6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-24 08:29:39 +00:00
Code Issues Projects Releases Wiki Activity

Revert r160194, which switched to use LV information for finding local

Browse Source 
kills.

This is causing miscompiles that I'm working on tracking down.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160196 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chandler Carruth 2012-07-13 22:23:32 +00:00
parent 5583415909
commit cb41e5f6f2
1 changed files with 54 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
lib/CodeGen/TwoAddressInstructionPass.cpp
View File

@ -483,6 +483,32 @@ static bool isTwoAddrUse(MachineInstr &MI, unsigned Reg, unsigned &DstReg) {
return false;
}
/// findLocalKill - Look for an instruction below MI in the MBB that kills the
/// specified register. Returns null if there are any other Reg use between the
/// instructions.
static
MachineInstr *findLocalKill(unsigned Reg, MachineBasicBlock *MBB,
MachineInstr *MI, MachineRegisterInfo *MRI,
DenseMap<MachineInstr*, unsigned> &DistanceMap) {
MachineInstr *KillMI = 0;
for (MachineRegisterInfo::use_nodbg_iterator
UI = MRI->use_nodbg_begin(Reg),
UE = MRI->use_nodbg_end(); UI != UE; ++UI) {
MachineInstr *UseMI = &*UI;
if (UseMI == MI || UseMI->getParent() != MBB)
continue;
if (DistanceMap.count(UseMI))
continue;
if (!UI.getOperand().isKill())
return 0;
if (KillMI)
return 0; // -O0 kill markers cannot be trusted?
KillMI = UseMI;
}
return KillMI;
}
/// findOnlyInterestingUse - Given a register, if has a single in-basic block
/// use, return the use instruction if it's a copy or a two-address use.
static
@ -879,18 +905,13 @@ TwoAddressInstructionPass::RescheduleMIBelowKill(MachineBasicBlock *MBB,
MachineBasicBlock::iterator &mi,
MachineBasicBlock::iterator &nmi,
unsigned Reg) {
// Bail immediately if we don't have LV available. We use it to find kills
// efficiently.
if (!LV)
return false;
MachineInstr *MI = &*mi;
DenseMap<MachineInstr*, unsigned>::iterator DI = DistanceMap.find(MI);
if (DI == DistanceMap.end())
// Must be created from unfolded load. Don't waste time trying this.
return false;
MachineInstr *KillMI = LV->getVarInfo(Reg).findKill(MBB);
MachineInstr *KillMI = findLocalKill(Reg, MBB, mi, MRI, DistanceMap);
if (!KillMI || KillMI->isCopy() || KillMI->isCopyLike())
// Don't mess with copies, they may be coalesced later.
return false;
@ -991,9 +1012,19 @@ TwoAddressInstructionPass::RescheduleMIBelowKill(MachineBasicBlock *MBB,
MBB->splice(KillPos, MBB, From, To);
DistanceMap.erase(DI);
// Update live variables
LV->removeVirtualRegisterKilled(Reg, KillMI);
LV->addVirtualRegisterKilled(Reg, MI);
if (LV) {
// Update live variables
LV->removeVirtualRegisterKilled(Reg, KillMI);
LV->addVirtualRegisterKilled(Reg, MI);
} else {
for (unsigned i = 0, e = KillMI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = KillMI->getOperand(i);
if (!MO.isReg() || !MO.isUse() || MO.getReg() != Reg)
continue;
MO.setIsKill(false);
}
MI->addRegisterKilled(Reg, 0);
}
return true;
}
@ -1030,18 +1061,13 @@ TwoAddressInstructionPass::RescheduleKillAboveMI(MachineBasicBlock *MBB,
MachineBasicBlock::iterator &mi,
MachineBasicBlock::iterator &nmi,
unsigned Reg) {
// Bail immediately if we don't have LV available. We use it to find kills
// efficiently.
if (!LV)
return false;
MachineInstr *MI = &*mi;
DenseMap<MachineInstr*, unsigned>::iterator DI = DistanceMap.find(MI);
if (DI == DistanceMap.end())
// Must be created from unfolded load. Don't waste time trying this.
return false;
MachineInstr *KillMI = LV->getVarInfo(Reg).findKill(MBB);
MachineInstr *KillMI = findLocalKill(Reg, MBB, mi, MRI, DistanceMap);
if (!KillMI || KillMI->isCopy() || KillMI->isCopyLike())
// Don't mess with copies, they may be coalesced later.
return false;
@ -1139,10 +1165,19 @@ TwoAddressInstructionPass::RescheduleKillAboveMI(MachineBasicBlock *MBB,
nmi = llvm::prior(InsertPos); // Backtrack so we process the moved instr.
DistanceMap.erase(DI);
// Update live variables
LV->removeVirtualRegisterKilled(Reg, KillMI);
LV->addVirtualRegisterKilled(Reg, MI);
if (LV) {
// Update live variables
LV->removeVirtualRegisterKilled(Reg, KillMI);
LV->addVirtualRegisterKilled(Reg, MI);
} else {
for (unsigned i = 0, e = KillMI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = KillMI->getOperand(i);
if (!MO.isReg() || !MO.isUse() || MO.getReg() != Reg)
continue;
MO.setIsKill(false);
}
MI->addRegisterKilled(Reg, 0);
}
return true;
}