[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands

This patch improves salvageDebugInfoImpl by allowing it to salvage arithmetic
operations with two or more non-const operands; this includes the GetElementPtr
instruction, and most Binary Operator instructions. These salvages produce
DIArgList locations and are only valid for dbg.values, as currently variadic
DIExpressions must use DW_OP_stack_value. This functionality is also only added
for salvageDebugInfoForDbgValues; other functions that directly call
salvageDebugInfoImpl (such as in ISel or Coroutine frame building) can be
updated in a later patch.

Differential Revision: https://reviews.llvm.org/D91722
This commit is contained in:
gbtozers 2020-09-30 19:15:44 +01:00 committed by Stephen Tozer
parent ea834c8365
commit c0f3dfb9f1
17 changed files with 399 additions and 132 deletions

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@ -2583,6 +2583,16 @@ public:
return Elements[I];
}
/// Return the number of unique location operands referred to (via
/// DW_OP_LLVM_arg) in this expression; this is not necessarily the number of
/// instances of DW_OP_LLVM_arg within the expression.
/// For example, for the expression:
/// (DW_OP_LLVM_arg 0, DW_OP_LLVM_arg 1, DW_OP_plus,
/// DW_OP_LLVM_arg 0, DW_OP_mul)
/// This function would return 2, as there are two unique location operands
/// (0 and 1).
uint64_t getNumLocationOperands() const;
/// Determine whether this represents a standalone constant value.
bool isConstant() const;
@ -2731,6 +2741,10 @@ public:
/// return true with an offset of zero.
bool extractIfOffset(int64_t &Offset) const;
/// Returns true iff this DIExpression contains at least one instance of
/// `DW_OP_LLVM_arg, n` for all n in [0, N).
bool hasAllLocationOps(unsigned N) const;
/// Checks if the last 4 elements of the expression are DW_OP_constu <DWARF
/// Address Space> DW_OP_swap DW_OP_xderef and extracts the <DWARF Address
/// Space>.

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@ -1122,7 +1122,9 @@ public:
/// must be at least as wide as the IntPtr type for the address space of
/// the base GEP pointer.
bool accumulateConstantOffset(const DataLayout &DL, APInt &Offset) const;
bool collectOffset(const DataLayout &DL, unsigned BitWidth,
SmallDenseMap<Value *, APInt, 8> &VariableOffsets,
APInt &ConstantOffset) const;
// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Instruction *I) {
return (I->getOpcode() == Instruction::GetElementPtr);

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@ -204,6 +204,11 @@ public:
void replaceVariableLocationOp(Value *OldValue, Value *NewValue);
void replaceVariableLocationOp(unsigned OpIdx, Value *NewValue);
/// Adding a new location operand will always result in this intrinsic using
/// an ArgList, and must always be accompanied by a new expression that uses
/// the new operand.
void addVariableLocationOps(ArrayRef<Value *> NewValues,
DIExpression *NewExpr);
void setVariable(DILocalVariable *NewVar) {
setArgOperand(1, MetadataAsValue::get(NewVar->getContext(), NewVar));

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@ -576,6 +576,12 @@ public:
Type *SourceType, ArrayRef<const Value *> Index, const DataLayout &DL,
APInt &Offset,
function_ref<bool(Value &, APInt &)> ExternalAnalysis = nullptr);
/// Collect the offset of this GEP as a map of Values to their associated
/// APInt multipliers, as well as a total Constant Offset.
bool collectOffset(const DataLayout &DL, unsigned BitWidth,
SmallDenseMap<Value *, APInt, 8> &VariableOffsets,
APInt &ConstantOffset) const;
};
class PtrToIntOperator

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@ -314,7 +314,8 @@ void salvageDebugInfoForDbgValues(Instruction &I,
/// appended to the expression. \p LocNo: the index of the location operand to
/// which \p I applies, should be 0 for debug info without a DIArgList.
DIExpression *salvageDebugInfoImpl(Instruction &I, DIExpression *DIExpr,
bool StackVal, unsigned LocNo);
bool StackVal, unsigned LocNo,
SmallVectorImpl<Value *> &AdditionalValues);
/// Point debug users of \p From to \p To or salvage them. Use this function
/// only when replacing all uses of \p From with \p To, with a guarantee that

