Replace some bit operations with simpler ones. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182226 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 479fb77..c9ee5fb 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -10434,17 +10434,15 @@
bool ARM::isBitFieldInvertedMask(unsigned v) {
if (v == 0xffffffff)
- return 0;
+ return false;
+
// there can be 1's on either or both "outsides", all the "inside"
// bits must be 0's
- unsigned int lsb = 0, msb = 31;
- while (v & (1 << msb)) --msb;
- while (v & (1 << lsb)) ++lsb;
- for (unsigned int i = lsb; i <= msb; ++i) {
- if (v & (1 << i))
- return 0;
- }
- return 1;
+ unsigned TO = CountTrailingOnes_32(v);
+ unsigned LO = CountLeadingOnes_32(v);
+ v = (v >> TO) << TO;
+ v = (v << LO) >> LO;
+ return v == 0;
}
/// isFPImmLegal - Returns true if the target can instruction select the