Reapply an improved version of r180816/180817.

Change the informal convention of DBG_VALUE machine instructions so that
we can express a register-indirect address with an offset of 0.
The old convention was that a DBG_VALUE is a register-indirect value if
the offset (operand 1) is nonzero. The new convention is that a DBG_VALUE
is register-indirect if the first operand is a register and the second
operand is an immediate. For plain register values the combination reg,
reg is used. MachineInstrBuilder::BuildMI knows how to build the new
DBG_VALUES.

rdar://problem/13658587

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185966 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index ec7c5bf..3e6db1c 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1563,8 +1563,9 @@ DIE *CompileUnit::constructVariableDIE(DbgVariable *DV,
     assert(DVInsn->getNumOperands() == 3);
     if (DVInsn->getOperand(0).isReg()) {
       const MachineOperand RegOp = DVInsn->getOperand(0);
-      if (int64_t Offset = DVInsn->getOperand(1).getImm()) {
-        MachineLocation Location(RegOp.getReg(), Offset);
+      // If the second operand is an immedieate, this is an indirect value.
+      if (DVInsn->getOperand(1).isImm()) {
+        MachineLocation Location(RegOp.getReg(), DVInsn->getOperand(1).getImm());
         addVariableAddress(*DV, VariableDie, Location);
       } else if (RegOp.getReg())
         addVariableAddress(*DV, VariableDie, MachineLocation(RegOp.getReg()));