[mlir][OpenMP] Reintroduce TODO for translation of linear clause (#143531)

Reintroduce a TODO for linear clause translation unless corner issues
(like linear variables being entities other than `alloca`, and support
for linear variables of types other than integer) are solved.

Author: NimishMishra

mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

@@ -432,6 +432,7 @@ static LogicalResult checkImplementationStatus(Operation &op) {
       })
       .Case([&](omp::WsloopOp op) {
         checkAllocate(op, result);
+        checkLinear(op, result);
         checkOrder(op, result);
         checkReduction(op, result);
       })

mlir/test/Target/LLVMIR/openmp-llvm.mlir

@@ -358,94 +358,6 @@ llvm.func @wsloop_simple(%arg0: !llvm.ptr) {
 
 // -----
 
-// CHECK-LABEL: wsloop_linear
-
-// CHECK: {{.*}} = alloca i32, i64 1, align 4
-// CHECK: %[[Y:.*]] = alloca i32, i64 1, align 4
-// CHECK: %[[X:.*]] = alloca i32, i64 1, align 4
-
-// CHECK: entry:
-// CHECK: %[[LINEAR_VAR:.*]] = alloca i32, align 4
-// CHECK: %[[LINEAR_RESULT:.*]] = alloca i32, align 4
-// CHECK: br label %omp_loop.preheader
-
-// CHECK: omp_loop.preheader:
-// CHECK: %[[LOAD:.*]] = load i32, ptr %[[X]], align 4
-// CHECK: store i32 %[[LOAD]], ptr %[[LINEAR_VAR]], align 4
-// CHECK: %omp_global_thread_num = call i32 @__kmpc_global_thread_num(ptr @2)
-// CHECK: call void @__kmpc_barrier(ptr @1, i32 %omp_global_thread_num)
-
-// CHECK: omp_loop.body:
-// CHECK: %[[LOOP_IV:.*]] = add i32 %omp_loop.iv, {{.*}}
-// CHECK: %[[LINEAR_LOAD:.*]] = load i32, ptr %[[LINEAR_VAR]], align 4
-// CHECK: %[[MUL:.*]] = mul i32 %[[LOOP_IV]], 1
-// CHECK: %[[ADD:.*]] = add i32 %[[LINEAR_LOAD]], %[[MUL]]
-// CHECK: store i32 %[[ADD]], ptr %[[LINEAR_RESULT]], align 4
-// CHECK: br label %omp.loop_nest.region
-
-// CHECK: omp.loop_nest.region:
-// CHECK: %[[LINEAR_LOAD:.*]] = load i32, ptr %[[LINEAR_RESULT]], align 4
-// CHECK: %[[ADD:.*]] = add i32 %[[LINEAR_LOAD]], 2
-// CHECK: store i32 %[[ADD]], ptr %[[Y]], align 4
-
-// CHECK: omp_loop.exit:
-// CHECK: call void @__kmpc_for_static_fini(ptr @2, i32 %omp_global_thread_num4)
-// CHECK: %omp_global_thread_num5 = call i32 @__kmpc_global_thread_num(ptr @2)
-// CHECK: call void @__kmpc_barrier(ptr @3, i32 %omp_global_thread_num5)
-// CHECK: br label %omp_loop.linear_finalization
-
-// CHECK: omp_loop.linear_finalization:
-// CHECK: %[[LAST_ITER:.*]] = load i32, ptr %p.lastiter, align 4
-// CHECK: %[[CMP:.*]] = icmp ne i32 %[[LAST_ITER]], 0
-// CHECK: br i1 %[[CMP]], label %omp_loop.linear_lastiter_exit, label %omp_loop.linear_exit
-
-// CHECK: omp_loop.linear_lastiter_exit:
-// CHECK: %[[LINEAR_RESULT_LOAD:.*]] = load i32, ptr %[[LINEAR_RESULT]], align 4
