Merge clang, llvm, lld, lldb, compiler-rt and libc++ 5.0.0 release.

MFC r309126 (by emaste):

  Correct lld llvm-tblgen dependency file name

MFC r309169:

  Get rid of separate Subversion mergeinfo properties for llvm-dwarfdump
  and llvm-lto.  The mergeinfo confuses Subversion enormously, and these
  directories will just use the mergeinfo for llvm itself.

MFC r312765:

  Pull in r276136 from upstream llvm trunk (by Wei Mi):

    Use ValueOffsetPair to enhance value reuse during SCEV expansion.

    In D12090, the ExprValueMap was added to reuse existing value during
    SCEV expansion. However, const folding and sext/zext distribution can
    make the reuse still difficult.

    A simplified case is: suppose we know S1 expands to V1 in
    ExprValueMap, and
      S1 = S2 + C_a
      S3 = S2 + C_b
    where C_a and C_b are different SCEVConstants. Then we'd like to
    expand S3 as V1 - C_a + C_b instead of expanding S2 literally. It is
    helpful when S2 is a complex SCEV expr and S2 has no entry in
    ExprValueMap, which is usually caused by the fact that S3 is
    generated from S1 after const folding.

    In order to do that, we represent ExprValueMap as a mapping from SCEV
    to ValueOffsetPair. We will save both S1->{V1, 0} and S2->{V1, C_a}
    into the ExprValueMap when we create SCEV for V1. When S3 is
    expanded, it will first expand S2 to V1 - C_a because of S2->{V1,
    C_a} in the map, then expand S3 to V1 - C_a + C_b.

    Differential Revision: https://reviews.llvm.org/D21313

  This should fix assertion failures when building OpenCV >= 3.1.

  PR:		215649

MFC r312831:

  Revert r312765 for now, since it causes assertions when building
  lang/spidermonkey24.

  Reported by:	antoine
  PR:		215649

MFC r316511 (by jhb):

  Add an implementation of __ffssi2() derived from __ffsdi2().

  Newer versions of GCC include an __ffssi2() symbol in libgcc and the
  compiler can emit calls to it in generated code.  This is true for at
  least GCC 6.2 when compiling world for mips and mips64.

  Reviewed by:	jmallett, dim
  Sponsored by:	DARPA / AFRL
  Differential Revision:	https://reviews.freebsd.org/D10086

MFC r318601 (by adrian):

  [libcompiler-rt] add bswapdi2/bswapsi2

  This is required for mips gcc 6.3 userland to build/run.

  Reviewed by:	emaste, dim
  Approved by:	emaste
  Differential Revision:	https://reviews.freebsd.org/D10838

MFC r318884 (by emaste):

  lldb: map TRAP_CAP to a trace trap

  In the absense of a more specific handler for TRAP_CAP (generated by
  ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
  trap.

  Example usage (testing the bug in PR219173):

  % proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
  ...
  (lldb) run
  Process 12980 launching
  Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
  Process 12980 stopped
  * thread #1, stop reason = trace
      frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
  ...

  In the future we should have LLDB control the trapcap procctl itself
  (as it does with ASLR), as well as report a specific stop reason.
  This change eliminates an assertion failure from LLDB for now.

MFC r319796:

  Remove a few unneeded files from libllvm, libclang and liblldb.

MFC r319885 (by emaste):

  lld: ELF: Fix ICF crash on absolute symbol relocations.

  If two sections contained relocations to absolute symbols with the same
  value we would crash when trying to access their sections. Add a check that
  both symbols point to sections before accessing their sections, and treat
  absolute symbols as equal if their values are equal.

  Obtained from:	LLD commit r292578

MFC r319918:

  Revert r319796 for now, it can cause undefined references when linking
  in some circumstances.

  Reported by:	Shawn Webb <shawn.webb@hardenedbsd.org>

MFC r319957 (by emaste):

  lld: Add armelf emulation mode

  Obtained from:	LLD r305375

MFC r321369:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 (trunk r308421).  Upstream has branched for the 5.0.0 release,
  which should be in about a month.  Please report bugs and regressions,
  so we can get them into the release.

  Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
  support to build; see UPDATING for more information.

MFC r321420:

  Add a few more object files to liblldb, which should solve errors when
  linking the lldb executable in some cases.  In particular, when the
  -ffunction-sections -fdata-sections options are turned off, or
  ineffective.

