Revert code changes made under r235976.

This issue was fixed elsewhere in r235396 in a more general way, hence these
changes no longer do anything. Keep the testcase however, to ensure that we
don't regress this for ARM.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236104 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/TargetInfo.h

@@ -204,11 +204,6 @@ protected:
   /// not for language specific address spaces
   bool UseAddrSpaceMapMangling;
 
-  /// \brief Specify if globals of a struct type containing bitfields should
-  /// have their alignment explicitly specified so as to ensure that LLVM uses
-  /// the correct alignment
-  bool EnforceBitfieldContainerAlignment;
-
 public:
   IntType getSizeType() const { return SizeType; }
   IntType getIntMaxType() const { return IntMaxType; }
@@ -459,11 +454,6 @@ public:
     return HasAlignMac68kSupport;
   }
 
-  /// \brief Check whether the alignment of bitfield struct should be enforced
-  bool enforceBitfieldContainerAlignment() const {
-    return EnforceBitfieldContainerAlignment;
-  }
-
   /// \brief Return the user string for the specified integer type enum.
   ///
   /// For example, SignedShort -> "short".

lib/Basic/TargetInfo.cpp

@@ -75,7 +75,6 @@ TargetInfo::TargetInfo(const llvm::Triple &T) : TargetOpts(), Triple(T) {
   RegParmMax = 0;
   SSERegParmMax = 0;
   HasAlignMac68kSupport = false;
-  EnforceBitfieldContainerAlignment = false;
 
   // Default to no types using fpret.
   RealTypeUsesObjCFPRet = 0;

lib/Basic/Targets.cpp

@@ -3983,9 +3983,6 @@ class ARMTargetInfo : public TargetInfo {
 
     ZeroLengthBitfieldBoundary = 0;
 
-    // Enforce the alignment of bitfield structs
-    EnforceBitfieldContainerAlignment = true;
-
     // Thumb1 add sp, #imm requires the immediate value be multiple of 4,
     // so set preferred for small types to 32.
     if (T.isOSBinFormatMachO()) {
@@ -4828,9 +4825,6 @@ public:
     UseBitFieldTypeAlignment = true;
     UseZeroLengthBitfieldAlignment = true;
 
-    // Enforce the alignment of bitfield structs
-    EnforceBitfieldContainerAlignment = true;
-
     // AArch64 targets default to using the ARM C++ ABI.
     TheCXXABI.set(TargetCXXABI::GenericAArch64);
   }

lib/CodeGen/CodeGenModule.cpp

@@ -1799,23 +1799,6 @@ CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
         D->getType().isConstant(Context) &&
         isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
       GV->setSection(".cp.rodata");
-
-    // The ARM/AArch64 ABI expects structs with bitfields to respect the proper
-    // container alignment, hence we have to enfore this in the IR so as to
-    // work around clang combining bitfields into one large type.
-    if (getContext().getTargetInfo().enforceBitfieldContainerAlignment()) {
-      if (const auto *RT = D->getType()->getAs<RecordType>()) {
-        const RecordDecl *RD = RT->getDecl();
-
-        for (auto I = RD->field_begin(), End = RD->field_end(); I != End; ++I) {
-          if ((*I)->isBitField()) {
-            const ASTRecordLayout &Info = getContext().getASTRecordLayout(RD);
-            GV->setAlignment(Info.getAlignment().getQuantity());
-            break;
-          }
-        }
-      }
-    }
   }
 
   if (AddrSpace != Ty->getAddressSpace())