Reland "[LiveDebugValues] Emit the debug entry values"

Emit replacements for clobbered parameters location if the parameter
has unmodified value throughout the funciton. This is basic scenario
where we can use the debug entry values.

([12/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>
Differential Revision: https://reviews.llvm.org/D58042

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365444 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index 36f17239483df8b59b58f0a4135928818cf379d6..c82c5b137507bb6c2a515c80e311cace40bc3767 100644 (file)
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -24,6 +24,7 @@
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/TargetOpcodes.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/MC/MCInstrDesc.h"
@@ -1018,6 +1019,12 @@ public:
       && getOperand(1).isImm();
   }
 
+  /// A DBG_VALUE is an entry value iff its debug expression contains the
+  /// DW_OP_entry_value DWARF operation.
+  bool isDebugEntryValue() const {
+    return isDebugValue() && getDebugExpression()->isEntryValue();
+  }
+
   /// Return true if the instruction is a debug value which describes a part of
   /// a variable as unavailable.
   bool isUndefDebugValue() const {

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index f0ceba50f1445e866512f033b9d4c020200720c0..4163fdbb177c41adb37ea1301bd1ef262cefeab0 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1128,6 +1128,12 @@ void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
     DwarfExpr.setMemoryLocationKind();
 
   DIExpressionCursor Cursor(DIExpr);
+
+  if (DIExpr->isEntryValue()) {
+    DwarfExpr.setEntryValueFlag();
+    DwarfExpr.addEntryValueExpression(Cursor);
+  }
+
   const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
   if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
     return;

diff --git a/lib/CodeGen/LiveDebugValues.cpp b/lib/CodeGen/LiveDebugValues.cpp
index 19bd354e611ab0624d35311c86bc7bfcd93b6842..a669e64692b91118131bffb7bfe659c3cf1910fd 100644 (file)
--- a/lib/CodeGen/LiveDebugValues.cpp
+++ b/lib/CodeGen/LiveDebugValues.cpp
@@ -39,6 +39,7 @@
 #include "llvm/CodeGen/TargetFrameLowering.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/Config/llvm-config.h"
@@ -185,7 +186,8 @@ private:
       InvalidKind = 0,
       RegisterKind,
       SpillLocKind,
-      ImmediateKind
+      ImmediateKind,
+      EntryValueKind
     } Kind = InvalidKind;
 
     /// The value location. Stored separately to avoid repeatedly
@@ -199,14 +201,15 @@ private:
       const ConstantInt *CImm;
     } Loc;
 
-    VarLoc(const MachineInstr &MI, LexicalScopes &LS)
-        : Var(MI), MI(MI), UVS(MI.getDebugLoc(), LS) {
+    VarLoc(const MachineInstr &MI, LexicalScopes &LS,
+          VarLocKind K = InvalidKind)
+        : Var(MI), MI(MI), UVS(MI.getDebugLoc(), LS){
       static_assert((sizeof(Loc) == sizeof(uint64_t)),
                     "hash does not cover all members of Loc");
       assert(MI.isDebugValue() && "not a DBG_VALUE");
       assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE");
       if (int RegNo = isDbgValueDescribedByReg(MI)) {
-        Kind = RegisterKind;
+        Kind = MI.isDebugEntryValue() ? EntryValueKind : RegisterKind;
         Loc.RegNo = RegNo;
       } else if (MI.getOperand(0).isImm()) {
         Kind = ImmediateKind;
@@ -218,6 +221,8 @@ private:
         Kind = ImmediateKind;
         Loc.CImm = MI.getOperand(0).getCImm();
       }
+      assert((Kind != ImmediateKind || !MI.isDebugEntryValue()) &&
+             "entry values must be register locations");
     }
 
     /// The constructor for spill locations.
@@ -256,12 +261,12 @@ private:
 
     /// This operator guarantees that VarLocs are sorted by Variable first.
     bool operator<(const VarLoc &Other) const {
-      if (Var == Other.Var)
-        return Loc.Hash < Other.Loc.Hash;
-      return Var < Other.Var;
+      return std::tie(Var, Kind, Loc.Hash) <
+             std::tie(Other.Var, Other.Kind, Other.Loc.Hash);
     }
   };
 
