// RUN: mlir-opt %s --transform-interpreter \
// RUN: --test-transform-dialect-erase-schedule \
// RUN: --math-uplift-to-fma \
// RUN: --convert-bufferization-to-memref \
// RUN: --test-lower-to-llvm |\
// RUN: FileCheck %s
// Fixed-size tensor types to be used in convolution.
// Named sizes are: N=5 OH=80 OW=100 F=C=128 KH=KW=3.
// Input is NHWC.
// Filter is CHWF.
// Ouptut is NHWF.
!tinput = tensor<5x82x102x128xf32>
!tfilter = tensor<128x3x3x128xf32>
!tbias = tensor<128xf32>
!toutput = tensor<5x80x100x128xf32>
// Function containing the convolution. Note that its arguments and results are
// tensors annotated with attributes from the `bufferization` dialect. These
// attributes hint the bufferization pass to assume buffers can be directly
// used for these tensors without reshaping.
func.func @conv(
%input: !tinput {bufferization.writable = false,
bufferization.access = "read",
bufferization.buffer_layout =
affine_map<(d0,d1,d2,d3)->(d0,d1,d2,d3)>},
%filter: !tfilter {bufferization.writable = false,
bufferization.access = "read",
bufferization.buffer_layout =
affine_map<(d0,d1,d2,d3)->(d0,d1,d2,d3)>},
%bias: !tbias {bufferization.writable = false,
bufferization.access = "read",
bufferization.buffer_layout = affine_map<(d0)->(d0)>},
%output: !toutput {bufferization.writable = true,
bufferization.buffer_layout =
affine_map<(d0,d1,d2,d3)->(d0,d1,d2,d3)>,
bufferization.access = "write"}) -> !toutput
// This requests a C-compatible interface to be emitted for the function
// when translating to LLVM IR.
attributes { llvm.emit_c_interface }
{
// Bias. Using a named Linalg operation for brevity.
%bias_init = tensor.empty() : !toutput
%biased = linalg.broadcast ins(%bias : !tbias)
outs(%bias_init : !toutput) dimensions = [0, 1, 2]
// Convolution proper. While Linalg has named operations for 2D convolutions,
// the one in the Halide example has an uncommon order of filter dimensions
// and is not supported. It also takes the fitler as first argument. This
// code recreates it faithfully using the generic form.
%convolved = linalg.generic {
iterator_types = ["parallel", "parallel", "parallel", "parallel",
"reduction", "reduction", "reduction"],
indexing_maps = [
affine_map<(n, y, x, c, rz, ry, rx) -> (rx, rz, ry, c)>,
affine_map<(n, y, x, c, rz, ry, rx) -> (n, y+rz, x+ry, rx)>,
affine_map<(n, y, x, c, rz, ry, rx) -> (n, y, x, c)>
]
} ins(%filter, %input: !tfilter, !tinput) outs(%biased : !toutput) {
^bb0(%in: f32, %f: f32, %b: f32):
// Note the fastmath attributes that allow operations to be recombined into
// %0 = math.fma %in, %f, %b : f32
// later on and to reorder reductions.
%m1 = arith.mulf %in, %f {fastmath = #arith.fastmath<fast>} : f32
%0 = arith.addf %b, %m1 {fastmath = #arith.fastmath<fast>} : f32
linalg.yield %0 : f32
} -> !toutput
// ReLU is just a max(0, x).
%c0 = arith.constant 0.0 : f32
%relued = linalg.generic {
iterator_types = ["parallel", "parallel", "parallel", "parallel"],
indexing_maps = [
affine_map<(d0, d1, d2, d3) -> ()>,
affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, d3)>,
affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, d3)>
]
} ins(%c0, %convolved : f32, !toutput)
outs(%output : !toutput) {
^bb0(%cst: f32, %in: f32, %out: f32):
%0 = llvm.intr.maxnum(%cst, %in) : (f32, f32) -> f32
linalg.yield %0 : f32
} -> !toutput
return %relued : !toutput
}
// Module containing the transformation script to be applied. The attribute
// is required to correctly verify the use of named (macro-like) sequences.
