[llvm] r185461 - [PowerPC] Support TLS variables in debug info

[Ulrich Weigand]

Author: uweigand
Date: Tue Jul  2 13:47:35 2013
New Revision: 185461

URL: http://llvm.org/viewvc/llvm-project?rev=185461&view=rev
Log:

[PowerPC] Support TLS variables in debug info

This adds an implementation of getDebugThreadLocalSymbol for
(64-bit) PowerPC.  This needs to return a generic MCExpr
since on ppc64, we need to add a bias of 0x8000 to the
value returned by the R_PPC64_DTPREL64 relocation.


Added:
    llvm/trunk/test/DebugInfo/PowerPC/tls-fission.ll
Modified:
    llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.cpp
    llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.h
    llvm/trunk/test/DebugInfo/PowerPC/tls.ll

Modified: llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.cpp?rev=185461&r1=185460&r2=185461&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.cpp Tue Jul  2 13:47:35 2013
@@ -55,3 +55,13 @@ SelectSectionForGlobal(const GlobalValue
 
   return DefaultSection;
 }
+
+const MCExpr *PPC64LinuxTargetObjectFile::
+getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
+  const MCExpr *Expr =
+    MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_PPC_DTPREL, getContext());
+  return MCBinaryExpr::CreateAdd(Expr,
+                                 MCConstantExpr::Create(0x8000, getContext()),
+                                 getContext());
+}
+

Modified: llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.h?rev=185461&r1=185460&r2=185461&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCTargetObjectFile.h Tue Jul  2 13:47:35 2013
@@ -25,6 +25,9 @@ namespace llvm {
     virtual const MCSection *
     SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
                            Mangler *Mang, const TargetMachine &TM) const;
+
+    /// \brief Describe a TLS variable address within debug info.
+    virtual const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const;
   };
 
 }  // end namespace llvm

Added: llvm/trunk/test/DebugInfo/PowerPC/tls-fission.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/PowerPC/tls-fission.ll?rev=185461&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/PowerPC/tls-fission.ll (added)
+++ llvm/trunk/test/DebugInfo/PowerPC/tls-fission.ll Tue Jul  2 13:47:35 2013
@@ -0,0 +1,31 @@
+; RUN: llc -split-dwarf=Enable -mtriple=powerpc64-unknown-linux-gnu -O0 -filetype=asm < %s | FileCheck %s
+
+; FIXME: add relocation and DWARF expression support to llvm-dwarfdump & use
+; that here instead of raw assembly printing
+
+; CHECK: debug_info.dwo
+; 3 bytes of data in this DW_FORM_block1 representation of the location of 'tls'
+; CHECK: .byte 3{{ *}}# DW_AT_location
+; DW_OP_const_index (0xfx == 252) to refer to the debug_addr table
+; CHECK-NEXT: .byte 252
+; an index of zero into the debug_addr table
+; CHECK-NEXT: .byte 0
+; DW_OP_GNU_push_tls_address
+; CHECK-NEXT: .byte 224
+; check that the expected TLS address description is the first thing in the debug_addr section
+; CHECK: debug_addr
+; CHECK-NEXT: .quad tls at dtprel+32768
+
+ at tls = thread_local global i32 0, align 4
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.4 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !2, metadata !3, metadata !2, metadata !"tls.dwo"} ; [ DW_TAG_compile_unit ] [/tmp/tls.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"tls.cpp", metadata !"/tmp"}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786484, i32 0, null, metadata !"tls", metadata !"tls", metadata !"", metadata !5, i32 1, metadata !6, i32 0, i32 1, i32* @tls, null} ; [ DW_TAG_variable ] [tls] [line 1] [def]
+!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/tmp/tls.cpp]
+!6 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!7 = metadata !{i32 2, metadata !"Dwarf Version", i32 3}

Modified: llvm/trunk/test/DebugInfo/PowerPC/tls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/PowerPC/tls.ll?rev=185461&r1=185460&r2=185461&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/PowerPC/tls.ll (original)
+++ llvm/trunk/test/DebugInfo/PowerPC/tls.ll Tue Jul  2 13:47:35 2013
@@ -1,10 +1,16 @@
-; RUN: llc -mtriple=powerpc-unknown-unknown -O0 -filetype=asm < %s | FileCheck %s
+; RUN: llc -mtriple=powerpc64-unknown-linux-gnu -O0 -filetype=asm < %s | FileCheck %s
 
 ; FIXME: add relocation and DWARF expression support to llvm-dwarfdump & use
 ; that here instead of raw assembly printing
 
-; CHECK: debug_info
-; CHECK-NOT: tls at DTPOFF
+; 10 bytes of data in this DW_FORM_block1 representation of the location of 'tls'
+; CHECK: .byte  10{{ *}}# DW_AT_location
+; DW_OP_const8u
+; CHECK: .byte  14
+; The debug relocation of the address of the tls variable
+; CHECK: .quad  tls at dtprel+32768
+; DW_OP_GNU_push_tls_address
+; CHECK: .byte  224
 
 @tls = thread_local global i32 7, align 4