[DebugInfo] Fix ARM/AArch64 prologue_end position. Related to D11268.

Summary:
This review is related to another review request http://reviews.llvm.org/D11268, does the same and merely fixes a couple of issues with it.

D11268 is quite old and has merge conflicts against the current trunk.
This request 
 - rebases D11268 onto the new trunk;
 - resolves the merge conflicts;
 - fixes the prologue_end tests, which do not pass due to the subprogram definitions not marked as distinct.

Reviewers: echristo, rengolin, kubabrecka

Subscribers: aemerson, rengolin, jyknight, dsanders, llvm-commits, asl

Differential Revision: http://reviews.llvm.org/D14338

llvm-svn: 252177

llvm/lib/Target/AArch64/AArch64FrameLowering.cpp

@@ -287,7 +287,10 @@ void AArch64FrameLowering::emitPrologue(MachineFunction &MF,
   AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
   bool needsFrameMoves = MMI.hasDebugInfo() || Fn->needsUnwindTableEntry();
   bool HasFP = hasFP(MF);
-  DebugLoc DL = MBB.findDebugLoc(MBBI);
+
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc DL;
 
   // All calls are tail calls in GHC calling conv, and functions have no
   // prologue/epilogue.
@@ -730,9 +733,6 @@ bool AArch64FrameLowering::spillCalleeSavedRegisters(
   DebugLoc DL;
   assert((Count & 1) == 0 && "Odd number of callee-saved regs to spill!");
 
-  if (MI != MBB.end())
-    DL = MI->getDebugLoc();
-
   for (unsigned i = 0; i < Count; i += 2) {
     unsigned idx = Count - i - 2;
     unsigned Reg1 = CSI[idx].getReg();

llvm/lib/Target/ARM/ARMFrameLowering.cpp

@@ -305,7 +305,11 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF,
   unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize();
   unsigned NumBytes = MFI->getStackSize();
   const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
-  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc dl;
+  
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
 
   // Determine the sizes of each callee-save spill areas and record which frame
@@ -893,7 +897,6 @@ void ARMFrameLowering::emitPushInst(MachineBasicBlock &MBB,
   const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
 
   DebugLoc DL;
-  if (MI != MBB.end()) DL = MI->getDebugLoc();
 
   SmallVector<std::pair<unsigned,bool>, 4> Regs;
   unsigned i = CSI.size();

llvm/lib/Target/ARM/Thumb1FrameLowering.cpp

@@ -100,7 +100,11 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF,
   assert(NumBytes >= ArgRegsSaveSize &&
          "ArgRegsSaveSize is included in NumBytes");
   const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
-  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc dl;
+  
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
   unsigned BasePtr = RegInfo->getBaseRegister();
   int CFAOffset = 0;
@@ -168,8 +172,6 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF,
 
   if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) {
     ++MBBI;
-    if (MBBI != MBB.end())
-      dl = MBBI->getDebugLoc();
   }
 
   // Determine starting offsets of spill areas.
@@ -546,8 +548,6 @@ spillCalleeSavedRegisters(MachineBasicBlock &MBB,
   DebugLoc DL;
   const TargetInstrInfo &TII = *STI.getInstrInfo();
 
-  if (MI != MBB.end()) DL = MI->getDebugLoc();
-
   MachineInstrBuilder MIB = BuildMI(MBB, MI, DL, TII.get(ARM::tPUSH));
   AddDefaultPred(MIB);
   for (unsigned i = CSI.size(); i != 0; --i) {

llvm/lib/Target/Mips/Mips16FrameLowering.cpp

@@ -39,7 +39,11 @@ void Mips16FrameLowering::emitPrologue(MachineFunction &MF,
   const Mips16InstrInfo &TII =
       *static_cast<const Mips16InstrInfo *>(STI.getInstrInfo());
   MachineBasicBlock::iterator MBBI = MBB.begin();
-  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc dl;
+
   uint64_t StackSize = MFI->getStackSize();
 
   // No need to allocate space on the stack.

llvm/lib/Target/Mips/Mips16ISelDAGToDAG.cpp

@@ -73,7 +73,7 @@ void Mips16DAGToDAGISel::initGlobalBaseReg(MachineFunction &MF) {
   MachineBasicBlock::iterator I = MBB.begin();
   MachineRegisterInfo &RegInfo = MF.getRegInfo();
   const TargetInstrInfo &TII = *Subtarget->getInstrInfo();
-  DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+  DebugLoc DL;
   unsigned V0, V1, V2, GlobalBaseReg = MipsFI->getGlobalBaseReg();
   const TargetRegisterClass *RC = &Mips::CPU16RegsRegClass;
 

