// RUN: mlir-opt %s --transform-interpreter | FileCheck %s
// RUN: mlir-opt %s --gpu-eliminate-barriers | FileCheck %s
module attributes {transform.with_named_sequence} {
transform.named_sequence @__transform_main(%arg0: !transform.any_op {transform.readonly}) {
%0 = transform.structured.match ops{["func.func"]} in %arg0 : (!transform.any_op) -> !transform.any_op
transform.apply_patterns to %0 {
transform.apply_patterns.gpu.eliminate_barriers
} : !transform.any_op
transform.yield
}
}
// CHECK-LABEL: @read_read_write
func.func @read_read_write(%arg0: memref<?xf32>, %arg1: index) attributes {__parallel_region_boundary_for_test} {
// CHECK: load
%0 = memref.load %arg0[%arg1] : memref<?xf32>
// The barrier between loads can be removed.
// CHECK-NOT: barrier
gpu.barrier
// CHECK: load
%1 = memref.load %arg0[%arg1] : memref<?xf32>
%2 = arith.addf %0, %1 : f32
// The barrier between load and store cannot be removed (unless we reason about accessed subsets).
// CHECK: barrier
gpu.barrier
// CHECK: store
memref.store %2, %arg0[%arg1] : memref<?xf32>
return
}
// CHECK-LABEL: @write_read_read
func.func @write_read_read(%arg0: memref<?xf32>, %arg1: index, %arg2: f32) -> f32
attributes {__parallel_region_boundary_for_test} {
// CHECK: store
memref.store %arg2, %arg0[%arg1] : memref<?xf32>
// The barrier between load and store cannot be removed (unless we reason about accessed subsets).
// CHECK: barrier
gpu.barrier
// CHECK: load
%0 = memref.load %arg0[%arg1] : memref<?xf32>
// CHECK-NOT: barrier
gpu.barrier
// CHECK: load
%1 = memref.load %arg0[%arg1] : memref<?xf32>
%2 = arith.addf %0, %1 : f32
return %2 : f32
}
// CHECK-LABEL: @write_in_a_loop
func.func @write_in_a_loop(%arg0: memref<?xf32>, %arg1: f32) attributes {__parallel_region_boundary_for_test} {
%c0 = arith.constant 0 : index
%c42 = arith.constant 42 : index
%c1 = arith.constant 1 : index
scf.for %i = %c0 to %c42 step %c1 {
memref.store %arg1, %arg0[%i] : memref<?xf32>
// Cannot remove this barrier because it guards write-after-write between different iterations.
// CHECK: barrier
gpu.barrier
}
return
}
// CHECK-LABEL: @read_read_write_loop
func.func @read_read_write_loop(%arg0: memref<?xf32>, %arg1: f32) attributes {__parallel_region_boundary_for_test} {
%c0 = arith.constant 0 : index
%c42 = arith.constant 42 : index
%c1 = arith.constant 1 : index
scf.for %i = %c0 to %c42 step %c1 {
// (Note that if subscript were different, this would have been a race with the store at the end of the loop).
%0 = memref.load %arg0[%i] : memref<?xf32>
// Guards read-after-write where the write happens on the previous iteration.
// CHECK: barrier
gpu.barrier
%1 = memref.load %arg0[%i] : memref<?xf32>
%2 = arith.addf %0, %1 : f32
// Guards write-after-read.
// CHECK: barrier
gpu.barrier
memref.store %2, %arg0[%i] : memref<?xf32>
}
return
}
// CHECK-LABEL: @read_read_write_loop_trailing_sync
func.func @read_read_write_loop_trailing_sync(%arg0: memref<?xf32>, %arg1: f32) attributes {__parallel_region_boundary_for_test} {
%c0 = arith.constant 0 : index
%c42 = arith.constant 42 : index
%c1 = arith.constant 1 : index
scf.for %i = %c0 to %c42 step %c1 {
// CHECK: load
%0 = memref.load %arg0[%i] : memref<?xf32>
// This can be removed because it only guards a read-after-read.
