[Mlir-commits] [mlir] [mlir] Add transformation to wrap scf::while in zero-trip-check (PR #81050)

[Jerry Wu]

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@@ -0,0 +1,40 @@
+// RUN: mlir-opt %s -test-wrap-scf-while-loop-in-zero-trip-check -split-input-file  | FileCheck %s
+
+func.func @wrap_while_loop_in_zero_trip_check(%bound : i32) -> i32 {
+  %cst0 = arith.constant 0 : i32
+  %cst5 = arith.constant 5 : i32
+  %res:2 = scf.while (%iter = %cst0) : (i32) -> (i32, i32) {
+    %cond = arith.cmpi slt, %iter, %bound : i32
+    %inv = arith.addi %bound, %cst5 : i32
+    scf.condition(%cond) %iter, %inv : i32, i32
+  } do {
+  ^bb0(%arg1: i32, %arg2: i32):
+    %next = arith.addi %arg1, %arg2 : i32
+    scf.yield %next : i32
+  }
+  return %res#0 : i32
+}
+
+// CHECK-LABEL: func.func @wrap_while_loop_in_zero_trip_check(
+// CHECK-SAME:      %[[ARG0:.*]]: i32) -> i32 {
+// CHECK-DAG:     %[[C0:.*]] = arith.constant 0 : i32
+// CHECK-DAG:     %[[C5:.*]] = arith.constant 5 : i32
+// CHECK-DAG:     %[[PRE_COND:.*]] = arith.cmpi slt, %[[C0]], %[[ARG0]] : i32
+// CHECK-DAG:     %[[PRE_INV:.*]] = arith.addi %[[ARG0]], %[[C5]] : i32
+// CHECK:         %[[IF:.*]]:2 = scf.if %[[PRE_COND]] -> (i32, i32) {
+// CHECK:           %[[WHILE:.*]]:2 = scf.while (
+// CHECK-SAME:          %[[ARG1:.*]] = %[[C0]], %[[ARG2:.*]] = %[[PRE_INV]]
+// CHECK-SAME:      ) : (i32, i32) -> (i32, i32) {
+// CHECK:             %[[NEXT:.*]] = arith.addi %[[ARG1]], %[[ARG2]] : i32
+// CHECK:             %[[COND:.*]] = arith.cmpi slt, %[[NEXT]], %[[ARG0]] : i32
+// CHECK:             %[[INV:.*]] = arith.addi %[[ARG0]], %[[C5]] : i32
+// CHECK:             scf.condition(%[[COND]]) %[[NEXT]], %[[INV]] : i32, i32
+// CHECK:           } do {
+// CHECK:           ^bb0(%[[ARG3:.*]]: i32, %[[ARG4:.*]]: i32):
+// CHECK:             scf.yield %[[ARG3]], %[[ARG4]] : i32, i32
+// CHECK:           }
+// CHECK:           scf.yield %[[WHILE]]#0, %[[WHILE]]#1 : i32, i32
+// CHECK:         } else {
+// CHECK:           scf.yield %[[C0]], %[[PRE_INV]] : i32, i32
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pzread wrote:

Done. Add a do while (all computation done in after block) and a while loop with all computation done in before block

https://github.com/llvm/llvm-project/pull/81050