Make size computation less brittle.

llvm-svn: 132222

2 files changed, 6 insertions, 30 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index b1aa8d244c3..4cd7cc969b1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -760,26 +760,6 @@ getDebugValueLocation(const MachineInstr *MI) const {
   return MachineLocation();
 }
 
-/// getDwarfRegOpSize - get size required to emit given machine location using
-/// dwarf encoding.
-unsigned AsmPrinter::getDwarfRegOpSize(const MachineLocation &MLoc) const {
-  const TargetRegisterInfo *RI = TM.getRegisterInfo();
-  unsigned DWReg = RI->getDwarfRegNum(MLoc.getReg(), false);
-  if (int Offset = MLoc.getOffset()) {
-    // If the value is at a certain offset from frame register then
-    // use DW_OP_breg.
-    if (DWReg < 32)
-      return 1 + MCAsmInfo::getSLEB128Size(Offset);
-    else
-      return 1 + MCAsmInfo::getULEB128Size(MLoc.getReg()) 
-        + MCAsmInfo::getSLEB128Size(Offset);
-  }
-  if (DWReg < 32)
-    return 1;
-
-  return 1 + MCAsmInfo::getULEB128Size(DWReg);
-}
-
 /// EmitDwarfRegOp - Emit dwarf register operation.
 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
   const TargetRegisterInfo *TRI = TM.getRegisterInfo();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 53580d76aa0..f29b1996cca 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2586,17 +2586,16 @@ void DwarfDebug::emitDebugLoc() {
       Asm->OutStreamer.EmitSymbolValue(Entry.Begin, Size, 0);
       Asm->OutStreamer.EmitSymbolValue(Entry.End, Size, 0);
       DIVariable DV(Entry.Variable);
+      Asm->OutStreamer.AddComment("Loc expr size");
+      MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
+      MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
+      Asm->EmitLabelDifference(end, begin, 2);
+      Asm->OutStreamer.EmitLabel(begin);
       if (DV.hasComplexAddress()) {
         unsigned N = DV.getNumAddrElements();
         unsigned i = 0;
-        Asm->OutStreamer.AddComment("Loc expr size");
         if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
           if (Entry.Loc.getOffset()) {
-            unsigned Size = Asm->getDwarfRegOpSize(Entry.Loc);
-            unsigned OffsetSize = 
-              MCAsmInfo::getSLEB128Size(DV.getAddrElement(1));
-            // breg + deref + plus + offset
-            Asm->EmitInt16(Size + 1 + 1 + OffsetSize + N - 2);
             i = 2;
             Asm->EmitDwarfRegOp(Entry.Loc);
             Asm->OutStreamer.AddComment("DW_OP_deref");
@@ -2608,12 +2607,10 @@ void DwarfDebug::emitDebugLoc() {
             // If first address element is OpPlus then emit
             // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
             MachineLocation Loc(Entry.Loc.getReg(), DV.getAddrElement(1));
-            Asm->EmitInt16(Asm->getDwarfRegOpSize(Loc) + N - 2);
             Asm->EmitDwarfRegOp(Loc);
             i = 2;
           }
         } else {
-          Asm->EmitInt16(Asm->getDwarfRegOpSize(Entry.Loc) + N);
           Asm->EmitDwarfRegOp(Entry.Loc);
         }
 
@@ -2628,10 +2625,9 @@ void DwarfDebug::emitDebugLoc() {
           else llvm_unreachable("unknown Opcode found in complex address");
         }
       } else {
-        Asm->OutStreamer.AddComment("Loc expr size");
-        Asm->EmitInt16(Asm->getDwarfRegOpSize(Entry.Loc));
         Asm->EmitDwarfRegOp(Entry.Loc);
       }
+      Asm->OutStreamer.EmitLabel(end);
     }
   }
 }