[llvm] r309651 - [StackColoring] Update AliasAnalysis information in stack coloring pass

Hiroshi 7 Inoue via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 3 08:47:53 PDT 2017


Hi Mikael, Mattias,

It looks like a bug in my patch. I do not intend to change that behavior.
Maybe we need `return false` depending on the results of
getUnderlyingObjectsForCodeGen.

I am sorry for bothering you.

-----
Hiroshi Inoue <inouehrs at jp.ibm.com>
IBM Research - Tokyo


Mikael Holmén <mikael.holmen at ericsson.com> wrote on 2017/10/03 14:22:19:

> From: Mikael Holmén <mikael.holmen at ericsson.com>
> To: Hiroshi 7 Inoue <INOUEHRS at jp.ibm.com>
> Cc: Mattias Eriksson V <mattias.v.eriksson at ericsson.com>, <llvm-
> commits at lists.llvm.org>, Hal Finkel <hfinkel at anl.gov>, Matthias
> Braun <matze at braunis.de>
> Date: 2017/10/03 14:22
> Subject: Re: [llvm] r309651 - [StackColoring] Update AliasAnalysis
> information in stack coloring pass

>
> Hi Hiroshi,
>
> On 10/02/2017 06:37 PM, Mattias Eriksson V wrote:
> > On 10/02/2017 06:20 PM, Hiroshi 7 Inoue wrote:
> >> Hi Mikael,
> >>
> >> Thank you for sharing your problem. I will investigate it.
> >> Do you have this problem with the latest code base? I have updated my
> >> first patch (r309651) in https://urldefense.proofpoint.com/v2/
> url?u=https-3A__reviews.llvm.org_rL309849&d=DwIF-g&c=jf_iaSHvJObTbx-
> siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
>
YkVI&m=LpTapfEiXCfaCXpeIggFCkGTbgEzp0_1t3xivK5Dkqg&s=FNJP45aHFjcZvjKgUenRJIUj7zz4zJUeAG5kNqCAsTE&e=

> .
> >
> > Hi, Hiroshi!
> >
> > Yes, we see the issue also with part 2 applied.
> >
>
> Yes as Mattias said part 2 suffers from the same problem since it also
> happily continues with memop #2 even after memop #1 was found to be
> non-identified, and fails to inform buildSchedGraph about it.
>
> Regards,
> Mikael
>
> > --
> > Mattias
> >
> >>
> >> Regards,
> >> Hiroshi
> >>
> >> -----
> >> Hiroshi Inoue <inouehrs at jp.ibm.com>
> >> IBM Research - Tokyo
> >>
> >>
> >> Mikael Holmén <mikael.holmen at ericsson.com> wrote on 2017/10/02
20:34:01:
> >>
> >>  > From: Mikael Holmén <mikael.holmen at ericsson.com>
> >>  > To: Hiroshi Inoue <inouehrs at jp.ibm.com>, <llvm-
> >>  > commits at lists.llvm.org>, "Hal Finkel" <hfinkel at anl.gov>, Matthias
> >>  > Braun <matze at braunis.de>
> >>  > Cc: Mattias Eriksson V <mattias.v.eriksson at ericsson.com>
> >>  > Date: 2017/10/02 20:35
> >>  > Subject: Re: [llvm] r309651 - [StackColoring] Update AliasAnalysis
> >>  > information in stack coloring pass
> >>  >
> >>  > Hi Hiroshi, Matthias and Hal,
> >>  >
> >>  > (CC my colleague Mattias)
> >>  >
> >>  > I think I've found a problem with this patch.
> >>  >
> >>  > Found it on my out-of-tree target, but I'll try to describe what's
> >>  > happening.
> >>  >
> >>  > The problem is during scheduling where we fail to identify a
> >> dependency
> >>  > between a store and a following load. The store _might_ store at
the
> >>  > same address as the load loads from, but it doesn't always do it.
It
> >>  > depends on earlier code flow.
> >>  >
> >>  > The store looks like:
> >>  >
> >>  >    mv_a32_r16_rmod1 %a0_32, %r1; mem:ST2[%_tmp9] ST2[@g_290]
> >>  >
> >>  > I.e. it has two memops describing the two different memory
> >> locations it
> >>  > might store to (is this weird?). They memory locations are
completely
> >>  > unrelated and describe the two locations the pointer %r1 can point
to.
> >>  >
> >>  > Before this patch, when ScheduleDAGInstrs::buildSchedGraph called
> >>  >
> >>  >      UnderlyingObjectsVector Objs;
> >>  >      getUnderlyingObjectsForInstr(&MI, MFI, Objs, MF.getDataLayout
());
> >>  >
> >>  > it got an empty Objs vector back since getUnderlyingObjectsForInstr
> >>  > found one non-identified object (%_tmp9) and then cleared the whole