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@ -1229,6 +1229,10 @@ void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
}
void SelectionDAGBuilder::salvageUnresolvedDbgValue(DanglingDebugInfo &DDI) {
// TODO: For the variadic implementation, instead of only checking the fail
// state of `handleDebugValue`, we need know specifically which values were
// invalid, so that we attempt to salvage only those values when processing
// a DIArgList.
assert(!DDI.getDI()->hasArgList() &&
"Not implemented for variadic dbg_values");
Value *V = DDI.getDI()->getValue(0);
@ -1252,16 +1256,21 @@ void SelectionDAGBuilder::salvageUnresolvedDbgValue(DanglingDebugInfo &DDI) {
while (isa<Instruction>(V)) {
Instruction &VAsInst = *cast<Instruction>(V);
// Temporary "0", awaiting real implementation.
DIExpression *NewExpr = salvageDebugInfoImpl(VAsInst, Expr, StackValue, 0);
SmallVector<Value *, 4> AdditionalValues;
DIExpression *SalvagedExpr =
salvageDebugInfoImpl(VAsInst, Expr, StackValue, 0, AdditionalValues);
// If we cannot salvage any further, and haven't yet found a suitable debug
// expression, bail out.
if (!NewExpr)
// TODO: If AdditionalValues isn't empty, then the salvage can only be
// represented with a DBG_VALUE_LIST, so we give up. When we have support
// here for variadic dbg_values, remove that condition.
if (!SalvagedExpr || !AdditionalValues.empty())
break;
// New value and expr now represent this debuginfo.
V = VAsInst.getOperand(0);
Expr = NewExpr;
Expr = SalvagedExpr;
// Some kind of simplification occurred: check whether the operand of the
// salvaged debug expression can be encoded in this DAG.

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@ -1236,6 +1236,17 @@ bool DIExpression::extractIfOffset(int64_t &Offset) const {
return false;
}
bool DIExpression::hasAllLocationOps(unsigned N) const {
SmallDenseSet<uint64_t, 4> SeenOps;
for (auto ExprOp : expr_ops())
if (ExprOp.getOp() == dwarf::DW_OP_LLVM_arg)
SeenOps.insert(ExprOp.getArg(0));
for (uint64_t Idx = 0; Idx < N; ++Idx)
if (!is_contained(SeenOps, Idx))
return false;
return true;
}
const DIExpression *DIExpression::extractAddressClass(const DIExpression *Expr,
unsigned &AddrClass) {
// FIXME: This seems fragile. Nothing that verifies that these elements
@ -1450,6 +1461,16 @@ Optional<DIExpression *> DIExpression::createFragmentExpression(
return DIExpression::get(Expr->getContext(), Ops);
}
uint64_t DIExpression::getNumLocationOperands() const {
uint64_t Result = 0;
for (auto ExprOp : expr_ops())
if (ExprOp.getOp() == dwarf::DW_OP_LLVM_arg)
Result = std::max(Result, ExprOp.getArg(0) + 1);
assert(hasAllLocationOps(Result) &&
"Expression is missing one or more location operands.");
return Result;
}
bool DIExpression::isConstant() const {
// Recognize DW_OP_constu C DW_OP_stack_value (DW_OP_LLVM_fragment Len Ofs)?.
if (getNumElements() != 3 && getNumElements() != 6)

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@ -1793,6 +1793,15 @@ bool GetElementPtrInst::accumulateConstantOffset(const DataLayout &DL,
return cast<GEPOperator>(this)->accumulateConstantOffset(DL, Offset);
}
bool GetElementPtrInst::collectOffset(
const DataLayout &DL, unsigned BitWidth,
SmallDenseMap<Value *, APInt, 8> &VariableOffsets,
APInt &ConstantOffset) const {
// Delegate to the generic GEPOperator implementation.
return cast<GEPOperator>(this)->collectOffset(DL, BitWidth, VariableOffsets,
ConstantOffset);
}
//===----------------------------------------------------------------------===//
// ExtractElementInst Implementation
//===----------------------------------------------------------------------===//

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@ -117,6 +117,23 @@ void DbgVariableIntrinsic::replaceVariableLocationOp(unsigned OpIdx,
0, MetadataAsValue::get(getContext(), DIArgList::get(getContext(), MDs)));
}
void DbgVariableIntrinsic::addVariableLocationOps(ArrayRef<Value *> NewValues,
DIExpression *NewExpr) {
assert(NewExpr->hasAllLocationOps(getNumVariableLocationOps() +
NewValues.size()) &&
"NewExpr for debug variable intrinsic does not reference every "
"location operand.");
assert(!is_contained(NewValues, nullptr) && "New values must be non-null");
setArgOperand(2, MetadataAsValue::get(getContext(), NewExpr));
SmallVector<ValueAsMetadata *, 4> MDs;
for (auto *VMD : location_ops())
MDs.push_back(getAsMetadata(VMD));
for (auto *VMD : NewValues)
MDs.push_back(getAsMetadata(VMD));
setArgOperand(
0, MetadataAsValue::get(getContext(), DIArgList::get(getContext(), MDs)));
}
Optional<uint64_t> DbgVariableIntrinsic::getFragmentSizeInBits() const {
if (auto Fragment = getExpression()->getFragmentInfo())
return Fragment->SizeInBits;