  Reported by:	Shawn Webb, Mark Millard

MFC r321433:

  Cleanup stale Options.inc files from the previous libllvm build for
  clang 4.0.0.  Otherwise, these can get included before the two newly
  generated ones (which are different) for clang 5.0.0.

  Reported by:	Mark Millard

MFC r321439 (by bdrewery):

  Move llvm Options.inc hack from r321433 for NO_CLEAN to lib/clang/libllvm.

  The files are only ever generated to .OBJDIR, not to WORLDTMP (as a
  sysroot) and are only ever included from a compilation.  So using
  a beforebuild target here removes the file before the compilation
  tries to include it.

MFC r321664:

  Pull in r308891 from upstream llvm trunk (by Benjamin Kramer):

    [CodeGenPrepare] Cut off FindAllMemoryUses if there are too many uses.

    This avoids excessive compile time. The case I'm looking at is
    Function.cpp from an old version of LLVM that still had the giant
    memcmp string matcher in it. Before r308322 this compiled in about 2
    minutes, after it, clang takes infinite* time to compile it. With
    this patch we're at 5 min, which is still bad but this is a
    pathological case.

    The cut off at 20 uses was chosen by looking at other cut-offs in LLVM
    for user scanning. It's probably too high, but does the job and is
    very unlikely to regress anything.

    Fixes PR33900.

    * I'm impatient and aborted after 15 minutes, on the bug report it was
      killed after 2h.

  Pull in r308986 from upstream llvm trunk (by Simon Pilgrim):

    [X86][CGP] Reduce memcmp() expansion to 2 load pairs (PR33914)

    D35067/rL308322 attempted to support up to 4 load pairs for memcmp
    inlining which resulted in regressions for some optimized libc memcmp
    implementations (PR33914).

    Until we can match these more optimal cases, this patch reduces the
    memcmp expansion to a maximum of 2 load pairs (which matches what we
    do for -Os).

    This patch should be considered for the 5.0.0 release branch as well

    Differential Revision: https://reviews.llvm.org/D35830

  These fix a hang (or extremely long compile time) when building older
  LLVM ports.

  Reported by:    antoine
  PR:             219139

MFC r321719:

  Pull in r309503 from upstream clang trunk (by Richard Smith):

    PR33902: Invalidate line number cache when adding more text to
    existing buffer.

    This led to crashes as the line number cache would report a bogus
    line number for a line of code, and we'd try to find a nonexistent
    column within the line when printing diagnostics.

  This fixes an assertion when building the graphics/champlain port.

  Reported by:	antoine, kwm
  PR:		219139

MFC r321723:

  Upgrade our copies of clang, llvm, lld and lldb to r309439 from the
  upstream release_50 branch.  This is just after upstream's 5.0.0-rc1.

MFC r322320:

  Upgrade our copies of clang, llvm and libc++ to r310316 from the
  upstream release_50 branch.

MFC r322326 (by emaste):

  lldb: Make i386-*-freebsd expression work on JIT path

  * Enable i386 ABI creation for freebsd
  * Added an extra argument in ABISysV_i386::PrepareTrivialCall for mmap
    syscall
  * Unlike linux, the last argument of mmap is actually 64-bit(off_t).
    This requires us to push an additional word for the higher order bits.
  * Prior to this change, ktrace dump will show mmap failures due to
    invalid argument coming from the 6th mmap argument.

  Submitted by:	Karnajit Wangkhem
  Differential Revision:	https://reviews.llvm.org/D34776

MFC r322360 (by emaste):

  lldb: Report inferior signals as signals, not exceptions, on FreeBSD

  This is the FreeBSD equivalent of LLVM r238549.

  This serves 2 purposes:

  * LLDB should handle inferior process signals SIGSEGV/SIGILL/SIGBUS/
    SIGFPE the way it is suppose to be handled. Prior to this fix these
    signals will neither create a coredump, nor exit from the debugger
    or work for signal handling scenario.
  * eInvalidCrashReason need not report "unknown crash reason" if we have
    a valid si_signo

  llvm.org/pr23699

  Patch by Karnajit Wangkhem

  Differential Revision:  https://reviews.llvm.org/D35223

  Submitted by:	Karnajit Wangkhem
  Obtained from:	LLVM r310591

MFC r322474 (by emaste):

  lld: Add `-z muldefs` option.

