From a4e6397fd9f2fbbd6affdfb0738813918cb21da0 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Mon, 25 Jun 2012 18:18:27 +0000 Subject: Enforce stricter liveness rules for PHIs. Verify that all paths from the entry block to a virtual register read pass through a def. Enable this check even when MRI->isSSA() is false. Verify that the live range of a virtual register is live out of all predecessor blocks, even for PHI-values. This requires that PHIElimination sometimes inserts IMPLICIT_DEF instruction in predecessor blocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159150 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineVerifier.cpp | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'lib/CodeGen/MachineVerifier.cpp') diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp index 92d9356e83..a443b51d15 100644 --- a/lib/CodeGen/MachineVerifier.cpp +++ b/lib/CodeGen/MachineVerifier.cpp @@ -1049,7 +1049,7 @@ void MachineVerifier::visitMachineFunctionAfter() { // Now check liveness info if available calcRegsRequired(); - if (MRI->isSSA() && !MF->empty()) { + if (!MF->empty()) { BBInfo &MInfo = MBBInfoMap[&MF->front()]; for (RegSet::iterator I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E; @@ -1332,15 +1332,18 @@ void MachineVerifier::verifyLiveIntervals() { ++MFI; continue; } + + // Is VNI a PHI-def in the current block? + bool IsPHI = VNI->isPHIDef() && + VNI->def == LiveInts->getMBBStartIdx(MFI); + // Check that VNI is live-out of all predecessors. for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(), PE = MFI->pred_end(); PI != PE; ++PI) { SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI); const VNInfo *PVNI = LI.getVNInfoBefore(PEnd); - if (VNI->isPHIDef() && VNI->def == LiveInts->getMBBStartIdx(MFI)) - continue; - + // All predecessors must have a live-out value. if (!PVNI) { report("Register not marked live out of predecessor", *PI); *OS << "Valno #" << VNI->id << " live into BB#" << MFI->getNumber() @@ -1349,12 +1352,14 @@ void MachineVerifier::verifyLiveIntervals() { continue; } - if (PVNI != VNI) { + // Only PHI-defs can take different predecessor values. + if (!IsPHI && PVNI != VNI) { report("Different value live out of predecessor", *PI); *OS << "Valno #" << PVNI->id << " live out of BB#" << (*PI)->getNumber() << '@' << PEnd << "\nValno #" << VNI->id << " live into BB#" << MFI->getNumber() - << '@' << LiveInts->getMBBStartIdx(MFI) << " in " << LI << '\n'; + << '@' << LiveInts->getMBBStartIdx(MFI) << " in " + << PrintReg(Reg) << ": " << LI << '\n'; } } if (&*MFI == EndMBB) -- cgit v1.2.3-18-g5258