[polly] r271128 - Determination of statements that contain matrix multiplication

Roman Gareev via llvm-commits llvm-commits at lists.llvm.org
Wed Jun 1 04:35:47 PDT 2016


Thank you for the comment. I’ll try to look into the issue soon.


2016-06-01 2:40 GMT+05:00 Mehdi Amini <mehdi.amini at apple.com>:
>
>> On May 28, 2016, at 9:17 AM, Roman Gareev via llvm-commits <llvm-commits at lists.llvm.org> wrote:
>>
>> Author: romangareev
>> Date: Sat May 28 11:17:58 2016
>> New Revision: 271128
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=271128&view=rev
>> Log:
>> Determination of statements that contain matrix multiplication
>>
>> Add determination of statements that contain, in particular,
>> matrix multiplications and can be optimized with [1] to try to
>> get close-to-peak performance. It can be enabled
>> via polly-pm-based-opts, which is false by default.
>>
>> Refs:
>> [1] - http://www.cs.utexas.edu/users/flame/pubs/TOMS-BLIS-Analytical.pdf
>>
>> Contributed-by: Roman Gareev <gareevroman at gmail.com>
>> Reviewed-by: Tobias Grosser <tobias at grosser.es>
>>
>> Differential Revision: http://reviews.llvm.org/D20575
>>
>> Added:
>>    polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts.ll
>>    polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts_2.ll
>> Modified:
>>    polly/trunk/include/polly/ScheduleOptimizer.h
>>    polly/trunk/lib/Transform/ScheduleOptimizer.cpp
>>
>> Modified: polly/trunk/include/polly/ScheduleOptimizer.h
>> URL: http://llvm.org/viewvc/llvm-project/polly/trunk/include/polly/ScheduleOptimizer.h?rev=271128&r1=271127&r2=271128&view=diff
>> ==============================================================================
>> --- polly/trunk/include/polly/ScheduleOptimizer.h (original)
>> +++ polly/trunk/include/polly/ScheduleOptimizer.h Sat May 28 11:17:58 2016
>> @@ -147,8 +147,45 @@ private:
>>   ///      - if vectorization is enabled
>>   ///
>>   /// @param Node The schedule node to (possibly) optimize.
>> -  /// @param User A pointer to forward some use information (currently unused).
>> +  /// @param User A pointer to forward some use information
>> +  ///        (currently unused).
>>   static isl_schedule_node *optimizeBand(isl_schedule_node *Node, void *User);
>> +
>> +  /// @brief Apply additional optimizations on the bands in the schedule tree.
>> +  ///
>> +  /// We apply the following
>> +  /// transformations:
>> +  ///
>> +  ///  - Tile the band
>> +  ///  - Prevectorize the schedule of the band (or the point loop in case of
>> +  ///    tiling).
>> +  ///      - if vectorization is enabled
>> +  ///
>> +  /// @param Node The schedule node to (possibly) optimize.
>> +  /// @param User A pointer to forward some use information
>> +  ///        (currently unused).
>> +  static isl_schedule_node *standardBandOpts(__isl_take isl_schedule_node *Node,
>> +                                             void *User);
>> +
>> +  /// @brief Check if this node contains a partial schedule that could
>> +  ///        probably be optimized with analytical modeling.
>> +  ///
>> +  /// isMatrMultPattern tries to determine whether the following conditions
>> +  /// are true:
>> +  /// 1. the partial schedule contains only one statement.
>> +  /// 2. there are exactly three input dimensions.
>> +  /// 3. all memory accesses of the statement will have stride 0 or 1, if we
>> +  ///    interchange loops (switch the variable used in the inner loop to
>> +  ///    the outer loop).
>> +  /// 4. all memory accesses of the statement except from the last one, are
>> +  ///    read memory access and the last one is write memory access.
>> +  /// 5. all subscripts of the last memory access of the statement don’t
>> +  ///    contain the variable used in the inner loop.
>> +  /// If this is the case, we could try to use an approach that is similar to
>> +  /// the one used to get close-to-peak performance of matrix multiplications.
>> +  ///
>> +  /// @param Node The node to check.
