[IR] Remove the DIFlagArgumentNotModified debug info flag

[djtodoro]

Summary

The IR part for D68206.

[djtodoro]

This was controlled by the experimental entry values option, so I guess we don't need to support for metadata upgrade.

[aprantl]

Since this was so short-lived I'm fine with pretending this never happened (in terms of bitcode upgrade).

[djtodoro]

That sounds good. Thanks!

[vsk]

+ 1

[djtodoro]

-Rebasing on top of the latest LLVM

[aprantl]

I have not bitcode compatibility concerns; this was barely in tree.

[aprantl]

s/not/no/

llvm/bindings/go/llvm/dibuilder.go

const (
   FlagArtificial
   FlagExplicit
   FlagPrototyped
   FlagObjcClassComplete
   FlagObjectPointer
   FlagVector
   FlagStaticMember
   FlagIndirectVariable
-  FlagArgumentNotModified
 )
 
 type DwarfLang uint32
 
 const (
   // http://dwarfstd.org/ShowIssue.php?issue=101014.1&type=open
   DW_LANG_Go DwarfLang = 0x0016
 )

llvm/docs/LangRef.rst

.. code-block:: text
     !4 = !DIExpression(DW_OP_constu, 2, DW_OP_swap, DW_OP_xderef)
     !5 = !DIExpression(DW_OP_constu, 42, DW_OP_stack_value)
 
 DIFlags
 """""""""""""""
 
 These flags encode various properties of DINodes.
 
-The `ArgumentNotModified` flag marks a function argument whose value
-is not modified throughout of a function. This flag is used to decide
-whether a DW_OP_LLVM_entry_value can be used in a location description
-after the function prologue. The language frontend is expected to compute
-this property for each DILocalVariable. The flag should be used
-only in optimized code.
-
 The `ExportSymbols` flag marks a class, struct or union whose members
 may be referenced as if they were defined in the containing class or
 union. This flag is used to decide whether the DW_AT_export_symbols can
 be used for the structure type.
 
 DIObjCProperty
 """"""""""""""
 

llvm/include/llvm/IR/DebugInfoFlags.def

 HANDLE_DI_FLAG((1 << 14), RValueReference)
 HANDLE_DI_FLAG((1 << 15), ExportSymbols)
 HANDLE_DI_FLAG((1 << 16), SingleInheritance)
 HANDLE_DI_FLAG((2 << 16), MultipleInheritance)
 HANDLE_DI_FLAG((3 << 16), VirtualInheritance)
 HANDLE_DI_FLAG((1 << 18), IntroducedVirtual)
 HANDLE_DI_FLAG((1 << 19), BitField)
 HANDLE_DI_FLAG((1 << 20), NoReturn)
-HANDLE_DI_FLAG((1 << 21), ArgumentNotModified)
 HANDLE_DI_FLAG((1 << 22), TypePassByValue)
 HANDLE_DI_FLAG((1 << 23), TypePassByReference)
 HANDLE_DI_FLAG((1 << 24), EnumClass)
 HANDLE_DI_FLAG((1 << 25), Thunk)
 HANDLE_DI_FLAG((1 << 26), NonTrivial)
 HANDLE_DI_FLAG((1 << 27), BigEndian)
 HANDLE_DI_FLAG((1 << 28), LittleEndian)
 HANDLE_DI_FLAG((1 << 29), AllCallsDescribed)

llvm/include/llvm/IR/DebugInfoMetadata.h

public:
 
   bool isParameter() const { return Arg; }
   unsigned getArg() const { return Arg; }
   DIFlags getFlags() const { return Flags; }
 
   bool isArtificial() const { return getFlags() & FlagArtificial; }
   bool isObjectPointer() const { return getFlags() & FlagObjectPointer; }
 