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@ -142,4 +142,61 @@ bool GEPOperator::accumulateConstantOffset(
}
return true;
}
bool GEPOperator::collectOffset(
const DataLayout &DL, unsigned BitWidth,
SmallDenseMap<Value *, APInt, 8> &VariableOffsets,
APInt &ConstantOffset) const {
assert(BitWidth == DL.getIndexSizeInBits(getPointerAddressSpace()) &&
"The offset bit width does not match DL specification.");
auto CollectConstantOffset = [&](APInt Index, uint64_t Size) {
Index = Index.sextOrTrunc(BitWidth);
APInt IndexedSize = APInt(BitWidth, Size);
ConstantOffset += Index * IndexedSize;
};
for (gep_type_iterator GTI = gep_type_begin(this), GTE = gep_type_end(this);
GTI != GTE; ++GTI) {
// Scalable vectors are multiplied by a runtime constant.
bool ScalableType = isa<ScalableVectorType>(GTI.getIndexedType());
Value *V = GTI.getOperand();
StructType *STy = GTI.getStructTypeOrNull();
// Handle ConstantInt if possible.
if (auto ConstOffset = dyn_cast<ConstantInt>(V)) {
if (ConstOffset->isZero())
continue;
// If the type is scalable and the constant is not zero (vscale * n * 0 =
// 0) bailout.
// TODO: If the runtime value is accessible at any point before DWARF
// emission, then we could potentially keep a forward reference to it
// in the debug value to be filled in later.
if (ScalableType)
return false;
// Handle a struct index, which adds its field offset to the pointer.
if (STy) {
unsigned ElementIdx = ConstOffset->getZExtValue();
const StructLayout *SL = DL.getStructLayout(STy);
// Element offset is in bytes.
CollectConstantOffset(APInt(BitWidth, SL->getElementOffset(ElementIdx)),
1);
continue;
}
CollectConstantOffset(ConstOffset->getValue(),
DL.getTypeAllocSize(GTI.getIndexedType()));
continue;
}
if (STy || ScalableType)
return false;
// Insert an initial offset of 0 for V iff none exists already, then
// increment the offset by IndexedSize.
VariableOffsets.try_emplace(V, BitWidth, 0);
APInt IndexedSize =
APInt(BitWidth, DL.getTypeAllocSize(GTI.getIndexedType()));
VariableOffsets[V] += IndexedSize;
}
return true;
}
} // namespace llvm

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@ -2172,10 +2172,15 @@ void coro::salvageDebugInfo(
} else if (auto *StInst = dyn_cast<StoreInst>(Storage)) {
Storage = StInst->getOperand(0);
} else if (auto *GEPInst = dyn_cast<GetElementPtrInst>(Storage)) {
Expr = llvm::salvageDebugInfoImpl(*GEPInst, Expr,
/*WithStackValue=*/false, 0);
if (!Expr)
return;
SmallVector<Value *> AdditionalValues;
DIExpression *SalvagedExpr = llvm::salvageDebugInfoImpl(
*GEPInst, Expr,
/*WithStackValue=*/false, 0, AdditionalValues);
// Debug declares cannot currently handle additional location
// operands.
if (!SalvagedExpr || !AdditionalValues.empty())
break;
Expr = SalvagedExpr;
Storage = GEPInst->getOperand(0);
} else if (auto *BCInst = dyn_cast<llvm::BitCastInst>(Storage))
Storage = BCInst->getOperand(0);

