[Mlir-commits] [mlir] c57c4f8 - [mlir][linalg] linalg.tiled_loop peeling
Matthias Springer
llvmlistbot at llvm.org
Mon Sep 6 17:50:21 PDT 2021
Author: Matthias Springer
Date: 2021-09-07T09:50:08+09:00
New Revision: c57c4f888c5e826765db64b7cf5f77c9709c4a6f
URL: https://github.com/llvm/llvm-project/commit/c57c4f888c5e826765db64b7cf5f77c9709c4a6f
DIFF: https://github.com/llvm/llvm-project/commit/c57c4f888c5e826765db64b7cf5f77c9709c4a6f.diff
LOG: [mlir][linalg] linalg.tiled_loop peeling
Differential Revision: https://reviews.llvm.org/D108270
Added:
mlir/test/Dialect/Linalg/tiled-loop-peeling.mlir
Modified:
mlir/include/mlir/Dialect/Linalg/Transforms/Transforms.h
mlir/include/mlir/Dialect/SCF/Transforms.h
mlir/lib/Dialect/Linalg/Transforms/Loops.cpp
mlir/lib/Dialect/SCF/Transforms/LoopSpecialization.cpp
mlir/test/lib/Dialect/Linalg/TestLinalgTransforms.cpp
Removed:
################################################################################
diff --git a/mlir/include/mlir/Dialect/Linalg/Transforms/Transforms.h b/mlir/include/mlir/Dialect/Linalg/Transforms/Transforms.h
index cb5e13f12131..9448a2d80967 100644
--- a/mlir/include/mlir/Dialect/Linalg/Transforms/Transforms.h
+++ b/mlir/include/mlir/Dialect/Linalg/Transforms/Transforms.h
@@ -1036,6 +1036,31 @@ class ConvOpVectorization : public OpRewritePattern<ConvOp> {
PatternRewriter &rewriter) const override;
};
+/// Rewrite a TiledLoopOp with bounds/step that potentially do not divide evenly
+/// into a TiledLoopOp where the step divides the iteration space evenly,
+/// followed by another TiledLoopOp for the last (partial) iteration (if any).
+/// This transformation is called "loop peeling".
+///
+/// This function peels the `idx`-th loop of the TiledLoopOp. To tile all loops
+/// in the loop nest, this function must be called multiple times.
+///
+/// After loop peeling, this function tries to simplify/canonicalize affine.min
+/// and affine.max ops in the body of the two TiledLoopOps. For more details,
+/// refer to `mlir::scf::peelAndCanonicalizeForLoop`.
+///
+/// The return value indicates whether the loop was rewritten or not. Loops are
+/// not rewritten if:
+/// * Loop step size is 1 or
+/// * Loop bounds and step size are static, and step already divides the
+/// iteration space evenly.
+///
+/// Note: This function rewrites the given TiledLoopOp in-place and clones the
+/// TileLoopOp operation for the last iteration. It replaces all uses of the
+/// unpeeled TiledLoopOp with the results of the newly generated TiledLoopOp.
+LogicalResult peelAndCanonicalizeTiledLoop(RewriterBase &rewriter,
+ TiledLoopOp loopOp, int64_t idx,
+ TiledLoopOp &result);
+
//===----------------------------------------------------------------------===//
// Support for staged pattern application.
//===----------------------------------------------------------------------===//
diff --git a/mlir/include/mlir/Dialect/SCF/Transforms.h b/mlir/include/mlir/Dialect/SCF/Transforms.h
index a9b8937a78af..4cbf43e42111 100644
--- a/mlir/include/mlir/Dialect/SCF/Transforms.h
+++ b/mlir/include/mlir/Dialect/SCF/Transforms.h
@@ -111,6 +111,24 @@ void naivelyFuseParallelOps(Region ®ion);
LogicalResult peelAndCanonicalizeForLoop(RewriterBase &rewriter, ForOp forOp,
scf::IfOp &ifOp);
+/// Try to simplify a min/max operation `op` after loop peeling. This function
+/// can simplify min/max operations such as (ub is the previous upper bound of
+/// the unpeeled loop):
+/// ```
+/// #map = affine_map<(d0)[s0, s1] -> (s0, -d0 + s1)>
+/// %r = affine.min #affine.min #map(%iv)[%step, %ub]
+/// ```
+/// and rewrites them into (in the case the peeled loop):
+/// ```
+/// %r = %step
+/// ```
+/// min/max operations inside the partial iteration are rewritten in a similar
+/// way.
