From 4c1ea6b115235208d3f812cb4c30e0b7cd385c13 Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Wed, 12 Feb 2014 19:34:44 +0000
Subject: [PATCH] Debug info: Bugfix for r201190: DW_OP_piece takes bytes, not
 bits. rdar://problem/16015314

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201253 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 5 +++--
 lib/CodeGen/AsmPrinter/DwarfUnit.cpp  | 3 ++-
 test/DebugInfo/X86/subreg.ll          | 2 +-
 test/DebugInfo/X86/subregisters.ll    | 2 +-
 4 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 32cf67ffb91..2f15c97f2de 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -931,8 +931,9 @@ void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
     } else {
       OutStreamer.AddComment("DW_OP_piece");
       EmitInt8(dwarf::DW_OP_piece);
-      OutStreamer.AddComment(Twine(Size));
-      EmitULEB128(Size);
+      unsigned ByteSize = Size / 8; // Assuming 8 bits per byte.
+      OutStreamer.AddComment(Twine(ByteSize));
+      EmitULEB128(ByteSize);
     }
   }
 }
diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index a6bae16b694..68a346887a4 100644
--- a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -470,8 +470,9 @@ void DwarfUnit::addRegisterOp(DIEBlock *TheDie, unsigned Reg) {
       addUInt(TheDie, dwarf::DW_FORM_data1, Size);
       addUInt(TheDie, dwarf::DW_FORM_data1, Offset);
     } else {
+      unsigned ByteSize = Size / 8; // Assuming 8 bits per byte.
       addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_piece);
-      addUInt(TheDie, dwarf::DW_FORM_data1, Size);
+      addUInt(TheDie, dwarf::DW_FORM_data1, ByteSize);
     }
   }
 }
diff --git a/test/DebugInfo/X86/subreg.ll b/test/DebugInfo/X86/subreg.ll
index 58e3bfc3bc3..94526ffae85 100644
--- a/test/DebugInfo/X86/subreg.ll
+++ b/test/DebugInfo/X86/subreg.ll
@@ -5,7 +5,7 @@
 
 ; CHECK: .byte   80                      # DW_OP_reg0
 ; CHECK: .byte   147                     # DW_OP_piece
-; CHECK: .byte   16                      # 16
+; CHECK: .byte   2                       # 2
 
 define i16 @f(i16 signext %zzz) nounwind {
 entry:
diff --git a/test/DebugInfo/X86/subregisters.ll b/test/DebugInfo/X86/subregisters.ll
index ac0c3839869..738ab02c0ca 100644
--- a/test/DebugInfo/X86/subregisters.ll
+++ b/test/DebugInfo/X86/subregisters.ll
@@ -7,7 +7,7 @@
 ; rdar://problem/16015314
 ;
 ; CHECK:  DW_AT_name [DW_FORM_strp]{{.*}} "a"
-; CHECK:    DW_AT_location [DW_FORM_block1]       (<0x03> 54 93 20 )
+; CHECK:    DW_AT_location [DW_FORM_block1]       (<0x03> 54 93 04 )
 ;
 ; struct bar {
 ;   int a;