// CHECK-NOT: barrier
gpu.barrier
// CHECK: load
%1 = memref.load %arg0[%i] : memref<?xf32>
%2 = arith.addf %0, %1 : f32
// CHECK: barrier
gpu.barrier
// CHECK: store
memref.store %2, %arg0[%i] : memref<?xf32>
// CHECK: barrier
gpu.barrier
}
return
}
// CHECK-LABEL: @write_write_noalias
func.func @write_write_noalias(%arg0: index, %arg1: f32) -> (memref<42xf32>, memref<10xf32>)
attributes {__parallel_region_boundary_for_test} {
%0 = memref.alloc() : memref<42xf32>
%1 = memref.alloc() : memref<10xf32>
// CHECK: store
memref.store %arg1, %0[%arg0] : memref<42xf32>
// This can be removed because we can prove two allocations don't alias.
// CHECK-NOT: barrier
gpu.barrier
// CHECK: store
memref.store %arg1, %1[%arg0] : memref<10xf32>
return %0, %1 : memref<42xf32>, memref<10xf32>
}
// CHECK-LABEL: @write_write_alloc_arg_noalias
func.func @write_write_alloc_arg_noalias(%arg0: index, %arg1: f32, %arg2: memref<?xf32>) -> (memref<42xf32>)
attributes {__parallel_region_boundary_for_test} {
%0 = memref.alloc() : memref<42xf32>
// CHECK: store
memref.store %arg1, %0[%arg0] : memref<42xf32>
// This can be removed because we can prove local allocation doesn't alias with a function argument.
// CHECK-NOT: barrier
gpu.barrier
// CHECK: store
memref.store %arg1, %arg2[%arg0] : memref<?xf32>
return %0 : memref<42xf32>
}
// CHECK-LABEL: @repeated_barrier
func.func @repeated_barrier(%arg0: memref<?xf32>, %arg1: index, %arg2: f32) -> f32
attributes {__parallel_region_boundary_for_test} {
%0 = memref.load %arg0[%arg1] : memref<?xf32>
// CHECK: gpu.barrier
gpu.barrier
// CHECK-NOT: gpu.barrier
gpu.barrier
memref.store %arg2, %arg0[%arg1] : memref<?xf32>
return %0 : f32
}
// CHECK-LABEL: @symmetric_stop
func.func @symmetric_stop(%val: f32) -> (f32, f32, f32, f32, f32)
attributes {__parallel_region_boundary_for_test} {
// CHECK: %[[A:.+]] = memref.alloc
// CHECK: %[[B:.+]] = memref.alloc
// CHECK: %[[C:.+]] = memref.alloc
%A = memref.alloc() : memref<f32>
%B = memref.alloc() : memref<f32>
%C = memref.alloc() : memref<f32>
// CHECK: memref.store %{{.*}}, %[[A]]
memref.store %val, %A[] : memref<f32>
// CHECK: gpu.barrier
gpu.barrier
// CHECK: memref.load %[[A]]
%0 = memref.load %A[] : memref<f32>
// CHECK: memref.store %{{.*}}, %[[B]]
memref.store %val, %B[] : memref<f32>
// This barrier is eliminated because the surrounding barriers are sufficient
// to guard write/read on all memrefs.
// CHECK-NOT: gpu.barrier
gpu.barrier
// CHECK: memref.load %[[A]]
%1 = memref.load %A[] : memref<f32>
// CHECK: memref.store %{{.*}} %[[C]]
memref.store %val, %C[] : memref<f32>
// CHECK: gpu.barrier
gpu.barrier
// CHECK: memref.load %[[A]]
// CHECK: memref.load %[[B]]
// CHECK: memref.load %[[C]]
%2 = memref.load %A[] : memref<f32>
%3 = memref.load %B[] : memref<f32>
%4 = memref.load %C[] : memref<f32>
return %0, %1, %2, %3, %4 : f32, f32, f32, f32, f32
}
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