diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp --- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -1480,11 +1480,24 @@ if (LSRange.size() == 0) return false; + // If this range is neither open ended nor a constant, then it is not a + // candidate for being validThroughout. + if (RangeEnd && !DbgValue->getOperand(0).isImm()) + return false; + // Determine if the DBG_VALUE is valid at the beginning of its lexical block. const MachineInstr *LScopeBegin = LSRange.front().first; // Early exit if the lexical scope begins outside of the current block. if (LScopeBegin->getParent() != MBB) return false; + + // If there are instructions belonging to our scope in another block, and + // we're not a constant (see DWARF2 comment below), then we can't be + // validThroughout. + const MachineInstr *LScopeEnd = LSRange.back().second; + if (RangeEnd && LScopeEnd->getParent() != MBB) + return false; + MachineBasicBlock::const_reverse_iterator Pred(DbgValue); for (++Pred; Pred != MBB->rend(); ++Pred) { if (Pred->getFlag(MachineInstr::FrameSetup)) @@ -1505,11 +1518,6 @@ if (!RangeEnd) return true; - // Fail if there are instructions belonging to our scope in another block. - const MachineInstr *LScopeEnd = LSRange.back().second; - if (LScopeEnd->getParent() != MBB) - return false; - // Single, constant DBG_VALUEs in the prologue are promoted to be live // throughout the function. This is a hack, presumably for DWARF v2 and not // necessarily correct. It would be much better to use a dbg.declare instead