> >> vector.
> >>  >
> >>  > With this patch, I instead get a non-empty Objs, containing only
> >> @g_290
> >>  > and because of that we don't add a chain dependency towards the
load
> >>  > following the store, and we get wrong code as a result.
> >>  >
> >>  > I know there is code in the method getUnderlyingObjectsForCodeGen
that
> >>  > looks for non-identified objects and if found it clears the Objects
> >>  > arrays, but the way it's implemented it doesn't help!
> >>  >
> >>  > In my current case where there are two memops and the first one is
> >>  > non-identified, we still continue with the second memop afterwards
and
> >>  > add that underlying object to the vector, and leave that to the
> >>  > schedgraph builder where we don't see any traces of any
non-identified
> >>  > object, and we build a graph with missing dependencies
> >>  >
> >>  > I suppose this difference is not intended?
> >>  >
> >>  > Regards,
> >>  > Mikael
> >>  >
> >>  > On 08/01/2017 05:32 AM, Hiroshi Inoue via llvm-commits wrote:
> >>  > > Author: inouehrs
> >>  > > Date: Mon Jul 31 20:32:15 2017
> >>  > > New Revision: 309651
> >>  > >
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject-3Frev-3D309651-26view-3Drev&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=e3Q5lQrWHghbIG_b8_wJ0PPVh5IF218IDKqkTOkGGV0&e=

> >>
> >>  > > Log:
> >>  > > [StackColoring] Update AliasAnalysis information in stack
> >> coloring pass
> >>  > >
> >>  > > Stack coloring pass need to maintain AliasAnalysis information
> >>  > when merging stack slots of different types.
> >>  > > Actually, there is a FIXME comment in StackColoring.cpp
> >>  > >
> >>  > > // FIXME: In order to enable the use of TBAA when using AA in
> >> CodeGen,
> >>  > > // we'll also need to update the TBAA nodes in MMOs with values
> >>  > > // derived from the merged allocas.
> >>  > >
> >>  > > But, TBAA has been already enabled in CodeGen without fixing this

> >> pass.
> >>  > > The incorrect TBAA metadata results in recent failures in
> >>  > bootstrap test on ppc64le (PR33928) by allowing unsafe instruction
> >> scheduling.
> >>  > > Although we observed the problem on ppc64le, this is a platform
> >>  > neutral issue.
> >>  > >
> >>  > > This patch makes the stack coloring pass maintains AliasAnalysis
> >>  > information when merging multiple stack slots.
> >>  > >
> >>  > >
> >>  > > Modified:
> >>  > >      llvm/trunk/include/llvm/Analysis/ValueTracking.h
> >>  > >      llvm/trunk/include/llvm/CodeGen/MachineFunction.h
> >>  > >      llvm/trunk/include/llvm/CodeGen/MachineInstr.h
> >>  > >      llvm/trunk/lib/Analysis/ValueTracking.cpp
> >>  > >      llvm/trunk/lib/CodeGen/MachineFunction.cpp
> >>  > >      llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp
> >>  > >      llvm/trunk/lib/CodeGen/StackColoring.cpp
> >>  > >
> >>  > > Modified: llvm/trunk/include/llvm/Analysis/ValueTracking.h
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_include_llvm_Analysis_ValueTracking.h-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=KsDAR0RUJBPSTneO3i2jMCIKtjKOSAi1260oq3nZfkA&e=