+  using DebugParamMap = SmallDenseMap<const DILocalVariable *, MachineInstr *>;
   using VarLocMap = UniqueVector<VarLoc>;
   using VarLocSet = SparseBitVector<>;
   using VarLocInMBB = SmallDenseMap<const MachineBasicBlock *, VarLocSet>;
@@ -347,17 +352,23 @@ private:
                           VarLocMap &VarLocIDs);
   void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
                                   VarLocMap &VarLocIDs, TransferMap &Transfers);
+  void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges,
+                       VarLocMap &VarLocIDs, TransferMap &Transfers,
+                       DebugParamMap &DebugEntryVals,
+                       SparseBitVector<> &KillSet);
   void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
                             VarLocMap &VarLocIDs, TransferMap &Transfers);
   void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
-                           const VarLocMap &VarLocIDs);
+                           VarLocMap &VarLocIDs, TransferMap &Transfers,
+                           DebugParamMap &DebugEntryVals);
   bool transferTerminatorInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
                               VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
 
   bool process(MachineInstr &MI, OpenRangesSet &OpenRanges,
                VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
-               TransferMap &Transfers, bool transferChanges,
-               OverlapMap &OverlapFragments, VarToFragments &SeenFragments);
+               TransferMap &Transfers, DebugParamMap &DebugEntryVals,
+               bool transferChanges, OverlapMap &OverlapFragments,
+               VarToFragments &SeenFragments);
 
   void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments,
                              OverlapMap &OLapMap);
@@ -568,6 +579,44 @@ void LiveDebugValues::transferDebugValue(const MachineInstr &MI,
   }
 }
 
+void LiveDebugValues::emitEntryValues(MachineInstr &MI,
+                                      OpenRangesSet &OpenRanges,
+                                      VarLocMap &VarLocIDs,
+                                      TransferMap &Transfers,
+                                      DebugParamMap &DebugEntryVals,
+                                      SparseBitVector<> &KillSet) {
+  MachineFunction *MF = MI.getParent()->getParent();
+  for (unsigned ID : KillSet) {
+    if (!VarLocIDs[ID].Var.getVar()->isParameter())
+      continue;
+
+    const MachineInstr *CurrDebugInstr = &VarLocIDs[ID].MI;
+
+    // If parameter's DBG_VALUE is not in the map that means we can't
+    // generate parameter's entry value.
+    if (!DebugEntryVals.count(CurrDebugInstr->getDebugVariable()))
+      continue;
+
+    auto ParamDebugInstr = DebugEntryVals[CurrDebugInstr->getDebugVariable()];
+    DIExpression *NewExpr = DIExpression::prepend(
+        ParamDebugInstr->getDebugExpression(), DIExpression::EntryValue);
+    MachineInstr *EntryValDbgMI =
+        BuildMI(*MF, ParamDebugInstr->getDebugLoc(), ParamDebugInstr->getDesc(),
+                ParamDebugInstr->isIndirectDebugValue(),
+                ParamDebugInstr->getOperand(0).getReg(),
+                ParamDebugInstr->getDebugVariable(), NewExpr);
+
+    if (ParamDebugInstr->isIndirectDebugValue())
+      EntryValDbgMI->getOperand(1).setImm(
+          ParamDebugInstr->getOperand(1).getImm());
+
+    Transfers.push_back({&MI, EntryValDbgMI});
+    VarLoc VL(*EntryValDbgMI, LS);
+    unsigned EntryValLocID = VarLocIDs.insert(VL);
+    OpenRanges.insert(EntryValLocID, VL.Var);
+  }
+}
+
 /// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
 /// with \p OldVarID should be deleted form \p OpenRanges and replaced with
 /// new VarLoc. If \p NewReg is different than default zero value then the
@@ -658,9 +707,9 @@ void LiveDebugValues::insertTransferDebugPair(
 }
 
 /// A definition of a register may mark the end of a range.
-void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
-                                          OpenRangesSet &OpenRanges,
-                                          const VarLocMap &VarLocIDs) {
+void LiveDebugValues::transferRegisterDef(
+    MachineInstr &MI, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs,
+    TransferMap &Transfers, DebugParamMap &DebugEntryVals) {
   MachineFunction *MF = MI.getMF();
   const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
   unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
@@ -690,6 +739,13 @@ void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
     }
   }
   OpenRanges.erase(KillSet, VarLocIDs);
+
+  if (auto *TPC = getAnalysisIfAvailable<TargetPassConfig>()) {
+    auto &TM = TPC->getTM<TargetMachine>();
+    if (TM.Options.EnableDebugEntryValues)
+      emitEntryValues(MI, OpenRanges, VarLocIDs, Transfers, DebugEntryVals,
+                      KillSet);
+  }
 }
 
