Move a method that creates constant ranges relative to another constant range

per icmp predicate out of predsimplify and into ConstantRange.

Add another utility method that determines whether one range is a subset of
another. Combine with the former to determine whether icmp pred range, range
is known to be true or not.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75357 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/ConstantRange.h

@@ -58,6 +58,12 @@ public:
   /// assert out if the two APInt's are not the same bit width.
   ConstantRange(const APInt& Lower, const APInt& Upper);
 
+  /// makeICmpRegion - Return the range of values that a value must be within
+  /// in order for the comparison specified by the predicate against range
+  /// Other to be true.
+  static ConstantRange makeICmpRegion(unsigned Pred,
+                                      const ConstantRange &Other);
+
   /// getLower - Return the lower value for this range...
   ///
   const APInt &getLower() const { return Lower; }
@@ -88,6 +94,10 @@ public:
   ///
   bool contains(const APInt &Val) const;
 
+  /// contains - Return true if the other range is a subset of this one.
+  ///
+  bool contains(const ConstantRange &CR) const;
+
   /// getSingleElement - If this set contains a single element, return it,
   /// otherwise return null.
   ///