vendor/llvm/llvm-release_370-r246257

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index b2fdee6c8e4c..6ca69a124297 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -1026,8 +1026,12 @@ PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) {
           // Replace this reference to the virtual register with the
           // scratch register.
           assert (ScratchReg && "Missing scratch register!");
+          MachineRegisterInfo &MRI = Fn.getRegInfo();
           Fn.getRegInfo().replaceRegWith(Reg, ScratchReg);
           
+          // Make sure MRI now accounts this register as used.
+          MRI.setPhysRegUsed(ScratchReg);
+
           // Because this instruction was processed by the RS before this
           // register was allocated, make sure that the RS now records the
           // register as being used.