  Obtained from:	LLVM r310757

MFC r322740:

  Upgrade our copies of clang, llvm, lld and libc++ to r311219 from the
  upstream release_50 branch.

MFC r322855:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r311606 from
  the upstream release_50 branch.

  As of this version, lib/msun's trig test should also work correctly
  again (see bug 220989 for more information).

  PR:		220989

MFC r323112:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r312293 from
  the upstream release_50 branch.  This corresponds to 5.0.0 rc4.

  As of this version, the cad/stepcode port should now compile in a more
  reasonable time on i386 (see bug 221836 for more information).

  PR:		221836

MFC r323245:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 release (upstream r312559).

  Release notes for llvm, clang and lld will be available here soon:
  <http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/clang/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/lld/docs/ReleaseNotes.html>

  Relnotes:	yes

(cherry picked from commit 12cd91cf4c6b96a24427c0de5374916f2808d263)

1 files changed, 237 insertions, 16 deletions

diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGOpenMPRuntime.h b/contrib/llvm/tools/clang/lib/CodeGen/CGOpenMPRuntime.h
index 61ddc70..5dcf999 100644
--- a/contrib/llvm/tools/clang/lib/CodeGen/CGOpenMPRuntime.h
+++ b/contrib/llvm/tools/clang/lib/CodeGen/CGOpenMPRuntime.h
@@ -96,15 +96,106 @@ struct OMPTaskDataTy final {
   SmallVector<const Expr *, 4> FirstprivateInits;
   SmallVector<const Expr *, 4> LastprivateVars;
   SmallVector<const Expr *, 4> LastprivateCopies;
+  SmallVector<const Expr *, 4> ReductionVars;
+  SmallVector<const Expr *, 4> ReductionCopies;
+  SmallVector<const Expr *, 4> ReductionOps;
   SmallVector<std::pair<OpenMPDependClauseKind, const Expr *>, 4> Dependences;
   llvm::PointerIntPair<llvm::Value *, 1, bool> Final;
   llvm::PointerIntPair<llvm::Value *, 1, bool> Schedule;
   llvm::PointerIntPair<llvm::Value *, 1, bool> Priority;
+  llvm::Value *Reductions = nullptr;
   unsigned NumberOfParts = 0;
   bool Tied = true;
   bool Nogroup = false;
 };
 