>> +  static bool isMatrMultPattern(__isl_keep isl_schedule_node *Node);
>> };
>>
>> #endif
>>
>> Modified: polly/trunk/lib/Transform/ScheduleOptimizer.cpp
>> URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Transform/ScheduleOptimizer.cpp?rev=271128&r1=271127&r2=271128&view=diff
>> ==============================================================================
>> --- polly/trunk/lib/Transform/ScheduleOptimizer.cpp (original)
>> +++ polly/trunk/lib/Transform/ScheduleOptimizer.cpp Sat May 28 11:17:58 2016
>> @@ -166,6 +166,11 @@ static cl::list<int>
>>                       cl::Hidden, cl::ZeroOrMore, cl::CommaSeparated,
>>                       cl::cat(PollyCategory));
>>
>> +static cl::opt<bool>
>> +    PMBasedOpts("polly-pattern-matching-based-opts",
>> +                cl::desc("Perform optimizations based on pattern matching"),
>> +                cl::init(false), cl::ZeroOrMore, cl::cat(PollyCategory));
>> +
>> /// @brief Create an isl_union_set, which describes the isolate option based
>> ///        on IsoalteDomain.
>> ///
>> @@ -359,11 +364,8 @@ bool ScheduleTreeOptimizer::isTileableBa
>> }
>>
>> __isl_give isl_schedule_node *
>> -ScheduleTreeOptimizer::optimizeBand(__isl_take isl_schedule_node *Node,
>> -                                    void *User) {
>> -  if (!isTileableBandNode(Node))
>> -    return Node;
>> -
>> +ScheduleTreeOptimizer::standardBandOpts(__isl_take isl_schedule_node *Node,
>> +                                        void *User) {
>>   if (FirstLevelTiling)
>>     Node = tileNode(Node, "1st level tiling", FirstLevelTileSizes,
>>                     FirstLevelDefaultTileSize);
>> @@ -396,6 +398,110 @@ ScheduleTreeOptimizer::optimizeBand(__is
>>   return Node;
>> }
>>
>> +/// @brief Check whether output dimensions of the map rely on the specified
>> +///        input dimension.
>> +///
>> +/// @param IslMap The isl map to be considered.
>> +/// @param DimNum The number of an input dimension to be checked.
>> +static bool isInputDimUsed(__isl_take isl_map *IslMap, unsigned DimNum) {
>> +  auto *CheckedAccessRelation =
>> +      isl_map_project_out(isl_map_copy(IslMap), isl_dim_in, DimNum, 1);
>> +  CheckedAccessRelation =
>> +      isl_map_insert_dims(CheckedAccessRelation, isl_dim_in, DimNum, 1);
>> +  auto *InputDimsId = isl_map_get_tuple_id(IslMap, isl_dim_in);
>> +  CheckedAccessRelation =
>> +      isl_map_set_tuple_id(CheckedAccessRelation, isl_dim_in, InputDimsId);
>> +  InputDimsId = isl_map_get_tuple_id(IslMap, isl_dim_out);
>> +  CheckedAccessRelation =
>> +      isl_map_set_tuple_id(CheckedAccessRelation, isl_dim_out, InputDimsId);
>> +  auto res = !isl_map_is_equal(CheckedAccessRelation, IslMap);
>> +  isl_map_free(CheckedAccessRelation);
>> +  isl_map_free(IslMap);
>> +  return res;
>> +}
>> +
>> +/// @brief Check if the SCoP statement could probably be optimized with
>> +///        analytical modeling.
>> +///
>> +/// containsMatrMult tries to determine whether the following conditions
>> +/// are true:
>> +/// 1. all memory accesses of the statement will have stride 0 or 1,
>> +///    if we interchange loops (switch the variable used in the inner
>> +///    loop to the outer loop).
>> +/// 2. all memory accesses of the statement except from the last one, are
>> +///    read memory access and the last one is write memory access.
>> +/// 3. all subscripts of the last memory access of the statement don’t contain
>> +///    the variable used in the inner loop.
>> +///
>> +/// @param PartialSchedule The PartialSchedule that contains a SCoP statement
>> +///        to check.
