From c69cbd0a7431b047dbc4a9758e81bf122926ba0a Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Sat, 25 Feb 2012 02:01:00 +0000 Subject: [PATCH] Make the peephole optimizer clear kill flags on a vreg if it's about to add new uses of the vreg, since the old kills may no longer be valid. This was causing -verify-machineinstrs to complain about uses after kills, and could potentially have been causing subtle register allocation issues, but I haven't come across a test case yet. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151425 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/PeepholeOptimizer.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/CodeGen/PeepholeOptimizer.cpp b/lib/CodeGen/PeepholeOptimizer.cpp index 203f2bffb7b..9c5c029000c 100644 --- a/lib/CodeGen/PeepholeOptimizer.cpp +++ b/lib/CodeGen/PeepholeOptimizer.cpp @@ -237,6 +237,10 @@ OptimizeExtInstr(MachineInstr *MI, MachineBasicBlock *MBB, if (PHIBBs.count(UseMBB)) continue; + // About to add uses of DstReg, clear DstReg's kill flags. + if (!Changed) + MRI->clearKillFlags(DstReg); + unsigned NewVR = MRI->createVirtualRegister(RC); BuildMI(*UseMBB, UseMI, UseMI->getDebugLoc(), TII->get(TargetOpcode::COPY), NewVR)