Implement ConstantRange::multiply based on the code in LoopVR.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75410 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index ad301c3..7fe1568 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -550,9 +550,19 @@
ConstantRange
ConstantRange::multiply(const ConstantRange &Other) const {
- // TODO: Implement multiply.
- return ConstantRange(getBitWidth(),
- !(isEmptySet() || Other.isEmptySet()));
+ if (isEmptySet() || Other.isEmptySet())
+ return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+ if (isFullSet() || Other.isFullSet())
+ return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+ ConstantRange this_zext = zeroExtend(getBitWidth() * 2);
+ ConstantRange Other_zext = Other.zeroExtend(getBitWidth() * 2);
+
+ ConstantRange Result_zext = ConstantRange(
+ this_zext.getLower() * Other_zext.getLower(),
+ ((this_zext.getUpper()-1) * (Other_zext.getUpper()-1)) + 1);
+
+ return Result_zext.truncate(getBitWidth());
}
ConstantRange