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@ -1812,17 +1812,26 @@ void llvm::salvageDebugInfoForDbgValues(
is_contained(DIILocation, &I) &&
"DbgVariableIntrinsic must use salvaged instruction as its location");
unsigned LocNo = std::distance(DIILocation.begin(), find(DIILocation, &I));
DIExpression *DIExpr =
salvageDebugInfoImpl(I, DII->getExpression(), StackValue, LocNo);
SmallVector<Value *, 4> AdditionalValues;
DIExpression *SalvagedExpr = salvageDebugInfoImpl(
I, DII->getExpression(), StackValue, LocNo, AdditionalValues);
// salvageDebugInfoImpl should fail on examining the first element of
// DbgUsers, or none of them.
if (!DIExpr)
if (!SalvagedExpr)
break;
DII->replaceVariableLocationOp(&I, I.getOperand(0));
DII->setExpression(DIExpr);
if (AdditionalValues.empty()) {
DII->setExpression(SalvagedExpr);
} else if (isa<DbgValueInst>(DII)) {
DII->addVariableLocationOps(AdditionalValues, SalvagedExpr);
} else {
// Do not salvage using DIArgList for dbg.addr/dbg.declare, as it is
// currently only valid for stack value expressions.
Value *Undef = UndefValue::get(I.getOperand(0)->getType());
DII->replaceVariableLocationOp(I.getOperand(0), Undef);
}
LLVM_DEBUG(dbgs() << "SALVAGE: " << *DII << '\n');
Salvaged = true;
}
@ -1837,12 +1846,27 @@ void llvm::salvageDebugInfoForDbgValues(
}
bool getSalvageOpsForGEP(GetElementPtrInst *GEP, const DataLayout &DL,
SmallVectorImpl<uint64_t> &Opcodes) {
uint64_t CurrentLocOps,
SmallVectorImpl<uint64_t> &Opcodes,
SmallVectorImpl<Value *> &AdditionalValues) {
unsigned BitWidth = DL.getIndexSizeInBits(GEP->getPointerAddressSpace());
// Rewrite a constant GEP into a DIExpression.
// Rewrite a GEP into a DIExpression.
SmallDenseMap<Value *, APInt, 8> VariableOffsets;
APInt ConstantOffset(BitWidth, 0);
if (!GEP->accumulateConstantOffset(DL, ConstantOffset))
if (!GEP->collectOffset(DL, BitWidth, VariableOffsets, ConstantOffset))
return false;
if (!VariableOffsets.empty() && !CurrentLocOps) {
Opcodes.insert(Opcodes.begin(), {dwarf::DW_OP_LLVM_arg, 0});
CurrentLocOps = 1;
}
for (auto Offset : VariableOffsets) {
AdditionalValues.push_back(Offset.first);
assert(Offset.second.isStrictlyPositive() &&
"Expected strictly positive multiplier for offset.");
Opcodes.append({dwarf::DW_OP_LLVM_arg, CurrentLocOps++, dwarf::DW_OP_constu,
Offset.second.getZExtValue(), dwarf::DW_OP_mul,
dwarf::DW_OP_plus});
}
DIExpression::appendOffset(Opcodes, ConstantOffset.getSExtValue());
return true;
}
@ -1877,14 +1901,19 @@ uint64_t getDwarfOpForBinOp(Instruction::BinaryOps Opcode) {
}
}
bool getSalvageOpsForBinOp(BinaryOperator *BI,
SmallVectorImpl<uint64_t> &Opcodes) {
// Rewrite binary operations with constant integer operands.
bool getSalvageOpsForBinOp(BinaryOperator *BI, uint64_t CurrentLocOps,
SmallVectorImpl<uint64_t> &Opcodes,
SmallVectorImpl<Value *> &AdditionalValues) {
// Handle binary operations with constant integer operands as a special case.
auto *ConstInt = dyn_cast<ConstantInt>(BI->getOperand(1));
if (!ConstInt || ConstInt->getBitWidth() > 64)
// Values wider than 64 bits cannot be represented within a DIExpression.
if (ConstInt && ConstInt->getBitWidth() > 64)
return false;
uint64_t Val = ConstInt->getSExtValue();
Instruction::BinaryOps BinOpcode = BI->getOpcode();
// Push any Constant Int operand onto the expression stack.
if (ConstInt) {
uint64_t Val = ConstInt->getSExtValue();
// Add or Sub Instructions with a constant operand can potentially be
// simplified.
if (BinOpcode == Instruction::Add || BinOpcode == Instruction::Sub) {
@ -1892,8 +1921,15 @@ bool getSalvageOpsForBinOp(BinaryOperator *BI,
DIExpression::appendOffset(Opcodes, Offset);
return true;
}
// Add constant int operand to expression stack.
Opcodes.append({dwarf::DW_OP_constu, Val});
} else {
if (!CurrentLocOps) {
Opcodes.append({dwarf::DW_OP_LLVM_arg, 0});
CurrentLocOps = 1;
}
Opcodes.append({dwarf::DW_OP_LLVM_arg, CurrentLocOps});
AdditionalValues.push_back(BI->getOperand(1));
}
// Add salvaged binary operator to expression stack, if it has a valid
// representation in a DIExpression.
@ -1905,9 +1941,11 @@ bool getSalvageOpsForBinOp(BinaryOperator *BI,
return true;
}
DIExpression *llvm::salvageDebugInfoImpl(Instruction &I,
DIExpression *SrcDIExpr,
bool WithStackValue, unsigned LocNo) {
DIExpression *
llvm::salvageDebugInfoImpl(Instruction &I, DIExpression *SrcDIExpr,
bool WithStackValue, unsigned LocNo,
SmallVectorImpl<Value *> &AdditionalValues) {
uint64_t CurrentLocOps = SrcDIExpr->getNumLocationOperands();
auto &M = *I.getModule();
auto &DL = M.getDataLayout();
@ -1921,7 +1959,7 @@ DIExpression *llvm::salvageDebugInfoImpl(Instruction &I,
};
// initializer-list helper for applying operators to the source DIExpression.
auto applyOps = [&](ArrayRef<uint64_t> Opcodes) -> DIExpression * {
auto applyOps = [&](ArrayRef<uint64_t> Opcodes) {
SmallVector<uint64_t, 8> Ops(Opcodes.begin(), Opcodes.end());
return doSalvage(Ops);
};
@ -1947,10 +1985,10 @@ DIExpression *llvm::salvageDebugInfoImpl(Instruction &I,
SmallVector<uint64_t, 8> Ops;
if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {
if (getSalvageOpsForGEP(GEP, DL, Ops))
if (getSalvageOpsForGEP(GEP, DL, CurrentLocOps, Ops, AdditionalValues))
return doSalvage(Ops);
} else if (auto *BI = dyn_cast<BinaryOperator>(&I)) {
if (getSalvageOpsForBinOp(BI, Ops))
if (getSalvageOpsForBinOp(BI, CurrentLocOps, Ops, AdditionalValues))
return doSalvage(Ops);
}
// *Not* to do: we should not attempt to salvage load instructions,