> >>
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/include/llvm/Analysis/ValueTracking.h (original)
> >>  > > +++ llvm/trunk/include/llvm/Analysis/ValueTracking.h Mon Jul 31
> >>  > 20:32:15 2017
> >>  > > @@ -312,6 +312,12 @@ template <typename T> class ArrayRef;
> >>  > >                               const DataLayout &DL, LoopInfo *LI
> >> = nullptr,
> >>  > >                               unsigned MaxLookup = 6);
> >>  > >
> >>  > > +  /// This is a wrapper around GetUnderlyingObjects and adds
> >>  > support for basic
> >>  > > +  /// ptrtoint+arithmetic+inttoptr sequences.
> >>  > > +  void getUnderlyingObjectsForCodeGen(const Value *V,
> >>  > > +                            SmallVectorImpl<Value *> &Objects,
> >>  > > +                            const DataLayout &DL);
> >>  > > +
> >>  > >     /// Return true if the only users of this pointer are
> >> lifetime markers.
> >>  > >     bool onlyUsedByLifetimeMarkers(const Value *V);
> >>  > >
> >>  > >
> >>  > > Modified: llvm/trunk/include/llvm/CodeGen/MachineFunction.h
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_include_llvm_CodeGen_MachineFunction.h-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=WJpDpSXhK9W0O2Y7ry9udwfGJezS0aC1GhsuQrPJ2a8&e=

> >>
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/include/llvm/CodeGen/MachineFunction.h (original)
> >>  > > +++ llvm/trunk/include/llvm/CodeGen/MachineFunction.h Mon Jul 31
> >>  > 20:32:15 2017
> >>  > > @@ -661,6 +661,12 @@ public:
> >>  > >     MachineMemOperand *getMachineMemOperand(const
> >> MachineMemOperand *MMO,
> >>  > >                                             int64_t Offset,
> >> uint64_t Size);
> >>  > >
> >>  > > +  /// Allocate a new MachineMemOperand by copying an existing
one,
> >>  > > +  /// replacing only AliasAnalysis information.
> >>  > MachineMemOperands are owned
> >>  > > +  /// by the MachineFunction and need not be explicitly
> >> deallocated.
> >>  > > +  MachineMemOperand *getMachineMemOperand(const
> >> MachineMemOperand *MMO,
> >>  > > +                                          const AAMDNodes
&AAInfo);
> >>  > > +
> >>  > >     using OperandCapacity =
ArrayRecycler<MachineOperand>::Capacity;
> >>  > >
> >>  > >     /// Allocate an array of MachineOperands. This is only
> >>  > intended for use by
> >>  > >
> >>  > > Modified: llvm/trunk/include/llvm/CodeGen/MachineInstr.h
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_include_llvm_CodeGen_MachineInstr.h-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=P1817BTam8xe_gWSipjZpR88qqNAdwIFFUXlfMpsB8I&e=

> >>
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/include/llvm/CodeGen/MachineInstr.h (original)
> >>  > > +++ llvm/trunk/include/llvm/CodeGen/MachineInstr.h Mon Jul 31
> >> 20:32:15 2017
> >>  > > @@ -379,6 +379,9 @@ public:
> >>  > >       return NumMemRefs == 1;
> >>  > >     }
> >>  > >
> >>  > > +  /// Return the number of memory operands.
> >>  > > +  unsigned getNumMemOperands() const { return NumMemRefs; }
> >>  > > +
> >>  > >     /// API for querying MachineInstr properties. They are the
> >>  > same as MCInstrDesc
> >>  > >     /// queries but they are bundle aware.
> >>  > >
> >>  > >
> >>  > > Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_Analysis_ValueTracking.cpp-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=kZRZpGyrwG9zEe89JDudBCkYnFPMzYQafnJFPQaCzCg&e=

> >>
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
> >>  > > +++ llvm/trunk/lib/Analysis/ValueTracking.cpp Mon Jul 31 20:32:15

