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

Roman Gareev via llvm-commits llvm-commits at lists.llvm.org
Sat May 28 09:17:59 PDT 2016


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);
+}
+
+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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