Initial cleanups of the param-attribute code in the bitcode reader/writer.

Rename the PARAMATTR_CODE_ENTRY to PARAMATTR_CODE_ENTRY_OLD. It will be replaced
by another encoding. Keep around the current LLVM attribute encoder/decoder
code, but move it to the bitcode directories so that no one's tempted to use
them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174335 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2013-02-04 23:32:23 +00:00
parent 638c63ccf7
commit f9271ea159
5 changed files with 59 additions and 66 deletions

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@ -77,7 +77,11 @@ namespace bitc {
/// PARAMATTR blocks have code for defining a parameter attribute set.
enum AttributeCodes {
PARAMATTR_CODE_ENTRY = 1 // ENTRY: [paramidx0, attr0, paramidx1, attr1...]
// FIXME: Remove `PARAMATTR_CODE_ENTRY_OLD' in 4.0
PARAMATTR_CODE_ENTRY_OLD = 1, // ENTRY: [paramidx0, attr0,
// paramidx1, attr1...]
PARAMATTR_CODE_ENTRY = 2 // ENTRY: [paramidx0, attrgrp0,
// paramidx1, attrgrp1...]
};
/// TYPE blocks have codes for each type primitive they use.
@ -143,6 +147,7 @@ namespace bitc {
METADATA_NAMED_NODE = 10, // NAMED_NODE: [n x mdnodes]
METADATA_ATTACHMENT = 11 // [m x [value, [n x [id, mdnode]]]
};
// The constants block (CONSTANTS_BLOCK_ID) describes emission for each
// constant and maintains an implicit current type value.
enum ConstantsCodes {

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@ -345,8 +345,8 @@ class AttrBuilder {
uint64_t StackAlignment;
public:
AttrBuilder() : Alignment(0), StackAlignment(0) {}
explicit AttrBuilder(uint64_t B) : Alignment(0), StackAlignment(0) {
addRawValue(B);
explicit AttrBuilder(uint64_t Val) : Alignment(0), StackAlignment(0) {
addRawValue(Val);
}
AttrBuilder(const Attribute &A) : Alignment(0), StackAlignment(0) {
addAttribute(A);
@ -433,11 +433,9 @@ public:
return !(*this == B);
}
// FIXME: Remove these.
// FIXME: Remove this in 4.0.
/// \brief Add the raw value to the internal representation.
///
/// N.B. This should be used ONLY for decoding LLVM bitcode!
AttrBuilder &addRawValue(uint64_t Val);
};
@ -446,18 +444,6 @@ namespace AttributeFuncs {
/// \brief Which attributes cannot be applied to a type.
AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
/// \brief This returns an integer containing an encoding of all the LLVM
/// attributes found in the given attribute bitset. Any change to this encoding
/// is a breaking change to bitcode compatibility.
uint64_t encodeLLVMAttributesForBitcode(AttributeSet Attrs, unsigned Index);
/// \brief This fills an AttrBuilder object with the LLVM attributes that have
/// been decoded from the given integer. This function must stay in sync with
/// 'encodeLLVMAttributesForBitcode'.
/// N.B. This should be used only by the bitcode reader!
void decodeLLVMAttributesForBitcode(LLVMContext &C, AttrBuilder &B,
uint64_t EncodedAttrs);
} // end AttributeFuncs namespace
} // end llvm namespace

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@ -428,6 +428,26 @@ Type *BitcodeReader::getTypeByID(unsigned ID) {
// Functions for parsing blocks from the bitcode file
//===----------------------------------------------------------------------===//
/// \brief This fills an AttrBuilder object with the LLVM attributes that have
/// been decoded from the given integer. This function must stay in sync with
/// 'encodeLLVMAttributesForBitcode'.
static void decodeLLVMAttributesForBitcode(AttrBuilder &B,
uint64_t EncodedAttrs) {
// FIXME: Remove in 4.0.
// The alignment is stored as a 16-bit raw value from bits 31--16. We shift
// the bits above 31 down by 11 bits.
unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
assert((!Alignment || isPowerOf2_32(Alignment)) &&
"Alignment must be a power of two.");
if (Alignment)
B.addAlignmentAttr(Alignment);
B.addRawValue(((EncodedAttrs & (0xffffULL << 32)) >> 11) |
(EncodedAttrs & 0xffff));
}
bool BitcodeReader::ParseAttributeBlock() {
if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
return Error("Malformed block record");
@ -459,14 +479,14 @@ bool BitcodeReader::ParseAttributeBlock() {
switch (Stream.readRecord(Entry.ID, Record)) {
default: // Default behavior: ignore.
break;
case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
case bitc::PARAMATTR_CODE_ENTRY_OLD: { // ENTRY: [paramidx0, attr0, ...]
// FIXME: Remove in 4.0.
if (Record.size() & 1)
return Error("Invalid ENTRY record");
for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
AttrBuilder B;
AttributeFuncs::decodeLLVMAttributesForBitcode(Context, B,
Record[i+1]);
decodeLLVMAttributesForBitcode(B, Record[i+1]);
Attrs.push_back(AttributeSet::get(Context, Record[i], B));
}

