[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/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 554cce1..2d615f2 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -135,10 +135,10 @@ void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
 
 /// EmitULEB128IntValue - Special case of EmitULEB128Value that avoids the
 /// client having to pass in a MCExpr for constant integers.
-void MCStreamer::EmitULEB128IntValue(uint64_t Value) {
+void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned PadTo) {
   SmallString<128> Tmp;
   raw_svector_ostream OSE(Tmp);
-  encodeULEB128(Value, OSE);
+  encodeULEB128(Value, OSE, PadTo);
   EmitBytes(OSE.str());
 }