diff --git a/mlir/lib/Dialect/Async/Transforms/AsyncParallelFor.cpp b/mlir/lib/Dialect/Async/Transforms/AsyncParallelFor.cpp
--- a/mlir/lib/Dialect/Async/Transforms/AsyncParallelFor.cpp
+++ b/mlir/lib/Dialect/Async/Transforms/AsyncParallelFor.cpp
@@ -265,6 +265,12 @@
                                type);
   func.setPrivate();
 
+  // Always inline parallel compute function. It gets inlined twice: into the
+  // `async.execute` body and into the main function computing result for the
+  // first block.
+  auto alwaysinline = rewriter.getStringAttr("alwaysinline");
+  func->setAttr("passthrough", rewriter.getArrayAttr({alwaysinline}));
+
   // Insert function into the module symbol table and assign it unique name.
   SymbolTable symbolTable(module);
   symbolTable.insert(func);
@@ -479,6 +485,11 @@
   FuncOp func = FuncOp::create(loc, "async_dispatch_fn", type);
   func.setPrivate();
 
+  // TODO: We do not inline async dispatch function, in some cases it leads to
+  // performance regressions because of poor vectorization of compute function.
+  auto noinline = rewriter.getStringAttr("noinline");
+  func->setAttr("passthrough", rewriter.getArrayAttr({noinline}));
+
   // Insert function into the module symbol table and assign it unique name.
   SymbolTable symbolTable(module);
   symbolTable.insert(func);
@@ -790,13 +801,18 @@
     SmallVector<int64_t> numIterations(op.getNumLoops());
     numIterations.back() = getInt(staticBounds.tripCounts.back());
 
+    // Check if we can potentially unroll the inner-most loop.
+    if (numIterations.back() > 0 && numIterations.back() <= maxIterations)
+      numUnrollableLoops++;
+
+    // Check if we can potentially unroll other loops in the loop nest.
     for (int i = op.getNumLoops() - 2; i >= 0; --i) {
       int64_t tripCount = getInt(staticBounds.tripCounts[i]);
       int64_t innerIterations = numIterations[i + 1];
       numIterations[i] = tripCount * innerIterations;
 
       // Update the number of inner loops that we can potentially unroll.
-      if (innerIterations > 0 && innerIterations <= maxIterations)
+      if (numIterations[i] > 0 && numIterations[i] <= maxIterations)
         numUnrollableLoops++;
     }
 
diff --git a/mlir/test/Dialect/Async/async-parallel-for-async-dispatch.mlir b/mlir/test/Dialect/Async/async-parallel-for-async-dispatch.mlir
--- a/mlir/test/Dialect/Async/async-parallel-for-async-dispatch.mlir
+++ b/mlir/test/Dialect/Async/async-parallel-for-async-dispatch.mlir
@@ -36,7 +36,7 @@
 // CHECK-SAME:    %[[GROUP:arg0]]: !async.group,
 // CHECK-SAME:    %[[BLOCK_START:arg1]]: index
 // CHECK-SAME:    %[[BLOCK_END:arg2]]: index
-// CHECK-SAME:  )
+// CHECK-SAME:  ) attributes {passthrough = ["noinline"]}
 // CHECK:         %[[C1:.*]] = arith.constant 1 : index
 // CHECK:         %[[C2:.*]] = arith.constant 2 : index
 // CHECK:         scf.while (%[[S0:.*]] = %[[BLOCK_START]],
diff --git a/mlir/test/Dialect/Async/async-parallel-for-compute-fn.mlir b/mlir/test/Dialect/Async/async-parallel-for-compute-fn.mlir
--- a/mlir/test/Dialect/Async/async-parallel-for-compute-fn.mlir
+++ b/mlir/test/Dialect/Async/async-parallel-for-compute-fn.mlir
@@ -30,7 +30,7 @@
 // CHECK-SAME:   %[[UB:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[STEP:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[MEMREF:arg[0-9]+]]: memref<?xf32>
-// CHECK-SAME: ) {
+// CHECK-SAME: ) attributes {passthrough = ["alwaysinline"]} {
 // CHECK:        %[[CST:.*]] = arith.constant 1.0{{.*}} : f32
 // CHECK:        scf.for
 // CHECK:          memref.store %[[CST]], %[[MEMREF]]
@@ -59,7 +59,7 @@
 // CHECK-SAME:   %[[UB:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[STEP:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[MEMREF:arg[0-9]+]]: memref<?xf32>
-// CHECK-SAME: ) {
+// CHECK-SAME: ) attributes {passthrough = ["alwaysinline"]} {
 // CHECK:        %[[CSTEP:.*]] = arith.constant 123 : index
 // CHECK-NOT:    %[[STEP]]
 // CHECK:        scf.for %[[I:arg[0-9]+]]
@@ -99,7 +99,7 @@
 // CHECK-SAME:   %[[STEP0:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[STEP1:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[MEMREF:arg[0-9]+]]: memref<?x10xf32>
-// CHECK-SAME: ) {
+// CHECK-SAME: ) attributes {passthrough = ["alwaysinline"]} {
 // CHECK:        scf.for %[[I:arg[0-9]+]]
 // CHECK:          arith.select
 // CHECK:          scf.for %[[J:arg[0-9]+]]
@@ -117,7 +117,7 @@
 // CHECK-SAME:   %[[STEP0:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[STEP1:arg[0-9]+]]: index,
 // CHECK-SAME:   %[[MEMREF:arg[0-9]+]]: memref<?x10xf32>
-// CHECK-SAME: ) {
+// CHECK-SAME: ) attributes {passthrough = ["alwaysinline"]} {
 // CHECK:        %[[C0:.*]] = arith.constant 0 : index
 // CHECK:        %[[C1:.*]] = arith.constant 1 : index
 // CHECK:        %[[C10:.*]] = arith.constant 10 : index