+LogicalResult rewritePeeledMinMaxOp(RewriterBase &rewriter, Operation *op,
+ AffineMap map, ValueRange operands,
+ bool isMin, Value iv, Value ub, Value step,
+ bool insideLoop);
+
/// Tile a parallel loop of the form
/// scf.parallel (%i0, %i1) = (%arg0, %arg1) to (%arg2, %arg3)
/// step (%arg4, %arg5)
diff --git a/mlir/lib/Dialect/Linalg/Transforms/Loops.cpp b/mlir/lib/Dialect/Linalg/Transforms/Loops.cpp
index 487ad383756d..71a363cb4ccd 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/Loops.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/Loops.cpp
@@ -12,6 +12,7 @@
#include "mlir/Dialect/Linalg/Passes.h"
#include "mlir/Dialect/Linalg/Transforms/Transforms.h"
#include "mlir/Dialect/Linalg/Utils/Utils.h"
+#include "mlir/Dialect/SCF/Transforms.h"
#include "mlir/Dialect/StandardOps/Utils/Utils.h"
#include "mlir/IR/AffineExpr.h"
#include "mlir/IR/AffineMap.h"
@@ -633,6 +634,119 @@ struct LowerTiledLoopsToSCF
};
} // namespace
+/// Rewrite a TiledLoopOp with bounds/step that potentially do not divide evenly
+/// into two TiledLoopOps: One where the step divides the iteration space
+/// evenly, followed another one for the last (partial) iteration (if any). This
+/// function only rewrites the `idx`-th loop of the loop nest represented by
+/// the TiledLoopOp. To peel the entire loop nest, this function must be called
+/// multiple times.
+///
+/// This function rewrites the given TiledLoopOp in-place and creates a new
+/// TiledLoopOp for the last iteration. It replaces all uses of the original
+/// TiledLoopOp with the results of the newly generated one.
+///
+/// The newly generated TiledLoopOp is returned via `result`. The boundary
+/// at which the loop is split (new upper bound) is returned via `splitBound`.
+/// The return value indicates whether the TiledLoopOp was rewritten or not.
+static LogicalResult peelTiledLoop(RewriterBase &b, TiledLoopOp loopOp,
+ int64_t idx, TiledLoopOp &result,
+ Value &splitBound) {
+ Value lb = loopOp.lowerBound()[idx], ub = loopOp.upperBound()[idx],
+ step = loopOp.step()[idx];
+ auto ubInt = getConstantIntValue(ub);
+
+ auto loc = loopOp.getLoc();
+ AffineExpr exprLb, exprUb, exprStep;
+ bindSymbols(b.getContext(), exprLb, exprUb, exprStep);
+ // New upper bound: %ub - (%ub - %lb) mod %step
+ auto modMap = AffineMap::get(0, 3, {exprUb - ((exprUb - exprLb) % exprStep)});
+ SmallVector<Value> operands{lb, ub, step};
+ mlir::canonicalizeMapAndOperands(&modMap, &operands);
+ modMap = mlir::simplifyAffineMap(modMap);
+ RewriterBase::InsertionGuard guard(b);
+ b.setInsertionPoint(loopOp);
+ splitBound = b.createOrFold<AffineApplyOp>(loc, modMap, operands);
+ // No specialization necessary if step already divides upper bound evenly.
+ if (splitBound == ub || (ubInt && ubInt == getConstantIntValue(splitBound)))
+ return failure();
+
+ // Create remainder loop.
+ b.setInsertionPointAfter(loopOp);
+ auto remainderLoop = cast<TiledLoopOp>(b.clone(*loopOp.getOperation()));
+ loopOp.replaceAllUsesWith(remainderLoop->getResults());
+ // Outputs: Take tensors from main loop's results. Take memrefs from main
+ // loop's outputs.
+ SmallVector<Value> remainderOutputs;
+ for (unsigned o = 0, t = 0; o < loopOp.getNumOutputs(); ++o) {
+ remainderOutputs.push_back(loopOp.outputs()[o].getType().isa<MemRefType>()
+ ? loopOp.outputs()[o]
+ : loopOp->getResult(t++));
+ }
+ remainderLoop.outputsMutable().assign(remainderOutputs);
+
+ // Set new loop bounds.
