diff options
Diffstat (limited to 'llvm/lib/CodeGen/LiveDebugVariables.cpp')
-rw-r--r-- | llvm/lib/CodeGen/LiveDebugVariables.cpp | 38 |
1 files changed, 11 insertions, 27 deletions
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp index 9de33d6..ce898cd 100644 --- a/llvm/lib/CodeGen/LiveDebugVariables.cpp +++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp @@ -119,33 +119,17 @@ public: DIExpression::replaceArg(Expression, OpIdx, DuplicatingIdx); } } - // FIXME: Debug values referencing 64+ unique machine locations are rare and - // currently unsupported for performance reasons. If we can verify that - // performance is acceptable for such debug values, we can increase the - // bit-width of LocNoCount to 14 to enable up to 16384 unique machine - // locations. We will also need to verify that this does not cause issues - // with LiveDebugVariables' use of IntervalMap. - if (LocNoVec.size() < 64) { - LocNoCount = LocNoVec.size(); - if (LocNoCount > 0) { - LocNos = std::make_unique<unsigned[]>(LocNoCount); - std::copy(LocNoVec.begin(), LocNoVec.end(), loc_nos_begin()); - } - } else { - LLVM_DEBUG(dbgs() << "Found debug value with 64+ unique machine " - "locations, dropping...\n"); - LocNoCount = 1; - // Turn this into an undef debug value list; right now, the simplest form - // of this is an expression with one arg, and an undef debug operand. - Expression = - DIExpression::get(Expr.getContext(), {dwarf::DW_OP_LLVM_arg, 0, - dwarf::DW_OP_stack_value}); - if (auto FragmentInfoOpt = Expr.getFragmentInfo()) - Expression = *DIExpression::createFragmentExpression( - Expression, FragmentInfoOpt->OffsetInBits, - FragmentInfoOpt->SizeInBits); - LocNos = std::make_unique<unsigned[]>(LocNoCount); - LocNos[0] = UndefLocNo; + // A debug value referencing 64+ unique machine locations is very likely + // to be the result of a bug earlier in the pipeline. If by some means this + // limit is validly reached, then we can add a byte to the size of + // LocNoCount. + assert(LocNoVec.size() < 64 && + "debug value containing 64+ unique machine locations is not " + "supported by Live Debug Variables"); + LocNoCount = LocNoVec.size(); + if (LocNoCount > 0) { + LocNos.reset(new unsigned[LocNoCount]()); + std::copy(LocNoVec.begin(), LocNoVec.end(), loc_nos_begin()); } } |