From 19b6486d3891c8a02a301aa1b44348a420772fcf Mon Sep 17 00:00:00 2001 From: Alkis Evlogimenos Date: Tue, 13 Jan 2004 06:24:30 +0000 Subject: [PATCH] Correctly compute live variable information for physical registers when an implicitely defined register is later used by an alias. For example: call foo %reg1024 = mov %AL The call implicitely defines EAX but only AL is used. Before this fix no information was available on AL. Now EAX and all its aliases except AL get defined and die at the call instruction whereas AL lives to be killed by the assignment. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10813 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LiveIntervalAnalysis.cpp | 17 ++++++--------- lib/CodeGen/LiveVariables.cpp | 31 +++++++++++----------------- lib/CodeGen/RegAllocLocal.cpp | 15 +++++++++++--- 3 files changed, 30 insertions(+), 33 deletions(-) diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index fe47a3661d8..f8c83f18ead 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -261,6 +261,8 @@ void LiveIntervals::handleRegisterDef(MachineBasicBlock* mbb, if (reg < MRegisterInfo::FirstVirtualRegister) { if (allocatableRegisters_[reg]) { handlePhysicalRegisterDef(mbb, mi, reg); + for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as) + handlePhysicalRegisterDef(mbb, mi, *as); } } else { @@ -300,10 +302,8 @@ void LiveIntervals::computeIntervals() instr->print(std::cerr, *tm_);); // handle implicit defs - for (const unsigned* id = tid.ImplicitDefs; *id; ++id) { - unsigned physReg = *id; - handlePhysicalRegisterDef(mbb, mi, physReg); - } + for (const unsigned* id = tid.ImplicitDefs; *id; ++id) + handleRegisterDef(mbb, mi, *id); // handle explicit defs for (int i = instr->getNumOperands() - 1; i >= 0; --i) { @@ -312,14 +312,9 @@ void LiveIntervals::computeIntervals() if (!mop.isRegister()) continue; - unsigned reg = mop.getAllocatedRegNum(); // handle defs - build intervals - if (mop.isDef()) { - if (reg < MRegisterInfo::FirstVirtualRegister) - handlePhysicalRegisterDef(mbb, mi, reg); - else - handleVirtualRegisterDef(mbb, mi, reg); - } + if (mop.isDef()) + handleRegisterDef(mbb, mi, mop.getAllocatedRegNum()); } } } diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index a622b05160d..1bfc6e553d6 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -117,14 +117,6 @@ void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) { if (PhysRegInfo[Reg]) { PhysRegInfo[Reg] = MI; PhysRegUsed[Reg] = true; - } else { - for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg); - *AliasSet; ++AliasSet) { - if (MachineInstr *LastUse = PhysRegInfo[*AliasSet]) { - PhysRegInfo[*AliasSet] = MI; - PhysRegUsed[*AliasSet] = true; - } - } } } @@ -135,20 +127,21 @@ void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI) { RegistersKilled.insert(std::make_pair(LastUse, Reg)); else RegistersDead.insert(std::make_pair(LastUse, Reg)); - } else { - for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg); - *AliasSet; ++AliasSet) { - if (MachineInstr *LastUse = PhysRegInfo[*AliasSet]) { - if (PhysRegUsed[*AliasSet]) - RegistersKilled.insert(std::make_pair(LastUse, *AliasSet)); - else - RegistersDead.insert(std::make_pair(LastUse, *AliasSet)); - PhysRegInfo[*AliasSet] = 0; // Kill the aliased register - } - } } PhysRegInfo[Reg] = MI; PhysRegUsed[Reg] = false; + + for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg); + *AliasSet; ++AliasSet) { + if (MachineInstr *LastUse = PhysRegInfo[*AliasSet]) { + if (PhysRegUsed[*AliasSet]) + RegistersKilled.insert(std::make_pair(LastUse, *AliasSet)); + else + RegistersDead.insert(std::make_pair(LastUse, *AliasSet)); + } + PhysRegInfo[*AliasSet] = MI; + PhysRegUsed[*AliasSet] = false; + } } bool LiveVariables::runOnMachineFunction(MachineFunction &MF) { diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp index 88699d0bcb4..5ffe5afc4db 100644 --- a/lib/CodeGen/RegAllocLocal.cpp +++ b/lib/CodeGen/RegAllocLocal.cpp @@ -232,9 +232,8 @@ void RA::removePhysReg(unsigned PhysReg) { std::vector::iterator It = std::find(PhysRegsUseOrder.begin(), PhysRegsUseOrder.end(), PhysReg); - assert(It != PhysRegsUseOrder.end() && - "Spilled a physical register, but it was not in use list!"); - PhysRegsUseOrder.erase(It); + if (It != PhysRegsUseOrder.end()) + PhysRegsUseOrder.erase(It); } @@ -550,6 +549,11 @@ void RA::AllocateBasicBlock(MachineBasicBlock &MBB) { spillPhysReg(MBB, I, Reg, true); // Spill any existing value in the reg PhysRegsUsed[Reg] = 0; // It is free and reserved now PhysRegsUseOrder.push_back(Reg); + for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg); + *AliasSet; ++AliasSet) { + PhysRegsUseOrder.push_back(*AliasSet); + PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now + } } // Loop over the implicit defs, spilling them as well. @@ -559,6 +563,11 @@ void RA::AllocateBasicBlock(MachineBasicBlock &MBB) { spillPhysReg(MBB, I, Reg); PhysRegsUseOrder.push_back(Reg); PhysRegsUsed[Reg] = 0; // It is free and reserved now + for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg); + *AliasSet; ++AliasSet) { + PhysRegsUseOrder.push_back(*AliasSet); + PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now + } } // Okay, we have allocated all of the source operands and spilled any values