> >> 2017
> >>  > > @@ -3277,6 +3277,70 @@ void llvm::GetUnderlyingObjects(Value *V
> >>  > >     } while (!Worklist.empty());
> >>  > >   }
> >>  > >
> >>  > > +/// This is the function that does the work of looking through
> >> basic
> >>  > > +/// ptrtoint+arithmetic+inttoptr sequences.
> >>  > > +static const Value *getUnderlyingObjectFromInt(const Value *V) {
> >>  > > +  do {
> >>  > > +    if (const Operator *U = dyn_cast<Operator>(V)) {
> >>  > > +      // If we find a ptrtoint, we can transfer control back to
the
> >>  > > +      // regular getUnderlyingObjectFromInt.
> >>  > > +      if (U->getOpcode() == Instruction::PtrToInt)
> >>  > > +        return U->getOperand(0);
> >>  > > +      // If we find an add of a constant, a multiplied value, or
> >>  > a phi, it's
> >>  > > +      // likely that the other operand will lead us to the base
> >>  > > +      // object. We don't have to worry about the case where the
> >>  > > +      // object address is somehow being computed by the
multiply,
> >>  > > +      // because our callers only care when the result is an
> >>  > > +      // identifiable object.
> >>  > > +      if (U->getOpcode() != Instruction::Add ||
> >>  > > +          (!isa<ConstantInt>(U->getOperand(1)) &&
> >>  > > +           Operator::getOpcode(U->getOperand(1)) !=
> >> Instruction::Mul &&
> >>  > > +           !isa<PHINode>(U->getOperand(1))))
> >>  > > +        return V;
> >>  > > +      V = U->getOperand(0);
> >>  > > +    } else {
> >>  > > +      return V;
> >>  > > +    }
> >>  > > +    assert(V->getType()->isIntegerTy() && "Unexpected operand
> >> type!");
> >>  > > +  } while (true);
> >>  > > +}
> >>  > > +
> >>  > > +/// This is a wrapper around GetUnderlyingObjects and adds
> >>  > support for basic
> >>  > > +/// ptrtoint+arithmetic+inttoptr sequences.
> >>  > > +void llvm::getUnderlyingObjectsForCodeGen(const Value *V,
> >>  > > +                          SmallVectorImpl<Value *> &Objects,
> >>  > > +                          const DataLayout &DL) {
> >>  > > +  SmallPtrSet<const Value *, 16> Visited;
> >>  > > +  SmallVector<const Value *, 4> Working(1, V);
> >>  > > +  do {
> >>  > > +    V = Working.pop_back_val();
> >>  > > +
> >>  > > +    SmallVector<Value *, 4> Objs;
> >>  > > +    GetUnderlyingObjects(const_cast<Value *>(V), Objs, DL);
> >>  > > +
> >>  > > +    for (Value *V : Objs) {
> >>  > > +      // If GetUnderlyingObjects fails to find an identifiable
> >> object,
> >>  > > +      // getUnderlyingObjectsForCodeGen also fails for safety.
> >>  > > +      if (!isIdentifiedObject(V)) {
> >>  > > +        Objects.clear();
> >>  > > +        return;
> >>  > > +      }
> >>  > > +
> >>  > > +      if (!Visited.insert(V).second)
> >>  > > +        continue;
> >>  > > +      if (Operator::getOpcode(V) == Instruction::IntToPtr) {
> >>  > > +        const Value *O =
> >>  > > +          getUnderlyingObjectFromInt(cast<User>(V)->getOperand
(0));
> >>  > > +        if (O->getType()->isPointerTy()) {
> >>  > > +          Working.push_back(O);
> >>  > > +          continue;
> >>  > > +        }
> >>  > > +      }
> >>  > > +      Objects.push_back(const_cast<Value *>(V));
> >>  > > +    }
> >>  > > +  } while (!Working.empty());
> >>  > > +}
> >>  > > +
> >>  > >   /// Return true if the only users of this pointer are lifetime
> >> markers.
> >>  > >   bool llvm::onlyUsedByLifetimeMarkers(const Value *V) {
> >>  > >     for (const User *U : V->users()) {
> >>  > >
> >>  > > Modified: llvm/trunk/lib/CodeGen/MachineFunction.cpp
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_CodeGen_MachineFunction.cpp-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=allS8M0h249MGa_Gx6zUREWD57UANqNdgqwsYI7vnBc&e=