module attributes { transform.with_named_sequence } {
// Apply transformations in a sequence to recreate the following Halide
// schedule:
//
// Var co, ci, xo, xi;
// relu.split(c, co, ci, vec * tile_w)
// .split(x, xo, xi, tile_h)
// .reorder(ci, xi, xo, y, n, co)
// .vectorize(ci, vec)
// .unroll(ci)
// .unroll(xi);
// conv.compute_at(relu, xo)
// .vectorize(c, vec)
// .unroll(c)
// .unroll(x)
// .unroll(y)
// .update()
// .reorder(c, x, y, r.x, r.y, r.z, n)
// .vectorize(c, vec)
// .unroll(c)
// .unroll(x)
// .unroll(y)
// .unroll(r.x, 2);
//
// where tile_w = 4, tile_h = 5, vec = 16. Note that unroll(y) and unroll(r.x)
// have no effect on the Halide IR as of 294f80c49bf3bb8582446613c25fcce03b82.
// Also note that the order of dimensions in Halide is inverted, e.g., co and
// n are the outermost loops in the respective reorder directives.
transform.named_sequence @__transform_main(
// This argument will point to the top-level module.
%arg0: !transform.any_op) {
// 1. Find the operations we are going to transform usnig their names. This
// is a simplistic approach that works when there are few operations in the
// IR to be transformed. More complex scenarios should rely on operations
// with `transform.match` prefix that are out of scope for this chapter.
%bias = transform.structured.match ops{["linalg.broadcast"]} in %arg0
: (!transform.any_op) -> !transform.any_op
%generics = transform.structured.match ops{["linalg.generic"]} in %arg0
: (!transform.any_op) -> !transform.any_op
%conv, %relu = transform.split_handle %generics
: (!transform.any_op) -> (!transform.any_op, !transform.any_op)
// 2. Initial tiling to start producing the loop structure. Note that the
// linalg.generic operation has the implicit loop order (n, y, x, c). Since
// the desired order of dimensions is (co, n, y, xo, xi, ci), we first tile
// only the c dimension to materialize the outermost co loop, and then tile
// the other dimensions since they are already in the expected order. Tiling
// by 1 produces the loop that iterates along the entire dimension. Tiling
// by 0 does not produce a loop. The size 64 is chosen as tiling by 4*16
// where 16 is the AVX512 vector length. Note that structured tiling doesn't
// remove the dimensions that became trivial (unit size) so the resulting
// sturucture is technically (co, no=n, yo=y, xo, [ni=1, yi=1, xi, ci])
// where brackets indicate implicit loops of the `linalg.generic` operation
// inside the loops produced by tiling.
//
// [n y x c]
%relu2, %co = transform.structured.tile_using_forall %relu
tile_sizes [0, 0, 0, 64]
: (!transform.any_op) -> (!transform.any_op, !transform.any_op)
%relu3, %n_y_xo = transform.structured.tile_using_forall %relu2
tile_sizes [1, 1, 5, 0]
: (!transform.any_op) -> (!transform.any_op, !transform.any_op)
// Compute_at is actually fusion into the given loop (given that we start
// with totally fissioned form, Halide starts with a fused form by reusing
// the loop iterators).
%conv2, %co2 = transform.structured.fuse_into_containing_op %conv into %co
: (!transform.any_op, !transform.any_op)
-> (!transform.any_op, !transform.any_op)
%conv3, %n_y_xo2 = transform.structured.fuse_into_containing_op %conv2
into %n_y_xo
: (!transform.any_op, !transform.any_op)
-> (!transform.any_op, !transform.any_op)
// Also fuse the bias that we represent as a separate operation and Halide
// represents as the "pure" (as opposed to "update") part of the conv
// expression. Note that fusion consumes both handles and produces new
// handles for chaining purposes.
%bias2, %co3 = transform.structured.fuse_into_containing_op %bias into %co2
: (!transform.any_op, !transform.any_op)
-> (!transform.any_op, !transform.any_op)
%bias3, %n_y_xo3 = transform.structured.fuse_into_containing_op %bias2
into %n_y_xo2
: (!transform.any_op, !transform.any_op)
-> (!transform.any_op, !transform.any_op)
// Clean up the result of fusion, which mechanically duplicates the producer
// operation in the consumer loop without removing the original operation.
