Implement udiv for ConstantRanges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75413 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index 7fe1568..04a1b68 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -592,10 +592,32 @@
}
ConstantRange
-ConstantRange::udiv(const ConstantRange &Other) const {
- // TODO: Implement udiv.
- return ConstantRange(getBitWidth(),
- !(isEmptySet() || Other.isEmptySet()));
+ConstantRange::udiv(const ConstantRange &RHS) const {
+ if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax() == 0)
+ return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+ if (RHS.isFullSet())
+ return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+ APInt Lower = getUnsignedMin().udiv(RHS.getUnsignedMax());
+
+ APInt RHS_umin = RHS.getUnsignedMin();
+ if (RHS_umin == 0) {
+ // We want the lowest value in RHS excluding zero. Usually that would be 1
+ // except for a range in the form of [X, 1) in which case it would be X.
+ if (RHS.getUpper() == 1)
+ RHS_umin = RHS.getLower();
+ else
+ RHS_umin = APInt(getBitWidth(), 1);
+ }
+
+ APInt Upper = getUnsignedMax().udiv(RHS_umin) + 1;
+
+ // If the LHS is Full and the RHS is a wrapped interval containing 1 then
+ // this could occur.
+ if (Lower == Upper)
+ return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+ return ConstantRange(Lower, Upper);
}
/// print - Print out the bounds to a stream...