> >>
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/lib/CodeGen/MachineFunction.cpp (original)
> >>  > > +++ llvm/trunk/lib/CodeGen/MachineFunction.cpp Mon Jul 31
> >> 20:32:15 2017
> >>  > > @@ -330,6 +330,20 @@ MachineFunction::getMachineMemOperand(co
> >>  > >                                  MMO->getOrdering(),
> >>  > MMO->getFailureOrdering());
> >>  > >   }
> >>  > >
> >>  > > +MachineMemOperand *
> >>  > > +MachineFunction::getMachineMemOperand(const MachineMemOperand
*MMO,
> >>  > > +                                      const AAMDNodes &AAInfo) {
> >>  > > +  MachinePointerInfo MPI = MMO->getValue() ?
> >>  > > +             MachinePointerInfo(MMO->getValue(),
> >> MMO->getOffset()) :
> >>  > > +             MachinePointerInfo(MMO->getPseudoValue(),
> >> MMO->getOffset());
> >>  > > +
> >>  > > +  return new (Allocator)
> >>  > > +             MachineMemOperand(MPI, MMO->getFlags(),
> >> MMO->getSize(),
> >>  > > +                               MMO->getBaseAlignment(), AAInfo,
> >>  > > +                               MMO->getRanges(),
> >> MMO->getSyncScopeID(),
> >>  > > +                               MMO->getOrdering(),
> >>  > MMO->getFailureOrdering());
> >>  > > +}
> >>  > > +
> >>  > >   MachineInstr::mmo_iterator
> >>  > >   MachineFunction::allocateMemRefsArray(unsigned long Num) {
> >>  > >     return Allocator.Allocate<MachineMemOperand *>(Num);
> >>  > >
> >>  > > Modified: llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_CodeGen_ScheduleDAGInstrs.cpp-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=Ivq088QzLr4wNpGbN-
> >>  > k6QDpkRPbrJE6Z8WYbQgbAfXE&e=
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp (original)
> >>  > > +++ llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp Mon Jul 31
> >> 20:32:15 2017
> >>  > > @@ -121,63 +121,6 @@ ScheduleDAGInstrs::ScheduleDAGInstrs(Mac
> >>  > >     SchedModel.init(ST.getSchedModel(), &ST, TII);
> >>  > >   }
> >>  > >
> >>  > > -/// This is the function that does the work of looking through
> >> basic
> >>  > > -/// ptrtoint+arithmetic+inttoptr sequences.
> >>  > > -static const Value *getUnderlyingObjectFromInt(const Value *V) {
> >>  > > -  do {
> >>  > > -    if (const Operator *U = dyn_cast<Operator>(V)) {
> >>  > > -      // If we find a ptrtoint, we can transfer control back to
the
> >>  > > -      // regular getUnderlyingObjectFromInt.
> >>  > > -      if (U->getOpcode() == Instruction::PtrToInt)
> >>  > > -        return U->getOperand(0);
> >>  > > -      // If we find an add of a constant, a multiplied value, or
> >>  > a phi, it's
> >>  > > -      // likely that the other operand will lead us to the base
> >>  > > -      // object. We don't have to worry about the case where the
> >>  > > -      // object address is somehow being computed by the
multiply,
> >>  > > -      // because our callers only care when the result is an
> >>  > > -      // identifiable object.
> >>  > > -      if (U->getOpcode() != Instruction::Add ||
> >>  > > -          (!isa<ConstantInt>(U->getOperand(1)) &&
> >>  > > -           Operator::getOpcode(U->getOperand(1)) !=
> >> Instruction::Mul &&
> >>  > > -           !isa<PHINode>(U->getOperand(1))))
> >>  > > -        return V;
> >>  > > -      V = U->getOperand(0);
> >>  > > -    } else {
> >>  > > -      return V;
> >>  > > -    }
> >>  > > -    assert(V->getType()->isIntegerTy() && "Unexpected operand
> >> type!");
> >>  > > -  } while (true);
> >>  > > -}
> >>  > > -
> >>  > > -/// This is a wrapper around GetUnderlyingObjects and adds
> >>  > support for basic
> >>  > > -/// ptrtoint+arithmetic+inttoptr sequences.
> >>  > > -static void getUnderlyingObjects(const Value *V,
> >>  > > -                                 SmallVectorImpl<Value *>
&Objects,
> >>  > > -                                 const DataLayout &DL) {
> >>  > > -  SmallPtrSet<const Value *, 16> Visited;
> >>  > > -  SmallVector<const Value *, 4> Working(1, V);
> >>  > > -  do {
> >>  > > -    V = Working.pop_back_val();
> >>  > > -
> >>  > > -    SmallVector<Value *, 4> Objs;
> >>  > > -    GetUnderlyingObjects(const_cast<Value *>(V), Objs, DL);
> >>  > > -
> >>  > > -    for (Value *V : Objs) {
> >>  > > -      if (!Visited.insert(V).second)
> >>  > > -        continue;
> >>  > > -      if (Operator::getOpcode(V) == Instruction::IntToPtr) {
> >>  > > -        const Value *O =
> >>  > > -          getUnderlyingObjectFromInt(cast<User>(V)->getOperand
(0));
> >>  > > -        if (O->getType()->isPointerTy()) {
> >>  > > -          Working.push_back(O);
> >>  > > -          continue;
> >>  > > -        }
> >>  > > -      }
> >>  > > -      Objects.push_back(const_cast<Value *>(V));
> >>  > > -    }
> >>  > > -  } while (!Working.empty());
> >>  > > -}
> >>  > > -
> >>  > >   /// If this machine instr has memory reference information and
> >>  > it can be tracked
> >>  > >   /// to a normal reference to a known object, return the Value
> >>  > for that object.
> >>  > >   static void getUnderlyingObjectsForInstr(const MachineInstr
*MI,
> >>  > > @@ -208,12 +151,10 @@ static void getUnderlyingObjectsForInstr
> >>  > >
> >>  > Objects.push_back(UnderlyingObjectsVector::value_type(PSV,
MayAlias));
> >>  > >         } else if (const Value *V = MMO->getValue()) {
> >>  > >           SmallVector<Value *, 4> Objs;
> >>  > > -        getUnderlyingObjects(V, Objs, DL);
> >>  > > +        getUnderlyingObjectsForCodeGen(V, Objs, DL);
> >>  > >
> >>  > >           for (Value *V : Objs) {
> >>  > > -          if (!isIdentifiedObject(V))
> >>  > > -            return false;
> >>  > > -
> >>  > > +          assert(isIdentifiedObject(V));
> >>  > > Objects.push_back(UnderlyingObjectsVector::value_type(V, true));
> >>  > >           }
> >>  > >         } else
> >>  > >
> >>  > > Modified: llvm/trunk/lib/CodeGen/StackColoring.cpp
> >>  > > URL: https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_CodeGen_StackColoring.cpp-3Frev-3D309651-26r1-3D309650-26r2-3D309651-26view-3Ddiff&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=GtnObcIhIwZTCrC2KWaTzADR6e8JEcuoyWSr5_hAM1Q&e=