-  /// Check that an argument is unmodified.
-  bool isNotModified() const { return getFlags() & FlagArgumentNotModified; }
-  /// Set the flag if an argument is unmodified.
-  void setIsNotModified() { Flags |= FlagArgumentNotModified; }
-
   /// Check that a location is valid for this variable.
   ///
   /// Check that \c DL exists, is in the same subprogram, and has the same
   /// inlined-at location as \c this.  (Otherwise, it's not a valid attachment
   /// to a \a DbgInfoIntrinsic.)
   bool isValidLocationForIntrinsic(const DILocation *DL) const {
     return DL && getScope()->getSubprogram() == DL->getScope()->getSubprogram();
   }

llvm/lib/CodeGen/LiveDebugValues.cpp

bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
   DenseMap<MachineBasicBlock *, unsigned int> BBToOrder;
   std::priority_queue<unsigned int, std::vector<unsigned int>,
                       std::greater<unsigned int>>
       Worklist;
   std::priority_queue<unsigned int, std::vector<unsigned int>,
                       std::greater<unsigned int>>
       Pending;
 
-  // Besides parameter's modification, check whether a DBG_VALUE is inlined
-  // in order to deduce whether the variable that it tracks comes from
-  // a different function. If that is the case we can't track its entry value.
-  auto IsUnmodifiedFuncParam = [&](const MachineInstr &MI) {
-    auto *DIVar = MI.getDebugVariable();
-    return DIVar->isParameter() && DIVar->isNotModified() &&
-           !MI.getDebugLoc()->getInlinedAt();
-  };
-
   const TargetLowering *TLI = MF.getSubtarget().getTargetLowering();
   unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
   Register FP = TRI->getFrameRegister(MF);
   auto IsRegOtherThanSPAndFP = [&](const MachineOperand &Op) -> bool {
     return Op.isReg() && Op.getReg() != SP && Op.getReg() != FP;
   };
 
   // Working set of currently collected debug variables mapped to DBG_VALUEs
   // representing candidates for production of debug entry values.
   DebugParamMap DebugEntryVals;
 
   MachineBasicBlock &First_MBB = *(MF.begin());
   // Only in the case of entry MBB collect DBG_VALUEs representing
   // function parameters in order to generate debug entry values for them.
   // Currently, we generate debug entry values only for parameters that are
   // unmodified throughout the function and located in a register.
   // TODO: Add support for parameters with non-empty debug expressions (for
   // example fragments).
   // TODO: Add support for modified arguments that can be expressed
   // by using its entry value.
   // TODO: Add support for local variables that are expressed in terms of
   // parameters entry values.
   for (auto &MI : First_MBB)
-    if (MI.isDebugValue() && IsUnmodifiedFuncParam(MI) &&
+    if (MI.isDebugValue() && !MI.getDebugLoc()->getInlinedAt() &&
         !MI.isIndirectDebugValue() && IsRegOtherThanSPAndFP(MI.getOperand(0)) &&
         !DebugEntryVals.count(MI.getDebugVariable()) &&
         MI.getDebugExpression()->getNumElements() == 0)
       DebugEntryVals[MI.getDebugVariable()] = &MI;
 
   // Initialize per-block structures and scan for fragment overlaps.
   for (auto &MBB : MF) {
     PendingInLocs[&MBB] = VarLocSet();

llvm/test/Assembler/debug-info.ll

 ; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
 ; RUN: verify-uselistorder %s
 
-; CHECK: !named = !{!0, !0, !1, !2, !3, !4, !5, !6, !7, !8, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37, !38, !39, !40, !41}
-!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37, !38, !39, !40, !41, !42, !43, !44}
+; CHECK: !named = !{!0, !0, !1, !2, !3, !4, !5, !6, !7, !8, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37, !38, !39}
+!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37, !38, !39, !40, !41, !42}
 
 ; CHECK:      !0 = !DISubrange(count: 3)
 ; CHECK-NEXT: !1 = !DISubrange(count: 3, lowerBound: 4)
 ; CHECK-NEXT: !2 = !DISubrange(count: 3, lowerBound: -5)
 !0 = !DISubrange(count: 3)
 !1 = !DISubrange(count: 3, lowerBound: 0)
 