+ b.updateRootInPlace(loopOp, [&]() {
+ SmallVector<Value> ubs = loopOp.upperBound();
+ ubs[idx] = splitBound;
+ loopOp.upperBoundMutable().assign(ubs);
+ });
+ SmallVector<Value> lbs = remainderLoop.lowerBound();
+ lbs[idx] = splitBound;
+ remainderLoop.lowerBoundMutable().assign(lbs);
+
+ result = remainderLoop;
+ return success();
+}
+
+template <typename OpTy, bool IsMin>
+static void
+rewriteAffineOpAfterPeeling(RewriterBase &rewriter, TiledLoopOp mainLoop,
+ TiledLoopOp remainderLoop, Value mainIv,
+ Value remainderIv, Value ub, Value step) {
+ mainLoop.walk([&](OpTy affineOp) {
+ AffineMap map = affineOp.getAffineMap();
+ (void)scf::rewritePeeledMinMaxOp(rewriter, affineOp, map,
+ affineOp.operands(), IsMin, mainIv, ub,
+ step, /*insideLoop=*/true);
+ });
+ remainderLoop.walk([&](OpTy affineOp) {
+ AffineMap map = affineOp.getAffineMap();
+ (void)scf::rewritePeeledMinMaxOp(rewriter, affineOp, map,
+ affineOp.operands(), IsMin, remainderIv,
+ ub, step, /*insideLoop=*/false);
+ });
+}
+
+LogicalResult mlir::linalg::peelAndCanonicalizeTiledLoop(RewriterBase &rewriter,
+ TiledLoopOp loopOp,
+ int64_t idx,
+ TiledLoopOp &result) {
+ int64_t numLoops = loopOp.iterator_types().size();
+ if (idx < 0 || numLoops <= idx)
+ return failure();
+ // Only parallel iterator supported.
+ if (!isParallelIterator(loopOp.iterator_types()[idx]))
+ return failure();
+
+ Value ub = loopOp.upperBound()[idx];
+ TiledLoopOp remainderLoop;
+ Value splitBound;
+ if (failed(peelTiledLoop(rewriter, loopOp, idx, remainderLoop, splitBound)))
+ return failure();
+
+ // Rewrite affine.min and affine.max ops.
+ Value mainIv = loopOp.getInductionVars()[idx], step = loopOp.step()[idx],
+ remainderIv = remainderLoop.getInductionVars()[idx];
+
+ rewriteAffineOpAfterPeeling<AffineMinOp, /*IsMin=*/true>(
+ rewriter, loopOp, remainderLoop, mainIv, remainderIv, ub, step);
+ rewriteAffineOpAfterPeeling<AffineMaxOp, /*IsMin=*/false>(
+ rewriter, loopOp, remainderLoop, mainIv, remainderIv, ub, step);
+
+ result = remainderLoop;
+ return success();
+}
+
void mlir::linalg::populateTiledLoopToSCFPattern(RewritePatternSet &patterns) {
patterns.add<TiledLoopToSCFPattern>(patterns.getContext());
}
diff --git a/mlir/lib/Dialect/SCF/Transforms/LoopSpecialization.cpp b/mlir/lib/Dialect/SCF/Transforms/LoopSpecialization.cpp
index b5e954317c12..fa6b5bcadfc4 100644
--- a/mlir/lib/Dialect/SCF/Transforms/LoopSpecialization.cpp
+++ b/mlir/lib/Dialect/SCF/Transforms/LoopSpecialization.cpp
@@ -324,25 +324,25 @@ canonicalizeMinMaxOp(RewriterBase &rewriter, Operation *op, AffineMap map,
/// ```
/// %r = %step
/// ```
-/// min/max operations inside the generated scf.if operation are rewritten in
-/// a similar way.
+/// min/max operations inside the partial iteration are rewritten in a similar
+/// way.
///
/// This function builds up a set of constraints, capable of proving that:
/// * Inside the peeled loop: min(step, ub - iv) == step
-/// * Inside the scf.if operation: min(step, ub - iv) == ub - iv
+/// * Inside the partial iteration: min(step, ub - iv) == ub - iv
///
/// Returns `success` if the given operation was replaced by a new operation;
/// `failure` otherwise.
///
/// Note: `ub` is the previous upper bound of the loop (before peeling).
/// `insideLoop` must be true for min/max ops inside the loop and false for
-/// affine.min ops inside the scf.for op. For an explanation of the other
+/// affine.min ops inside the partial iteration. For an explanation of the other
/// parameters, see comment of `canonicalizeMinMaxOpInLoop`.
