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Fix AsmWriter to account for dynamic bit offsets #146704

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Merged
merged 1 commit into from
Jul 7, 2025
Merged

Fix AsmWriter to account for dynamic bit offsets #146704

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82 changes: 41 additions & 41 deletions llvm/lib/IR/AsmWriter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1914,6 +1914,8 @@ struct MDFieldPrinter {
bool ShouldSkipEmpty = true);
void printMetadata(StringRef Name, const Metadata *MD,
bool ShouldSkipNull = true);
void printMetadataOrInt(StringRef Name, const Metadata *MD, bool IsUnsigned,
bool ShouldSkipZero = true);
template <class IntTy>
void printInt(StringRef Name, IntTy Int, bool ShouldSkipZero = true);
void printAPInt(StringRef Name, const APInt &Int, bool IsUnsigned,
Expand Down Expand Up @@ -1986,6 +1988,21 @@ void MDFieldPrinter::printMetadata(StringRef Name, const Metadata *MD,
writeMetadataAsOperand(Out, MD, WriterCtx);
}

void MDFieldPrinter::printMetadataOrInt(StringRef Name, const Metadata *MD,
bool IsUnsigned, bool ShouldSkipZero) {
if (!MD)
return;

if (auto *CI = dyn_cast<ConstantAsMetadata>(MD)) {
auto *CV = cast<ConstantInt>(CI->getValue());
if (IsUnsigned)
printInt(Name, CV->getZExtValue(), ShouldSkipZero);
else
printInt(Name, CV->getSExtValue(), ShouldSkipZero);
} else
printMetadata(Name, MD);
}

template <class IntTy>
void MDFieldPrinter::printInt(StringRef Name, IntTy Int, bool ShouldSkipZero) {
if (ShouldSkipZero && !Int)
Expand Down Expand Up @@ -2129,38 +2146,21 @@ static void writeDISubrange(raw_ostream &Out, const DISubrange *N,
Out << "!DISubrange(";
MDFieldPrinter Printer(Out, WriterCtx);

auto *Count = N->getRawCountNode();
if (auto *CE = dyn_cast_or_null<ConstantAsMetadata>(Count)) {
auto *CV = cast<ConstantInt>(CE->getValue());
Printer.printInt("count", CV->getSExtValue(),
/* ShouldSkipZero */ false);
} else
Printer.printMetadata("count", Count, /*ShouldSkipNull */ true);
Printer.printMetadataOrInt("count", N->getRawCountNode(),
/* IsUnsigned */ false,
/* ShouldSkipZero */ false);

// A lowerBound of constant 0 should not be skipped, since it is different
// from an unspecified lower bound (= nullptr).
auto *LBound = N->getRawLowerBound();
if (auto *LE = dyn_cast_or_null<ConstantAsMetadata>(LBound)) {
auto *LV = cast<ConstantInt>(LE->getValue());
Printer.printInt("lowerBound", LV->getSExtValue(),
/* ShouldSkipZero */ false);
} else
Printer.printMetadata("lowerBound", LBound, /*ShouldSkipNull */ true);

auto *UBound = N->getRawUpperBound();
if (auto *UE = dyn_cast_or_null<ConstantAsMetadata>(UBound)) {
auto *UV = cast<ConstantInt>(UE->getValue());
Printer.printInt("upperBound", UV->getSExtValue(),
/* ShouldSkipZero */ false);
} else
Printer.printMetadata("upperBound", UBound, /*ShouldSkipNull */ true);

auto *Stride = N->getRawStride();
if (auto *SE = dyn_cast_or_null<ConstantAsMetadata>(Stride)) {
auto *SV = cast<ConstantInt>(SE->getValue());
Printer.printInt("stride", SV->getSExtValue(), /* ShouldSkipZero */ false);
} else
Printer.printMetadata("stride", Stride, /*ShouldSkipNull */ true);
Printer.printMetadataOrInt("lowerBound", N->getRawLowerBound(),
/* IsUnsigned */ false,
/* ShouldSkipZero */ false);
Printer.printMetadataOrInt("upperBound", N->getRawUpperBound(),
/* IsUnsigned */ false,
/* ShouldSkipZero */ false);
Printer.printMetadataOrInt("stride", N->getRawStride(),
/* IsUnsigned */ false,
/* ShouldSkipZero */ false);

