Add a getNumSignBits() method to APInt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126379 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index b91d5dc..d1fd3e5 100644
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -1193,6 +1193,12 @@
/// @brief Count the number of leading one bits.
unsigned countLeadingOnes() const;
+ /// Computes the number of leading bits of this APInt that are equal to its
+ /// sign bit.
+ unsigned getNumSignBits() const {
+ return isNegative() ? countLeadingOnes() : countLeadingZeros();
+ }
+
/// countTrailingZeros - This function is an APInt version of the
/// countTrailingZeros_{32,64} functions in MathExtras.h. It counts
/// the number of zeros from the least significant bit to the first set bit.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 2fb2f2d..0b7cbcc 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2088,12 +2088,7 @@
case ISD::Constant: {
const APInt &Val = cast<ConstantSDNode>(Op)->getAPIntValue();
- // If negative, return # leading ones.
- if (Val.isNegative())
- return Val.countLeadingOnes();
-
- // Return # leading zeros.
- return Val.countLeadingZeros();
+ return Val.getNumSignBits();
}
case ISD::SIGN_EXTEND: