[mips] Fix 'jumpy' debug line info around calls.

Summary:
At the moment, address calculation is taking the debug line info from the
address node (e.g. TargetGlobalAddress). When a function is called multiple
times, this results in output of the form:

  .loc $first_call_location
  .. address calculation ..
  .. function call ..
  .. address calculation ..
  .loc $second_call_location
  .. function call ..
  .loc $first_call_location
  .. address calculation ..
  .loc $third_call_location
  .. function call ..

This patch makes address calculations for function calls take the debug line
info for the call node and results in output of the form:
  .loc $first_call_location
  .. address calculation ..
  .. function call ..
  .loc $second_call_location
  .. address calculation ..
  .. function call ..
  .loc $third_call_location
  .. address calculation ..
  .. function call ..

All other address calculations continue to use the address node.

Test Plan: Fixes test/DebugInfo/multiline.ll on a mips host.

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D7050

llvm-svn: 227005

llvm/lib/Target/Mips/Mips16ISelLowering.cpp

@@ -497,14 +497,14 @@ getOpndList(SmallVectorImpl<SDValue> &Ops,
   SDValue JumpTarget = Callee;
 
   // T9 should contain the address of the callee function if
-  // -reloction-model=pic or it is an indirect call.
+  // -relocation-model=pic or it is an indirect call.
   if (IsPICCall || !GlobalOrExternal) {
     unsigned V0Reg = Mips::V0;
     if (NeedMips16Helper) {
       RegsToPass.push_front(std::make_pair(V0Reg, Callee));
       JumpTarget = DAG.getExternalSymbol(Mips16HelperFunction, getPointerTy());
       ExternalSymbolSDNode *S = cast<ExternalSymbolSDNode>(JumpTarget);
-      JumpTarget = getAddrGlobal(S, JumpTarget.getValueType(), DAG,
+      JumpTarget = getAddrGlobal(S, CLI.DL, JumpTarget.getValueType(), DAG,
                                  MipsII::MO_GOT, Chain,
                                  FuncInfo->callPtrInfo(S->getSymbol()));
     } else

llvm/lib/Target/Mips/MipsISelLowering.cpp

@@ -1613,22 +1613,22 @@ SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
 
     if (TLOF.IsGlobalInSmallSection(GV, getTargetMachine()))
       // %gp_rel relocation
-      return getAddrGPRel(N, Ty, DAG);
+      return getAddrGPRel(N, SDLoc(N), Ty, DAG);
 
     // %hi/%lo relocation
-    return getAddrNonPIC(N, Ty, DAG);
+    return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
   }
 
   if (GV->hasInternalLinkage() || (GV->hasLocalLinkage() && !isa<Function>(GV)))
-    return getAddrLocal(N, Ty, DAG,
+    return getAddrLocal(N, SDLoc(N), Ty, DAG,
                         Subtarget.isABI_N32() || Subtarget.isABI_N64());
 
   if (LargeGOT)
-    return getAddrGlobalLargeGOT(N, Ty, DAG, MipsII::MO_GOT_HI16,
+    return getAddrGlobalLargeGOT(N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16,
                                  MipsII::MO_GOT_LO16, DAG.getEntryNode(),
                                  MachinePointerInfo::getGOT());
 
-  return getAddrGlobal(N, Ty, DAG,
+  return getAddrGlobal(N, SDLoc(N), Ty, DAG,
                        (Subtarget.isABI_N32() || Subtarget.isABI_N64())
                            ? MipsII::MO_GOT_DISP
                            : MipsII::MO_GOT16,
@@ -1642,9 +1642,9 @@ SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
 
   if (getTargetMachine().getRelocationModel() != Reloc::PIC_ &&
       !Subtarget.isABI_N64())
-    return getAddrNonPIC(N, Ty, DAG);
+    return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
 
-  return getAddrLocal(N, Ty, DAG,
+  return getAddrLocal(N, SDLoc(N), Ty, DAG,
                       Subtarget.isABI_N32() || Subtarget.isABI_N64());
 }
 
@@ -1735,9 +1735,9 @@ lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
 
   if (getTargetMachine().getRelocationModel() != Reloc::PIC_ &&
       !Subtarget.isABI_N64())
-    return getAddrNonPIC(N, Ty, DAG);
+    return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
 
-  return getAddrLocal(N, Ty, DAG,
+  return getAddrLocal(N, SDLoc(N), Ty, DAG,
                       Subtarget.isABI_N32() || Subtarget.isABI_N64());
 }
 
@@ -1754,12 +1754,12 @@ lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
 
     if (TLOF.IsConstantInSmallSection(N->getConstVal(), getTargetMachine()))
       // %gp_rel relocation
-      return getAddrGPRel(N, Ty, DAG);
+      return getAddrGPRel(N, SDLoc(N), Ty, DAG);
 
-    return getAddrNonPIC(N, Ty, DAG);
+    return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
   }
 
