diff options
Diffstat (limited to 'lib/CodeGen/VirtRegMap.cpp')
| -rw-r--r-- | lib/CodeGen/VirtRegMap.cpp | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp index f0dd40d1e1..6122dc1bb4 100644 --- a/lib/CodeGen/VirtRegMap.cpp +++ b/lib/CodeGen/VirtRegMap.cpp @@ -50,6 +50,10 @@ namespace { clEnumVal(local, " local spiller"), clEnumValEnd), cl::init(local)); + + // TEMPORARY option to test a fix. + cl::opt<bool> + SpillerCheckLiveOut("spiller-check-liveout", cl::Hidden); } //===----------------------------------------------------------------------===// @@ -81,7 +85,8 @@ void VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int frameIndex) { } void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI, - unsigned OpNo, MachineInstr *NewMI) { + unsigned OpNo, MachineInstr *NewMI, + bool LiveOut) { // Move previous memory references folded to new instruction. MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(NewMI); for (MI2VirtMapTy::iterator I = MI2VirtMap.lower_bound(OldMI), @@ -96,6 +101,7 @@ void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI, MRInfo = isRef; } else { MRInfo = OldMI->getOperand(OpNo).isUse() ? isModRef : isMod; + if (LiveOut) MRInfo = (ModRef)(MRInfo | isLiveOut); } // add new memory reference @@ -727,10 +733,14 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, const VirtRegMap &VRM) { MaybeDeadStores.erase(MDSI); else { // If we get here, the store is dead, nuke it now. - assert(MR == VirtRegMap::isMod && "Can't be modref!"); - MBB.erase(MDSI->second); - MaybeDeadStores.erase(MDSI); - ++NumDSE; + assert(!(MR & VirtRegMap::isRef) && "Can't be modref!"); + // Don't nuke it if the value is needed in another block. + if (!SpillerCheckLiveOut || !(MR & VirtRegMap::isLiveOut)) { + DEBUG(std::cerr << " Killed store:\t" << *MDSI->second); + MBB.erase(MDSI->second); + MaybeDeadStores.erase(MDSI); + ++NumDSE; + } } } |