llvm/lib/Target/Mips/Mips16InstrInfo.cpp

@@ -196,7 +196,7 @@ static void addSaveRestoreRegs(MachineInstrBuilder &MIB,
 void Mips16InstrInfo::makeFrame(unsigned SP, int64_t FrameSize,
                                 MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator I) const {
-  DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+  DebugLoc DL;
   MachineFunction &MF = *MBB.getParent();
   MachineFrameInfo *MFI    = MF.getFrameInfo();
   const BitVector Reserved = RI.getReservedRegs(MF);
@@ -263,7 +263,7 @@ void Mips16InstrInfo::adjustStackPtrBig(unsigned SP, int64_t Amount,
                                         MachineBasicBlock &MBB,
                                         MachineBasicBlock::iterator I,
                                         unsigned Reg1, unsigned Reg2) const {
-  DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+  DebugLoc DL;
   //
   // li reg1, constant
   // move reg2, sp
@@ -446,7 +446,7 @@ const MCInstrDesc &Mips16InstrInfo::AddiuSpImm(int64_t Imm) const {
 
 void Mips16InstrInfo::BuildAddiuSpImm
   (MachineBasicBlock &MBB, MachineBasicBlock::iterator I, int64_t Imm) const {
-  DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+  DebugLoc DL;
   BuildMI(MBB, I, DL, AddiuSpImm(Imm)).addImm(Imm);
 }
 

llvm/lib/Target/Sparc/SparcFrameLowering.cpp

@@ -44,7 +44,7 @@ void SparcFrameLowering::emitSPAdjustment(MachineFunction &MF,
                                           unsigned ADDrr,
                                           unsigned ADDri) const {
 
-  DebugLoc dl = (MBBI != MBB.end()) ? MBBI->getDebugLoc() : DebugLoc();
+  DebugLoc dl;
   const SparcInstrInfo &TII =
       *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo());
 
@@ -93,7 +93,9 @@ void SparcFrameLowering::emitPrologue(MachineFunction &MF,
   const SparcRegisterInfo &RegInfo =
       *static_cast<const SparcRegisterInfo *>(MF.getSubtarget().getRegisterInfo());
   MachineBasicBlock::iterator MBBI = MBB.begin();
-  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc dl;
   bool NeedsStackRealignment = RegInfo.needsStackRealignment(MF);
 
   // FIXME: unfortunately, returning false from canRealignStack

llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp

@@ -133,7 +133,7 @@ spillCalleeSavedRegisters(MachineBasicBlock &MBB,
   const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
   SystemZMachineFunctionInfo *ZFI = MF.getInfo<SystemZMachineFunctionInfo>();
   bool IsVarArg = MF.getFunction()->isVarArg();
-  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+  DebugLoc DL;
 
   // Scan the call-saved GPRs and find the bounds of the register spill area.
   unsigned LowGPR = 0;
@@ -322,7 +322,10 @@ void SystemZFrameLowering::emitPrologue(MachineFunction &MF,
   const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
   const std::vector<CalleeSavedInfo> &CSI = MFFrame->getCalleeSavedInfo();
   bool HasFP = hasFP(MF);
-  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc DL;
 
   // The current offset of the stack pointer from the CFA.
   int64_t SPOffsetFromCFA = -SystemZMC::CFAOffsetFromInitialSP;

llvm/lib/Target/X86/X86FrameLowering.cpp

@@ -640,6 +640,9 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF,
           ? getX86SubSuperRegister(FramePtr, MVT::i64, false)
           : FramePtr;
   unsigned BasePtr = TRI->getBaseRegister();
+  
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
   DebugLoc DL;
 
   // Add RETADDR move area to callee saved frame size.

llvm/test/DebugInfo/AArch64/prologue_end.ll

@@ -0,0 +1,43 @@
+; RUN: llc -disable-fp-elim -O0 %s -mtriple aarch64-apple-darwin -o - | FileCheck %s
+
+; int func(void);
+; void prologue_end_test() {
+;   func();
+;   func();
+; }
+
+define void @prologue_end_test() nounwind uwtable {
+  ; CHECK: prologue_end_test:
+  ; CHECK: .cfi_startproc
+  ; CHECK: stp x29, x30
+  ; CHECK: mov x29, sp
+  ; CHECK: sub sp, sp
+  ; CHECK: .loc 1 3 3 prologue_end
+  ; CHECK: bl _func
+  ; CHECK: bl _func
+entry:
+  %call = call i32 @func(), !dbg !11
+  %call1 = call i32 @func(), !dbg !12
+  ret void, !dbg !13
+}
+
+declare i32 @func()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 242129)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "foo.c", directory: "/tmp")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "prologue_end_test", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: false, function: void ()* @prologue_end_test, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 2}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"PIC Level", i32 2}
+!10 = !{!"clang version 3.7.0 (trunk 242129)"}
+!11 = !DILocation(line: 3, column: 3, scope: !4)
+!12 = !DILocation(line: 4, column: 3, scope: !4)
+!13 = !DILocation(line: 5, column: 1, scope: !4)