 !2 = !DISubrange(count: 3, lowerBound: 4)

 ; CHECK-NEXT: !37 = !DIFile(filename: "file", directory: "dir", checksumkind: CSK_MD5, checksum: "3a420e2646916a475e68de8d48f779f5", source: "int source() { }\0A")
 !39 = !DIFile(filename: "file", directory: "dir", source: "int source() { }\0A")
 !40 = !DIFile(filename: "file", directory: "dir", checksumkind: CSK_MD5, checksum: "3a420e2646916a475e68de8d48f779f5", source: "int source() { }\0A")
 
 ; CHECK-NEXT: !38 = !DIBasicType(name: "u64.be", size: 64, align: 1, encoding: DW_ATE_unsigned, flags: DIFlagBigEndian)
 ; CHECK-NEXT: !39 = !DIBasicType(name: "u64.le", size: 64, align: 1, encoding: DW_ATE_unsigned, flags: DIFlagLittleEndian)
 !41 = !DIBasicType(name: "u64.be", size: 64, align: 1, encoding: DW_ATE_unsigned, flags: DIFlagBigEndian)
 !42 = !DIBasicType(name: "u64.le", size: 64, align: 1, encoding: DW_ATE_unsigned, flags: DIFlagLittleEndian)
-
-; CHECK-NEXT: !40 = distinct !DISubprogram(name: "fn", scope: {{.*}}, file: {{.*}}, spFlags: 0)
-; CHECK-NEXT: !41 = !DILocalVariable(name: "Name", arg: 1, scope: {{.*}}, file: {{.*}}, line: 13, type: {{.*}}, flags: DIFlagArgumentNotModified)
-!43 = distinct !DISubprogram(name: "fn", scope: !12, file: !12, spFlags: 0)
-!44 = !DILocalVariable(name: "Name", arg: 1, scope: !43, file: !12, line: 13, type: !7, flags: DIFlagArgumentNotModified)

llvm/test/DebugInfo/MIR/Hexagon/live-debug-values-bundled-entry-values.mir

--- |
   !8 = !{i32 2, !"Dwarf Version", i32 4}
   !9 = !{i32 2, !"Debug Info Version", i32 3}
   !10 = !{i32 1, !"wchar_size", i32 4}
   !11 = !{!"clang version 10.0.0"}
   !12 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 3, type: !13, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
   !13 = !DISubroutineType(types: !14)
   !14 = !{!7, !7}
   !15 = !{!16}
-  !16 = !DILocalVariable(name: "arg", arg: 1, scope: !12, file: !1, line: 3, type: !7, flags: DIFlagArgumentNotModified)
+  !16 = !DILocalVariable(name: "arg", arg: 1, scope: !12, file: !1, line: 3, type: !7)
   !17 = !DILocation(line: 0, scope: !12)
   !18 = !DILocation(line: 4, scope: !12)
   !19 = !DILocation(line: 5, scope: !12)
   !20 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 8, type: !13, scopeLine: 8, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !21)
   !21 = !{!22}
-  !22 = !DILocalVariable(name: "arg", arg: 1, scope: !20, file: !1, line: 8, type: !7, flags: DIFlagArgumentNotModified)
+  !22 = !DILocalVariable(name: "arg", arg: 1, scope: !20, file: !1, line: 8, type: !7)
   !23 = !DILocation(line: 0, scope: !20)
   !24 = !DILocation(line: 9, scope: !20)
   !25 = !DILocation(line: 9, scope: !26)
   !26 = distinct !DILexicalBlock(scope: !20, file: !1, line: 9)
   !27 = !DILocation(line: 10, scope: !20)
 