 /// Decide if @MI is a spill instruction and return true if it is. We use 2
@@ -941,12 +997,14 @@ void LiveDebugValues::accumulateFragmentMap(MachineInstr &MI,
 /// This routine creates OpenRanges and OutLocs.
 bool LiveDebugValues::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
                               VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
-                              TransferMap &Transfers, bool transferChanges,
+                              TransferMap &Transfers, DebugParamMap &DebugEntryVals,
+                              bool transferChanges,
                               OverlapMap &OverlapFragments,
                               VarToFragments &SeenFragments) {
   bool Changed = false;
   transferDebugValue(MI, OpenRanges, VarLocIDs);
-  transferRegisterDef(MI, OpenRanges, VarLocIDs);
+  transferRegisterDef(MI, OpenRanges, VarLocIDs, Transfers,
+                      DebugEntryVals);
   if (transferChanges) {
     transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
     transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers);
@@ -1100,6 +1158,43 @@ bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
 
   enum : bool { dontTransferChanges = false, transferChanges = true };
 
+  // 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();
+  unsigned 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 that are described as 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) &&
+        !MI.isIndirectDebugValue() && IsRegOtherThanSPAndFP(MI.getOperand(0)) &&
+        !DebugEntryVals.count(MI.getDebugVariable()) &&
+        !MI.getDebugExpression()->isFragment())
+      DebugEntryVals[MI.getDebugVariable()] = &MI;
+
   // Initialize every mbb with OutLocs.
   // We are not looking at any spill instructions during the initial pass
   // over the BBs. The LiveDebugVariables pass has already created DBG_VALUE
@@ -1107,9 +1202,16 @@ bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
   // within the BB in which the spill occurs.
   for (auto &MBB : MF) {
     for (auto &MI : MBB) {
-      process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
+      process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers, DebugEntryVals,
               dontTransferChanges, OverlapFragments, SeenFragments);
     }
+    // Add any entry DBG_VALUE instructions necessitated by parameter
+    // clobbering.
+    for (auto &TR : Transfers) {
+      MBB.insertAfter(MachineBasicBlock::iterator(*TR.TransferInst),
+                     TR.DebugInst);
+    }
+    Transfers.clear();
   }
 
   auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool {
@@ -1158,7 +1260,8 @@ bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
         for (auto &MI : *MBB)
           OLChanged |=
               process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
-                      transferChanges, OverlapFragments, SeenFragments);
+                      DebugEntryVals, transferChanges, OverlapFragments,
+                      SeenFragments);
 
         // Add any DBG_VALUE instructions necessitated by spills.
         for (auto &TR : Transfers)

diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index f9b548653cf5fd6a862ad8d43a7ada336335b3bd..0ad792ac62cf4f9f22d29394848e7216ed399e4f 100644 (file)
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -840,7 +840,7 @@ void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
   if (MI->isTerminator() && !TII->isPredicated(*MI)) {
     if (!FirstTerminator)
       FirstTerminator = MI;
-  } else if (FirstTerminator) {
+  } else if (FirstTerminator && !MI->isDebugEntryValue()) {
     report("Non-terminator instruction after the first terminator", MI);
     errs() << "First terminator was:\t" << *FirstTerminator;
   }

