From 5d52165e4e2f83e6e66063382f323435da21090d Mon Sep 17 00:00:00 2001 From: Bob Wilson Date: Tue, 29 Jun 2010 18:42:49 +0000 Subject: Fix a register scavenger crash when dealing with undefined subregs. The LowerSubregs pass needs to preserve implicit def operands attached to EXTRACT_SUBREG instructions when it replaces those instructions with copies. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107189 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LowerSubregs.cpp | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'lib/CodeGen/LowerSubregs.cpp') diff --git a/lib/CodeGen/LowerSubregs.cpp b/lib/CodeGen/LowerSubregs.cpp index 78d8de4b67..2dfd07f7f2 100644 --- a/lib/CodeGen/LowerSubregs.cpp +++ b/lib/CodeGen/LowerSubregs.cpp @@ -62,6 +62,7 @@ namespace { void TransferKillFlag(MachineInstr *MI, unsigned SrcReg, const TargetRegisterInfo *TRI, bool AddIfNotFound = false); + void TransferImplicitDefs(MachineInstr *MI); }; char LowerSubregsInstructionPass::ID = 0; @@ -104,6 +105,22 @@ LowerSubregsInstructionPass::TransferKillFlag(MachineInstr *MI, } } +/// TransferImplicitDefs - MI is a pseudo-instruction, and the lowered +/// replacement instructions immediately precede it. Copy any implicit-def +/// operands from MI to the replacement instruction. +void +LowerSubregsInstructionPass::TransferImplicitDefs(MachineInstr *MI) { + MachineBasicBlock::iterator CopyMI = MI; + --CopyMI; + + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + MachineOperand &MO = MI->getOperand(i); + if (!MO.isReg() || !MO.isImplicit() || MO.isUse()) + continue; + CopyMI->addOperand(MachineOperand::CreateReg(MO.getReg(), true, true)); + } +} + bool LowerSubregsInstructionPass::LowerExtract(MachineInstr *MI) { MachineBasicBlock *MBB = MI->getParent(); @@ -149,6 +166,7 @@ bool LowerSubregsInstructionPass::LowerExtract(MachineInstr *MI) { TransferDeadFlag(MI, DstReg, TRI); if (MI->getOperand(1).isKill()) TransferKillFlag(MI, SuperReg, TRI, true); + TransferImplicitDefs(MI); DEBUG({ MachineBasicBlock::iterator dMI = MI; dbgs() << "subreg: " << *(--dMI); -- cgit v1.2.3-70-g09d2