 ...
 ---

llvm/test/DebugInfo/MIR/X86/DW_OP_entry_value.mir

--- |
   !7 = !{i32 2, !"Dwarf Version", i32 4}
   !8 = !{i32 2, !"Debug Info Version", i32 3}
   !9 = !{i32 1, !"wchar_size", i32 4}
   !10 = !{!"clang version 9.0.0 "}
   !11 = distinct !DISubprogram(name: "foo", scope: !3, file: !3, line: 9, type: !12, scopeLine: 9, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !14)
   !12 = !DISubroutineType(types: !13)
   !13 = !{!6, !6, !6, !6}
   !14 = !{!15, !16, !17}
-  !15 = !DILocalVariable(name: "p", arg: 1, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
-  !16 = !DILocalVariable(name: "q", arg: 2, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
-  !17 = !DILocalVariable(name: "r", arg: 3, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
+  !15 = !DILocalVariable(name: "p", arg: 1, scope: !11, file: !3, line: 9, type: !6)
+  !16 = !DILocalVariable(name: "q", arg: 2, scope: !11, file: !3, line: 9, type: !6)
+  !17 = !DILocalVariable(name: "r", arg: 3, scope: !11, file: !3, line: 9, type: !6)
   !18 = !DILocation(line: 9, column: 13, scope: !11)
   !19 = !{i32 213}
 
 ...
 ---
 name:            foo
 alignment:       16
 tracksRegLiveness: true

llvm/test/DebugInfo/MIR/X86/avoid-single-entry-value-location.mir

--- |
   !8 = !{i32 2, !"Dwarf Version", i32 5}
   !9 = !{i32 2, !"Debug Info Version", i32 3}
   !10 = !{i32 1, !"wchar_size", i32 4}
   !11 = !{!"clang version 9.0.0"}
   !12 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 5, type: !13, scopeLine: 5, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
   !13 = !DISubroutineType(types: !14)
   !14 = !{null, !7, !7}
   !15 = !{!16, !17}
-  !16 = !DILocalVariable(name: "x", arg: 1, scope: !12, file: !1, line: 5, type: !7, flags: DIFlagArgumentNotModified)
+  !16 = !DILocalVariable(name: "x", arg: 1, scope: !12, file: !1, line: 5, type: !7)
   !17 = !DILocalVariable(name: "y", scope: !12, file: !1, line: 5, type: !7)
   !18 = !DILocation(line: 0, scope: !12)
 
 ...
 ---
 name:            fn1
 alignment:       16
 tracksRegLiveness: true

llvm/test/DebugInfo/MIR/X86/dbgcall-site-interpretation.mir

--- |
   !7 = !{i32 1, !"wchar_size", i32 4}
   !8 = !{!"clang version 9.0.0"}
   !9 = distinct !DISubprogram(name: "baa", scope: !1, file: !1, line: 10, type: !10, scopeLine: 10, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13)
   !10 = !DISubroutineType(types: !11)
   !11 = !{!12, !12, !12, !12, !12}
   !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
   !13 = !{!14, !15, !16, !17, !18, !19, !20}
   !14 = !DILocalVariable(name: "arg1", arg: 1, scope: !9, file: !1, line: 10, type: !12)
-  !15 = !DILocalVariable(name: "arg2", arg: 2, scope: !9, file: !1, line: 10, type: !12, flags: DIFlagArgumentNotModified)
+  !15 = !DILocalVariable(name: "arg2", arg: 2, scope: !9, file: !1, line: 10, type: !12)
   !16 = !DILocalVariable(name: "arg3", arg: 3, scope: !9, file: !1, line: 10, type: !12)
-  !17 = !DILocalVariable(name: "arg4", arg: 4, scope: !9, file: !1, line: 10, type: !12, flags: DIFlagArgumentNotModified)
+  !17 = !DILocalVariable(name: "arg4", arg: 4, scope: !9, file: !1, line: 10, type: !12)
   !18 = !DILocalVariable(name: "local1", scope: !9, file: !1, line: 11, type: !12)
   !19 = !DILocalVariable(name: "local2", scope: !9, file: !1, line: 11, type: !12)
   !20 = !DILocalVariable(name: "local3", scope: !9, file: !1, line: 11, type: !12)
   !21 = !DILocation(line: 10, column: 13, scope: !9)
 