>> +static bool containsMatrMult(__isl_keep isl_map *PartialSchedule) {
>> +  auto InputDimsId = isl_map_get_tuple_id(PartialSchedule, isl_dim_in);
>> +  auto *ScpStmt = static_cast<ScopStmt *>(isl_id_get_user(InputDimsId));
>> +  isl_id_free(InputDimsId);
>> +  if (ScpStmt->size() <= 1)
>> +    return false;
>> +  auto MemA = ScpStmt->begin();
>> +  for (unsigned i = 0; i < ScpStmt->size() - 2 && MemA != ScpStmt->end();
>> +       i++, MemA++)
>> +    if (!(*MemA)->isRead() or
>> +        ((*MemA)->isArrayKind() and
>> +         !((*MemA)->isStrideOne(isl_map_copy(PartialSchedule)) or
>> +           (*MemA)->isStrideZero(isl_map_copy(PartialSchedule)))))
>> +      return false;
>> +  MemA++;
>> +  if (!(*MemA)->isWrite() or !(*MemA)->isArrayKind() or
>> +      !((*MemA)->isStrideOne(isl_map_copy(PartialSchedule)) or
>> +        (*MemA)->isStrideZero(isl_map_copy(PartialSchedule))))
>> +    return false;
>> +  auto DimNum = isl_map_dim(PartialSchedule, isl_dim_in);
>> +  return !isInputDimUsed((*MemA)->getAccessRelation(), DimNum - 1);
>> +}
>> +
>> +/// @brief Circular shift of output dimensions of the integer map.
>> +///
>> +/// @param IslMap The isl map to be modified.
>> +static __isl_give isl_map *circularShiftOutputDims(__isl_take isl_map *IslMap) {
>> +  auto InputDimsId = isl_map_get_tuple_id(IslMap, isl_dim_in);
>> +  auto DimNum = isl_map_dim(IslMap, isl_dim_out);
>> +  IslMap = isl_map_move_dims(IslMap, isl_dim_in, 0, isl_dim_out, DimNum - 1, 1);
>> +  IslMap = isl_map_move_dims(IslMap, isl_dim_out, 0, isl_dim_in, 0, 1);
>> +  return isl_map_set_tuple_id(IslMap, isl_dim_in, InputDimsId);
>> +}
>
> Coverity is reporting a potential issue here:
>
> *** CID 1356130:  Insecure data handling  (INTEGER_OVERFLOW)
> /tools/polly/lib/Transform/ScheduleOptimizer.cpp: 469 in circularShiftOutputDims(isl_map *)()
> 463     /// @param IslMap The isl map to be modified.
> 464     static __isl_give isl_map *circularShiftOutputDims(__isl_take isl_map *IslMap) {
> 465       auto InputDimsId = isl_map_get_tuple_id(IslMap, isl_dim_in);
> 466       auto DimNum = isl_map_dim(IslMap, isl_dim_out);
> 467       IslMap = isl_map_move_dims(IslMap, isl_dim_in, 0, isl_dim_out, DimNum - 1, 1);
> 468       IslMap = isl_map_move_dims(IslMap, isl_dim_out, 0, isl_dim_in, 0, 1);
>>>>     CID 1356130:  Insecure data handling  (INTEGER_OVERFLOW)
>>>>     Overflowed or truncated value (or a value computed from an overflowed or truncated value) "isl_map_set_tuple_id(IslMap, isl_dim_in, InputDimsId)" used as return value.
> 469       return isl_map_set_tuple_id(IslMap, isl_dim_in, InputDimsId);
> 470     }
>
>
> --
> Mehdi
>
>
>
>
>> +
>> +bool ScheduleTreeOptimizer::isMatrMultPattern(
>> +    __isl_keep isl_schedule_node *Node) {
>> +  auto *PartialSchedule =
>> +      isl_schedule_node_band_get_partial_schedule_union_map(Node);
>> +  if (isl_union_map_n_map(PartialSchedule) != 1)
>> +    return false;
>> +  auto *NewPartialSchedule = isl_map_from_union_map(PartialSchedule);
>> +  auto DimNum = isl_map_dim(NewPartialSchedule, isl_dim_in);
>> +  if (DimNum != 3) {
>> +    isl_map_free(NewPartialSchedule);
>> +    return false;
>> +  }
>> +  NewPartialSchedule = circularShiftOutputDims(NewPartialSchedule);
>> +  if (containsMatrMult(NewPartialSchedule)) {
>> +    isl_map_free(NewPartialSchedule);
>> +    return true;
>> +  }
>> +  isl_map_free(NewPartialSchedule);
>> +  return false;
>> +}
>> +
>> +__isl_give isl_schedule_node *
>> +ScheduleTreeOptimizer::optimizeBand(__isl_take isl_schedule_node *Node,
>> +                                    void *User) {
>> +  if (!isTileableBandNode(Node))
>> +    return Node;
>> +
>> +  if (PMBasedOpts && isMatrMultPattern(Node))
