[opaque pointer type] encode the pointee type of global variables
authorDavid Blaikie <dblaikie@gmail.com>
Mon, 27 Apr 2015 19:58:56 +0000 (19:58 +0000)
committerDavid Blaikie <dblaikie@gmail.com>
Mon, 27 Apr 2015 19:58:56 +0000 (19:58 +0000)
Use a few extra bits in the const field (after widening it from a fixed
single bit) to stash the address space which is no longer provided by
the type (and an extra bit in there to specify that we're using that new
encoding).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235911 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/Reader/BitcodeReader.cpp
lib/Bitcode/Writer/BitcodeWriter.cpp

index b6528cb..1e9a8eb 100644 (file)
@@ -2876,12 +2876,18 @@ std::error_code BitcodeReader::ParseModule(bool Resume,
       Type *Ty = getTypeByID(Record[0]);
       if (!Ty)
         return Error("Invalid record");
-      if (!Ty->isPointerTy())
-        return Error("Invalid type for value");
-      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
-      Ty = cast<PointerType>(Ty)->getElementType();
+      bool isConstant = Record[1] & 1;
+      bool explicitType = Record[1] & 2;
+      unsigned AddressSpace;
+      if (explicitType) {
+        AddressSpace = Record[1] >> 2;
+      } else {
+        if (!Ty->isPointerTy())
+          return Error("Invalid type for value");
+        AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
+        Ty = cast<PointerType>(Ty)->getElementType();
+      }
 
-      bool isConstant = Record[1];
       uint64_t RawLinkage = Record[3];
       GlobalValue::LinkageTypes Linkage = getDecodedLinkage(RawLinkage);
       unsigned Alignment;
index b8baabd..840b75e 100644 (file)
@@ -590,7 +590,7 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   unsigned MaxGlobalType = 0;
   for (const GlobalValue &GV : M->globals()) {
     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
-    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getType()));
+    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
     if (GV.hasSection()) {
       // Give section names unique ID's.
       unsigned &Entry = SectionMap[GV.getSection()];
@@ -631,10 +631,12 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
                               Log2_32_Ceil(MaxGlobalType+1)));
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5));      // Linkage.
-    if (MaxAlignment == 0)                                      // Alignment.
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
+                                                           //| explicitType << 1
+                                                           //| constant
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
+    if (MaxAlignment == 0)                                 // Alignment.
       Abbv->Add(BitCodeAbbrevOp(0));
     else {
       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
@@ -659,8 +661,8 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
     //             linkage, alignment, section, visibility, threadlocal,
     //             unnamed_addr, externally_initialized, dllstorageclass,
     //             comdat]
-    Vals.push_back(VE.getTypeID(GV.getType()));
-    Vals.push_back(GV.isConstant());
+    Vals.push_back(VE.getTypeID(GV.getValueType()));
+    Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
     Vals.push_back(GV.isDeclaration() ? 0 :
                    (VE.getValueID(GV.getInitializer()) + 1));
     Vals.push_back(getEncodedLinkage(GV));