 ...
 ---
 name:            baa

llvm/test/DebugInfo/MIR/X86/dbginfo-entryvals.mir

--- |
   !6 = !{i32 2, !"Debug Info Version", i32 3}
   !7 = !{i32 1, !"wchar_size", i32 4}
   !8 = !{!"clang version 9.0.0"}
   !9 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 15, type: !10, scopeLine: 15, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13)
   !10 = !DISubroutineType(types: !11)
   !11 = !{null, !12, !12}
   !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
   !13 = !{!14, !15, !16, !17}
-  !14 = !DILocalVariable(name: "x", arg: 1, scope: !9, file: !1, line: 15, type: !12, flags: DIFlagArgumentNotModified)
-  !15 = !DILocalVariable(name: "y", arg: 2, scope: !9, file: !1, line: 15, type: !12, flags: DIFlagArgumentNotModified)
-  !16 = !DILocalVariable(name: "u", scope: !9, file: !1, line: 16, type: !12, flags: DIFlagArgumentNotModified)
-  !17 = !DILocalVariable(name: "a", scope: !9, file: !1, line: 21, type: !12, flags: DIFlagArgumentNotModified)
+  !14 = !DILocalVariable(name: "x", arg: 1, scope: !9, file: !1, line: 15, type: !12)
+  !15 = !DILocalVariable(name: "y", arg: 2, scope: !9, file: !1, line: 15, type: !12)
+  !16 = !DILocalVariable(name: "u", scope: !9, file: !1, line: 16, type: !12)
+  !17 = !DILocalVariable(name: "a", scope: !9, file: !1, line: 21, type: !12)
   !18 = !DILocation(line: 15, column: 10, scope: !9)
 
 ...
 ---
 name:            fn1
 alignment:       16
 tracksRegLiveness: true
 liveins:         []

llvm/test/DebugInfo/MIR/X86/debug-call-site-param.mir

--- |
   !7 = !{i32 2, !"Debug Info Version", i32 3}
   !8 = !{i32 1, !"wchar_size", i32 4}
   !9 = !{!"clang version 9.0.0"}
   !10 = distinct !DISubprogram(name: "baa", scope: !1, file: !1, line: 4, type: !11, scopeLine: 4, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !14)
   !11 = !DISubroutineType(types: !12)
   !12 = !{null, !13, !13, !13}
   !13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
   !14 = !{!15, !16, !17, !18}
-  !15 = !DILocalVariable(name: "arg1", arg: 1, scope: !10, file: !1, line: 4, type: !13, flags: DIFlagArgumentNotModified)
-  !16 = !DILocalVariable(name: "arg2", arg: 2, scope: !10, file: !1, line: 4, type: !13, flags: DIFlagArgumentNotModified)
-  !17 = !DILocalVariable(name: "arg3", arg: 3, scope: !10, file: !1, line: 4, type: !13, flags: DIFlagArgumentNotModified)
+  !15 = !DILocalVariable(name: "arg1", arg: 1, scope: !10, file: !1, line: 4, type: !13)
+  !16 = !DILocalVariable(name: "arg2", arg: 2, scope: !10, file: !1, line: 4, type: !13)
+  !17 = !DILocalVariable(name: "arg3", arg: 3, scope: !10, file: !1, line: 4, type: !13)
   !18 = !DILocalVariable(name: "local1", scope: !10, file: !1, line: 5, type: !13)
   !19 = !DILocation(line: 4, column: 14, scope: !10)
   !20 = !DILocation(line: 4, column: 24, scope: !10)
   !21 = !DILocation(line: 4, column: 34, scope: !10)
   !22 = !DILocation(line: 5, column: 3, scope: !10)
   !23 = !DILocation(line: 5, column: 16, scope: !10)
   !24 = !DILocation(line: 5, column: 7, scope: !10)
 