>> +    DEBUG(dbgs() << "The matrix multiplication pattern was detected\n");
>> +
>> +  return standardBandOpts(Node, User);
>> +}
>> +
>> __isl_give isl_schedule *
>> ScheduleTreeOptimizer::optimizeSchedule(__isl_take isl_schedule *Schedule) {
>>   isl_schedule_node *Root = isl_schedule_get_root(Schedule);
>>
>> Added: polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts.ll
>> URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts.ll?rev=271128&view=auto
>> ==============================================================================
>> --- polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts.ll (added)
>> +++ polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts.ll Sat May 28 11:17:58 2016
>> @@ -0,0 +1,65 @@
>> +; RUN: opt %loadPolly -polly-opt-isl -debug < %s 2>&1| FileCheck %s
>> +; RUN: opt %loadPolly -polly-opt-isl -polly-pattern-matching-based-opts=true -debug < %s 2>&1| FileCheck %s --check-prefix=PATTERN-MATCHING-OPTS
>> +; REQUIRES: asserts
>> +; CHECK-NOT: The matrix multiplication pattern was detected
>> +; PATTERN-MATCHING-OPTS: The matrix multiplication pattern was detected
>> +
>> +define internal void @kernel_gemm(i32 %arg, i32 %arg1, i32 %arg2, double %arg3, double %arg4, [1056 x double]* %arg5, [1024 x double]* %arg6, [1056 x double]* %arg7) {
>> +bb:
>> +  br label %bb8
>> +
>> +bb8:                                              ; preds = %bb39, %bb
>> +  %tmp = phi i32 [ 0, %bb ], [ %tmp40, %bb39 ]
>> +  %tmp9 = icmp slt i32 %tmp, 1056
>> +  br i1 %tmp9, label %bb10, label %bb41
>> +
>> +bb10:                                             ; preds = %bb8
>> +  br label %bb11
>> +
>> +bb11:                                             ; preds = %bb37, %bb10
>> +  %tmp12 = phi i32 [ 0, %bb10 ], [ %tmp38, %bb37 ]
>> +  %tmp13 = icmp slt i32 %tmp12, 1056
>> +  br i1 %tmp13, label %bb14, label %bb39
>> +
>> +bb14:                                             ; preds = %bb11
>> +  %tmp15 = sext i32 %tmp12 to i64
>> +  %tmp16 = sext i32 %tmp to i64
>> +  %tmp17 = getelementptr inbounds [1056 x double], [1056 x double]* %arg5, i64 %tmp16
>> +  %tmp18 = getelementptr inbounds [1056 x double], [1056 x double]* %tmp17, i64 0, i64 %tmp15
>> +  %tmp19 = load double, double* %tmp18, align 8
>> +  %tmp20 = fmul double %tmp19, %arg4
>> +  store double %tmp20, double* %tmp18, align 8
>> +  br label %bb21
>> +
>> +bb21:                                             ; preds = %bb24, %bb14
>> +  %tmp22 = phi i32 [ 0, %bb14 ], [ %tmp36, %bb24 ]
>> +  %tmp23 = icmp slt i32 %tmp22, 1024
>> +  br i1 %tmp23, label %bb24, label %bb37
>> +
>> +bb24:                                             ; preds = %bb21
>> +  %tmp25 = sext i32 %tmp22 to i64
>> +  %tmp26 = getelementptr inbounds [1024 x double], [1024 x double]* %arg6, i64 %tmp16
>> +  %tmp27 = getelementptr inbounds [1024 x double], [1024 x double]* %tmp26, i64 0, i64 %tmp25
>> +  %tmp28 = load double, double* %tmp27, align 8
>> +  %tmp29 = fmul double %arg3, %tmp28
>> +  %tmp30 = getelementptr inbounds [1056 x double], [1056 x double]* %arg7, i64 %tmp25
>> +  %tmp31 = getelementptr inbounds [1056 x double], [1056 x double]* %tmp30, i64 0, i64 %tmp15
>> +  %tmp32 = load double, double* %tmp31, align 8
>> +  %tmp33 = fmul double %tmp29, %tmp32
>> +  %tmp34 = load double, double* %tmp18, align 8
>> +  %tmp35 = fadd double %tmp34, %tmp33
>> +  store double %tmp35, double* %tmp18, align 8
>> +  %tmp36 = add nsw i32 %tmp22, 1
>> +  br label %bb21
>> +
>> +bb37:                                             ; preds = %bb21
>> +  %tmp38 = add nsw i32 %tmp12, 1
>> +  br label %bb11
>> +
>> +bb39:                                             ; preds = %bb11