// The original operation is now "dead": it has no uses and no side effects
// so it can be removed by dead-code elimination (DCE) that runs as part of
// pattern rewriting. The transform dialect allows to apply a combination
// of named pattern sets, exposed as operations, in one sweep to an
// isolated-from-above container payload operation. Note that we don't
// actually need any patterns for DCE to run, just trigger the rewriting.
//
// This step is optional. The transformation can continue without it and
// produce the same final IR, but makes it easier to manually examine the
// intermediate stages.
%f00 = transform.structured.match ops{["func.func"]} in %arg0
: (!transform.any_op) -> !transform.any_op
transform.apply_patterns to %f00 {
} : !transform.any_op
// The loop reordering requested for the convolution operation requires
// putting reduction loops (r.z, r.y. r.x) before the "inner" loops xi, ci.
// The "inner" loops are still implicit as part of the linalg.generic
// operation, and we need to materialize reduction loops around it by tiling
// with size 1. Since we are producing reduction loops, we indicate that we
// are tiling a reduction and request a sequential `scf.for` loops (parallel
// reductions are supported by `scf.forall`, but we don't need those here).
//
// This transform operation is more capable than merely producing
// (reduction) loops: the transformed code performs `tile_size` partial
// reductions of `N / tile_size` elements, potentially in parallel by
// changing the dimension kind of the structured operation inside the loop,
// and then performs a final reduction of these partial results by producing
// a new “combiner” structured operation after the loops. In our case,
// tile_size = 1 along all dimensions, so the reduction is entirely
// performed by the generated loops. The combiner structured operation is
// still produced and adds up the reduction result with the initial value.
%red_fill, %conv4, %combining, %rz_ry_rx
= transform.structured.tile_reduction_using_for %conv3 by
// n y x c rz ry rx
tile_sizes=[0, 0, 0, 0, 1, 1, 1]
: (!transform.any_op)
-> (!transform.any_op, !transform.any_op, !transform.any_op,
!transform.any_op)
// At this point, the inner Linalg operations have implicit iteration spaces
// of 5x64 size, with some additional unit-size dimensions. Completely
// replicating Halide schedule would require materializing the loops with
// 5 and 4 iterations, respectively, unrolling those loops and marking the
// remaining 16-point iteration space for vectorization.
//
// This is unnecessary in MLIR that supports multi-dimensional vectors,
// which will be decomposed into target-specific sizes during the lowering.
// Therefore, this schedule stops here.
// Transform the named broadcast operation used for bias into the generic
// form before vectorization to prevent special cases from kicking in.
transform.structured.generalize %bias3
: (!transform.any_op) -> !transform.any_op
// Use the named macro to perform most of the lowering.
transform.include @lower failures(propagate) (%arg0)
: (!transform.any_op) -> ()
transform.yield
}
// Named sequence of transformations is a macro-like object that can be
// included from another place in the transform dialect, but doesn't allow for
// recursion. This can be reused in other scenarios.
transform.named_sequence @lower(
%arg0: !transform.any_op {transform.consumed}) {
%f00 = transform.structured.match ops{["func.func"]} in %arg0
: (!transform.any_op) -> !transform.any_op
// Simplify the code as tiling and fusion may have produced a lot of
// operations computing tensor subsets and loop ranges, some of which may be
// duplicated or excessively complex. Simplification involving
// canonicalization, common subexpression elimination, loop invariant code
// motion and various rewrite patterns can be applied directly from the
// transform dialect. Furthermore, an arbitrary combination of rewrite
// patterns can be applied in one sweep to a given scope, a functionality
// that cannot be achieved with conventional compiler passes that apply each
// group of patterns separately (at least without creating a new pass for
// each combination of pattern groups).