+/// Class intended to support codegen of all kind of the reduction clauses.
+class ReductionCodeGen {
+private:
+  /// Data required for codegen of reduction clauses.
+  struct ReductionData {
+    /// Reference to the original shared item.
+    const Expr *Ref = nullptr;
+    /// Helper expression for generation of private copy.
+    const Expr *Private = nullptr;
+    /// Helper expression for generation reduction operation.
+    const Expr *ReductionOp = nullptr;
+    ReductionData(const Expr *Ref, const Expr *Private, const Expr *ReductionOp)
+        : Ref(Ref), Private(Private), ReductionOp(ReductionOp) {}
+  };
+  /// List of reduction-based clauses.
+  SmallVector<ReductionData, 4> ClausesData;
+
+  /// List of addresses of original shared variables/expressions.
+  SmallVector<std::pair<LValue, LValue>, 4> SharedAddresses;
+  /// Sizes of the reduction items in chars.
+  SmallVector<std::pair<llvm::Value *, llvm::Value *>, 4> Sizes;
+  /// Base declarations for the reduction items.
+  SmallVector<const VarDecl *, 4> BaseDecls;
+
+  /// Emits lvalue for shared expresion.
+  LValue emitSharedLValue(CodeGenFunction &CGF, const Expr *E);
+  /// Emits upper bound for shared expression (if array section).
+  LValue emitSharedLValueUB(CodeGenFunction &CGF, const Expr *E);
+  /// Performs aggregate initialization.
+  /// \param N Number of reduction item in the common list.
+  /// \param PrivateAddr Address of the corresponding private item.
+  /// \param SharedLVal Address of the original shared variable.
+  /// \param DRD Declare reduction construct used for reduction item.
+  void emitAggregateInitialization(CodeGenFunction &CGF, unsigned N,
+                                   Address PrivateAddr, LValue SharedLVal,
+                                   const OMPDeclareReductionDecl *DRD);
+
+public:
+  ReductionCodeGen(ArrayRef<const Expr *> Shareds,
+                   ArrayRef<const Expr *> Privates,
+                   ArrayRef<const Expr *> ReductionOps);
+  /// Emits lvalue for a reduction item.
+  /// \param N Number of the reduction item.
+  void emitSharedLValue(CodeGenFunction &CGF, unsigned N);
+  /// Emits the code for the variable-modified type, if required.
+  /// \param N Number of the reduction item.
+  void emitAggregateType(CodeGenFunction &CGF, unsigned N);
+  /// Emits the code for the variable-modified type, if required.
+  /// \param N Number of the reduction item.
+  /// \param Size Size of the type in chars.
+  void emitAggregateType(CodeGenFunction &CGF, unsigned N, llvm::Value *Size);
+  /// Performs initialization of the private copy for the reduction item.
+  /// \param N Number of the reduction item.
+  /// \param PrivateAddr Address of the corresponding private item.
+  /// \param DefaultInit Default initialization sequence that should be
+  /// performed if no reduction specific initialization is found.
+  /// \param SharedLVal Address of the original shared variable.
+  void
+  emitInitialization(CodeGenFunction &CGF, unsigned N, Address PrivateAddr,
+                     LValue SharedLVal,
+                     llvm::function_ref<bool(CodeGenFunction &)> DefaultInit);
+  /// Returns true if the private copy requires cleanups.
+  bool needCleanups(unsigned N);
+  /// Emits cleanup code for the reduction item.
+  /// \param N Number of the reduction item.
+  /// \param PrivateAddr Address of the corresponding private item.
+  void emitCleanups(CodeGenFunction &CGF, unsigned N, Address PrivateAddr);
+  /// Adjusts \p PrivatedAddr for using instead of the original variable
+  /// address in normal operations.
+  /// \param N Number of the reduction item.
+  /// \param PrivateAddr Address of the corresponding private item.
+  Address adjustPrivateAddress(CodeGenFunction &CGF, unsigned N,
+                               Address PrivateAddr);
+  /// Returns LValue for the reduction item.
+  LValue getSharedLValue(unsigned N) const { return SharedAddresses[N].first; }
+  /// Returns the size of the reduction item (in chars and total number of
+  /// elements in the item), or nullptr, if the size is a constant.
+  std::pair<llvm::Value *, llvm::Value *> getSizes(unsigned N) const {
+    return Sizes[N];
+  }
+  /// Returns the base declaration of the reduction item.
+  const VarDecl *getBaseDecl(unsigned N) const { return BaseDecls[N]; }
+  /// Returns true if the initialization of the reduction item uses initializer
+  /// from declare reduction construct.
+  bool usesReductionInitializer(unsigned N) const;
+};
+
 class CGOpenMPRuntime {
 protected:
   CodeGenModule &CGM;
@@ -121,7 +212,7 @@ protected:
   /// \param OutlinedFnID Outlined function ID value to be defined by this call.
   /// \param IsOffloadEntry True if the outlined function is an offload entry.
   /// \param CodeGen Lambda codegen specific to an accelerator device.
-  /// An oulined function may not be an entry if, e.g. the if clause always
+  /// An outlined function may not be an entry if, e.g. the if clause always
   /// evaluates to false.
   virtual void emitTargetOutlinedFunctionHelper(const OMPExecutableDirective &D,
                                                 StringRef ParentName,
@@ -527,6 +618,7 @@ public:
   /// Get combiner/initializer for the specified user-defined reduction, if any.
   virtual std::pair<llvm::Function *, llvm::Function *>
   getUserDefinedReduction(const OMPDeclareReductionDecl *D);
+
   /// \brief Emits outlined function for the specified OpenMP parallel directive
   /// \a D. This outlined function has type void(*)(kmp_int32 *ThreadID,
   /// kmp_int32 BoundID, struct context_vars*).
@@ -535,7 +627,19 @@ public:
   /// \param InnermostKind Kind of innermost directive (for simple directives it
   /// is a directive itself, for combined - its innermost directive).
   /// \param CodeGen Code generation sequence for the \a D directive.
-  virtual llvm::Value *emitParallelOrTeamsOutlinedFunction(
+  virtual llvm::Value *emitParallelOutlinedFunction(
+      const OMPExecutableDirective &D, const VarDecl *ThreadIDVar,
+      OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen);
+
+  /// \brief Emits outlined function for the specified OpenMP teams directive
+  /// \a D. This outlined function has type void(*)(kmp_int32 *ThreadID,
+  /// kmp_int32 BoundID, struct context_vars*).
+  /// \param D OpenMP directive.
+  /// \param ThreadIDVar Variable for thread id in the current OpenMP region.
+  /// \param InnermostKind Kind of innermost directive (for simple directives it
+  /// is a directive itself, for combined - its innermost directive).
+  /// \param CodeGen Code generation sequence for the \a D directive.
+  virtual llvm::Value *emitTeamsOutlinedFunction(
       const OMPExecutableDirective &D, const VarDecl *ThreadIDVar,
       OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen);
 
