Use a kill, not a dead definition, update comment

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6131 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-05-12 17:37:30 +00:00
parent 45343ea5ac
commit b52e0241c0

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@ -87,12 +87,11 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
MachineInstr *PHICopy = *(AfterPHIsIt-1);
// Add information to LiveVariables to know that the incoming value is
// dead. This says that the register is dead, not killed, because we
// cannot use the live variable information to indicate that the variable
// is defined in multiple entry blocks. Instead, we pretend that this
// instruction defined it and killed it at the same time.
// killed. Note that because the value is defined in several places (once
// each for each incoming block), the "def" block and instruction fields
// for the VarInfo is not filled in.
//
LV->addVirtualRegisterDead(IncomingReg, &MBB, PHICopy);
LV->addVirtualRegisterKilled(IncomingReg, &MBB, PHICopy);
// Since we are going to be deleting the PHI node, if it is the last use
// of any registers, or if the value itself is dead, we need to move this