commit 0a41c8e7a050c837c609cbcbc8342024701cd14b
author Valentin Clement (バレンタイン クレメン) <clementval@gmail.com> Thu Aug 29 11:27:42 2024 -0700
committer GitHub <noreply@github.com> Thu Aug 29 11:27:42 2024 -0700
tree e3b10ee4f6e615ffbcede80f4e540094276f4b1c
parent 1ace91f925ad87c3e5eb836ad58fdffe60c4aea6

[flang][cuda] Avoid generating cuf.data_transfer in OpenACC region (#106435)

`cuf.data_transfer` will be converted to runtime calls to cuda runtime
api and these are not supported in device code. assignment in OpenACC
region will be handled by the OpenACC code gen so we avoid to generate
data transfer on them.

flang/lib/Lower/Bridge.cpp

diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index c48daba..078e17b 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -4380,9 +4380,14 @@
   // Check if the insertion point is currently in a device context. HostDevice
   // subprogram are not considered fully device context so it will return false
   // for it.
-  static bool isDeviceContext(fir::FirOpBuilder &builder) {
+  // If the insertion point is inside an OpenACC region op, it is considered
+  // device context.
+  static bool isCudaDeviceContext(fir::FirOpBuilder &builder) {
     if (builder.getRegion().getParentOfType<cuf::KernelOp>())
       return true;
+    if (builder.getRegion()
+            .getParentOfType<mlir::acc::ComputeRegionOpInterface>())
+      return true;
     if (auto funcOp =
             builder.getRegion().getParentOfType<mlir::func::FuncOp>()) {
       if (auto cudaProcAttr =
@@ -4401,7 +4406,8 @@
     mlir::Location loc = getCurrentLocation();
     fir::FirOpBuilder &builder = getFirOpBuilder();
 
-    bool isInDeviceContext = isDeviceContext(builder);
+    bool isInDeviceContext = isCudaDeviceContext(builder);
+
     bool isCUDATransfer = (Fortran::evaluate::HasCUDADeviceAttrs(assign.lhs) ||
                            Fortran::evaluate::HasCUDADeviceAttrs(assign.rhs)) &&
                           !isInDeviceContext;

flang/test/Lower/CUDA/cuda-data-transfer.cuf

diff --git a/flang/test/Lower/CUDA/cuda-data-transfer.cuf b/flang/test/Lower/CUDA/cuda-data-transfer.cuf
index 42b37fb..f189bf9 100644
--- a/flang/test/Lower/CUDA/cuda-data-transfer.cuf
+++ b/flang/test/Lower/CUDA/cuda-data-transfer.cuf
@@ -1,4 +1,4 @@
-! RUN: bbc -emit-hlfir -fcuda %s -o - | FileCheck %s
+! RUN: bbc -emit-hlfir -fopenacc -fcuda %s -o - | FileCheck %s
 
 ! Test CUDA Fortran data transfer using assignment statements.
 
@@ -290,3 +290,45 @@
 ! CHECK: %[[SHAPE:.*]] = fir.shape %{{.*}} : (index) -> !fir.shape<1>
 ! CHECK: %[[AHOST:.*]]:2 = hlfir.declare %[[ARG1]](%{{.*}}) dummy_scope %{{.*}} {uniq_name = "_QFsub15Ea_host"} : (!fir.ref<!fir.array<?xf32>>, !fir.shape<1>, !fir.dscope) -> (!fir.box<!fir.array<?xf32>>, !fir.ref<!fir.array<?xf32>>)
 ! CHECK: cuf.data_transfer %[[AHOST]]#1 to %[[ADEV]]#1, %[[SHAPE]] : !fir.shape<1> {transfer_kind = #cuf.cuda_transfer<host_device>} : !fir.ref<!fir.array<?xf32>>, !fir.ref<!fir.array<?xf32>>
+
+! Check that cuf.data_transfer are not generated within OpenACC region
+subroutine sub16()
+  integer, parameter :: n = 10
+  real, device :: adev(n)
+  real :: ahost(n)
+  real, managed :: b
+  integer :: i
+
+  adev = ahost
+  !$acc parallel loop deviceptr(adev) 
+  do i = 1, n
+    adev(i) = adev(i) + b
+  enddo
+
+  !$acc kernels deviceptr(adev) 
+  do i = 1, n
+    adev(i) = adev(i) + b
+  enddo
+  !$acc end kernels
+
+
+  !$acc serial deviceptr(adev) 
+  do i = 1, n
+    adev(i) = adev(i) + b
+  enddo
+  !$acc end serial
+end subroutine
+
+! CHECK-LABEL: func.func @_QPsub16()
+! CHECK: cuf.data_transfer
+! CHECK: acc.parallel
+! CHECK-NOT: cuf.data_transfer
+! CHECK: hlfir.assign
+
+! CHECK: acc.kernels
+! CHECK-NOT: cuf.data_transfer
+! CHECK: hlfir.assign
+
+! CHECK: acc.serial
+! CHECK-NOT: cuf.data_transfer
+! CHECK: hlfir.assign