transform.apply_patterns to %f00 {
transform.apply_patterns.canonicalization
transform.apply_patterns.linalg.tiling_canonicalization
} : !transform.any_op
transform.apply_cse to %f00 : !transform.any_op
%all_loops = transform.structured.match interface{LoopLikeInterface}
in %arg0
: (!transform.any_op) -> !transform.any_op
transform.apply_licm to %all_loops : !transform.any_op
// Tiling-by-one as a way of materializing loops produced operations
// processing 4+D types where only a handful of dimension isn’t unit-sized,
// e.g., tensor<1x1x1x5x64xf32> where 5 and 64 are tile sizes. Remove such
// unit dimensions before vectorization, for clarity.
transform.apply_patterns to %f00 {
transform.apply_patterns.linalg.fold_unit_extent_dims_via_reshapes
} : !transform.any_op
// Vectorize the remaining non-unit dimensions in structured operations.
// This essentially rewrites operations on `tensor<5x64xf32>` into
// opreations on `vector<5x64xf32>`. Further lowering in MLIR and LLVM will
// decompose this into a sequence of operations on single-dimensional
// vectors of the platform-relevant size, e.g., `vector<16xf32>` for AVX512.
// High-level vector primitives, such as `vector.transpose` and
// `vector.broadcast` can be introduced at this stage. They will be later
// lowered to sequences of lower-level primitives such as `vector.shuffle`
// depending on the selected lowering strategy.
%fv = transform.structured.vectorize_children_and_apply_patterns %f00
: (!transform.any_op) -> !transform.any_op
// Vectorization may have created new opportunities for cleanups. In
// particular, tensor subsetting operations can be composed with vector
// operations, and vector transfer (multi-dimensional load/store) operations
// can be recombined and hoisted out of loops.
transform.apply_patterns to %fv {
transform.apply_patterns.canonicalization
transform.apply_patterns.tensor.fold_tensor_subset_ops_into_vector_transfers
} : !transform.any_op
transform.apply_cse to %fv : !transform.any_op
transform.structured.hoist_redundant_vector_transfers %fv
: (!transform.any_op) -> !transform.any_op
// Apply bufferization that rewrites the remaining operations on tensors
// as operations on structured buffer (memref) types, including the function
// API. MLIR bufferization uses destination-passing style meaning that a
// buffer is shared between one of the operation's operands and its result.
//
// Since bufferization rewrites function signatures, it is applied as a
// module-wise transformation. Therefore, it invalidates all previously
// defined handles. Bufferization is usually a late step in the
// transformation process, so invalidation is not an issue. However, if
// other transformations, such as loop unrolling, are required after
// bufferization, new handles should be produced using the match operations.
//
// One-shot bufferization itself does not produce buffer deallocations,
// which may lead to leaks. So we have to run the buffer deallocation pass
// pipeline to avoid them. Note that the transform dialect seamlessly runs
// named passes and pass pipelines: if desired, one could replace complex
// --pass-pipeline expressions with operations. Note that we apply the
// pipeline to functions rather than entire module to avoid running it
// on the transform IR that is contained in the module.
%arg1 = transform.bufferization.one_shot_bufferize %arg0 {
bufferize_function_boundaries = true,
function_boundary_type_conversion = 1 : i32 }
: (!transform.any_op) -> !transform.any_op
%f = transform.structured.match ops{["func.func"]} in %arg1
: (!transform.any_op) -> !transform.any_op
transform.apply_registered_pass "buffer-deallocation-pipeline" to %f
: (!transform.any_op) -> !transform.any_op
// Apply general canonicalization and CSE to each function after
// bufferization as new simplification opportunities may have appeared.
%fb = transform.structured.match ops{["func.func"]} in %arg1
: (!transform.any_op) -> !transform.any_op
transform.apply_patterns to %fb {
transform.apply_patterns.canonicalization
} : !transform.any_op
transform.apply_cse to %fb : !transform.any_op
// Lower complex, multidimensional vector operations into simpler
// primitives. This particular selection of the pattern groups corresponds
// to vector dialect operations present in the payload IR at this stage.