@@ -659,16 +763,50 @@ public:
   ///
   virtual bool isDynamic(OpenMPScheduleClauseKind ScheduleKind) const;
 
+  /// struct with the values to be passed to the dispatch runtime function
+  struct DispatchRTInput {
+    /// Loop lower bound
+    llvm::Value *LB = nullptr;
+    /// Loop upper bound
+    llvm::Value *UB = nullptr;
+    /// Chunk size specified using 'schedule' clause (nullptr if chunk
+    /// was not specified)
+    llvm::Value *Chunk = nullptr;
+    DispatchRTInput() = default;
+    DispatchRTInput(llvm::Value *LB, llvm::Value *UB, llvm::Value *Chunk)
+        : LB(LB), UB(UB), Chunk(Chunk) {}
+  };
+
+  /// Call the appropriate runtime routine to initialize it before start
+  /// of loop.
+
+  /// This is used for non static scheduled types and when the ordered
+  /// clause is present on the loop construct.
+  /// Depending on the loop schedule, it is necessary to call some runtime
+  /// routine before start of the OpenMP loop to get the loop upper / lower
+  /// bounds \a LB and \a UB and stride \a ST.
+  ///
+  /// \param CGF Reference to current CodeGenFunction.
+  /// \param Loc Clang source location.
+  /// \param ScheduleKind Schedule kind, specified by the 'schedule' clause.
+  /// \param IVSize Size of the iteration variable in bits.
+  /// \param IVSigned Sign of the iteration variable.
+  /// \param Ordered true if loop is ordered, false otherwise.
+  /// \param DispatchValues struct containing llvm values for lower bound, upper
+  /// bound, and chunk expression.
+  /// For the default (nullptr) value, the chunk 1 will be used.
+  ///
   virtual void emitForDispatchInit(CodeGenFunction &CGF, SourceLocation Loc,
                                    const OpenMPScheduleTy &ScheduleKind,
                                    unsigned IVSize, bool IVSigned, bool Ordered,
-                                   llvm::Value *UB,
-                                   llvm::Value *Chunk = nullptr);
+                                   const DispatchRTInput &DispatchValues);
 