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@ -702,12 +702,12 @@ if.end: ; preds = %if.then, %entry
; CHECK-NEXT: }
; CHECK-NEXT: .section .debug_info
; CHECK-NEXT: {
; CHECK-NEXT:.b32 10029 // Length of Unit
; CHECK-NEXT:.b32 10034 // Length of Unit
; CHECK-NEXT:.b8 2 // DWARF version number
; CHECK-NEXT:.b8 0
; CHECK-NEXT:.b32 .debug_abbrev // Offset Into Abbrev. Section
; CHECK-NEXT:.b8 8 // Address Size (in bytes)
; CHECK-NEXT:.b8 1 // Abbrev [1] 0xb:0x2726 DW_TAG_compile_unit
; CHECK-NEXT:.b8 1 // Abbrev [1] 0xb:0x272b DW_TAG_compile_unit
; CHECK-NEXT:.b8 0 // DW_AT_producer
; CHECK-NEXT:.b8 4 // DW_AT_language
; CHECK-NEXT:.b8 0
@ -8306,7 +8306,7 @@ if.end: ; preds = %if.then, %entry
; CHECK-NEXT:.b8 3 // DW_AT_decl_line
; CHECK-NEXT:.b32 3345 // DW_AT_type
; CHECK-NEXT:.b8 0 // End Of Children Mark
; CHECK-NEXT:.b8 40 // Abbrev [40] 0x2671:0xbf DW_TAG_subprogram
; CHECK-NEXT:.b8 40 // Abbrev [40] 0x2671:0xc4 DW_TAG_subprogram
; CHECK-NEXT:.b64 Lfunc_begin0 // DW_AT_low_pc
; CHECK-NEXT:.b64 Lfunc_end0 // DW_AT_high_pc
; CHECK-NEXT:.b8 1 // DW_AT_frame_base
@ -8386,7 +8386,7 @@ if.end: ; preds = %if.then, %entry
; CHECK-NEXT:.b8 12 // DW_AT_call_file
; CHECK-NEXT:.b8 6 // DW_AT_call_line
; CHECK-NEXT:.b8 37 // DW_AT_call_column
; CHECK-NEXT:.b8 43 // Abbrev [43] 0x2711:0x1e DW_TAG_inlined_subroutine
; CHECK-NEXT:.b8 43 // Abbrev [43] 0x2711:0x23 DW_TAG_inlined_subroutine
; CHECK-NEXT:.b32 9791 // DW_AT_abstract_origin
; CHECK-NEXT:.b64 Ltmp9 // DW_AT_low_pc
; CHECK-NEXT:.b64 Ltmp10 // DW_AT_high_pc
@ -8395,6 +8395,8 @@ if.end: ; preds = %if.then, %entry
; CHECK-NEXT:.b8 5 // DW_AT_call_column
; CHECK-NEXT:.b8 44 // Abbrev [44] 0x2729:0x5 DW_TAG_formal_parameter
; CHECK-NEXT:.b32 9820 // DW_AT_abstract_origin
; CHECK-NEXT:.b8 44 // Abbrev [44] 0x272e:0x5 DW_TAG_formal_parameter
; CHECK-NEXT:.b32 9829 // DW_AT_abstract_origin
; CHECK-NEXT:.b8 0 // End Of Children Mark
; CHECK-NEXT:.b8 0 // End Of Children Mark
; CHECK-NEXT:.b8 0 // End Of Children Mark

