From 969c9ef0dd271905136f21a6c51dd0839ef01cce Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Fri, 14 Oct 2011 23:34:37 +0000 Subject: [PATCH] Mark the invoke call instruction as implicitly defining the callee-saved registers. The callee-saved registers cannot be live across an invoke call because the control flow may continue along the exceptional edge. When this happens, all of the callee-saved registers are no longer valid. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142018 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMISelLowering.cpp | 33 ++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 2ac52cfc366..f3bc719450f 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -5883,11 +5883,15 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const { PrevMBB = CurMBB; } - // Remove the landing pad successor from the invoke block and replace it with - // the new dispatch block. + const ARMBaseInstrInfo *AII = static_cast(TII); + const ARMBaseRegisterInfo &RI = AII->getRegisterInfo(); + const unsigned *SavedRegs = RI.getCalleeSavedRegs(MF); for (SmallPtrSet::iterator I = InvokeBBs.begin(), E = InvokeBBs.end(); I != E; ++I) { MachineBasicBlock *BB = *I; + + // Remove the landing pad successor from the invoke block and replace it + // with the new dispatch block. for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(), SE = BB->succ_end(); SI != SE; ++SI) { MachineBasicBlock *SMBB = *SI; @@ -5898,6 +5902,31 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const { } BB->addSuccessor(DispatchBB); + + // Find the invoke call and mark all of the callee-saved registers as + // 'implicit defined' so that they're spilled. This prevents code from + // moving instructions to before the EH block, where they will never be + // executed. + for (MachineBasicBlock::reverse_iterator + II = BB->rbegin(), IE = BB->rend(); II != IE; ++II) { + if (!II->getDesc().isCall()) continue; + + DenseMap DefRegs; + for (MachineInstr::mop_iterator + OI = II->operands_begin(), OE = II->operands_end(); + OI != OE; ++OI) { + if (!OI->isReg()) continue; + DefRegs[OI->getReg()] = true; + } + + MachineInstrBuilder MIB(&*II); + + for (unsigned i = 0; SavedRegs[i] != 0; ++i) + if (!DefRegs[SavedRegs[i]]) + MIB.addReg(SavedRegs[i], RegState::Implicit | RegState::Define); + + break; + } } // The instruction is gone now. -- 2.34.1