[MS][ARM64] Hoist __ImageBase handling into TargetLoweringObjectFileCOFF

All COFF targets should use @IMGREL32 relocations for symbol differences
against __ImageBase. Do the same for getSectionForConstant, so that
immediates lowered to globals get merged across TUs.

Patch by Chris January

Differential Revision: https://reviews.llvm.org/D47783

llvm-svn: 334523

1 files changed, 0 insertions, 97 deletions

diff --git a/llvm/lib/Target/X86/X86TargetObjectFile.cpp b/llvm/lib/Target/X86/X86TargetObjectFile.cpp
index fb35a6b2ec1..505c4fa07b7 100644
--- a/llvm/lib/Target/X86/X86TargetObjectFile.cpp
+++ b/llvm/lib/Target/X86/X86TargetObjectFile.cpp
@@ -91,100 +91,3 @@ void X86SolarisTargetObjectFile::Initialize(MCContext &Ctx,
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
   InitializeELF(TM.Options.UseInitArray);
 }
-
-const MCExpr *X86WindowsTargetObjectFile::lowerRelativeReference(
-    const GlobalValue *LHS, const GlobalValue *RHS,
-    const TargetMachine &TM) const {
-  // Our symbols should exist in address space zero, cowardly no-op if
-  // otherwise.
-  if (LHS->getType()->getPointerAddressSpace() != 0 ||
-      RHS->getType()->getPointerAddressSpace() != 0)
-    return nullptr;
-
-  // Both ptrtoint instructions must wrap global objects:
-  // - Only global variables are eligible for image relative relocations.
-  // - The subtrahend refers to the special symbol __ImageBase, a GlobalVariable.
-  // We expect __ImageBase to be a global variable without a section, externally
-  // defined.
-  //
-  // It should look something like this: @__ImageBase = external constant i8
-  if (!isa<GlobalObject>(LHS) || !isa<GlobalVariable>(RHS) ||
-      LHS->isThreadLocal() || RHS->isThreadLocal() ||
-      RHS->getName() != "__ImageBase" || !RHS->hasExternalLinkage() ||
-      cast<GlobalVariable>(RHS)->hasInitializer() || RHS->hasSection())
-    return nullptr;
-
-  return MCSymbolRefExpr::create(TM.getSymbol(LHS),
-                                 MCSymbolRefExpr::VK_COFF_IMGREL32,
-                                 getContext());
-}
-
-static std::string APIntToHexString(const APInt &AI) {
-  unsigned Width = (AI.getBitWidth() / 8) * 2;
-  std::string HexString = utohexstr(AI.getLimitedValue(), /*LowerCase=*/true);
-  unsigned Size = HexString.size();
-  assert(Width >= Size && "hex string is too large!");
-  HexString.insert(HexString.begin(), Width - Size, '0');
-
-  return HexString;
-}
-
-static std::string scalarConstantToHexString(const Constant *C) {
-  Type *Ty = C->getType();
-  if (isa<UndefValue>(C)) {
-    return APIntToHexString(APInt::getNullValue(Ty->getPrimitiveSizeInBits()));
-  } else if (const auto *CFP = dyn_cast<ConstantFP>(C)) {
-    return APIntToHexString(CFP->getValueAPF().bitcastToAPInt());
-  } else if (const auto *CI = dyn_cast<ConstantInt>(C)) {
-    return APIntToHexString(CI->getValue());
-  } else {
-    unsigned NumElements;
-    if (isa<VectorType>(Ty))
-      NumElements = Ty->getVectorNumElements();
-    else
-      NumElements = Ty->getArrayNumElements();
-    std::string HexString;
-    for (int I = NumElements - 1, E = -1; I != E; --I)
-      HexString += scalarConstantToHexString(C->getAggregateElement(I));
-    return HexString;
-  }
-}
-
-MCSection *X86WindowsTargetObjectFile::getSectionForConstant(
-    const DataLayout &DL, SectionKind Kind, const Constant *C,
-    unsigned &Align) const {
-  if (Kind.isMergeableConst() && C) {
-    const unsigned Characteristics = COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
-                                     COFF::IMAGE_SCN_MEM_READ |
-                                     COFF::IMAGE_SCN_LNK_COMDAT;
-    std::string COMDATSymName;
-    if (Kind.isMergeableConst4()) {
-      if (Align <= 4) {
-        COMDATSymName = "__real@" + scalarConstantToHexString(C);
-        Align = 4;
-      }
-    } else if (Kind.isMergeableConst8()) {
-      if (Align <= 8) {
-        COMDATSymName = "__real@" + scalarConstantToHexString(C);
-        Align = 8;
-      }
-    } else if (Kind.isMergeableConst16()) {
-      if (Align <= 16) {
-        COMDATSymName = "__xmm@" + scalarConstantToHexString(C);
-        Align = 16;
-      }
-    } else if (Kind.isMergeableConst32()) {
-      if (Align <= 32) {
-        COMDATSymName = "__ymm@" + scalarConstantToHexString(C);
-        Align = 32;
-      }
-    }
-
-    if (!COMDATSymName.empty())
-      return getContext().getCOFFSection(".rdata", Characteristics, Kind,
-                                         COMDATSymName,
-                                         COFF::IMAGE_COMDAT_SELECT_ANY);
-  }
-
-  return TargetLoweringObjectFile::getSectionForConstant(DL, Kind, C, Align);
-}