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@ -0,0 +1,56 @@
; RUN: opt %s -dce -S | FileCheck %s
; Tests the salvaging of GEP instructions, specifically struct indexing and
; non-constant array indexing.
%struct.S = type { i32, i32 }
; CHECK: call void @llvm.dbg.value(metadata !DIArgList(%struct.S* %ptr, i64 %offset),
; CHECK-SAME: ![[VAR_OFFSET_PTR:[0-9]+]],
; CHECK-SAME: !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_constu, 8, DW_OP_mul, DW_OP_plus, DW_OP_plus_uconst, 4, DW_OP_stack_value))
; CHECK: ![[VAR_OFFSET_PTR]] = !DILocalVariable(name: "offset_ptr"
define void @"?foo@@YAXPEAUS@@_J@Z"(%struct.S* %ptr, i64 %offset) !dbg !8 {
entry:
call void @llvm.dbg.value(metadata i64 %offset, metadata !20, metadata !DIExpression()), !dbg !24
call void @llvm.dbg.value(metadata %struct.S* %ptr, metadata !21, metadata !DIExpression()), !dbg !24
%arrayidx = getelementptr inbounds %struct.S, %struct.S* %ptr, i64 %offset, !dbg !25
%b = getelementptr inbounds %struct.S, %struct.S* %arrayidx, i32 0, i32 1, !dbg !25
call void @llvm.dbg.value(metadata i32* %b, metadata !22, metadata !DIExpression()), !dbg !24
ret void, !dbg !26
}
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5, !6}
!llvm.ident = !{!7}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 11.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
!1 = !DIFile(filename: "salvage-gep.cpp", directory: "/")
!2 = !{}
!3 = !{i32 2, !"CodeView", i32 1}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 2}
!6 = !{i32 7, !"PIC Level", i32 2}
!7 = !{!"clang version 11.0.0"}
!8 = distinct !DISubprogram(name: "foo", linkageName: "?foo@@YAXPEAUS@@_J@Z", scope: !9, file: !9, line: 7, type: !10, scopeLine: 7, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !19)
!9 = !DIFile(filename: ".\\salvage-gep.cpp", directory: "/")
!10 = !DISubroutineType(types: !11)
!11 = !{null, !12, !18}
!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
!13 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !9, line: 2, size: 64, flags: DIFlagTypePassByValue, elements: !14, identifier: ".?AUS@@")
!14 = !{!15, !17}
!15 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !13, file: !9, line: 3, baseType: !16, size: 32)
!16 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!17 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !13, file: !9, line: 4, baseType: !16, size: 32, offset: 32)
!18 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed)
!19 = !{!20, !21, !22}
!20 = !DILocalVariable(name: "offset", arg: 2, scope: !8, file: !9, line: 7, type: !18)
!21 = !DILocalVariable(name: "ptr", arg: 1, scope: !8, file: !9, line: 7, type: !12)
!22 = !DILocalVariable(name: "offset_ptr", scope: !8, file: !9, line: 8, type: !23)
!23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
!24 = !DILocation(line: 0, scope: !8)
!25 = !DILocation(line: 8, scope: !8)
!26 = !DILocation(line: 9, scope: !8)

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@ -0,0 +1,45 @@
; RUN: opt %s -dce -S | FileCheck %s
; Tests the salvaging of binary operators that use more than one non-constant
; SSA value.
; CHECK: call void @llvm.dbg.value(metadata !DIArgList(i32 %a, i32 %b),
; CHECK-SAME: ![[VAR_C:[0-9]+]],
; CHECK-SAME: !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_plus, DW_OP_stack_value))
; CHECK: ![[VAR_C]] = !DILocalVariable(name: "c"
define i32 @"?multiply@@YAHHH@Z"(i32 %a, i32 %b) !dbg !8 {
entry:
call void @llvm.dbg.value(metadata i32 %b, metadata !12, metadata !DIExpression()), !dbg !13
call void @llvm.dbg.value(metadata i32 %a, metadata !14, metadata !DIExpression()), !dbg !13
%add = add nsw i32 %a, %b, !dbg !15
call void @llvm.dbg.value(metadata i32 %add, metadata !16, metadata !DIExpression()), !dbg !13
%mul = mul nsw i32 %a, %b, !dbg !17
ret i32 %mul, !dbg !17
}
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5, !6}
!llvm.ident = !{!7}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 11.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
!1 = !DIFile(filename: "test.cpp", directory: "/")
!2 = !{}
!3 = !{i32 2, !"CodeView", i32 1}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 2}
!6 = !{i32 7, !"PIC Level", i32 2}
!7 = !{!"clang version 11.0.0"}
!8 = distinct !DISubprogram(name: "multiply", linkageName: "?multiply@@YAHHH@Z", scope: !1, file: !1, line: 1, type: !9, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
!9 = !DISubroutineType(types: !10)
!10 = !{!11, !11, !11}
!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!12 = !DILocalVariable(name: "b", arg: 2, scope: !8, file: !1, line: 1, type: !11)
!13 = !DILocation(line: 0, scope: !8)
!14 = !DILocalVariable(name: "a", arg: 1, scope: !8, file: !1, line: 1, type: !11)
!15 = !DILocation(line: 2, scope: !8)
!16 = !DILocalVariable(name: "c", scope: !8, file: !1, line: 2, type: !11)
!17 = !DILocation(line: 3, scope: !8)

View File

@ -33,23 +33,25 @@ sink1:
; value range.
; CHECK-LABEL: define i32 @bar(
; CHECK: call void @llvm.dbg.value(metadata i32* undef,
; CHECK: call void @llvm.dbg.value(metadata <vscale x 4 x i32>* undef,
; CHECK-NEXT: br label %sink2
define i32 @bar(i32 *%a, i32 %b) !dbg !70 {
define i32 @bar(<vscale x 4 x i32>* %a, i32 %b) !dbg !70 {
entry:
%gep = getelementptr i32, i32 *%a, i32 %b
call void @llvm.dbg.value(metadata i32* %gep, metadata !73, metadata !12), !dbg !74
%gep = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* %a, i32 %b
call void @llvm.dbg.value(metadata <vscale x 4 x i32>* %gep, metadata !73, metadata !12), !dbg !74
br label %sink2
sink2:
; CHECK-LABEL: sink2:
; CHECK: call void @llvm.dbg.value(metadata i32* %gep,
; CHECK: call void @llvm.dbg.value(metadata <vscale x 4 x i32>* %gep,
; CHECK-SAME: metadata !{{[0-9]+}}, metadata !DIExpression())
; CHECK-NEXT: load
; CHECK-NEXT: extractelement
; CHECK-NEXT: ret
%0 = load i32, i32* %gep
ret i32 %0
%0 = load <vscale x 4 x i32>, <vscale x 4 x i32>* %gep
%extract = extractelement <vscale x 4 x i32> %0, i32 1
ret i32 %extract
}
; This GEP is sunk, and has multiple debug uses in the same block. Check that