-static LogicalResult rewritePeeledMinMaxOp(RewriterBase &rewriter,
- Operation *op, AffineMap map,
- ValueRange operands, bool isMin,
- Value iv, Value ub, Value step,
- bool insideLoop) {
+LogicalResult mlir::scf::rewritePeeledMinMaxOp(RewriterBase &rewriter,
+ Operation *op, AffineMap map,
+ ValueRange operands, bool isMin,
+ Value iv, Value ub, Value step,
+ bool insideLoop) {
FlatAffineValueConstraints constraints;
constraints.appendDimId({iv, ub, step});
if (auto constUb = getConstantIntValue(ub))
@@ -374,14 +374,16 @@ static void
rewriteAffineOpAfterPeeling(RewriterBase &rewriter, ForOp forOp, scf::IfOp ifOp,
Value iv, Value splitBound, Value ub, Value step) {
forOp.walk([&](OpTy affineOp) {
- (void)rewritePeeledMinMaxOp(rewriter, affineOp, affineOp.getAffineMap(),
- affineOp.operands(), IsMin, iv, ub, step,
- /*insideLoop=*/true);
+ AffineMap map = affineOp.getAffineMap();
+ (void)scf::rewritePeeledMinMaxOp(rewriter, affineOp, map,
+ affineOp.operands(), IsMin, iv, ub, step,
+ /*insideLoop=*/true);
});
ifOp.walk([&](OpTy affineOp) {
- (void)rewritePeeledMinMaxOp(rewriter, affineOp, affineOp.getAffineMap(),
- affineOp.operands(), IsMin, splitBound, ub,
- step, /*insideLoop=*/false);
+ AffineMap map = affineOp.getAffineMap();
+ (void)scf::rewritePeeledMinMaxOp(rewriter, affineOp, map,
+ affineOp.operands(), IsMin, splitBound, ub,
+ step, /*insideLoop=*/false);
});
}
diff --git a/mlir/test/Dialect/Linalg/tiled-loop-peeling.mlir b/mlir/test/Dialect/Linalg/tiled-loop-peeling.mlir
new file mode 100644
index 000000000000..8df6f15ae674
--- /dev/null
+++ b/mlir/test/Dialect/Linalg/tiled-loop-peeling.mlir
@@ -0,0 +1,215 @@
+// RUN: mlir-opt %s -allow-unregistered-dialect -test-linalg-transform-patterns=test-tiled-loop-peeling=2 -split-input-file | FileCheck %s -check-prefix=CHECK-TILE-2
+// RUN: mlir-opt %s -allow-unregistered-dialect -test-linalg-transform-patterns=test-tiled-loop-peeling=0,1,2 -split-input-file | FileCheck %s -check-prefix=CHECK-TILE-012
+
+// CHECK-TILE-2-LABEL: func @tiled_loop_3d_tensor(
+// CHECK-TILE-2-SAME: %[[input:.*]]: tensor<?x?x?xf32>, %[[s0:.*]]: index, %[[s1:.*]]: index, %[[s2:.*]]: index
+// CHECK-TILE-2-DAG: %[[c0:.*]] = constant 0 : index
+// CHECK-TILE-2-DAG: %[[c1:.*]] = constant 1 : index
+// CHECK-TILE-2-DAG: %[[c2:.*]] = constant 2 : index
+// CHECK-TILE-2: %[[dim0:.*]] = tensor.dim %[[input]], %[[c0]]
+// CHECK-TILE-2: %[[dim1:.*]] = tensor.dim %[[input]], %[[c1]]
+// CHECK-TILE-2: %[[dim2:.*]] = tensor.dim %[[input]], %[[c2]]
+// CHECK-TILE-2: %[[init_tensor:.*]] = linalg.init_tensor
+// CHECK-TILE-2: %[[split_bound:.*]] = affine.apply
+// CHECK-TILE-2: %[[r1:.*]] = linalg.tiled_loop (%[[iv0:.*]], %[[iv1:.*]], %[[iv2:.*]]) = (%[[c0]], %[[c0]], %[[c0]])
+// CHECK-TILE-2-SAME: to (%[[dim0]], %[[dim1]], %[[split_bound]])
+// CHECK-TILE-2-SAME: step (%[[s0]], %[[s1]], %[[s2]])
+// CHECK-TILE-2-SAME: ins (%[[loop_in1:.*]] = %[[input]]: tensor<?x?x?xf32>)
+// CHECK-TILE-2-SAME: outs (%[[loop_out1:.*]] = %[[init_tensor]]: tensor<?x?x?xf32>) {
+// CHECK-TILE-2: %[[min0_1:.*]] = affine.min
+// CHECK-TILE-2: %[[min1_1:.*]] = affine.min
+// CHECK-TILE-2: %[[in_slice1:.*]] = tensor.extract_slice %[[loop_in1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_1]], %[[min1_1]], %[[s2]]]