diff --git a/test/DebugInfo/MIR/X86/avoid-single-entry-value-location.mir b/test/DebugInfo/MIR/X86/avoid-single-entry-value-location.mir
new file mode 100644 (file)
index 0000000..06ed00c
--- /dev/null
+++ b/test/DebugInfo/MIR/X86/avoid-single-entry-value-location.mir
@@ -0,0 +1,67 @@
+# RUN: llc -mtriple=x86_64-pc-linux %s -dwarf-version=5 -start-after=livedebugvalues -filetype=obj -o %t
+# RUN: llvm-dwarfdump -v %t | FileCheck %s
+#
+# CHECK: DW_AT_location {{.*}} (DW_OP_entry_value
+#
+--- |
+  ; ModuleID = 'test.ll'
+  source_filename = "test.c"
+  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+  target triple = "x86_64-unknown-linux-gnu"
+  
+  ; Function Attrs: noinline nounwind uwtable
+  define dso_local void @fn1(i8* %x) local_unnamed_addr !dbg !12 {
+  entry:
+    call void @llvm.dbg.value(metadata i8* %x, metadata !16, metadata !DIExpression()), !dbg !18
+    %0 = ptrtoint i8* %x to i64, !dbg !18
+    %y = trunc i64 %0 to i32, !dbg !18
+    call void @llvm.dbg.value(metadata i32 %y, metadata !17, metadata !DIExpression()), !dbg !18
+    tail call void @fn2(i32 7), !dbg !18
+    ret void, !dbg !18
+  }
+  
+  declare !dbg !4 dso_local void @fn2(i32) local_unnamed_addr
+  
+  ; Function Attrs: nounwind readnone speculatable
+  declare void @llvm.dbg.value(metadata, metadata, metadata)
+  
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!8, !9, !10}
+  !llvm.ident = !{!11}
+  
+  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
+  !1 = !DIFile(filename: "test.c", directory: "/dir")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DISubprogram(name: "fn2", scope: !1, file: !1, line: 1, type: !5, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
+  !5 = !DISubroutineType(types: !6)
+  !6 = !{null, !7}
+  !7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !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)
+  !17 = !DILocalVariable(name: "y", scope: !12, file: !1, line: 5, type: !7)
+  !18 = !DILocation(line: 0, scope: !12)
+
+...
+---
+name:            fn1
+alignment:       4
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+  liveins: $rdi
+    DBG_VALUE $rdi, $noreg, !16, !DIExpression(), debug-location !18
+    DBG_VALUE $edi, $noreg, !16, !DIExpression(), debug-location !18
+    DBG_VALUE $edi, $noreg, !17, !DIExpression(), debug-location !18
+    $edi = KILL renamable $edi, implicit killed $rdi, debug-location !18
+    DBG_VALUE $rdi, $noreg, !16, !DIExpression(DW_OP_entry_value, 1), debug-location !18
+    TAILJMPd64 @fn2, csr_64, implicit $rsp, implicit $ssp, implicit $rsp, implicit $ssp, implicit killed $edi, debug-location !18
+
+...

diff --git a/test/DebugInfo/MIR/X86/dbginfo-entryvals.mir b/test/DebugInfo/MIR/X86/dbginfo-entryvals.mir
new file mode 100644 (file)
index 0000000..d273531
--- /dev/null
+++ b/test/DebugInfo/MIR/X86/dbginfo-entryvals.mir
@@ -0,0 +1,79 @@
+# RUN: llc -debug-entry-values -run-pass=livedebugvalues -march=x86-64 -o - %s | FileCheck %s
+#
+#extern void fn2(int);
+#
+#__attribute__((noinline))
+#void
+#fn1 (int x, int y) {
+#  int u = x + y;
+#  if (x > 1)
+#    u += 1;
+#  else
+#    u += 2;
+#  int a = 7;
+#  fn2 (a);
+#  u --;
+#}
+# CHECK: DBG_VALUE $edi, $noreg, !14, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+# CHECK: DBG_VALUE $esi, $noreg, !15, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+
+--- |
+  ; ModuleID = 'test.c'
+  source_filename = "test.c"
+  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+  
+  ; Function Attrs: noinline nounwind uwtable
+  define dso_local void @fn1(i32 %x, i32 %y) local_unnamed_addr !dbg !9 {
+  entry:
+    call void @llvm.dbg.value(metadata i32 %x, metadata !14, metadata !DIExpression()), !dbg !18
+    call void @llvm.dbg.value(metadata i32 %y, metadata !15, metadata !DIExpression()), !dbg !18
+    call void @llvm.dbg.value(metadata i32 7, metadata !17, metadata !DIExpression()), !dbg !18
+    tail call void @fn2(i32 7), !dbg !18
+    ret void, !dbg !18
+  }
+  
+  declare !dbg !4 dso_local void @fn2(i32) local_unnamed_addr
+  
+  ; Function Attrs: nounwind readnone speculatable
+  declare void @llvm.dbg.value(metadata, metadata, metadata)
+  
+  
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!5, !6, !7}
+  !llvm.ident = !{!8}
+  
+  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
+  !1 = !DIFile(filename: "test.c", directory: "/dir")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DISubprogram(name: "fn2", scope: !1, file: !1, line: 11, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
+  !5 = !{i32 2, !"Dwarf Version", i32 4}
+  !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)
+  !18 = !DILocation(line: 15, column: 10, scope: !9)
+
+...
+---
+name:            fn1
+alignment:       4
+tracksRegLiveness: true
+liveins:         []
+body:             |
+  bb.0.entry:
+    DBG_VALUE $edi, $noreg, !14, !DIExpression(), debug-location !18
+    DBG_VALUE $esi, $noreg, !15, !DIExpression(), debug-location !18
+    DBG_VALUE 7, $noreg, !17, !DIExpression(), debug-location !18
+    $edi = MOV32ri 7, debug-location !18
+    TAILJMPd64 @fn2, csr_64, implicit $rsp, implicit $ssp, implicit $rsp, implicit $ssp, implicit killed $edi, debug-location !18
+
+...