   /// \brief Call the appropriate runtime routine to initialize it before start
   /// of loop.
   ///
-  /// Depending on the loop schedule, it is nesessary to call some runtime
+  /// This is used only in case of static schedule, when the user did not
+  /// specify a ordered clause on the loop construct.
+  /// Depending on the loop schedule, it is necessary to call some runtime
   /// routine before start of the OpenMP loop to get the loop upper / lower
   /// bounds \a LB and \a UB and stride \a ST.
   ///
@@ -676,7 +814,7 @@ public:
   /// \param Loc Clang source location.
   /// \param ScheduleKind Schedule kind, specified by the 'schedule' clause.
   /// \param IVSize Size of the iteration variable in bits.
-  /// \param IVSigned Sign of the interation variable.
+  /// \param IVSigned Sign of the iteration variable.
   /// \param Ordered true if loop is ordered, false otherwise.
   /// \param IL Address of the output variable in which the flag of the
   /// last iteration is returned.
@@ -685,7 +823,7 @@ public:
   /// \param UB Address of the output variable in which the upper iteration
   /// number is returned.
   /// \param ST Address of the output variable in which the stride value is
-  /// returned nesessary to generated the static_chunked scheduled loop.
+  /// returned necessary to generated the static_chunked scheduled loop.
   /// \param Chunk Value of the chunk for the static_chunked scheduled loop.
   /// For the default (nullptr) value, the chunk 1 will be used.
   ///
@@ -700,7 +838,7 @@ public:
   /// \param Loc Clang source location.
   /// \param SchedKind Schedule kind, specified by the 'dist_schedule' clause.
   /// \param IVSize Size of the iteration variable in bits.
-  /// \param IVSigned Sign of the interation variable.
+  /// \param IVSigned Sign of the iteration variable.
   /// \param Ordered true if loop is ordered, false otherwise.
   /// \param IL Address of the output variable in which the flag of the
   /// last iteration is returned.
@@ -709,7 +847,7 @@ public:
   /// \param UB Address of the output variable in which the upper iteration
   /// number is returned.
   /// \param ST Address of the output variable in which the stride value is
-  /// returned nesessary to generated the static_chunked scheduled loop.
+  /// returned necessary to generated the static_chunked scheduled loop.
   /// \param Chunk Value of the chunk for the static_chunked scheduled loop.
   /// For the default (nullptr) value, the chunk 1 will be used.
   ///
@@ -726,7 +864,7 @@ public:
   /// \param CGF Reference to current CodeGenFunction.
   /// \param Loc Clang source location.
   /// \param IVSize Size of the iteration variable in bits.
-  /// \param IVSigned Sign of the interation variable.
+  /// \param IVSigned Sign of the iteration variable.
   ///
   virtual void emitForOrderedIterationEnd(CodeGenFunction &CGF,
                                           SourceLocation Loc, unsigned IVSize,
@@ -745,7 +883,7 @@ public:
   ///          kmp_int[32|64] *p_lower, kmp_int[32|64] *p_upper,
   ///          kmp_int[32|64] *p_stride);
   /// \param IVSize Size of the iteration variable in bits.
-  /// \param IVSigned Sign of the interation variable.
+  /// \param IVSigned Sign of the iteration variable.
   /// \param IL Address of the output variable in which the flag of the
   /// last iteration is returned.
   /// \param LB Address of the output variable in which the lower iteration
@@ -797,6 +935,14 @@ public:
                                  SourceLocation Loc, bool PerformInit,
                                  CodeGenFunction *CGF = nullptr);
 
