From: David Blaikie <dblaikie@gmail.com>
Date: Sat, 15 Feb 2014 19:34:03 +0000 (+0000)
Subject: DebugInfo: Deduplicate entries in the fission address table
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=132a2879413c203a2f25ba90a1fa5d44ae1f7832;p=oota-llvm.git

DebugInfo: Deduplicate entries in the fission address table

This broke in r185459 while TLS support was being generalized to handle
non-symbol TLS representations.

I thought about/tried having an enum rather than a bool to track the
TLS-ness of the address table entry, but namespaces and naming seemed
more hassle than it was worth for only one caller that needed to specify
this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201469 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 4a7abe50e65..70db96e43a1 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -265,16 +265,12 @@ unsigned DwarfFile::getStringPoolIndex(StringRef Str) {
   return Entry.second;
 }
 
-unsigned DwarfFile::getAddrPoolIndex(const MCSymbol *Sym) {
-  return getAddrPoolIndex(MCSymbolRefExpr::Create(Sym, Asm->OutContext));
-}
-
-unsigned DwarfFile::getAddrPoolIndex(const MCExpr *Sym) {
-  std::pair<DenseMap<const MCExpr *, unsigned>::iterator, bool> P =
-      AddressPool.insert(std::make_pair(Sym, NextAddrPoolNumber));
+unsigned DwarfFile::getAddrPoolIndex(const MCSymbol *Sym, bool TLS) {
+  std::pair<AddrPool::iterator, bool> P = AddressPool.insert(
+      std::make_pair(Sym, AddressPoolEntry(NextAddrPoolNumber, TLS)));
   if (P.second)
     ++NextAddrPoolNumber;
-  return P.first->second;
+  return P.first->second.Number;
 }
 
 // Define a unique number for the abbreviation.
@@ -2548,10 +2544,12 @@ void DwarfFile::emitAddresses(const MCSection *AddrSection) {
   // Order the address pool entries by ID
   SmallVector<const MCExpr *, 64> Entries(AddressPool.size());
 
-  for (DenseMap<const MCExpr *, unsigned>::iterator I = AddressPool.begin(),
-                                                    E = AddressPool.end();
+  for (AddrPool::iterator I = AddressPool.begin(), E = AddressPool.end();
        I != E; ++I)
-    Entries[I->second] = I->first;
+    Entries[I->second.Number] =
+        I->second.TLS
+            ? Asm->getObjFileLowering().getDebugThreadLocalSymbol(I->first)
+            : MCSymbolRefExpr::Create(I->first, Asm->OutContext);
 
   for (unsigned i = 0, e = Entries.size(); i != e; ++i)
     Asm->OutStreamer.EmitValue(Entries[i],
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 9cc12108e8f..c1d78587121 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -244,10 +244,15 @@ class DwarfFile {
   unsigned NextStringPoolNumber;
   std::string StringPref;
 
+  struct AddressPoolEntry {
+    unsigned Number;
+    bool TLS;
+    AddressPoolEntry(unsigned Number, bool TLS) : Number(Number), TLS(TLS) {}
+  };
   // Collection of addresses for this unit and assorted labels.
   // A Symbol->unsigned mapping of addresses used by indirect
   // references.
-  typedef DenseMap<const MCExpr *, unsigned> AddrPool;
+  typedef DenseMap<const MCSymbol *, AddressPoolEntry> AddrPool;
   AddrPool AddressPool;
   unsigned NextAddrPoolNumber;
 
@@ -303,8 +308,7 @@ public:
 
   /// \brief Returns the index into the address pool with the given
   /// label/symbol.
-  unsigned getAddrPoolIndex(const MCExpr *Sym);
-  unsigned getAddrPoolIndex(const MCSymbol *Sym);
+  unsigned getAddrPoolIndex(const MCSymbol *Sym, bool TLS = false);
 
   /// \brief Returns the address pool.
   AddrPool *getAddrPool() { return &AddressPool; }
diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index ae92b6aa6d2..18070462b4a 100644
--- a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1580,8 +1580,6 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
       unsigned PointerSize = Asm->getDataLayout().getPointerSize();
       assert((PointerSize == 4 || PointerSize == 8) &&
              "Add support for other sizes if necessary");
-      const MCExpr *Expr =
-          Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym);
       // Based on GCC's support for TLS:
       if (!DD->useSplitDwarf()) {
         // 1) Start with a constNu of the appropriate pointer size
@@ -1589,10 +1587,12 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
                 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
         // 2) containing the (relocated) offset of the TLS variable
         //    within the module's TLS block.
-        addExpr(Block, dwarf::DW_FORM_udata, Expr);
+        addExpr(Block, dwarf::DW_FORM_udata,
+                Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
       } else {
         addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
-        addUInt(Block, dwarf::DW_FORM_udata, DU->getAddrPoolIndex(Expr));
+        addUInt(Block, dwarf::DW_FORM_udata,
+                DU->getAddrPoolIndex(Sym, /* TLS */ true));
       }
       // 3) followed by a custom OP to make the debugger do a TLS lookup.
       addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
diff --git a/test/DebugInfo/X86/tls.ll b/test/DebugInfo/X86/tls.ll
index 30307daf582..e49b12fbf54 100644
--- a/test/DebugInfo/X86/tls.ll
+++ b/test/DebugInfo/X86/tls.ll
@@ -43,8 +43,7 @@
 ; FISSION: .byte 3 # DW_AT_location
 ; DW_OP_GNU_addr_index
 ; FISSION-NEXT: .byte 251
-; FIXME: This should be '1' to share the address table entry with the variable location above
-; FISSION-NEXT: .byte 2
+; FISSION-NEXT: .byte 1
 ; DW_OP_stack_value
 ; FISSION-NEXT: .byte 159
 
@@ -52,8 +51,7 @@
 ; FISSION: .section    .debug_addr
 ; FISSION-NEXT: .quad  tls@DTPOFF
 ; FISSION-NEXT: .quad  glbl
-; FIXME: Deduplicate the debug_addr list
-; FISSION-NEXT: .quad  glbl
+; FISSION-NOT: .quad  glbl
 
 ; Generated from: