misched: Fix the DAG builder to handle an undef operand at ExitSU.
Assertion failed: (VNI && "No value to read by operand")
rdar://12790267.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169071 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index 2b00b59..fd75576 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -210,7 +210,8 @@
Uses[Reg].push_back(PhysRegSUOper(&ExitSU, -1));
else {
assert(!IsPostRA && "Virtual register encountered after regalloc.");
- addVRegUseDeps(&ExitSU, i);
+ if (MO.readsReg()) // ignore undef operands
+ addVRegUseDeps(&ExitSU, i);
}
}
} else {