From cf724f078623e786fc92335fdb0ec70b46f2e86d Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Sun, 8 May 2011 19:21:08 +0000 Subject: Remove an assertion to fix PR9872. It can happen that a live debug variable is the last use of a sub-register, and the register allocator will pick a larger register class for the virtual register. If the allocated register doesn't support the sub-register index, just use %noreg for the debug variables instead of asserting. In PR9872, a debug variable ends up in the sub_8bit_hi part of a GR32_ABCD register. The register is split and one part is inflated to GR32 and assigned %ESI because there are no more normal uses of sub_8bit_hi. Since %ESI doesn't have that sub-register, substPhysReg asserted. Now it will simply insert a %noreg instead, and the debug variable will be marked unavailable in that range. We don't currently have a way of saying: !"value" is in bits 8-15 of %ESI, I don't know if DWARF even supports that. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131073 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LiveDebugVariables.cpp | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'lib/CodeGen/LiveDebugVariables.cpp') diff --git a/lib/CodeGen/LiveDebugVariables.cpp b/lib/CodeGen/LiveDebugVariables.cpp index 783a7e1ded..292928f8e7 100644 --- a/lib/CodeGen/LiveDebugVariables.cpp +++ b/lib/CodeGen/LiveDebugVariables.cpp @@ -840,6 +840,9 @@ UserValue::rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI) { unsigned VirtReg = Loc.getReg(); if (VRM.isAssignedReg(VirtReg) && TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) { + // This can create a %noreg operand in rare cases when the sub-register + // index is no longer available. That means the user value is in a + // non-existent sub-register, and %noreg is exactly what we want. Loc.substPhysReg(VRM.getPhys(VirtReg), TRI); } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT && VRM.isSpillSlotUsed(VRM.getStackSlot(VirtReg))) { @@ -942,6 +945,7 @@ void LDVImpl::emitDebugValues(VirtRegMap *VRM) { DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n"); const TargetInstrInfo *TII = MF->getTarget().getInstrInfo(); for (unsigned i = 0, e = userValues.size(); i != e; ++i) { + DEBUG(userValues[i]->print(dbgs(), &MF->getTarget())); userValues[i]->rewriteLocations(*VRM, *TRI); userValues[i]->emitDebugValues(VRM, *LIS, *TII); } -- cgit v1.2.3-18-g5258