llvm/test/DebugInfo/ARM/prologue_end.ll

@@ -0,0 +1,46 @@
+; RUN: llc -disable-fp-elim -O0 %s -mtriple armv7-apple-darwin -o - | FileCheck %s
+; RUN: llc -disable-fp-elim -O0 %s -mtriple thumbv1-apple-darwin -o - | FileCheck %s
+
+; int func(void);
+; void prologue_end_test() {
+;   func();
+;   func();
+; }
+
+define void @prologue_end_test() nounwind uwtable {
+  ; CHECK: prologue_end_test:
+  ; CHECK: .cfi_startproc
+  ; CHECK: push {r7, lr}
+  ; CHECK: {{mov r7, sp|add r7, sp}}
+  ; CHECK: sub sp
+  ; CHECK: .loc 1 3 3 prologue_end
+  ; CHECK: bl {{_func|Ltmp}}
+  ; CHECK: bl {{_func|Ltmp}}
+entry:
+  %call = call i32 @func(), !dbg !13
+  %call1 = call i32 @func(), !dbg !14
+  ret void, !dbg !15
+}
+
+declare i32 @func()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9, !10, !11}
+!llvm.ident = !{!12}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 242129)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "foo.c", directory: "/tmp")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "prologue_end_test", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: false, function: void ()* @prologue_end_test, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 2}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{i32 1, !"min_enum_size", i32 4}
+!11 = !{i32 1, !"PIC Level", i32 2}
+!12 = !{!"clang version 3.7.0 (trunk 242129)"}
+!13 = !DILocation(line: 3, column: 3, scope: !4)
+!14 = !DILocation(line: 4, column: 3, scope: !4)
+!15 = !DILocation(line: 5, column: 1, scope: !4)

llvm/test/DebugInfo/Sparc/prologue_end.ll

@@ -0,0 +1,41 @@
+; RUN: llc -disable-fp-elim -O0 %s -mtriple sparc -o - | FileCheck %s
+
+; int func(void);
+; void prologue_end_test() {
+;   func();
+;   func();
+; }
+
+define void @prologue_end_test() nounwind uwtable {
+  ; CHECK: prologue_end_test:
+  ; CHECK: .cfi_startproc
+  ; CHECK: save %sp
+  ; CHECK: .loc 1 3 3 prologue_end
+  ; CHECK: call func
+  ; CHECK: call func
+entry:
+  %call = call i32 @func(), !dbg !11
+  %call1 = call i32 @func(), !dbg !12
+  ret void, !dbg !13
+}
+
+declare i32 @func()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 242129)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "foo.c", directory: "/tmp")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "prologue_end_test", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: false, function: void ()* @prologue_end_test, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 2}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"PIC Level", i32 2}
+!10 = !{!"clang version 3.7.0 (trunk 242129)"}
+!11 = !DILocation(line: 3, column: 3, scope: !4)
+!12 = !DILocation(line: 4, column: 3, scope: !4)
+!13 = !DILocation(line: 5, column: 1, scope: !4)

llvm/test/DebugInfo/SystemZ/prologue_end.ll

@@ -0,0 +1,42 @@
+; RUN: llc -disable-fp-elim -O0 %s -mtriple s390x-linux-gnu -o - | FileCheck %s
+
+; int func(void);
+; void prologue_end_test() {
+;   func();
+;   func();
+; }
+
+define void @prologue_end_test() nounwind uwtable {
+  ; CHECK: prologue_end_test:
+  ; CHECK: .cfi_startproc
+  ; CHECK: aghi
+  ; CHECK: lgr
+  ; CHECK: .loc 1 3 3 prologue_end
+  ; CHECK: brasl {{.*}}, func
+  ; CHECK: brasl {{.*}}, func
+entry:
+  %call = call i32 @func(), !dbg !11
+  %call1 = call i32 @func(), !dbg !12
+  ret void, !dbg !13
+}
+
+declare i32 @func()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 242129)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "foo.c", directory: "/tmp")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "prologue_end_test", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: false, function: void ()* @prologue_end_test, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 2}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"PIC Level", i32 2}
+!10 = !{!"clang version 3.7.0 (trunk 242129)"}
+!11 = !DILocation(line: 3, column: 3, scope: !4)
+!12 = !DILocation(line: 4, column: 3, scope: !4)
+!13 = !DILocation(line: 5, column: 1, scope: !4)