View File

@ -3,93 +3,71 @@
; Check that reassociate pass now undefs debug intrinsics that reference a value
; that gets dropped and cannot be salvaged.
define hidden i32 @main() local_unnamed_addr {
; CHECK-NOT: %add = fadd fast float %a, %b
; CHECK: call void @llvm.dbg.value(metadata float undef, metadata [[VAR_X:![0-9]+]], metadata !DIExpression())
; CHECK-LABEL: if.then:
; CHECK-NOT: %add1 = fadd fast float %add, %c
; CHECK: call void @llvm.dbg.value(metadata float undef, metadata [[VAR_Y:![0-9]+]], metadata !DIExpression())
; CHECK-LABEL: !0 =
; CHECK-DAG: [[VAR_Y]] = !DILocalVariable(name: "y"
; CHECK-DAG: [[VAR_X]] = !DILocalVariable(name: "x"
define float @"?foo@@YAMMMMM@Z"(float %a, float %b, float %c, float %d) !dbg !8 {
entry:
%foo = alloca i32, align 4, !dbg !20
%foo.0.foo.0..sroa_cast = bitcast i32* %foo to i8*, !dbg !20
call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %foo.0.foo.0..sroa_cast), !dbg !20
store volatile i32 4, i32* %foo, align 4, !dbg !20, !tbaa !21
%foo.0.foo.0. = load volatile i32, i32* %foo, align 4, !dbg !25, !tbaa !21
%foo.0.foo.0.15 = load volatile i32, i32* %foo, align 4, !dbg !27, !tbaa !21
%foo.0.foo.0.16 = load volatile i32, i32* %foo, align 4, !dbg !28, !tbaa !21
; CHECK-NOT: %add = add nsw i32 %foo.0.foo.0., %foo.0.foo.0.15
%add = add nsw i32 %foo.0.foo.0., %foo.0.foo.0.15, !dbg !29
; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[VAR_A:![0-9]+]], metadata !DIExpression())
call void @llvm.dbg.value(metadata i32 %add, metadata !19, metadata !DIExpression()), !dbg !26
%foo.0.foo.0.17 = load volatile i32, i32* %foo, align 4, !dbg !30, !tbaa !21
%cmp = icmp eq i32 %foo.0.foo.0.17, 4, !dbg !30
br i1 %cmp, label %if.then, label %if.end, !dbg !32
call void @llvm.dbg.value(metadata float %d, metadata !12, metadata !DIExpression()), !dbg !13
call void @llvm.dbg.value(metadata float %c, metadata !14, metadata !DIExpression()), !dbg !13
call void @llvm.dbg.value(metadata float %b, metadata !15, metadata !DIExpression()), !dbg !13
call void @llvm.dbg.value(metadata float %a, metadata !16, metadata !DIExpression()), !dbg !13
%add = fadd fast float %a, %b, !dbg !17
call void @llvm.dbg.value(metadata float %add, metadata !18, metadata !DIExpression()), !dbg !13
%cmp = fcmp fast oeq float %d, 4.000000e+00, !dbg !19
br i1 %cmp, label %if.then, label %return, !dbg !19
; CHECK-LABEL: if.then:
if.then:
; CHECK-NOT: %add1 = add nsw i32 %add, %foo.0.foo.0.16
%add1 = add nsw i32 %add, %foo.0.foo.0.16, !dbg !33
; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[VAR_A]], metadata !DIExpression())
call void @llvm.dbg.value(metadata i32 %add1, metadata !19, metadata !DIExpression()), !dbg !26
; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[VAR_CHEESE:![0-9]+]], metadata !DIExpression())
call void @llvm.dbg.value(metadata i32 %add, metadata !18, metadata !DIExpression()), !dbg !26
%sub = add nsw i32 %add, -12, !dbg !34
%sub3 = sub nsw i32 %add1, %sub, !dbg !34
%mul = mul nsw i32 %sub3, 20, !dbg !36
%div = sdiv i32 %mul, 3, !dbg !37
br label %if.end, !dbg !38
if.then: ; preds = %entry
%add1 = fadd fast float %add, %c, !dbg !20
call void @llvm.dbg.value(metadata float %add1, metadata !23, metadata !DIExpression()), !dbg !24
%sub = fsub fast float %add, 1.200000e+01, !dbg !25
%sub2 = fsub fast float %add1, %sub, !dbg !25
%mul = fmul fast float %sub2, 2.000000e+01, !dbg !25
%div = fdiv fast float %mul, 3.000000e+00, !dbg !25
br label %return, !dbg !25
if.end:
%a.0 = phi i32 [ %div, %if.then ], [ 0, %entry ], !dbg !39
call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %foo.0.foo.0..sroa_cast), !dbg !40
ret i32 %a.0, !dbg !41
return: ; preds = %entry, %if.then
%retval.0 = phi float [ %div, %if.then ], [ 0.000000e+00, %entry ], !dbg !13
ret float %retval.0, !dbg !26
}
declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
