Add signExtend to ConstantRange, to complement zeroExtend and truncate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35733 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index dd3e44e..79a85b8 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -346,6 +346,23 @@
return ConstantRange(L, U);
}
+/// signExtend - Return a new range in the specified integer type, which must
+/// be strictly larger than the current type. The returned range will
+/// correspond to the possible range of values as if the source range had been
+/// sign extended.
+ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const {
+ unsigned SrcTySize = getBitWidth();
+ assert(SrcTySize < DstTySize && "Not a value extension");
+ if (isFullSet()) {
+ return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1),
+ APInt::getLowBitsSet(DstTySize, SrcTySize-1));
+ }
+
+ APInt L = Lower; L.sext(DstTySize);
+ APInt U = Upper; U.sext(DstTySize);
+ return ConstantRange(L, U);
+}
+
/// truncate - Return a new range in the specified integer type, which must be
/// strictly smaller than the current type. The returned range will
/// correspond to the possible range of values as if the source range had been