+// CHECK-TILE-2: %[[out_slice1:.*]] = tensor.extract_slice %[[loop_out1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_1]], %[[min1_1]], %[[s2]]]
+// CHECK-TILE-2: %[[mod_slice1:.*]] = tensor.insert_slice %{{.*}} into %[[loop_out1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_1]], %[[min1_1]], %[[s2]]]
+// CHECK-TILE-2: linalg.yield %[[mod_slice1]]
+// CHECK-TILE-2: %[[r2:.*]] = linalg.tiled_loop (%[[iv0:.*]], %[[iv1:.*]], %[[iv2:.*]]) = (%[[c0]], %[[c0]], %[[split_bound]])
+// CHECK-TILE-2-SAME: to (%[[dim0]], %[[dim1]], %[[dim2]])
+// CHECK-TILE-2-SAME: step (%[[s0]], %[[s1]], %[[s2]])
+// CHECK-TILE-2-SAME: ins (%[[loop_in2:.*]] = %[[input]]: tensor<?x?x?xf32>)
+// CHECK-TILE-2-SAME: outs (%[[loop_out2:.*]] = %[[r1]]: tensor<?x?x?xf32>) {
+// CHECK-TILE-2: %[[min0_2:.*]] = affine.min
+// CHECK-TILE-2: %[[min1_2:.*]] = affine.min
+// CHECK-TILE-2: %[[apply2:.*]] = affine.apply
+// CHECK-TILE-2: %[[in_slice2:.*]] = tensor.extract_slice %[[loop_in1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_2]], %[[min1_2]], %[[apply2]]]
+// CHECK-TILE-2: %[[out_slice2:.*]] = tensor.extract_slice %[[loop_out1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_2]], %[[min1_2]], %[[apply2]]]
+// CHECK-TILE-2: %[[mod_slice2:.*]] = tensor.insert_slice %{{.*}} into %[[loop_out1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_2]], %[[min1_2]], %[[apply2]]]
+// CHECK-TILE-2: linalg.yield %[[mod_slice2]]
+// CHECK-TILE-2: return %[[r2]]
+
+// CHECK-TILE-012-LABEL: func @tiled_loop_3d_tensor
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012: linalg.tiled_loop {{.*}} {
+// CHECK-TILE-012: linalg.yield
+// CHECK-TILE-012: }
+// CHECK-TILE-012-NOT: linalg.tiled_loop
+
+func @tiled_loop_3d_tensor(%arg0: tensor<?x?x?xf32>, %s0: index, %s1: index,
+ %s2: index) -> tensor<?x?x?xf32> {
+ %cst = constant 0.000000e+00 : f32
+ %c0 = constant 0 : index
+ %c1 = constant 1 : index
+ %c2 = constant 2 : index
+ %c8 = constant 8 : index
+ %dim0 = tensor.dim %arg0, %c0 : tensor<?x?x?xf32>
+ %dim1 = tensor.dim %arg0, %c1 : tensor<?x?x?xf32>
+ %dim2 = tensor.dim %arg0, %c2 : tensor<?x?x?xf32>
+ %output = linalg.init_tensor [%dim0, %dim1, %dim2] : tensor<?x?x?xf32>
+ %result = linalg.tiled_loop
+ (%arg1, %arg2, %arg3) = (%c0, %c0, %c0) to (%dim0, %dim1, %dim2)
+ step (%s0, %s1, %s2) ins (%arg4 = %arg0: tensor<?x?x?xf32>)
+ outs (%arg5 = %output: tensor<?x?x?xf32>) {
+ %min0 = affine.min affine_map<(d0, d1)[s0] -> (d1, -d0 + s0)>(%arg1, %s0)[%dim0]
+ %min1 = affine.min affine_map<(d0, d1)[s0] -> (d1, -d0 + s0)>(%arg2, %s1)[%dim1]
+ %min2 = affine.min affine_map<(d0, d1)[s0] -> (d1, -d0 + s0)>(%arg3, %s2)[%dim2]
+ %in_slice = tensor.extract_slice %arg4[%arg1, %arg2, %arg3] [%min0, %min1, %min2] [1, 1, 1]: tensor<?x?x?xf32> to tensor<?x?x?xf32>
+ %out_slice = tensor.extract_slice %arg5[%arg1, %arg2, %arg3] [%min0, %min1, %min2] [1, 1, 1] : tensor<?x?x?xf32> to tensor<?x?x?xf32>
+ %comp = "computation"(%in_slice, %out_slice) : (tensor<?x?x?xf32>, tensor<?x?x?xf32>) -> tensor<?x?x?xf32>
+ %updated_slice = tensor.insert_slice %comp into %arg5[%arg1, %arg2, %arg3] [%min0, %min1, %min2] [1, 1, 1] : tensor<?x?x?xf32> into tensor<?x?x?xf32>
+ linalg.yield %updated_slice : tensor<?x?x?xf32>
+ }
+ return %result : tensor<?x?x?xf32>
+}
+
+// -----
+
