));
-	  wide_int max = r.upper_bound ();
-	  maxi = wi::floor_log2 (max) + 1;
-	}
-      r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
-      return true;
-
     CASE_CFN_PARITY:
       r.set (build_zero_cst (type), build_one_cst (type));
       return true;
diff --git a/gcc/gimple-range-op.cc b/gcc/gimple-range-op.cc
index 45384d990ae..84837f8ee43 100644
--- a/gcc/gimple-range-op.cc
+++ b/gcc/gimple-range-op.cc
@@ -387,6 +387,33 @@ cfn_toupper_tolower::fold_range (irange &r, tree type, const irange &lh,
   return true;
 }
 
+// Implement range operator for CFN_BUILT_IN_FFS and CFN_BUILT_IN_POPCOUNT.
+class cfn_popcount : public range_operator
+{
+public:
+  using range_operator::fold_range;
+  virtual bool fold_range (irange &r, tree type, const irange &lh,
+			   const irange &, relation_kind) const
+  {
+    if (lh.undefined_p ())
+      return false;
+    // __builtin_ffs* and __builtin_popcount* return [0, prec].
+    int prec = TYPE_PRECISION (lh.type ());
+    // If arg is non-zero, then ffs or popcount are non-zero.
+    int mini = range_includes_zero_p (&lh) ? 0 : 1;
+    int maxi = prec;
+
+    // If some high bits are known to be zero, decrease the maximum.
+    int_range_max tmp = lh;
+    if (TYPE_SIGN (tmp.type ()) == SIGNED)
+      range_cast (tmp, unsigned_type_for (tmp.type ()));
+    wide_int max = tmp.upper_bound ();
+    maxi = wi::floor_log2 (max) + 1;
+    r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
+    return true;
+  }
+} op_cfn_popcount;
+
 // Set up a gimple_range_op_handler for any built in function which can be
 // supported via range-ops.
 
@@ -435,6 +462,13 @@ gimple_range_op_handler::maybe_builtin_call ()
 	}
       break;
 
+    CASE_CFN_FFS:
+    CASE_CFN_POPCOUNT:
+      m_op1 = gimple_call_arg (call, 0);
+      m_int = &op_cfn_popcount;
+      m_valid = true;
+      break;
+
     default:
       break;
     }