> >>
> >>  > >
> >>  >
> >>
>
==============================================================================

> >>
> >>  > > --- llvm/trunk/lib/CodeGen/StackColoring.cpp (original)
> >>  > > +++ llvm/trunk/lib/CodeGen/StackColoring.cpp Mon Jul 31 20:32:15
> >> 2017
> >>  > > @@ -37,6 +37,7 @@
> >>  > >   #include "llvm/CodeGen/MachineRegisterInfo.h"
> >>  > >   #include "llvm/CodeGen/Passes.h"
> >>  > >   #include "llvm/CodeGen/PseudoSourceValue.h"
> >>  > > +#include "llvm/CodeGen/SelectionDAGNodes.h"
> >>  > >   #include "llvm/CodeGen/SlotIndexes.h"
> >>  > >   #include "llvm/CodeGen/StackProtector.h"
> >>  > >   #include "llvm/CodeGen/WinEHFuncInfo.h"
> >>  > > @@ -889,6 +890,10 @@ void StackColoring::remapInstructions(De
> >>  > >
> >>  > >     // Keep a list of *allocas* which need to be remapped.
> >>  > >     DenseMap<const AllocaInst*, const AllocaInst*> Allocas;
> >>  > > +
> >>  > > +  // Keep a list of allocas which has been affected by the
remap.
> >>  > > +  SmallPtrSet<const AllocaInst*, 32> MergedAllocas;
> >>  > > +
> >>  > >     for (const std::pair<int, int> &SI : SlotRemap) {
> >>  > >       const AllocaInst *From = MFI->getObjectAllocation
(SI.first);
> >>  > >       const AllocaInst *To = MFI->getObjectAllocation(SI.second);
> >>  > > @@ -908,6 +913,10 @@ void StackColoring::remapInstructions(De
> >>  > >         Inst = Cast;
> >>  > >       }
> >>  > >
> >>  > > +    // We keep both slots to maintain AliasAnalysis metadata
later.
> >>  > > +    MergedAllocas.insert(From);
> >>  > > +    MergedAllocas.insert(To);
> >>  > > +
> >>  > >       // Allow the stack protector to adjust its value map to
> >>  > account for the
> >>  > >       // upcoming replacement.
> >>  > >       SP->adjustForColoring(From, To);
> >>  > > @@ -939,13 +948,6 @@ void StackColoring::remapInstructions(De
> >>  > >
> >>  > >         // Update the MachineMemOperand to use the new alloca.
> >>  > >         for (MachineMemOperand *MMO : I.memoperands()) {
> >>  > > -        // FIXME: In order to enable the use of TBAA when using
> >>  > AA in CodeGen,
> >>  > > -        // we'll also need to update the TBAA nodes in MMOs with