+// CHECK-TILE-2-LABEL: func @tiled_loop_3d_memref(
+// CHECK-TILE-2-SAME: %[[input:.*]]: memref<?x?x?xf32>, %[[output:.*]]: memref<?x?x?xf32>, %[[s0:.*]]: index, %[[s1:.*]]: index, %[[s2:.*]]: index
+// CHECK-TILE-2-DAG: %[[c0:.*]] = constant 0 : index
+// CHECK-TILE-2-DAG: %[[c1:.*]] = constant 1 : index
+// CHECK-TILE-2-DAG: %[[c2:.*]] = constant 2 : index
+// CHECK-TILE-2: %[[dim0:.*]] = memref.dim %[[input]], %[[c0]]
+// CHECK-TILE-2: %[[dim1:.*]] = memref.dim %[[input]], %[[c1]]
+// CHECK-TILE-2: %[[dim2:.*]] = memref.dim %[[input]], %[[c2]]
+// CHECK-TILE-2: %[[split_bound:.*]] = affine.apply
+// CHECK-TILE-2: linalg.tiled_loop (%[[iv0:.*]], %[[iv1:.*]], %[[iv2:.*]]) = (%[[c0]], %[[c0]], %[[c0]])
+// CHECK-TILE-2-SAME: to (%[[dim0]], %[[dim1]], %[[split_bound]])
+// CHECK-TILE-2-SAME: step (%[[s0]], %[[s1]], %[[s2]])
+// CHECK-TILE-2-SAME: ins (%[[loop_in1:.*]] = %[[input]]: memref<?x?x?xf32>)
+// CHECK-TILE-2-SAME: outs (%[[loop_out1:.*]] = %[[output]]: memref<?x?x?xf32>) {
+// CHECK-TILE-2: %[[min0_1:.*]] = affine.min
+// CHECK-TILE-2: %[[min1_1:.*]] = affine.min
+// CHECK-TILE-2: memref.subview %[[loop_in1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_1]], %[[min1_1]], %[[s2]]]
+// CHECK-TILE-2: linalg.yield
+// CHECK-TILE-2: linalg.tiled_loop (%[[iv0:.*]], %[[iv1:.*]], %[[iv2:.*]]) = (%[[c0]], %[[c0]], %[[split_bound]])
+// CHECK-TILE-2-SAME: to (%[[dim0]], %[[dim1]], %[[dim2]])
+// CHECK-TILE-2-SAME: step (%[[s0]], %[[s1]], %[[s2]])
+// CHECK-TILE-2-SAME: ins (%[[loop_in2:.*]] = %[[input]]: memref<?x?x?xf32>)
+// CHECK-TILE-2-SAME: outs (%[[loop_out2:.*]] = %[[output]]: memref<?x?x?xf32>) {
+// CHECK-TILE-2: %[[min0_2:.*]] = affine.min
+// CHECK-TILE-2: %[[min1_2:.*]] = affine.min
+// CHECK-TILE-2: %[[apply2:.*]] = affine.apply
+// CHECK-TILE-2: memref.subview %[[loop_in1]][%[[iv0]], %[[iv1]], %[[iv2]]] [%[[min0_2]], %[[min1_2]], %[[apply2]]]
+// CHECK-TILE-2: linalg.yield
+// CHECK-TILE-2: return
+
+// CHECK-TILE-012-LABEL: func @tiled_loop_3d_memref
+
+!memref_subview_type = type memref<?x?x?xf32, affine_map<(d0, d1, d2)[s0, s1, s2] -> (d0 * s1 + s0 + d1 * s2 + d2)>>
+
+func @tiled_loop_3d_memref(%arg0: memref<?x?x?xf32>, %output: memref<?x?x?xf32>,
+ %s0: index, %s1: index, %s2: index) {
+ %cst = constant 0.000000e+00 : f32
+ %c0 = constant 0 : index
+ %c1 = constant 1 : index
+ %c2 = constant 2 : index
+ %c8 = constant 8 : index
+ %dim0 = memref.dim %arg0, %c0 : memref<?x?x?xf32>
+ %dim1 = memref.dim %arg0, %c1 : memref<?x?x?xf32>
+ %dim2 = memref.dim %arg0, %c2 : memref<?x?x?xf32>
+ linalg.tiled_loop
+ (%arg1, %arg2, %arg3) = (%c0, %c0, %c0) to (%dim0, %dim1, %dim2)
+ step (%s0, %s1, %s2) ins (%arg4 = %arg0: memref<?x?x?xf32>)
+ outs (%arg5 = %output : memref<?x?x?xf32>) {
+ %min0 = affine.min affine_map<(d0, d1)[s0] -> (d1, -d0 + s0)>(%arg1, %s0)[%dim0]
+ %min1 = affine.min affine_map<(d0, d1)[s0] -> (d1, -d0 + s0)>(%arg2, %s1)[%dim1]
+ %min2 = affine.min affine_map<(d0, d1)[s0] -> (d1, -d0 + s0)>(%arg3, %s2)[%dim2]
+ %in_slice = memref.subview %arg4[%arg1, %arg2, %arg3] [%min0, %min1, %min2] [1, 1, 1]: memref<?x?x?xf32> to !memref_subview_type
+ "computation"(%in_slice) : (!memref_subview_type) -> memref<?x?x?xf32>
+ linalg.yield
+ }
+ return
+}
+
+// -----
+
+// CHECK-TILE-2-LABEL: func @step_1_do_not_peel