-// CHECK: store i32 %[[LINEAR_RESULT_LOAD]], ptr %[[X]], align 4
-// CHECK: br label %omp_loop.linear_exit
-
-// CHECK: omp_loop.linear_exit:
-// CHECK: %omp_global_thread_num6 = call i32 @__kmpc_global_thread_num(ptr @2)
-// CHECK: call void @__kmpc_barrier(ptr @1, i32 %omp_global_thread_num6)
-// CHECK: br label %omp_loop.after
-
-llvm.func @wsloop_linear() {
-  %0 = llvm.mlir.constant(1 : i64) : i64
-  %1 = llvm.alloca %0 x i32 {bindc_name = "i", pinned} : (i64) -> !llvm.ptr
-  %2 = llvm.mlir.constant(1 : i64) : i64
-  %3 = llvm.alloca %2 x i32 {bindc_name = "y"} : (i64) -> !llvm.ptr
-  %4 = llvm.mlir.constant(1 : i64) : i64
-  %5 = llvm.alloca %4 x i32 {bindc_name = "x"} : (i64) -> !llvm.ptr
-  %6 = llvm.mlir.constant(1 : i64) : i64
-  %7 = llvm.alloca %6 x i32 {bindc_name = "i"} : (i64) -> !llvm.ptr
-  %8 = llvm.mlir.constant(2 : i32) : i32
-  %9 = llvm.mlir.constant(10 : i32) : i32
-  %10 = llvm.mlir.constant(1 : i32) : i32
-  %11 = llvm.mlir.constant(1 : i64) : i64
-  %12 = llvm.mlir.constant(1 : i64) : i64
-  %13 = llvm.mlir.constant(1 : i64) : i64
-  %14 = llvm.mlir.constant(1 : i64) : i64
-  omp.wsloop linear(%5 = %10 : !llvm.ptr) {
-    omp.loop_nest (%arg0) : i32 = (%10) to (%9) inclusive step (%10) {
-      llvm.store %arg0, %1 : i32, !llvm.ptr
-      %15 = llvm.load %5 : !llvm.ptr -> i32
-      %16 = llvm.add %15, %8 : i32
-      llvm.store %16, %3 : i32, !llvm.ptr
-      %17 = llvm.add %arg0, %10 : i32
-      %18 = llvm.icmp "sgt" %17, %9 : i32
-      llvm.cond_br %18, ^bb1, ^bb2
-    ^bb1:  // pred: ^bb0
-      llvm.store %17, %1 : i32, !llvm.ptr
-      llvm.br ^bb2
-    ^bb2:  // 2 preds: ^bb0, ^bb1
-      omp.yield
-     }
-   }
-  llvm.return
-}
-
-// -----
-
 // CHECK-LABEL: @wsloop_inclusive_1
 llvm.func @wsloop_inclusive_1(%arg0: !llvm.ptr) {
   %0 = llvm.mlir.constant(42 : index) : i64

mlir/test/Target/LLVMIR/openmp-todo.mlir

@@ -511,6 +511,18 @@ llvm.func @wsloop_allocate(%lb : i32, %ub : i32, %step : i32, %x : !llvm.ptr) {
 
 // -----
 
+llvm.func @wsloop_linear(%lb : i32, %ub : i32, %step : i32, %x : !llvm.ptr) {
+  // expected-error@below {{not yet implemented: Unhandled clause linear in omp.wsloop operation}}
+  // expected-error@below {{LLVM Translation failed for operation: omp.wsloop}}
+  omp.wsloop linear(%x = %step : !llvm.ptr) {
+    omp.loop_nest (%iv) : i32 = (%lb) to (%ub) step (%step) {
+      omp.yield
+    }
+  }
+  llvm.return
+}
+
+// -----
 llvm.func @wsloop_order(%lb : i32, %ub : i32, %step : i32) {
   // expected-error@below {{not yet implemented: Unhandled clause order in omp.wsloop operation}}
   // expected-error@below {{LLVM Translation failed for operation: omp.wsloop}}