// Many of these groups can be parameterized to use different strategies or
// lower-level primitives offering performance trade-offs. In this case, we
// are selecting the simplest strategies.
transform.apply_patterns to %fb {
transform.apply_patterns.vector.lower_contraction
lowering_strategy = parallelarith
transform.apply_patterns.vector.lower_transfer
max_transfer_rank = 1
transform.apply_patterns.vector.lower_transpose
lowering_strategy = eltwise
transform.apply_patterns.vector.lower_shape_cast
} : !transform.any_op
// These patterns apply in a separate sweep to avoid transfer-to-scf
// patterns overlap with lower-transfer patterns as they apply to the same
// kind of operations. These patterns may produce local allocations to act
// as temporary caches deep inside loops, which could lead to catastrophic
// performance. Such allocations are moved onto the stack and hoisted from
// all the surrounding loops.
transform.apply_patterns to %fb {
transform.apply_patterns.vector.transfer_to_scf
transform.apply_patterns.memref.alloc_to_alloca
} : !transform.any_op
transform.bufferization.buffer_loop_hoisting %fb : !transform.any_op
// A final round of cleanups additionally includes patterns to simplify
// buffer aliasing operations that may have been introduced during
// bufferization and could result in excessively complex address
// computation.
transform.apply_patterns to %fb {
transform.apply_patterns.memref.fold_memref_alias_ops
transform.apply_patterns.canonicalization
} : !transform.any_op
transform.apply_cse to %fb : !transform.any_op
transform.yield
}
}
// The core computation, at the LLVM dialect level, must correspond to five
// immediately adjacent fma on vector<64xf32>.
// CHECK: %[[R0:.+]] = llvm.mlir.undef : !llvm.array<5 x vector<64xf32>>
// CHECK: %[[V:.+]] = llvm.load %{{.*}} : !llvm.ptr -> !llvm.array<5 x vector<64xf32>>
// CHECK-NEXT: %[[LINE0:.+]] = llvm.extractvalue %[[V]][0] : !llvm.array<5 x vector<64xf32>>
// CHECK-NEXT: %[[FMA0:.+]] = llvm.intr.fma(%{{.*}}, %{{.*}}, %[[LINE0]])
// CHECK-SAME: -> vector<64xf32>
// CHECK-NEXT: %[[R1:.+]] = llvm.insertvalue %[[FMA0]], %[[R0]][0]
// CHECK-NEXT: %[[LINE1:.+]] = llvm.extractvalue %[[V]][1] : !llvm.array<5 x vector<64xf32>>
// CHECK-NEXT: %[[FMA1:.+]] = llvm.intr.fma(%{{.*}}, %{{.*}}, %[[LINE1]])
// CHECK-SAME: -> vector<64xf32>
// CHECK-NEXT: %[[R2:.+]] = llvm.insertvalue %[[FMA1]], %[[R1]][1]
// CHECK-NEXT: %[[LINE2:.+]] = llvm.extractvalue %[[V]][2] : !llvm.array<5 x vector<64xf32>>
// CHECK-NEXT: %[[FMA2:.+]] = llvm.intr.fma(%{{.*}}, %{{.*}}, %[[LINE2]])
// CHECK-SAME: -> vector<64xf32>
// CHECK-NEXT: %[[R3:.+]] = llvm.insertvalue %[[FMA2]], %[[R2]][2]
// CHECK-NEXT: %[[LINE3:.+]] = llvm.extractvalue %[[V]][3] : !llvm.array<5 x vector<64xf32>>
// CHECK-NEXT: %[[FMA3:.+]] = llvm.intr.fma(%{{.*}}, %{{.*}}, %[[LINE3]])
// CHECK-SAME: -> vector<64xf32>
// CHECK-NEXT: %[[R4:.+]] = llvm.insertvalue %[[FMA3]], %[[R3]][3]
// CHECK-NEXT: %[[LINE4:.+]] = llvm.extractvalue %[[V]][4] : !llvm.array<5 x vector<64xf32>>
// CHECK-NEXT: %[[FMA4:.+]] = llvm.intr.fma(%{{.*}}, %{{.*}}, %[[LINE4]])
// CHECK-SAME: -> vector<64xf32>
// CHECK-NEXT: %[[R5:.+]] = llvm.insertvalue %[[FMA4]], %[[R4]][4]
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