[opaque pointer type] encode the pointee type of global variables

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

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index b6528cbbeccb2ba7df4f44b86d8864d772c6e22d..1e9a8eb7fd1fd4499d303d24616bfc1e325050d3 100644 (file)
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -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;

diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index b8baabd22d8ad23f8cd35eb46fb278ba5aa0d627..840b75e496f2dd9e0820e37bc166d077629bd2c0 100644 (file)
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -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));