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@ -161,7 +161,30 @@ static void WriteStringRecord(unsigned Code, StringRef Str,
Stream.EmitRecord(Code, Vals, AbbrevToUse);
}
// Emit information about parameter attributes.
/// \brief This returns an integer containing an encoding of all the LLVM
/// attributes found in the given attribute bitset. Any change to this encoding
/// is a breaking change to bitcode compatibility.
/// N.B. This should be used only by the bitcode writer!
static uint64_t encodeLLVMAttributesForBitcode(AttributeSet Attrs,
unsigned Index) {
// FIXME: Remove in 4.0!
// FIXME: It doesn't make sense to store the alignment information as an
// expanded out value, we should store it as a log2 value. However, we can't
// just change that here without breaking bitcode compatibility. If this ever
// becomes a problem in practice, we should introduce new tag numbers in the
// bitcode file and have those tags use a more efficiently encoded alignment
// field.
// Store the alignment in the bitcode as a 16-bit raw value instead of a 5-bit
// log2 encoded value. Shift the bits above the alignment up by 11 bits.
uint64_t EncodedAttrs = Attrs.Raw(Index) & 0xffff;
if (Attrs.hasAttribute(Index, Attribute::Alignment))
EncodedAttrs |= Attrs.getParamAlignment(Index) << 16;
EncodedAttrs |= (Attrs.Raw(Index) & (0xffffULL << 21)) << 11;
return EncodedAttrs;
}
static void WriteAttributeTable(const ValueEnumerator &VE,
BitstreamWriter &Stream) {
const std::vector<AttributeSet> &Attrs = VE.getAttributes();
@ -175,12 +198,11 @@ static void WriteAttributeTable(const ValueEnumerator &VE,
for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
unsigned Index = A.getSlotIndex(i);
Record.push_back(Index);
Record.push_back(AttributeFuncs::
encodeLLVMAttributesForBitcode(A.getSlotAttributes(i),
Record.push_back(encodeLLVMAttributesForBitcode(A.getSlotAttributes(i),
Index));
}
Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY_OLD, Record);
Record.clear();
}

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@ -927,6 +927,7 @@ bool AttrBuilder::operator==(const AttrBuilder &B) {
}
AttrBuilder &AttrBuilder::addRawValue(uint64_t Val) {
// FIXME: Remove this in 4.0.
if (!Val) return *this;
for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
@ -967,44 +968,3 @@ AttributeSet AttributeFuncs::typeIncompatible(Type *Ty, uint64_t Index) {
return AttributeSet::get(Ty->getContext(), Index, Incompatible);
}
/// \brief This returns an integer containing an encoding of all the LLVM
/// attributes found in the given attribute bitset. Any change to this encoding
/// is a breaking change to bitcode compatibility.
/// N.B. This should be used only by the bitcode reader!
uint64_t AttributeFuncs::encodeLLVMAttributesForBitcode(AttributeSet Attrs,
unsigned Index) {
// FIXME: It doesn't make sense to store the alignment information as an
// expanded out value, we should store it as a log2 value. However, we can't
// just change that here without breaking bitcode compatibility. If this ever
// becomes a problem in practice, we should introduce new tag numbers in the
// bitcode file and have those tags use a more efficiently encoded alignment
// field.
// Store the alignment in the bitcode as a 16-bit raw value instead of a 5-bit
// log2 encoded value. Shift the bits above the alignment up by 11 bits.
uint64_t EncodedAttrs = Attrs.Raw(Index) & 0xffff;
if (Attrs.hasAttribute(Index, Attribute::Alignment))
EncodedAttrs |= Attrs.getParamAlignment(Index) << 16;
EncodedAttrs |= (Attrs.Raw(Index) & (0xffffULL << 21)) << 11;
return EncodedAttrs;
}
/// \brief This fills an AttrBuilder object with the LLVM attributes that have
/// been decoded from the given integer. This function must stay in sync with
/// 'encodeLLVMAttributesForBitcode'.
/// N.B. This should be used only by the bitcode reader!
void AttributeFuncs::decodeLLVMAttributesForBitcode(LLVMContext &C,
AttrBuilder &B,
uint64_t EncodedAttrs) {
// The alignment is stored as a 16-bit raw value from bits 31--16. We shift
// the bits above 31 down by 11 bits.
unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
assert((!Alignment || isPowerOf2_32(Alignment)) &&
"Alignment must be a power of two.");
if (Alignment)
B.addAlignmentAttr(Alignment);
B.addRawValue(((EncodedAttrs & (0xffffULL << 32)) >> 11) |
(EncodedAttrs & 0xffff));
}