ARM: Fix more fast-isel verifier failures.
Teach the generic instruction selection helper functions to constrain
the register classes of their input operands. For non-physical register
references, the generic code needs to be careful not to mess that up
when replacing references to result registers. As the comment indicates
for MachineRegisterInfo::replaceRegWith(), it's important to call
constrainRegClass() first.
rdar://12594152
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188593 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index e60adbf..17ccdb2 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -497,6 +497,10 @@
if (J == E) break;
To = J->second;
}
+ // Make sure the new register has a sufficiently constrained register class.
+ if (TargetRegisterInfo::isVirtualRegister(From) &&
+ TargetRegisterInfo::isVirtualRegister(To))
+ MRI.constrainRegClass(To, MRI.getRegClass(From));
// Replace it.
MRI.replaceRegWith(From, To);
}