diff --git a/test/DebugInfo/MIR/X86/multiple-param-dbg-value-entry.mir b/test/DebugInfo/MIR/X86/multiple-param-dbg-value-entry.mir
new file mode 100644 (file)
index 0000000..c136d41
--- /dev/null
+++ b/test/DebugInfo/MIR/X86/multiple-param-dbg-value-entry.mir
@@ -0,0 +1,83 @@
+# RUN: llc -debug-entry-values -run-pass=livedebugvalues -march=x86-64 -o - %s| FileCheck %s
+#
+#int global;
+#int foo(int p, int q, int r) {
+#  global = p + 1;
+#  asm __volatile("" : : : "edi", "esi", "edx");
+#  return 123;
+#}
+#
+# Verify that DW_OP_entry_values are generated for parameters with multiple
+# DBG_VALUEs at entry block.
+# CHECK: DBG_VALUE $edi, $noreg, !{{.*}}, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+# CHECK: DBG_VALUE $edx, $noreg, !{{.*}}, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+# CHECK: DBG_VALUE $esi, $noreg, !{{.*}}, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+
+--- |
+  ; ModuleID = 'multiple-param-dbg-value-entry.ll'
+  source_filename = "multiple-param-dbg-value-entry.c"
+  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+  
+  @global = common dso_local local_unnamed_addr global i32 0, align 4, !dbg !0
+  
+  define dso_local i32 @foo(i32 %p, i32 %q, i32 %r) local_unnamed_addr !dbg !11 {
+  entry:
+    call void @llvm.dbg.value(metadata i32 %p, metadata !15, metadata !DIExpression()), !dbg !18
+    call void @llvm.dbg.value(metadata i32 %q, metadata !16, metadata !DIExpression()), !dbg !18
+    call void @llvm.dbg.value(metadata i32 %r, metadata !17, metadata !DIExpression()), !dbg !18
+    %add = add nsw i32 %p, 1, !dbg !18
+    store i32 %add, i32* @global, align 4, !dbg !18
+    tail call void asm sideeffect "", "~{edi},~{esi},~{edx},~{dirflag},~{fpsr},~{flags}"(), !dbg !18, !srcloc !19
+    ret i32 123, !dbg !18
+  }
+  
+  ; Function Attrs: nounwind readnone speculatable
+  declare void @llvm.dbg.value(metadata, metadata, metadata)
+  
+  !llvm.dbg.cu = !{!2}
+  !llvm.module.flags = !{!7, !8, !9}
+  !llvm.ident = !{!10}
+  
+  !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+  !1 = distinct !DIGlobalVariable(name: "global", scope: !2, file: !3, line: 8, type: !6, isLocal: false, isDefinition: true)
+  !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 9.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+  !3 = !DIFile(filename: "multiple-param-dbg-value-entry.c", directory: "/")
+  !4 = !{}
+  !5 = !{!0}
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !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)
+  !18 = !DILocation(line: 9, column: 13, scope: !11)
+  !19 = !{i32 213}
+
+...
+---
+name:            foo
+alignment:       4
+tracksRegLiveness: true
+liveins:         
+  - { reg: '$edi' }
+body:             |
+  bb.0.entry:
+    liveins: $edi
+  
+    DBG_VALUE $edi, $noreg, !15, !DIExpression(), debug-location !18
+    DBG_VALUE $edi, $noreg, !15, !DIExpression(), debug-location !18
+    DBG_VALUE $esi, $noreg, !16, !DIExpression(), debug-location !18
+    DBG_VALUE $edx, $noreg, !17, !DIExpression(), debug-location !18
+    renamable $edi = nsw INC32r killed renamable $edi, implicit-def dead $eflags, debug-location !18
+    MOV32mr $rip, 1, $noreg, @global, $noreg, killed renamable $edi, debug-location !18 :: (store 4 into @global)
+    INLINEASM &"", 1, 12, implicit-def dead early-clobber $edi, 12, implicit-def dead early-clobber $esi, 12, implicit-def dead early-clobber $edx, 12, implicit-def dead early-clobber $df, 12, implicit-def dead early-clobber $fpsw, 12, implicit-def dead early-clobber $eflags, !19, debug-location !18
+    $eax = MOV32ri 123, debug-location !18
+    RETQ killed $eax, debug-location !18
+
+...