[Mlir-commits] [mlir] Refactor LoopFuseSiblingOp and support parallel fusion (PR #94391)

[Ivan Butygin]

================
@@ -47,6 +47,59 @@ module attributes {transform.with_named_sequence} {
 
 // -----
 
+// CHECK-LABEL: func @fuse_two_parallel
+// CHECK-SAME:   ([[A:%.*]]: {{.*}}, [[B:%.*]]: {{.*}}) {
+func.func @fuse_two_parallel(%A: memref<2x2xf32>, %B: memref<2x2xf32>) {
+// CHECK-DAG:  [[C2:%.*]] = arith.constant 2 : index
+// CHECK-DAG:  [[C0:%.*]] = arith.constant 0 : index
+// CHECK-DAG:  [[C1:%.*]] = arith.constant 1 : index
+// CHECK-DAG:  [[C1FP:%.*]] = arith.constant 1.
+  %c2 = arith.constant 2 : index
+  %c0 = arith.constant 0 : index
+  %c1 = arith.constant 1 : index
+  %c1fp = arith.constant 1.0 : f32
+// CHECK:      [[SUM:%.*]] = memref.alloc()
+  %sum = memref.alloc()  : memref<2x2xf32>
+// CHECK:      scf.parallel ([[I:%.*]], [[J:%.*]]) = ([[C0]], [[C0]])
+// CHECK-SAME:     to ([[C2]], [[C2]]) step ([[C1]], [[C1]]) {
+// CHECK:        [[B_ELEM:%.*]] = memref.load [[B]]{{\[}}[[I]], [[J]]]
+// CHECK:        [[SUM_ELEM:%.*]] = arith.addf [[B_ELEM]], [[C1FP]]
+// CHECK:        memref.store [[SUM_ELEM]], [[SUM]]{{\[}}[[I]], [[J]]]
+// CHECK-NOT:  scf.parallel
+// CHECK:        [[SUM_ELEM_:%.*]] = memref.load [[SUM]]{{\[}}[[I]], [[J]]]
+// CHECK:        [[A_ELEM:%.*]] = memref.load [[A]]{{\[}}[[I]], [[J]]]
+// CHECK:        [[PRODUCT_ELEM:%.*]] = arith.mulf [[SUM_ELEM_]], [[A_ELEM]]
+// CHECK:        memref.store [[PRODUCT_ELEM]], [[B]]{{\[}}[[I]], [[J]]]
+// CHECK:        scf.reduce
+// CHECK:      }
+  scf.parallel (%i, %j) = (%c0, %c0) to (%c2, %c2) step (%c1, %c1) {
+    %B_elem = memref.load %B[%i, %j] : memref<2x2xf32>
+    %sum_elem = arith.addf %B_elem, %c1fp : f32
+    memref.store %sum_elem, %sum[%i, %j] : memref<2x2xf32>
+    scf.reduce
+  }
+  scf.parallel (%i, %j) = (%c0, %c0) to (%c2, %c2) step (%c1, %c1) {
+    %sum_elem = memref.load %sum[%i, %j] : memref<2x2xf32>
+    %A_elem = memref.load %A[%i, %j] : memref<2x2xf32>
+    %product_elem = arith.mulf %sum_elem, %A_elem : f32
+    memref.store %product_elem, %B[%i, %j] : memref<2x2xf32>
+    scf.reduce
+  }
+// CHECK:      memref.dealloc [[SUM]]
+  memref.dealloc %sum : memref<2x2xf32>
+  return
+}
+module attributes {transform.with_named_sequence} {
+  transform.named_sequence @__transform_main(%arg0: !transform.any_op {transform.readonly}) {
+    %0 = transform.structured.match ops{["scf.parallel"]} in %arg0 : (!transform.any_op) -> !transform.any_op
+    %parallel:2 = transform.split_handle %0 :  (!transform.any_op) -> (!transform.any_op, !transform.any_op)
+    %fused = transform.loop.fuse_sibling %parallel#0 into %parallel#1 : (!transform.any_op,!transform.any_op) ->  !transform.any_op
----------------
Hardcode84 wrote:

Is this op symmetrical? What will happen if we do `transform.loop.fuse_sibling %parallel#1 into %parallel#0`?

https://github.com/llvm/llvm-project/pull/94391