[llvm-commits] CVS: llvm/lib/Bytecode/Reader/Reader.cpp Reader.h

Chris Lattner lattner at cs.uiuc.edu
Tue Aug 3 16:41:41 PDT 2004



Changes in directory llvm/lib/Bytecode/Reader:

Reader.cpp updated: 1.120 -> 1.121
Reader.h updated: 1.9 -> 1.10
---
Log message:

Do not do a linear std::find to reconstruct information we had, but later threw
away.  This speeds up by .bc reader by 30% in a profile build on 252.eon.


---
Diffs of the changes:  (+24 -29)

Index: llvm/lib/Bytecode/Reader/Reader.cpp
diff -u llvm/lib/Bytecode/Reader/Reader.cpp:1.120 llvm/lib/Bytecode/Reader/Reader.cpp:1.121
--- llvm/lib/Bytecode/Reader/Reader.cpp:1.120	Mon Jul 26 21:34:49 2004
+++ llvm/lib/Bytecode/Reader/Reader.cpp	Tue Aug  3 18:41:28 2004
@@ -26,7 +26,6 @@
 #include "llvm/Support/GetElementPtrTypeIterator.h"
 #include "Support/StringExtras.h"
 #include <sstream>
-
 using namespace llvm;
 
 namespace {
@@ -294,7 +293,7 @@
   if (!CompactionTypes.empty()) {
     if (ID >= CompactionTypes.size())
       error("Type ID out of range for compaction table!");
-    return CompactionTypes[ID];
+    return CompactionTypes[ID].first;
   }
 
   // Is it a module-level type?
@@ -337,12 +336,11 @@
 
   // Scan the compaction table for the type if needed.
   if (!CompactionTypes.empty()) {
-    std::vector<const Type*>::const_iterator I = 
-      find(CompactionTypes.begin(), CompactionTypes.end(), Ty);
+    for (unsigned i = 0, e = CompactionTypes.size(); i != e; ++i)
+      if (CompactionTypes[i].first == Ty)
+        return Type::FirstDerivedTyID + i; 
 
-    if (I == CompactionTypes.end())
-      error("Couldn't find type specified in compaction table!");
-    return Type::FirstDerivedTyID + (&*I - &CompactionTypes[0]);
+    error("Couldn't find type specified in compaction table!");
   }
 
   // Check the function level types first...
@@ -403,15 +401,10 @@
     // By default, the global type id is the type id passed in
     unsigned GlobalTyID = type;
 
-    // If the type plane was compactified, figure out the global type ID
-    // by adding the derived type ids and the distance.
-    if (!CompactionTypes.empty() && type >= Type::FirstDerivedTyID) {
-      const Type *Ty = CompactionTypes[type-Type::FirstDerivedTyID];
-      TypeListTy::iterator I = 
-        find(ModuleTypes.begin(), ModuleTypes.end(), Ty);
-      assert(I != ModuleTypes.end());
-      GlobalTyID = Type::FirstDerivedTyID + (&*I - &ModuleTypes[0]);
-    }
+    // If the type plane was compactified, figure out the global type ID by
+    // adding the derived type ids and the distance.
+    if (!CompactionTypes.empty() && type >= Type::FirstDerivedTyID)
+      GlobalTyID = CompactionTypes[type-Type::FirstDerivedTyID].second;
 
     if (hasImplicitNull(GlobalTyID)) {
       if (Num == 0)
@@ -1053,7 +1046,7 @@
     if (read_typeid(TypeSlot))
       error("Invalid type in compaction table: type type");
     const Type *Typ = getGlobalTableType(TypeSlot);
-    CompactionTypes.push_back(Typ);
+    CompactionTypes.push_back(std::make_pair(Typ, TypeSlot));
     if (Handler) Handler->handleCompactionTableType(i, TypeSlot, Typ);
   }
 }


Index: llvm/lib/Bytecode/Reader/Reader.h
diff -u llvm/lib/Bytecode/Reader/Reader.h:1.9 llvm/lib/Bytecode/Reader/Reader.h:1.10
--- llvm/lib/Bytecode/Reader/Reader.h:1.9	Sun Jul 25 16:32:51 2004
+++ llvm/lib/Bytecode/Reader/Reader.h	Tue Aug  3 18:41:28 2004
@@ -193,7 +193,7 @@
   void ParseFunctionBody(Function* Func);
 
   /// @brief Parse the type list portion of a compaction table
-  void BytecodeReader::ParseCompactionTypes( unsigned NumEntries );
+  void ParseCompactionTypes(unsigned NumEntries);
 
   /// @brief Parse a compaction table
   void ParseCompactionTable();
@@ -243,12 +243,13 @@
   BufPtr At;           ///< Where we're currently parsing at
 
   /// Information about the module, extracted from the bytecode revision number.
+  ///
   unsigned char RevisionNum;        // The rev # itself
 
   /// Flags to distinguish LLVM 1.0 & 1.1 bytecode formats (revision #0)
 
-  /// Revision #0 had an explicit alignment of data only for the ModuleGlobalInfo
-  /// block.  This was fixed to be like all other blocks in 1.2
+  /// Revision #0 had an explicit alignment of data only for the
+  /// ModuleGlobalInfo block.  This was fixed to be like all other blocks in 1.2
   bool hasInconsistentModuleGlobalInfo;
 
   /// Revision #0 also explicitly encoded zero values for primitive types like
@@ -270,12 +271,12 @@
   bool hasTypeDerivedFromValue;
 
   /// LLVM 1.2 and earlier encoded block headers as two uint (8 bytes), one for
-  /// the size and one for the type. This is a bit wasteful, especially for small 
-  /// files where the 8 bytes per block is a large fraction of the total block 
-  /// size. In LLVM 1.3, the block type and length are encoded into a single 
-  /// uint32 by restricting the number of block types (limit 31) and the maximum
-  /// size of a block (limit 2^27-1=134,217,727). Note that the module block
-  /// still uses the 8-byte format so the maximum size of a file can be
+  /// the size and one for the type. This is a bit wasteful, especially for
+  /// small files where the 8 bytes per block is a large fraction of the total
+  /// block size. In LLVM 1.3, the block type and length are encoded into a
+  /// single uint32 by restricting the number of block types (limit 31) and the
+  /// maximum size of a block (limit 2^27-1=134,217,727). Note that the module
+  /// block still uses the 8-byte format so the maximum size of a file can be
   /// 2^32-1 bytes long.
   bool hasLongBlockHeaders;
 
@@ -295,9 +296,10 @@
   /// LLVM 1.2 and earlier encoded the file version as part of the module block
   /// but this information may be needed to
 
-  /// CompactionTable - If a compaction table is active in the current function,
-  /// this is the mapping that it contains.
-  std::vector<const Type*> CompactionTypes;
+  /// CompactionTypes - If a compaction table is active in the current function,
+  /// this is the mapping that it contains.  We keep track of what resolved type
+  /// it is as well as what global type entry it is.
+  std::vector<std::pair<const Type*, unsigned> > CompactionTypes;
 
   /// @brief If a compaction table is active in the current function,
   /// this is the mapping that it contains.






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