llvm/test/DebugInfo/MIR/X86/multiple-param-dbg-value-entry.mir

--- |
   !7 = !{i32 2, !"Dwarf Version", i32 4}
   !8 = !{i32 2, !"Debug Info Version", i32 3}
   !9 = !{i32 1, !"wchar_size", i32 4}
   !10 = !{!"clang version 9.0.0 "}
   !11 = distinct !DISubprogram(name: "foo", scope: !3, file: !3, line: 9, type: !12, scopeLine: 9, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !14)
   !12 = !DISubroutineType(types: !13)
   !13 = !{!6, !6, !6, !6}
   !14 = !{!15, !16, !17}
-  !15 = !DILocalVariable(name: "p", arg: 1, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
-  !16 = !DILocalVariable(name: "q", arg: 2, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
-  !17 = !DILocalVariable(name: "r", arg: 3, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
+  !15 = !DILocalVariable(name: "p", arg: 1, scope: !11, file: !3, line: 9, type: !6)
+  !16 = !DILocalVariable(name: "q", arg: 2, scope: !11, file: !3, line: 9, type: !6)
+  !17 = !DILocalVariable(name: "r", arg: 3, scope: !11, file: !3, line: 9, type: !6)
   !18 = !DILocation(line: 9, column: 13, scope: !11)
   !19 = !{i32 213}
 
 ...
 ---
 name:            foo
 alignment:       16
 tracksRegLiveness: true

llvm/test/DebugInfo/Mips/entry-value-non-empty-expr.ll

 !12 = !DISubroutineType(types: !13)
 !13 = !{null}
 !14 = !DILocation(line: 7, scope: !11)
 !15 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 5, type: !16, scopeLine: 5, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !19)
 !16 = !DISubroutineType(types: !17)
 !17 = !{null, !18}
 !18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 32)
 !19 = !{!20}
-!20 = !DILocalVariable(name: "p", arg: 1, scope: !15, file: !1, line: 5, type: !18, flags: DIFlagArgumentNotModified)
+!20 = !DILocalVariable(name: "p", arg: 1, scope: !15, file: !1, line: 5, type: !18)
 !21 = !DILocation(line: 0, scope: !15)
 !22 = !DILocation(line: 5, scope: !15)

llvm/test/tools/llvm-dwarfdump/X86/locstats.ll

 !12 = !{i32 2, !"Dwarf Version", i32 4}
 !13 = !{i32 2, !"Debug Info Version", i32 3}
 !14 = !{i32 1, !"wchar_size", i32 4}
 !15 = !{!"clang version 10.0.0"}
 !16 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 6, type: !17, scopeLine: 7, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !19)
 !17 = !DISubroutineType(types: !18)
 !18 = !{null, !7, !7}
 !19 = !{!20, !21, !22, !23}
-!20 = !DILocalVariable(name: "x", arg: 1, scope: !16, file: !1, line: 6, type: !7, flags: DIFlagArgumentNotModified)
-!21 = !DILocalVariable(name: "y", arg: 2, scope: !16, file: !1, line: 6, type: !7, flags: DIFlagArgumentNotModified)
+!20 = !DILocalVariable(name: "x", arg: 1, scope: !16, file: !1, line: 6, type: !7)
+!21 = !DILocalVariable(name: "y", arg: 2, scope: !16, file: !1, line: 6, type: !7)
 !22 = !DILocalVariable(name: "u", scope: !16, file: !1, line: 8, type: !7)
 !23 = !DILocalVariable(name: "a", scope: !16, file: !1, line: 18, type: !7)
 !24 = !DILocation(line: 0, scope: !16)
 !25 = !DILocation(line: 20, column: 3, scope: !16)
 !26 = !DILocation(line: 22, column: 1, scope: !16)
 !27 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 25, type: !28, scopeLine: 26, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !30)
 !28 = !DISubroutineType(types: !29)
 !29 = !{!7}
 !30 = !{!31, !32}
 !31 = !DILocalVariable(name: "l", scope: !27, file: !1, line: 27, type: !7)
 !32 = !DILocalVariable(name: "k", scope: !27, file: !1, line: 27, type: !7)
 !33 = !DILocation(line: 27, column: 3, scope: !27)
 !34 = !DILocation(line: 0, scope: !27)
 !35 = !DILocation(line: 29, column: 3, scope: !27)
 !36 = !DILocation(line: 30, column: 3, scope: !27)
 !37 = !DILocation(line: 32, column: 8, scope: !27)

