When emitting a cmp with 0 for a lowered select, mask out the high
bits of the value carying the boolean condition, as their contents
are undefined. This fixes rdar://10887484.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 8a02162..94ddf86 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -2841,6 +2841,11 @@
}
}
+ // ARM's BooleanContents value is UndefinedBooleanContent. Mask out the
+ // undefined bits before doing a full-word comparison with zero.
+ Cond = DAG.getNode(ISD::AND, dl, Cond.getValueType(), Cond,
+ DAG.getConstant(1, Cond.getValueType()));
+
return DAG.getSelectCC(dl, Cond,
DAG.getConstant(0, Cond.getValueType()),
SelectTrue, SelectFalse, ISD::SETNE);