Ensure all defs referring to a virtual register are marked dead by addRegisterDead().

There can be multiple defs for a single virtual register when they are defining
sub-registers.

The missing <dead> flag was stopping the inline spiller from eliminating dead
code after rematerialization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128888 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 7 deletions

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index dce05d3e3f..0d137ebba2 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1543,13 +1543,8 @@ bool MachineInstr::addRegisterDead(unsigned IncomingReg,
       continue;
 
     if (Reg == IncomingReg) {
-      if (!Found) {
-        if (MO.isDead())
-          // The register is already marked dead.
-          return true;
-        MO.setIsDead();
-        Found = true;
-      }
+      MO.setIsDead();
+      Found = true;
     } else if (hasAliases && MO.isDead() &&
                TargetRegisterInfo::isPhysicalRegister(Reg)) {
       // There exists a super-register that's marked dead.