llvm/test/tools/llvm-dwarfdump/X86/stats-dbg-callsite-info.ll

 !7 = !{i32 2, !"Debug Info Version", i32 3}
 !8 = !{i32 1, !"wchar_size", i32 4}
 !9 = !{!"clang version 9.0.0"}
 !10 = distinct !DISubprogram(name: "baa", scope: !1, file: !1, line: 4, type: !11, scopeLine: 4, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !14)
 !11 = !DISubroutineType(types: !12)
 !12 = !{null, !13, !13, !13}
 !13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 !14 = !{!15, !16, !17, !18}
-!15 = !DILocalVariable(name: "arg1", arg: 1, scope: !10, file: !1, line: 4, type: !13, flags: DIFlagArgumentNotModified)
-!16 = !DILocalVariable(name: "arg2", arg: 2, scope: !10, file: !1, line: 4, type: !13, flags: DIFlagArgumentNotModified)
-!17 = !DILocalVariable(name: "arg3", arg: 3, scope: !10, file: !1, line: 4, type: !13, flags: DIFlagArgumentNotModified)
+!15 = !DILocalVariable(name: "arg1", arg: 1, scope: !10, file: !1, line: 4, type: !13)
+!16 = !DILocalVariable(name: "arg2", arg: 2, scope: !10, file: !1, line: 4, type: !13)
+!17 = !DILocalVariable(name: "arg3", arg: 3, scope: !10, file: !1, line: 4, type: !13)
 !18 = !DILocalVariable(name: "local1", scope: !10, file: !1, line: 5, type: !13)
 !19 = !DILocation(line: 4, column: 14, scope: !10)
 !20 = !DILocation(line: 4, column: 24, scope: !10)
 !21 = !DILocation(line: 4, column: 34, scope: !10)
 !22 = !DILocation(line: 5, column: 3, scope: !10)
 !23 = !DILocation(line: 5, column: 16, scope: !10)
 !24 = !DILocation(line: 5, column: 7, scope: !10)

llvm/test/tools/llvm-dwarfdump/X86/valid-call-site-GNU-extensions.ll

 !12 = !{i32 2, !"Debug Info Version", i32 3}
 !13 = !{i32 1, !"wchar_size", i32 4}
 !14 = !{!"clang version 10.0.0"}
 !15 = distinct !DISubprogram(name: "fn2", scope: !1, file: !1, line: 6, type: !16, scopeLine: 6, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !19)
 !16 = !DISubroutineType(types: !17)
 !17 = !{null, !18}
 !18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
 !19 = !{!20, !21}
-!20 = !DILocalVariable(name: "arg", arg: 1, scope: !15, file: !1, line: 6, type: !18, flags: DIFlagArgumentNotModified)
+!20 = !DILocalVariable(name: "arg", arg: 1, scope: !15, file: !1, line: 6, type: !18)
 !21 = !DILocalVariable(name: "a", scope: !15, file: !1, line: 7, type: !7)
 !22 = !DILocation(line: 0, scope: !15)
 !23 = !DILocation(line: 7, column: 11, scope: !15)
 !24 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 12, type: !25, scopeLine: 12, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !27)
 !25 = !DISubroutineType(types: !17)
 !26 = !{!7}
 !27 = !{!28}
 !28 = !DILocalVariable(name: "x", scope: !24, file: !1, line: 13, type: !7)
 !29 = !DILocation(line: 13, column: 3, scope: !24)
 !30 = !DILocation(line: 0, scope: !24)