-  return getAddrLocal(N, Ty, DAG,
+  return getAddrLocal(N, SDLoc(N), Ty, DAG,
                       Subtarget.isABI_N32() || Subtarget.isABI_N64());
 }
 
@@ -2681,15 +2681,15 @@ MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       InternalLinkage = Val->hasInternalLinkage();
 
       if (InternalLinkage)
-        Callee = getAddrLocal(G, Ty, DAG,
+        Callee = getAddrLocal(G, DL, Ty, DAG,
                               Subtarget.isABI_N32() || Subtarget.isABI_N64());
       else if (LargeGOT) {
-        Callee = getAddrGlobalLargeGOT(G, Ty, DAG, MipsII::MO_CALL_HI16,
+        Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
                                        MipsII::MO_CALL_LO16, Chain,
                                        FuncInfo->callPtrInfo(Val));
         IsCallReloc = true;
       } else {
-        Callee = getAddrGlobal(G, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
+        Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
                                FuncInfo->callPtrInfo(Val));
         IsCallReloc = true;
       }
@@ -2702,15 +2702,15 @@ MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
     const char *Sym = S->getSymbol();
 
     if (!Subtarget.isABI_N64() && !IsPIC) // !N64 && static
-      Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy(),
-                                            MipsII::MO_NO_FLAG);
+      Callee =
+          DAG.getTargetExternalSymbol(Sym, getPointerTy(), MipsII::MO_NO_FLAG);
     else if (LargeGOT) {
-      Callee = getAddrGlobalLargeGOT(S, Ty, DAG, MipsII::MO_CALL_HI16,
+      Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
                                      MipsII::MO_CALL_LO16, Chain,
                                      FuncInfo->callPtrInfo(Sym));
       IsCallReloc = true;
     } else { // N64 || PIC
-      Callee = getAddrGlobal(S, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
+      Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
                              FuncInfo->callPtrInfo(Sym));
       IsCallReloc = true;
     }

llvm/lib/Target/Mips/MipsISelLowering.h

@@ -272,9 +272,8 @@ namespace llvm {
     //
     // (add (load (wrapper $gp, %got(sym)), %lo(sym))
     template <class NodeTy>
-    SDValue getAddrLocal(NodeTy *N, EVT Ty, SelectionDAG &DAG,
+    SDValue getAddrLocal(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG,
                          bool IsN32OrN64) const {
-      SDLoc DL(N);
       unsigned GOTFlag = IsN32OrN64 ? MipsII::MO_GOT_PAGE : MipsII::MO_GOT;
       SDValue GOT = DAG.getNode(MipsISD::Wrapper, DL, Ty, getGlobalReg(DAG, Ty),
                                 getTargetNode(N, Ty, DAG, GOTFlag));
@@ -291,11 +290,10 @@ namespace llvm {
     // computing a global symbol's address:
     //
     // (load (wrapper $gp, %got(sym)))
-    template<class NodeTy>
-    SDValue getAddrGlobal(NodeTy *N, EVT Ty, SelectionDAG &DAG,
+    template <class NodeTy>
+    SDValue getAddrGlobal(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG,
                           unsigned Flag, SDValue Chain,
                           const MachinePointerInfo &PtrInfo) const {
-      SDLoc DL(N);
       SDValue Tgt = DAG.getNode(MipsISD::Wrapper, DL, Ty, getGlobalReg(DAG, Ty),
                                 getTargetNode(N, Ty, DAG, Flag));
       return DAG.getLoad(Ty, DL, Chain, Tgt, PtrInfo, false, false, false, 0);
@@ -305,14 +303,13 @@ namespace llvm {
     // computing a global symbol's address in large-GOT mode:
     //
     // (load (wrapper (add %hi(sym), $gp), %lo(sym)))
-    template<class NodeTy>
-    SDValue getAddrGlobalLargeGOT(NodeTy *N, EVT Ty, SelectionDAG &DAG,
-                                  unsigned HiFlag, unsigned LoFlag,
-                                  SDValue Chain,
+    template <class NodeTy>
+    SDValue getAddrGlobalLargeGOT(NodeTy *N, SDLoc DL, EVT Ty,
+                                  SelectionDAG &DAG, unsigned HiFlag,
+                                  unsigned LoFlag, SDValue Chain,
                                   const MachinePointerInfo &PtrInfo) const {
-      SDLoc DL(N);
-      SDValue Hi = DAG.getNode(MipsISD::Hi, DL, Ty,
-                               getTargetNode(N, Ty, DAG, HiFlag));
+      SDValue Hi =
+          DAG.getNode(MipsISD::Hi, DL, Ty, getTargetNode(N, Ty, DAG, HiFlag));
       Hi = DAG.getNode(ISD::ADD, DL, Ty, Hi, getGlobalReg(DAG, Ty));
       SDValue Wrapper = DAG.getNode(MipsISD::Wrapper, DL, Ty, Hi,
                                     getTargetNode(N, Ty, DAG, LoFlag));
@@ -324,9 +321,9 @@ namespace llvm {
     // computing a symbol's address in non-PIC mode:
     //
     // (add %hi(sym), %lo(sym))
-    template<class NodeTy>
-    SDValue getAddrNonPIC(NodeTy *N, EVT Ty, SelectionDAG &DAG) const {
-      SDLoc DL(N);
+    template <class NodeTy>
+    SDValue getAddrNonPIC(NodeTy *N, SDLoc DL, EVT Ty,
+                          SelectionDAG &DAG) const {
       SDValue Hi = getTargetNode(N, Ty, DAG, MipsII::MO_ABS_HI);
       SDValue Lo = getTargetNode(N, Ty, DAG, MipsII::MO_ABS_LO);
       return DAG.getNode(ISD::ADD, DL, Ty,
@@ -338,9 +335,8 @@ namespace llvm {
     // computing a symbol's address using gp-relative addressing:
     //
     // (add $gp, %gp_rel(sym))
-    template<class NodeTy>
-    SDValue getAddrGPRel(NodeTy *N, EVT Ty, SelectionDAG &DAG) const {
-      SDLoc DL(N);
+    template <class NodeTy>
+    SDValue getAddrGPRel(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG) const {
       assert(Ty == MVT::i32);
       SDValue GPRel = getTargetNode(N, Ty, DAG, MipsII::MO_GPREL);
       return DAG.getNode(ISD::ADD, DL, Ty,

