From f27229ee5ad121247b9c79e7605b19fccf781d8d Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Mon, 27 Jun 2011 15:00:36 +0000 Subject: [PATCH] Track live-out physical registers in MachineDCE. Patch by Sanjoy Das! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133910 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/DeadMachineInstructionElim.cpp | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/lib/CodeGen/DeadMachineInstructionElim.cpp b/lib/CodeGen/DeadMachineInstructionElim.cpp index fdc1d914214..6de6c0cb81b 100644 --- a/lib/CodeGen/DeadMachineInstructionElim.cpp +++ b/lib/CodeGen/DeadMachineInstructionElim.cpp @@ -110,9 +110,14 @@ bool DeadMachineInstructionElim::runOnMachineFunction(MachineFunction &MF) { LivePhysRegs.set(Reg); } - // FIXME: Add live-ins from sucessors to LivePhysRegs. Normally, physregs - // are not live across blocks, but some targets (x86) can have flags live - // out of a block. + // Add live-ins from sucessors to LivePhysRegs. Normally, physregs are not + // live across blocks, but some targets (x86) can have flags live out of a + // block. + for (MachineBasicBlock::succ_iterator S = MBB->succ_begin(), + E = MBB->succ_end(); S != E; S++) + for (MachineBasicBlock::livein_iterator LI = (*S)->livein_begin(); + LI != (*S)->livein_end(); LI++) + LivePhysRegs.set(*LI); // Now scan the instructions and delete dead ones, tracking physreg // liveness as we go. -- 2.34.1