[Mlir-commits] [mlir] fa8fc9f - [MLIR, OpenMP] Support for flush operation, and translating the same to LLVM IR

[Kiran Kumar T P]

Author: Kiran Kumar T P
Date: 2020-05-19T17:01:25+05:30
New Revision: fa8fc9ffcc9b5f97360e99481ef2fc6df24fe01e

URL: https://github.com/llvm/llvm-project/commit/fa8fc9ffcc9b5f97360e99481ef2fc6df24fe01e
DIFF: https://github.com/llvm/llvm-project/commit/fa8fc9ffcc9b5f97360e99481ef2fc6df24fe01e.diff

LOG: [MLIR, OpenMP] Support for flush operation, and translating the same to LLVM IR

Summary:
This patch adds support for flush operation in OpenMP dialect and translation of this construct to LLVM IR.
The OpenMP IRBuilder is used for this translation.
The patch includes code changes and testcase modifications.

Reviewed By: ftynse, kiranchandramohan

Differential Revision: https://reviews.llvm.org/D79937

Added: 
    

Modified: 
    mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
    mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
    mlir/test/Dialect/OpenMP/ops.mlir
    mlir/test/Target/openmp-llvm.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index f283d3a7bf3d..af5e0433ef3c 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -33,6 +33,23 @@ def BarrierOp : OpenMP_Op<"barrier"> {
   let assemblyFormat = "attr-dict";
 }
 
+//===----------------------------------------------------------------------===//
+// 2.13.7 flush Construct
+//===----------------------------------------------------------------------===//
+def FlushOp : OpenMP_Op<"flush"> {
+  let summary = "flush construct";
+  let description = [{
+    The flush construct executes the OpenMP flush operation. This operation
+    makes a thread’s temporary view of memory consistent with memory and
+    enforces an order on the memory operations of the variables explicitly
+    specified or implied.
+  }];
+
+  let arguments = (ins Variadic<AnyType>:$varList);
+
+  let assemblyFormat = "attr-dict ($varList^ `:` type($varList))?";
+}
+
 def TaskwaitOp : OpenMP_Op<"taskwait"> {
   let summary = "taskwait construct";
   let description = [{

diff  --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 4cfa05ee33a3..960986917432 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -330,6 +330,18 @@ ModuleTranslation::convertOmpOperation(Operation &opInst,
         ompBuilder->CreateTaskyield(builder.saveIP());
         return success();
       })
+      .Case([&](omp::FlushOp) {
+        // No support in Openmp runtime funciton (__kmpc_flush) to accept
+        // the argument list.
+        // OpenMP standard states the following:
+        //  "An implementation may implement a flush with a list by ignoring
+        //   the list, and treating it the same as a flush without a list."
+        //
+        // The argument list is discarded so that, flush with a list is treated
+        // same as a flush without a list.
+        ompBuilder->CreateFlush(builder.saveIP());
+        return success();
+      })
       .Default([&](Operation *inst) {
         return inst->emitError("unsupported OpenMP operation: ")
                << inst->getName();

diff  --git a/mlir/test/Dialect/OpenMP/ops.mlir b/mlir/test/Dialect/OpenMP/ops.mlir
index e26ad4236266..8a556196b0ea 100644
--- a/mlir/test/Dialect/OpenMP/ops.mlir
+++ b/mlir/test/Dialect/OpenMP/ops.mlir
@@ -17,3 +17,21 @@ func @omp_taskyield() -> () {
   omp.taskyield
   return
 }
+
+// CHECK-LABEL: func @omp_flush
+// CHECK-SAME: %[[ARG0:.*]]: !llvm.i32
+func @omp_flush(%arg0 : !llvm.i32) -> () {
+  // Test without data var
+  // CHECK: omp.flush
+  omp.flush
+
+  // Test with one data var
+  // CHECK: omp.flush %[[ARG0]] : !llvm.i32
+  "omp.flush"(%arg0) : (!llvm.i32) -> ()
+
+  // Test with two data var
+  // CHECK: omp.flush %[[ARG0]], %[[ARG0]] : !llvm.i32, !llvm.i32
+  "omp.flush"(%arg0, %arg0): (!llvm.i32, !llvm.i32) -> ()
+
+  return
+}

diff  --git a/mlir/test/Target/openmp-llvm.mlir b/mlir/test/Target/openmp-llvm.mlir
index 0bd1601d7868..ddfc2a4cf786 100644
--- a/mlir/test/Target/openmp-llvm.mlir
+++ b/mlir/test/Target/openmp-llvm.mlir
@@ -1,7 +1,7 @@
 // RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
 
-// CHECK-LABEL: define void @empty()
-llvm.func @empty() {
+// CHECK-LABEL: define void @test_stand_alone_directives()
+llvm.func @test_stand_alone_directives() {
   // CHECK: [[OMP_THREAD:%.*]] = call i32 @__kmpc_global_thread_num(%struct.ident_t* @{{[0-9]+}})
   // CHECK-NEXT:  call void @__kmpc_barrier(%struct.ident_t* @{{[0-9]+}}, i32 [[OMP_THREAD]])
   omp.barrier
@@ -14,6 +14,21 @@ llvm.func @empty() {
   // CHECK-NEXT:  [[RET_VAL:%.*]] = call i32 @__kmpc_omp_taskyield(%struct.ident_t* @{{[0-9]+}}, i32 [[OMP_THREAD2]], i32 0)
   omp.taskyield
 
-// CHECK-NEXT:    ret void
+  // CHECK-NEXT:    ret void
+  llvm.return
+}
+
+// CHECK-LABEL: define void @test_flush_construct(i32 %0)
+llvm.func @test_flush_construct(%arg0: !llvm.i32) {
+  // CHECK: call void @__kmpc_flush(%struct.ident_t* @{{[0-9]+}}
+  omp.flush
+
+  // CHECK: call void @__kmpc_flush(%struct.ident_t* @{{[0-9]+}}
+  omp.flush %arg0 : !llvm.i32
+
+  // CHECK: call void @__kmpc_flush(%struct.ident_t* @{{[0-9]+}}
+  omp.flush %arg0, %arg0 : !llvm.i32, !llvm.i32
+
+  // CHECK-NEXT:    ret void
   llvm.return
 }