Move bit field endianness to backend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26639 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/DwarfWriter.cpp b/lib/CodeGen/DwarfWriter.cpp
index ce82d9748862945d437f8a76594301295209c8ea..68aeb101d69bef4153acf8c87dac52b04f67e1d1 100644 (file)
--- a/lib/CodeGen/DwarfWriter.cpp
+++ b/lib/CodeGen/DwarfWriter.cpp
@@ -1323,6 +1323,7 @@ DIE *DwarfWriter::NewType(DIE *Context, TypeDesc *TyDesc) {
         unsigned Line = MemberDesc->getLine();
         TypeDesc *MemTy = MemberDesc->getFromType();
         uint64_t Size = MemberDesc->getSize();
+        uint64_t Align = MemberDesc->getAlign();
         uint64_t Offset = MemberDesc->getOffset();
    
         // Construct member die.
@@ -1338,27 +1339,42 @@ DIE *DwarfWriter::NewType(DIE *Context, TypeDesc *TyDesc) {
           Member->AddUInt(DW_AT_decl_line, 0, Line);
         }
         
-        // FIXME - Bitfields not quite right but getting there.
-        uint64_t ByteSize = Size;
-        uint64_t ByteOffset = Offset;
+        // Most of the time the field info is the same as the members.
+        uint64_t FieldSize = Size;
+        uint64_t FieldAlign = Align;
+        uint64_t FieldOffset = Offset;
         
         if (TypeDesc *FromTy = MemberDesc->getFromType()) {
            Member->AddDIEntry(DW_AT_type, DW_FORM_ref4,
                               NewType(Context, FromTy));
-           ByteSize = FromTy->getSize();
+           FieldSize = FromTy->getSize();
+           FieldAlign = FromTy->getSize();
         }
         
-        if (ByteSize != Size) {
-          ByteOffset -=  Offset % ByteSize;
-          Member->AddUInt(DW_AT_byte_size, 0, ByteSize >> 3);
-          Member->AddUInt(DW_AT_bit_size, 0, Size % ByteSize);
-          Member->AddUInt(DW_AT_bit_offset, 0, Offset - ByteOffset);
+        // Unless we have a bit field.
+        if (FieldSize != Size) {
+          // Construct the alignment mask.
+          uint64_t AlignMask = ~(FieldAlign - 1);
+          // Determine the high bit + 1 of the declared size.
+          uint64_t HiMark = (Offset + FieldSize) & AlignMask;
+          // Work backwards to determine the base offset of the field.
+          FieldOffset = HiMark - FieldSize;
+          // Now normalize offset to the field.
+          Offset -= FieldOffset;
+          
+          // Maybe we need to work from the other.
+          const TargetData &TD = Asm->TM.getTargetData();
+          if (TD.isLittleEndian()) Offset = FieldSize - (Offset + Size);
+          
+          Member->AddUInt(DW_AT_byte_size, 0, FieldSize >> 3);
+          Member->AddUInt(DW_AT_bit_size, 0, Size);
+          Member->AddUInt(DW_AT_bit_offset, 0, Offset);
         }
         
         // Add computation for offset.
         DIEBlock *Block = new DIEBlock();
         Block->AddUInt(DW_FORM_data1, DW_OP_plus_uconst);
-        Block->AddUInt(DW_FORM_udata, ByteOffset >> 3);
+        Block->AddUInt(DW_FORM_udata, FieldOffset >> 3);
         Block->ComputeSize(*this);
         Member->AddBlock(DW_AT_data_member_location, 0, Block);
         

diff --git a/lib/CodeGen/MachineDebugInfo.cpp b/lib/CodeGen/MachineDebugInfo.cpp
index e18a2430b63c7b2a93c44acd52bf97f6f528474f..fa755f1923e9f14eb62a81e8357d33bd6151fbdf 100644 (file)
--- a/lib/CodeGen/MachineDebugInfo.cpp
+++ b/lib/CodeGen/MachineDebugInfo.cpp
@@ -653,6 +653,7 @@ TypeDesc::TypeDesc(unsigned T)
 , Name("")
 , File(NULL)
 , Size(0)
+, Align(0)
 , Offset(0)
 {}
 
@@ -666,6 +667,7 @@ void TypeDesc::ApplyToFields(DIVisitor *Visitor) {
   Visitor->Apply((DebugInfoDesc *&)File);
   Visitor->Apply(Line);
   Visitor->Apply(Size);
+  Visitor->Apply(Align);
   Visitor->Apply(Offset);
 }
 
@@ -690,6 +692,7 @@ void TypeDesc::dump() {
             << "File(" << File << "), "
             << "Line(" << Line << "), "
             << "Size(" << Size << "), "
+            << "Align(" << Align << "), "
             << "Offset(" << Offset << ")\n";
 }
 #endif