> >> values
> >>  > > -        // derived from the merged allocas. When doing this,
> >>  > we'll need to use
> >>  > > -        // the same variant of GetUnderlyingObjects that is used

> >> by the
> >>  > > -        // instruction scheduler (that can look through
> >> ptrtoint/inttoptr
> >>  > > -        // pairs).
> >>  > > -
> >>  > >           // We've replaced IR-level uses of the remapped
> >> allocas,so we only
> >>  > >           // need to replace direct uses here.
> >>  > >           const AllocaInst *AI =
> >>  > dyn_cast_or_null<AllocaInst>(MMO->getValue());
> >>  > > @@ -997,6 +999,48 @@ void StackColoring::remapInstructions(De
> >>  > >           MO.setIndex(ToSlot);
> >>  > >           FixedInstr++;
> >>  > >         }
> >>  > > +
> >>  > > +      // We adjust AliasAnalysis information for merged stack
> >> slots.
> >>  > > +      MachineSDNode::mmo_iterator MemOps =
> >>  > > +          MF->allocateMemRefsArray(I.getNumMemOperands());
> >>  > > +      unsigned MemOpIdx = 0;
> >>  > > +      bool ReplaceMemOps = false;
> >>  > > +      for (MachineMemOperand *MMO : I.memoperands()) {
> >>  > > +        // If this memory location can be a slot remapped here,
> >>  > > +        // we remove AA information.
> >>  > > +        bool MayHaveConflictingAAMD = false;
> >>  > > +        if (MMO->getAAInfo()) {
> >>  > > +          if (const Value *MMOV = MMO->getValue()) {
> >>  > > +            SmallVector<Value *, 4> Objs;
> >>  > > +            getUnderlyingObjectsForCodeGen(MMOV, Objs,
> >>  > MF->getDataLayout());
> >>  > > +
> >>  > > +            if (Objs.empty())
> >>  > > +              MayHaveConflictingAAMD = true;
> >>  > > +            else
> >>  > > +              for (Value *V : Objs) {
> >>  > > +                // If this memory location comes from a known
> >> stack slot
> >>  > > +                // that is not remapped, we continue checking.
> >>  > > +                // Otherwise, we need to invalidate AA
infomation.
> >>  > > +                const AllocaInst *AI =
> >> dyn_cast_or_null<AllocaInst>(V);
> >>  > > +                if (AI && MergedAllocas.count(AI)) {
> >>  > > +                  MayHaveConflictingAAMD = true;
> >>  > > +                  break;
> >>  > > +                }
> >>  > > +              }
> >>  > > +          }
> >>  > > +        }
> >>  > > +        if (MayHaveConflictingAAMD) {
> >>  > > +          MemOps[MemOpIdx++] = MF->getMachineMemOperand(MMO,
> >> AAMDNodes());
> >>  > > +          ReplaceMemOps = true;
> >>  > > +        }
> >>  > > +        else
> >>  > > +          MemOps[MemOpIdx++] = MMO;
> >>  > > +      }
> >>  > > +
> >>  > > +      // If any memory operand is updated, set memory references
of
> >>  > > +      // this instruction.
> >>  > > +      if (ReplaceMemOps)
> >>  > > +        I.setMemRefs(std::make_pair(MemOps,
> >> I.getNumMemOperands()));
> >>  > >       }
> >>  > >
> >>  > >     // Update the location of C++ catch objects for the MSVC
> >>  > personality routine.
> >>  > >
> >>  > >
> >>  > > _______________________________________________
> >>  > > llvm-commits mailing list
> >>  > > llvm-commits at lists.llvm.org
> >>  > > https://urldefense.proofpoint.com/v2/url?
> >>  >
> >>
>
u=http-3A__lists.llvm.org_cgi-2Dbin_mailman_listinfo_llvm-2Dcommits&d=DwICaQ&c=jf_iaSHvJObTbx-

> >>
> >>  > siA1ZOg&r=m0X4DAZw5Qh-99BsgZP4_s5n1wQ8Sz4aTCPvRS-
> >>  >
> >>
>
YkVI&m=mIxa9fsPE91JBDyRBM9jO3Gnmf1VjsdJcurWlZTiDmA&s=ybOAOXxp0X9Ut7wbe4GMXq94sxexsNZIn0-

> >>
> >>  > _6pvOmdI&e=
> >>  > >
> >>  >
> >>
> >
> >
>
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