declare void @llvm.dbg.declare(metadata, metadata, metadata) #2
declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
declare void @llvm.dbg.value(metadata, metadata, metadata) #2
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5, !6}
!llvm.ident = !{!7}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 10.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, debugInfoForProfiling: true, nameTableKind: None)
!1 = !DIFile(filename: "test.cpp", directory: "F:\")
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 11.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
!1 = !DIFile(filename: "undef_intrinsics_when_deleting_instructions.cpp", directory: "/")
!2 = !{}
!3 = !{i32 2, !"Dwarf Version", i32 4}
!3 = !{i32 2, !"CodeView", i32 1}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 2}
!6 = !{i32 7, !"PIC Level", i32 2}
!7 = !{!"clang version 10.0.0"}
!8 = distinct !DISubprogram(name: "main", scope: !9, file: !9, line: 1, type: !10, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13)
!9 = !DIFile(filename: "./test.cpp", directory: "F:\")
!10 = !DISubroutineType(types: !11)
!11 = !{!12}
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !{!14, !16, !17, !18, !19}
!14 = !DILocalVariable(name: "foo", scope: !8, file: !9, line: 2, type: !15)
!15 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !12)
!16 = !DILocalVariable(name: "read1", scope: !8, file: !9, line: 3, type: !12)
!17 = !DILocalVariable(name: "read2", scope: !8, file: !9, line: 4, type: !12)
; CHECK: [[VAR_CHEESE]] = !DILocalVariable(name: "cheese"
!18 = !DILocalVariable(name: "cheese", scope: !8, file: !9, line: 6, type: !12)
; CHECK: [[VAR_A]] = !DILocalVariable(name: "a"
!19 = !DILocalVariable(name: "a", scope: !8, file: !9, line: 7, type: !12)
!20 = !DILocation(line: 2, scope: !8)
!21 = !{!22, !22, i64 0}
!22 = !{!"int", !23, i64 0}
!23 = !{!"omnipotent char", !24, i64 0}
!24 = !{!"Simple C++ TBAA"}
!25 = !DILocation(line: 3, scope: !8)
!26 = !DILocation(line: 0, scope: !8)
!27 = !DILocation(line: 4, scope: !8)
!28 = !DILocation(line: 6, scope: !8)
!29 = !DILocation(line: 7, scope: !8)
!30 = !DILocation(line: 10, scope: !31)
!31 = distinct !DILexicalBlock(scope: !8, file: !9, line: 10)
!32 = !DILocation(line: 10, scope: !8)
!33 = !DILocation(line: 8, scope: !8)
!34 = !DILocation(line: 12, scope: !35)
!35 = distinct !DILexicalBlock(scope: !31, file: !9, line: 10)
!36 = !DILocation(line: 13, scope: !35)
!37 = !DILocation(line: 14, scope: !35)
!38 = !DILocation(line: 15, scope: !35)
!39 = !DILocation(line: 0, scope: !31)
!40 = !DILocation(line: 20, scope: !8)
!41 = !DILocation(line: 19, scope: !8)
!7 = !{!"clang version 11.0.0"}
!8 = distinct !DISubprogram(name: "foo", linkageName: "?foo@@YAMMMMM@Z", scope: !1, file: !1, line: 1, type: !9, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
!9 = !DISubroutineType(types: !10)
!10 = !{!11, !11, !11, !11, !11}
!11 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float)
!12 = !DILocalVariable(name: "d", arg: 4, scope: !8, file: !1, line: 1, type: !11)
!13 = !DILocation(line: 0, scope: !8)
!14 = !DILocalVariable(name: "c", arg: 3, scope: !8, file: !1, line: 1, type: !11)
!15 = !DILocalVariable(name: "b", arg: 2, scope: !8, file: !1, line: 1, type: !11)
!16 = !DILocalVariable(name: "a", arg: 1, scope: !8, file: !1, line: 1, type: !11)
!17 = !DILocation(line: 2, scope: !8)
!18 = !DILocalVariable(name: "x", scope: !8, file: !1, line: 2, type: !11)
!19 = !DILocation(line: 3, scope: !8)
!20 = !DILocation(line: 4, scope: !21)
!21 = distinct !DILexicalBlock(scope: !22, file: !1, line: 3)
!22 = distinct !DILexicalBlock(scope: !8, file: !1, line: 3)
!23 = !DILocalVariable(name: "y", scope: !21, file: !1, line: 4, type: !11)
!24 = !DILocation(line: 0, scope: !21)
!25 = !DILocation(line: 5, scope: !21)
!26 = !DILocation(line: 8, scope: !8)