llvm/test/DebugInfo/Mips/fn-call-line.ll

@@ -0,0 +1,84 @@
+; RUN: llc -mtriple=mips-linux-gnu -filetype=asm -asm-verbose=0 -O0 < %s | FileCheck %s
+; RUN: llc -mtriple=mips-linux-gnu -filetype=obj -O0 < %s | llvm-dwarfdump -debug-dump=line - | FileCheck %s --check-prefix=INT
+
+; Mips used to generate 'jumpy' debug line info around calls. The address
+; calculation for each call to f1() would share the same line info so it would
+; emit output of the form:
+;   .loc $first_call_location
+;   .. address calculation ..
+;   .. function call ..
+;   .. address calculation ..
+;   .loc $second_call_location
+;   .. function call ..
+;   .loc $first_call_location
+;   .. address calculation ..
+;   .loc $third_call_location
+;   .. function call ..
+;   ...
+; which would cause confusing stepping behaviour for the end user.
+;
+; This test checks that we emit more user friendly debug line info of the form:
+;   .loc $first_call_location
+;   .. address calculation ..
+;   .. function call ..
+;   .loc $second_call_location
+;   .. address calculation ..
+;   .. function call ..
+;   .loc $third_call_location
+;   .. address calculation ..
+;   .. function call ..
+;   ...
+;
+; Generated with clang from fn-call-line.c:
+; void f1();
+; void f2() {
+;   f1();
+;   f1();
+; }
+
+; CHECK: .loc	1 3 3
+; CHECK-NOT: .loc
+; CHECK: %call16(f1) 
+; CHECK-NOT: .loc
+; CHECK: .loc	1 4 3
+; CHECK-NOT: .loc
+; CHECK: %call16(f1) 
+
+; INT: {{^}}Address
+; INT: -----
+; INT-NEXT: 2 0 1 0 0 is_stmt{{$}}
+; INT-NEXT: 3 3 1 0 0 is_stmt prologue_end{{$}}
+; INT-NEXT: 4 3 1 0 0 is_stmt{{$}}
+
+
+; Function Attrs: nounwind uwtable
+define void @f2() #0 {
+entry:
+  call void (...)* @f1(), !dbg !11
+  call void (...)* @f1(), !dbg !12
+  ret void, !dbg !13
+}
+
+declare void @f1(...) #1
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!8, !9}
+!llvm.ident = !{!10}
+
+!0 = !{!"0x11\0012\00clang version 3.7.0 (trunk 226641)\000\00\000\00\001", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/fn-call-line.c] [DW_LANG_C99]
+!1 = !{!"fn-call-line.c", !"/tmp/dbginfo"}
+!2 = !{}
+!3 = !{!4}
+!4 = !{!"0x2e\00f2\00f2\00\002\000\001\000\000\000\000\002", !1, !5, !6, null, void ()* @f2, null, null, !2} ; [ DW_TAG_subprogram ] [line 2] [def] [f2]
+!5 = !{!"0x29", !1}                               ; [ DW_TAG_file_type ] [/tmp/dbginfo/fn-call-line.c]
+!6 = !{!"0x15\00\000\000\000\000\000\000", null, null, null, !7, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = !{null}
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 2}
+!10 = !{!"clang version 3.7.0 (trunk 226641)"}
+!11 = !MDLocation(line: 3, column: 3, scope: !4)
+!12 = !MDLocation(line: 4, column: 3, scope: !4)
+!13 = !MDLocation(line: 5, column: 1, scope: !4)