+// CHECK-TILE-2: linalg.tiled_loop
+// CHECK-TILE-2-NOT: linalg.tiled_loop
+
+// CHECK-TILE-012-LABEL: func @step_1_do_not_peel
+
+func @step_1_do_not_peel(%arg0: tensor<?x?x?xf32>) -> tensor<?x?x?xf32> {
+ %cst = constant 0.000000e+00 : f32
+ %c0 = constant 0 : index
+ %c1 = constant 1 : index
+ %c2 = constant 2 : index
+ %c8 = constant 8 : index
+ %dim0 = tensor.dim %arg0, %c0 : tensor<?x?x?xf32>
+ %dim1 = tensor.dim %arg0, %c1 : tensor<?x?x?xf32>
+ %dim2 = tensor.dim %arg0, %c2 : tensor<?x?x?xf32>
+ %output = linalg.init_tensor [%dim0, %dim1, %dim2] : tensor<?x?x?xf32>
+ %result = linalg.tiled_loop
+ (%arg1, %arg2, %arg3) = (%c0, %c0, %c0) to (%dim0, %dim1, %dim2)
+ step (%c1, %c1, %c1) ins (%arg4 = %arg0: tensor<?x?x?xf32>)
+ outs (%arg5 = %output: tensor<?x?x?xf32>) {
+ %in_slice = tensor.extract_slice %arg4[%arg1, %arg2, %arg3] [%c1, %c1, %c1] [1, 1, 1]: tensor<?x?x?xf32> to tensor<?x?x?xf32>
+ %out_slice = tensor.extract_slice %arg5[%arg1, %arg2, %arg3] [%c1, %c1, %c1] [1, 1, 1] : tensor<?x?x?xf32> to tensor<?x?x?xf32>
+ %comp = "computation"(%in_slice, %out_slice) : (tensor<?x?x?xf32>, tensor<?x?x?xf32>) -> tensor<?x?x?xf32>
+ %updated_slice = tensor.insert_slice %comp into %arg5[%arg1, %arg2, %arg3] [%c1, %c1, %c1] [1, 1, 1] : tensor<?x?x?xf32> into tensor<?x?x?xf32>
+ linalg.yield %updated_slice : tensor<?x?x?xf32>
+ }
+ return %result : tensor<?x?x?xf32>
+}
+
+// -----
+
+// CHECK-TILE-2-LABEL: func @divides_evenly_do_not_peel
+// CHECK-TILE-2: linalg.tiled_loop
+// CHECK-TILE-2-NOT: linalg.tiled_loop
+
+// CHECK-TILE-012-LABEL: func @divides_evenly_do_not_peel
+
+func @divides_evenly_do_not_peel(%arg0: tensor<?x?x?xf32>, %s: index)
+ -> tensor<?x?x?xf32> {
+ %cst = constant 0.000000e+00 : f32
+ %c0 = constant 0 : index
+ %c1 = constant 1 : index
+ %c2 = constant 2 : index
+ %c8 = constant 8 : index
+ %c64 = constant 64 : index
+ %dim0 = tensor.dim %arg0, %c0 : tensor<?x?x?xf32>
+ %dim1 = tensor.dim %arg0, %c1 : tensor<?x?x?xf32>
+ %dim2 = tensor.dim %arg0, %c2 : tensor<?x?x?xf32>
+ %output = linalg.init_tensor [%dim0, %dim1, %dim2] : tensor<?x?x?xf32>
+ %result = linalg.tiled_loop
+ (%arg1, %arg2, %arg3) = (%c0, %c0, %c0) to (%dim0, %dim1, %c64)
+ step (%s, %s, %c8) ins (%arg4 = %arg0: tensor<?x?x?xf32>)
+ outs (%arg5 = %output: tensor<?x?x?xf32>) {
+ %in_slice = tensor.extract_slice %arg4[%arg1, %arg2, %arg3] [%c1, %c1, %c1] [1, 1, 1]: tensor<?x?x?xf32> to tensor<?x?x?xf32>
+ %out_slice = tensor.extract_slice %arg5[%arg1, %arg2, %arg3] [%c1, %c1, %c1] [1, 1, 1] : tensor<?x?x?xf32> to tensor<?x?x?xf32>
+ %comp = "computation"(%in_slice, %out_slice) : (tensor<?x?x?xf32>, tensor<?x?x?xf32>) -> tensor<?x?x?xf32>
+ %updated_slice = tensor.insert_slice %comp into %arg5[%arg1, %arg2, %arg3] [%c1, %c1, %c1] [1, 1, 1] : tensor<?x?x?xf32> into tensor<?x?x?xf32>
+ linalg.yield %updated_slice : tensor<?x?x?xf32>
+ }
+ return %result : tensor<?x?x?xf32>
+}
diff --git a/mlir/test/lib/Dialect/Linalg/TestLinalgTransforms.cpp b/mlir/test/lib/Dialect/Linalg/TestLinalgTransforms.cpp
index 7bf84c205d37..108c25e9cda8 100644
--- a/mlir/test/lib/Dialect/Linalg/TestLinalgTransforms.cpp
+++ b/mlir/test/lib/Dialect/Linalg/TestLinalgTransforms.cpp
@@ -22,6 +22,7 @@
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallVector.h"
using namespace mlir;
