From b5491378b16c8f0fc9fa001dffc249acec9037fc Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 23 Apr 2007 18:58:34 +0000
Subject: [PATCH] implement reading of abbrevs, and writing of abbreviated
 global varrs.

llvm-svn: 36367
---
 llvm/lib/Bitcode/Reader/BitcodeReader.cpp |  9 ++++++---
 llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 10 +++++++---
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index f464e33f6a03..ba4ba8db80ee 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -94,7 +94,8 @@ bool BitcodeReader::ParseTypeTable(BitstreamReader &Stream) {
     }
     
     if (Code == bitc::DEFINE_ABBREV) {
-      assert(0 && "Abbrevs not implemented yet!");
+      Stream.ReadAbbrevRecord();
+      continue;
     }
     
     // Read a record.
@@ -231,7 +232,8 @@ bool BitcodeReader::ParseTypeSymbolTable(BitstreamReader &Stream) {
     }
     
     if (Code == bitc::DEFINE_ABBREV) {
-      assert(0 && "Abbrevs not implemented yet!");
+      Stream.ReadAbbrevRecord();
+      continue;
     }
     
     // Read a record.
@@ -294,7 +296,8 @@ bool BitcodeReader::ParseModule(BitstreamReader &Stream,
     }
     
     if (Code == bitc::DEFINE_ABBREV) {
-      assert(0 && "Abbrevs not implemented yet!");
+      Stream.ReadAbbrevRecord();
+      continue;
     }
     
     // Read a record.
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index d78ea29b5646..633036e5a923 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -204,9 +204,11 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   // compute the maximum alignment value.
   std::map<std::string, unsigned> SectionMap;
   unsigned MaxAlignment = 0;
+  unsigned MaxGlobalType = 0;
   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
        GV != E; ++GV) {
     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
+    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
     
     if (!GV->hasSection()) continue;
     // Give section names unique ID's.
@@ -229,10 +231,12 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   
   // Emit abbrev for globals, now that we know # sections and max alignment.
   unsigned SimpleGVarAbbrev = 0;
-  if (!M->global_empty() && 0) { 
+  if (!M->global_empty()) { 
     // Add an abbrev for common globals with no visibility or thread localness.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
+                              Log2_32_Ceil(MaxGlobalType+1)));
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 1)); // Constant.
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 3)); // Linkage.
@@ -241,7 +245,7 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
     else {
       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
-                               Log2_32_Ceil(MaxEncAlignment)));
+                               Log2_32_Ceil(MaxEncAlignment+1)));
     }
     if (SectionMap.empty())                                    // Section.
       Abbv->Add(BitCodeAbbrevOp(0));
@@ -300,7 +304,7 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 
 /// WriteModule - Emit the specified module to the bitstream.
 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
-  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 2);
+  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
   
   // Emit the version number if it is non-zero.
   if (CurVersion) {