+  /// Creates artificial threadprivate variable with name \p Name and type \p
+  /// VarType.
+  /// \param VarType Type of the artificial threadprivate variable.
+  /// \param Name Name of the artificial threadprivate variable.
+  virtual Address getAddrOfArtificialThreadPrivate(CodeGenFunction &CGF,
+                                                   QualType VarType,
+                                                   StringRef Name);
+
   /// \brief Emit flush of the variables specified in 'omp flush' directive.
   /// \param Vars List of variables to flush.
   virtual void emitFlush(CodeGenFunction &CGF, ArrayRef<const Expr *> Vars,
@@ -880,6 +1026,32 @@ public:
                                     OpenMPDirectiveKind InnermostKind,
                                     const RegionCodeGenTy &CodeGen,
                                     bool HasCancel = false);
+
+  /// Emits reduction function.
+  /// \param ArgsType Array type containing pointers to reduction variables.
+  /// \param Privates List of private copies for original reduction arguments.
+  /// \param LHSExprs List of LHS in \a ReductionOps reduction operations.
+  /// \param RHSExprs List of RHS in \a ReductionOps reduction operations.
+  /// \param ReductionOps List of reduction operations in form 'LHS binop RHS'
+  /// or 'operator binop(LHS, RHS)'.
+  llvm::Value *emitReductionFunction(CodeGenModule &CGM, llvm::Type *ArgsType,
+                                     ArrayRef<const Expr *> Privates,
+                                     ArrayRef<const Expr *> LHSExprs,
+                                     ArrayRef<const Expr *> RHSExprs,
+                                     ArrayRef<const Expr *> ReductionOps);
+
+  /// Emits single reduction combiner
+  void emitSingleReductionCombiner(CodeGenFunction &CGF,
+                                   const Expr *ReductionOp,
+                                   const Expr *PrivateRef,
+                                   const DeclRefExpr *LHS,
+                                   const DeclRefExpr *RHS);
+
+  struct ReductionOptionsTy {
+    bool WithNowait;
+    bool SimpleReduction;
+    OpenMPDirectiveKind ReductionKind;
+  };
   /// \brief Emit a code for reduction clause. Next code should be emitted for
   /// reduction:
   /// \code
@@ -916,14 +1088,63 @@ public:
   /// \param RHSExprs List of RHS in \a ReductionOps reduction operations.
   /// \param ReductionOps List of reduction operations in form 'LHS binop RHS'
   /// or 'operator binop(LHS, RHS)'.
-  /// \param WithNowait true if parent directive has also nowait clause, false
-  /// otherwise.
+  /// \param Options List of options for reduction codegen:
+  ///     WithNowait true if parent directive has also nowait clause, false
+  ///     otherwise.
+  ///     SimpleReduction Emit reduction operation only. Used for omp simd
+  ///     directive on the host.
+  ///     ReductionKind The kind of reduction to perform.
   virtual void emitReduction(CodeGenFunction &CGF, SourceLocation Loc,
                              ArrayRef<const Expr *> Privates,
                              ArrayRef<const Expr *> LHSExprs,
                              ArrayRef<const Expr *> RHSExprs,
                              ArrayRef<const Expr *> ReductionOps,
-                             bool WithNowait, bool SimpleReduction);
+                             ReductionOptionsTy Options);
+
+  /// Emit a code for initialization of task reduction clause. Next code
+  /// should be emitted for reduction:
+  /// \code
+  ///
+  /// _task_red_item_t red_data[n];
+  /// ...
+  /// red_data[i].shar = &origs[i];
+  /// red_data[i].size = sizeof(origs[i]);
+  /// red_data[i].f_init = (void*)RedInit<i>;
+  /// red_data[i].f_fini = (void*)RedDest<i>;
+  /// red_data[i].f_comb = (void*)RedOp<i>;
+  /// red_data[i].flags = <Flag_i>;
+  /// ...
+  /// void* tg1 = __kmpc_task_reduction_init(gtid, n, red_data);
+  /// \endcode
+  ///
+  /// \param LHSExprs List of LHS in \a Data.ReductionOps reduction operations.
+  /// \param RHSExprs List of RHS in \a Data.ReductionOps reduction operations.
+  /// \param Data Additional data for task generation like tiedness, final
+  /// state, list of privates, reductions etc.
+  virtual llvm::Value *emitTaskReductionInit(CodeGenFunction &CGF,
+                                             SourceLocation Loc,
+                                             ArrayRef<const Expr *> LHSExprs,
+                                             ArrayRef<const Expr *> RHSExprs,
+                                             const OMPTaskDataTy &Data);
+
+  /// Required to resolve existing problems in the runtime. Emits threadprivate
+  /// variables to store the size of the VLAs/array sections for
+  /// initializer/combiner/finalizer functions + emits threadprivate variable to
+  /// store the pointer to the original reduction item for the custom
+  /// initializer defined by declare reduction construct.
+  /// \param RCG Allows to reuse an existing data for the reductions.
+  /// \param N Reduction item for which fixups must be emitted.
+  virtual void emitTaskReductionFixups(CodeGenFunction &CGF, SourceLocation Loc,
+                                       ReductionCodeGen &RCG, unsigned N);
+
+  /// Get the address of `void *` type of the privatue copy of the reduction
+  /// item specified by the \p SharedLVal.
+  /// \param ReductionsPtr Pointer to the reduction data returned by the
+  /// emitTaskReductionInit function.
+  /// \param SharedLVal Address of the original reduction item.
+  virtual Address getTaskReductionItem(CodeGenFunction &CGF, SourceLocation Loc,
+                                       llvm::Value *ReductionsPtr,
+                                       LValue SharedLVal);
 
   /// \brief Emit code for 'taskwait' directive.
   virtual void emitTaskwaitCall(CodeGenFunction &CGF, SourceLocation Loc);
@@ -952,7 +1173,7 @@ public:
   /// \param OutlinedFnID Outlined function ID value to be defined by this call.
   /// \param IsOffloadEntry True if the outlined function is an offload entry.
   /// \param CodeGen Code generation sequence for the \a D directive.
-  /// An oulined function may not be an entry if, e.g. the if clause always
+  /// An outlined function may not be an entry if, e.g. the if clause always
   /// evaluates to false.
   virtual void emitTargetOutlinedFunction(const OMPExecutableDirective &D,
                                           StringRef ParentName,
@@ -991,7 +1212,7 @@ public:
   virtual bool emitTargetGlobalVariable(GlobalDecl GD);
 
   /// \brief Emit the global \a GD if it is meaningful for the target. Returns
-  /// if it was emitted succesfully.
+  /// if it was emitted successfully.
   /// \param GD Global to scan.
   virtual bool emitTargetGlobal(GlobalDecl GD);