Out << ")";
}
Expand Down Expand Up @@ -2226,13 +2226,13 @@ static void writeDIEnumerator(raw_ostream &Out, const DIEnumerator *N,
}

static void writeDIBasicType(raw_ostream &Out, const DIBasicType *N,
AsmWriterContext &) {
AsmWriterContext &WriterCtx) {
Out << "!DIBasicType(";
MDFieldPrinter Printer(Out);
MDFieldPrinter Printer(Out, WriterCtx);
if (N->getTag() != dwarf::DW_TAG_base_type)
Printer.printTag(N);
Printer.printString("name", N->getName());
Printer.printInt("size", N->getSizeInBits());
Printer.printMetadataOrInt("size", N->getRawSizeInBits(), true);
Printer.printInt("align", N->getAlignInBits());
Printer.printDwarfEnum("encoding", N->getEncoding(),
dwarf::AttributeEncodingString);
Expand All @@ -2242,13 +2242,13 @@ static void writeDIBasicType(raw_ostream &Out, const DIBasicType *N,
}

static void writeDIFixedPointType(raw_ostream &Out, const DIFixedPointType *N,
AsmWriterContext &) {
AsmWriterContext &WriterCtx) {
Out << "!DIFixedPointType(";
MDFieldPrinter Printer(Out);
MDFieldPrinter Printer(Out, WriterCtx);
if (N->getTag() != dwarf::DW_TAG_base_type)
Printer.printTag(N);
Printer.printString("name", N->getName());
Printer.printInt("size", N->getSizeInBits());
Printer.printMetadataOrInt("size", N->getRawSizeInBits(), true);
Printer.printInt("align", N->getAlignInBits());
Printer.printDwarfEnum("encoding", N->getEncoding(),
dwarf::AttributeEncodingString);
Expand All @@ -2275,7 +2275,7 @@ static void writeDIStringType(raw_ostream &Out, const DIStringType *N,
Printer.printMetadata("stringLengthExpression", N->getRawStringLengthExp());
Printer.printMetadata("stringLocationExpression",
N->getRawStringLocationExp());
Printer.printInt("size", N->getSizeInBits());
Printer.printMetadataOrInt("size", N->getRawSizeInBits(), true);
Printer.printInt("align", N->getAlignInBits());
Printer.printDwarfEnum("encoding", N->getEncoding(),
dwarf::AttributeEncodingString);
Expand All @@ -2293,9 +2293,9 @@ static void writeDIDerivedType(raw_ostream &Out, const DIDerivedType *N,
Printer.printInt("line", N->getLine());
Printer.printMetadata("baseType", N->getRawBaseType(),
/* ShouldSkipNull */ false);
Printer.printInt("size", N->getSizeInBits());
Printer.printMetadataOrInt("size", N->getRawSizeInBits(), true);
Printer.printInt("align", N->getAlignInBits());
Printer.printInt("offset", N->getOffsetInBits());
Printer.printMetadataOrInt("offset", N->getRawOffsetInBits(), true);
Printer.printDIFlags("flags", N->getFlags());
Printer.printMetadata("extraData", N->getRawExtraData());
if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
Expand Down Expand Up @@ -2323,7 +2323,7 @@ static void writeDISubrangeType(raw_ostream &Out, const DISubrangeType *N,
Printer.printMetadata("scope", N->getRawScope());
Printer.printMetadata("file", N->getRawFile());
Printer.printInt("line", N->getLine());
Printer.printInt("size", N->getSizeInBits());
Printer.printMetadataOrInt("size", N->getRawSizeInBits(), true);
Printer.printInt("align", N->getAlignInBits());
Printer.printDIFlags("flags", N->getFlags());
Printer.printMetadata("baseType", N->getRawBaseType(),
Expand All @@ -2345,9 +2345,9 @@ static void writeDICompositeType(raw_ostream &Out, const DICompositeType *N,
Printer.printMetadata("file", N->getRawFile());
Printer.printInt("line", N->getLine());
Printer.printMetadata("baseType", N->getRawBaseType());
Printer.printInt("size", N->getSizeInBits());
Printer.printMetadataOrInt("size", N->getRawSizeInBits(), true);
Printer.printInt("align", N->getAlignInBits());
Printer.printInt("offset", N->getOffsetInBits());
Printer.printMetadataOrInt("offset", N->getRawOffsetInBits(), true);
Printer.printInt("num_extra_inhabitants", N->getNumExtraInhabitants());
Printer.printDIFlags("flags", N->getFlags());
Printer.printMetadata("elements", N->getRawElements());
Expand Down
4 changes: 3 additions & 1 deletion llvm/test/DebugInfo/X86/dynamic-bitfield.ll
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Original file line number Diff line number Diff line change
@@ -1,4 +1,6 @@
; RUN: llc -mtriple=x86_64 -O0 -filetype=obj -o - %s | llvm-dwarfdump -v -debug-info - | FileCheck %s
; The use of llvm-dis here tests that round-tripping the IR works
; correctly for the expression case.
; RUN: llvm-as < %s | llvm-dis | llc -mtriple=x86_64 -O0 -filetype=obj -o - | llvm-dwarfdump -v -debug-info - | FileCheck %s

; A basic test of using a DIExpression for DW_AT_data_bit_offset and
; DW_AT_bit_size.
Expand Down