using namespace mlir::linalg;
@@ -109,6 +110,10 @@ struct TestLinalgTransforms
ListOption<unsigned> testInterchangePattern{
*this, "test-interchange-pattern", llvm::cl::MiscFlags::CommaSeparated,
llvm::cl::desc("Test the interchange pattern.")};
+ ListOption<unsigned> testTiledLoopPeeling{
+ *this, "test-tiled-loop-peeling",
+ llvm::cl::desc("Test peeling of linalg.tiled_loop ops"),
+ llvm::cl::OneOrMore, llvm::cl::MiscFlags::CommaSeparated};
};
} // end anonymous namespace
@@ -575,6 +580,65 @@ static void applyInterchangePattern(FuncOp funcOp,
(void)applyPatternsAndFoldGreedily(funcOp, std::move(interchangePattern));
}
+static constexpr char kPeeledLoopsLabel[] = "__peeled_loops__";
+
+namespace {
+/// Peel TiledLoopOps, i.e., split them into two loops: One loop where the
+/// `idx`-th loop contains only "full" iterations and a second loop for the
+/// remaining partial iteration (if any).
+struct TiledLoopPeelingPattern : public OpRewritePattern<TiledLoopOp> {
+ TiledLoopPeelingPattern(MLIRContext *ctx, int64_t idx)
+ : OpRewritePattern<TiledLoopOp>(ctx), idx(idx) {}
+
+ LogicalResult matchAndRewrite(TiledLoopOp loopOp,
+ PatternRewriter &rewriter) const override {
+ SmallVector<int64_t> peeledLoops;
+ if (loopOp->hasAttr(kPeeledLoopsLabel)) {
+ auto attr = loopOp->getAttr(kPeeledLoopsLabel).cast<ArrayAttr>();
+ peeledLoops =
+ llvm::to_vector<4>(llvm::map_range(attr, [](Attribute attr) {
+ return attr.cast<IntegerAttr>().getInt();
+ }));
+ // Check if the loop was already peeled.
+ if (llvm::find(peeledLoops, idx) != peeledLoops.end())
+ return failure();
+ }
+
+ if (static_cast<int64_t>(loopOp.iterator_types().size()) <= idx)
+ return failure();
+
+ // Peel loop and canonicalize.
+ TiledLoopOp result;
+ if (failed(linalg::peelAndCanonicalizeTiledLoop(rewriter, loopOp, idx,
+ result)))
+ return failure();
+ peeledLoops.push_back(idx);
+
+ // Apply label, so that the same loop is not rewritten a second time.
+ rewriter.updateRootInPlace(loopOp, [&]() {
+ loopOp->setAttr(kPeeledLoopsLabel, rewriter.getI64ArrayAttr(peeledLoops));
+ });
+ result->setAttr(kPeeledLoopsLabel, rewriter.getI64ArrayAttr(peeledLoops));
+ return success();
+ }
+
+ /// Index of loop to peel.
+ int64_t idx;
+};
+} // namespace
+
+static void applyTiledLoopPeelingPattern(FuncOp funcOp,
+ ArrayRef<unsigned> loops) {
+ MLIRContext *ctx = funcOp.getContext();
+ RewritePatternSet patterns(ctx);
+ for (unsigned idx : loops)
+ patterns.add<TiledLoopPeelingPattern>(ctx, idx);
+ (void)applyPatternsAndFoldGreedily(funcOp, std::move(patterns));
+
+ // Drop the marker.
+ funcOp.walk([](TiledLoopOp op) { op->removeAttr(kPeeledLoopsLabel); });
+}
+
/// Apply transformations specified as patterns.
void TestLinalgTransforms::runOnFunction() {
auto lambda = [&](void *) {
@@ -612,6 +676,8 @@ void TestLinalgTransforms::runOnFunction() {
return applyGeneralizePadTensorPatterns(getFunction());
if (testSwapSubTensorPadTensor)
return applyExtractSliceOfPadTensorSwapPattern(getFunction());
+ if (testTiledLoopPeeling.hasValue())
+ return applyTiledLoopPeelingPattern(getFunction(), testTiledLoopPeeling);
if (testTileAndPadPattern)
return applyTileAndPadPattern(getFunction(), tileSizesForPadding);
if (testHoistPadding) {
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