>> +  %tmp40 = add nsw i32 %tmp, 1
>> +  br label %bb8
>> +
>> +bb41:                                             ; preds = %bb8
>> +  ret void
>> +}
>>
>> Added: polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts_2.ll
>> URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts_2.ll?rev=271128&view=auto
>> ==============================================================================
>> --- polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts_2.ll (added)
>> +++ polly/trunk/test/ScheduleOptimizer/pattern-matching-based-opts_2.ll Sat May 28 11:17:58 2016
>> @@ -0,0 +1,63 @@
>> +; RUN: opt %loadPolly -polly-opt-isl -polly-pattern-matching-based-opts=true -debug < %s 2>&1 | FileCheck %s
>> +; REQUIRES: asserts
>> +; CHECK-NOT: The matrix multiplication pattern was detected
>> +
>> +define internal void @kernel_gemm(i32 %arg, i32 %arg1, i32 %arg2, double %arg3, double %arg4, [1056 x double]* %arg5, [1024 x double]* %arg6, [1056 x double]* %arg7) {
>> +bb:
>> +  br label %bb8
>> +
>> +bb8:                                              ; preds = %bb39, %bb
>> +  %tmp = phi i32 [ 0, %bb ], [ %tmp40, %bb39 ]
>> +  %tmp9 = icmp slt i32 %tmp, 1056
>> +  br i1 %tmp9, label %bb10, label %bb41
>> +
>> +bb10:                                             ; preds = %bb8
>> +  br label %bb11
>> +
>> +bb11:                                             ; preds = %bb37, %bb10
>> +  %tmp12 = phi i32 [ 0, %bb10 ], [ %tmp38, %bb37 ]
>> +  %tmp13 = icmp slt i32 %tmp12, 1056
>> +  br i1 %tmp13, label %bb14, label %bb39
>> +
>> +bb14:                                             ; preds = %bb11
>> +  %tmp15 = sext i32 %tmp12 to i64
>> +  %tmp16 = sext i32 %tmp to i64
>> +  %tmp17 = getelementptr inbounds [1056 x double], [1056 x double]* %arg5, i64 %tmp16
>> +  %tmp18 = getelementptr inbounds [1056 x double], [1056 x double]* %tmp17, i64 0, i64 %tmp15
>> +  %tmp19 = load double, double* %tmp18, align 8
>> +  %tmp20 = fmul double %tmp19, %arg4
>> +  store double %tmp20, double* %tmp18, align 8
>> +  br label %bb21
>> +
>> +bb21:                                             ; preds = %bb24, %bb14
>> +  %tmp22 = phi i32 [ 0, %bb14 ], [ %tmp36, %bb24 ]
>> +  %tmp23 = icmp slt i32 %tmp22, 1024
>> +  br i1 %tmp23, label %bb24, label %bb37
>> +
>> +bb24:                                             ; preds = %bb21
>> +  %tmp25 = sext i32 %tmp22 to i64
>> +  %tmp26 = getelementptr inbounds [1024 x double], [1024 x double]* %arg6, i64 %tmp16
>> +  %tmp27 = getelementptr inbounds [1024 x double], [1024 x double]* %tmp26, i64 0, i64 %tmp25
>> +  %tmp28 = load double, double* %tmp27, align 8
>> +  %tmp29 = fmul double %arg3, %tmp28
>> +  %tmp30 = getelementptr inbounds [1056 x double], [1056 x double]* %arg7, i64 %tmp25
>> +  %tmp31 = getelementptr inbounds [1056 x double], [1056 x double]* %tmp30, i64 0, i64 %tmp15
>> +  %tmp32 = load double, double* %tmp31, align 8
>> +  %tmp33 = fmul double %tmp29, %tmp32
>> +  %tmp34 = load double, double* %tmp18, align 8
>> +  %tmp35 = fadd double %tmp34, %tmp33
>> +  store double %tmp35, double* %tmp18, align 8
>> +  %tmp36 = add nsw i32 %tmp22, 1
>> +  br label %bb21
>> +
>> +bb37:                                             ; preds = %bb21
>> +  %tmp38 = add nsw i32 %tmp12, 2
>> +  br label %bb11
>> +
>> +bb39:                                             ; preds = %bb11
>> +  %tmp40 = add nsw i32 %tmp, 1
>> +  br label %bb8
>> +
>> +bb41:                                             ; preds = %bb8
>> +  ret void
>> +}
>>
>>
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>



-- 
                                    Cheers, Roman Gareev.


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