DebugInfo: Use loclistx for DWARFv5 location lists to reduce the number of relocations

This only implements the non-dwo part, but loclistx is necessary to use
location lists in DWARFv5, so it's a precursor to that work - and
generally reduces relocations (only using one reloc, then
indexes/relative offsets for all location list references) in non-split
DWARF.

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index f4134da48ca..c4d5b717b25 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -798,6 +798,8 @@ void DIEBlock::print(raw_ostream &O) const {
 //===----------------------------------------------------------------------===//
 
 unsigned DIELocList::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
+  if (Form == dwarf::DW_FORM_loclistx)
+    return getULEB128Size(Index);
   if (Form == dwarf::DW_FORM_data4)
     return 4;
   if (Form == dwarf::DW_FORM_sec_offset)
@@ -808,6 +810,10 @@ unsigned DIELocList::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 /// EmitValue - Emit label value.
 ///
 void DIELocList::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
+  if (Form == dwarf::DW_FORM_loclistx) {
+    AP->EmitULEB128(Index);
+    return;
+  }
   DwarfDebug *DD = AP->getDwarfDebug();
   MCSymbol *Label = DD->getDebugLocs().getList(Index).Label;
   AP->emitDwarfSymbolReference(Label, /*ForceOffset*/ DD->useSplitDwarf());