[DebugInfo] Introduce DW_OP_LLVM_convert

Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.

The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.

For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.

Differential Revision: https://reviews.llvm.org/D56587

llvm-svn: 356442

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
index 7a62b6bfc6a..6fdf1451a63 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
@@ -42,11 +42,11 @@ void AsmPrinter::EmitSLEB128(int64_t Value, const char *Desc) const {
   OutStreamer->EmitSLEB128IntValue(Value);
 }
 
-void AsmPrinter::EmitULEB128(uint64_t Value, const char *Desc) const {
+void AsmPrinter::EmitULEB128(uint64_t Value, const char *Desc, unsigned PadTo) const {
   if (isVerbose() && Desc)
     OutStreamer->AddComment(Desc);
 
-  OutStreamer->EmitULEB128IntValue(Value);
+  OutStreamer->EmitULEB128IntValue(Value, PadTo);
 }
 
 /// Emit something like ".uleb128 Hi-Lo".