[OpenMP] Add support for handling declare target to clause when unified memory is required

Summary:
This patch adds support for the handling of the variables under the declare target to clause.

The variables in this case are handled like link variables are. A pointer is created on the host and then mapped to the device. The runtime will then copy the address of the host variable in the device pointer.

Reviewers: ABataev, AlexEichenberger, caomhin

Reviewed By: ABataev

Subscribers: guansong, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63108

llvm-svn: 363959

3 files changed, 66 insertions, 40 deletions

diff --git a/clang/test/OpenMP/declare_target_codegen.cpp b/clang/test/OpenMP/declare_target_codegen.cpp
index d4b209ff053..71c6875b9e4 100644
--- a/clang/test/OpenMP/declare_target_codegen.cpp
+++ b/clang/test/OpenMP/declare_target_codegen.cpp
@@ -20,10 +20,10 @@
 // CHECK-DAG: weak constant %struct.__tgt_offload_entry { i8* bitcast (i32* @bbb to i8*),
 // CHECK-DAG: @ccc = external global i32,
 // CHECK-DAG: @ddd ={{ dso_local | }}global i32 0,
-// CHECK-DAG: @hhh_decl_tgt_link_ptr = common global i32* null
-// CHECK-DAG: @ggg_decl_tgt_link_ptr = common global i32* null
-// CHECK-DAG: @fff_decl_tgt_link_ptr = common global i32* null
-// CHECK-DAG: @eee_decl_tgt_link_ptr = common global i32* null
+// CHECK-DAG: @hhh_decl_tgt_ref_ptr = common global i32* null
+// CHECK-DAG: @ggg_decl_tgt_ref_ptr = common global i32* null
+// CHECK-DAG: @fff_decl_tgt_ref_ptr = common global i32* null
+// CHECK-DAG: @eee_decl_tgt_ref_ptr = common global i32* null
 // CHECK-DAG: @{{.*}}maini1{{.*}}aaa = internal global i64 23,
 // CHECK-DAG: @b ={{ dso_local | }}global i32 15,
 // CHECK-DAG: @d ={{ dso_local | }}global i32 0,
diff --git a/clang/test/OpenMP/declare_target_link_codegen.cpp b/clang/test/OpenMP/declare_target_link_codegen.cpp
index 36c295b2de5..2f92eb6fbd8 100644
--- a/clang/test/OpenMP/declare_target_link_codegen.cpp
+++ b/clang/test/OpenMP/declare_target_link_codegen.cpp
@@ -18,15 +18,15 @@
 #define HEADER
 
 // HOST-DAG: @c = external global i32,
-// HOST-DAG: @c_decl_tgt_link_ptr = global i32* @c
+// HOST-DAG: @c_decl_tgt_ref_ptr = global i32* @c
 // DEVICE-NOT: @c =
-// DEVICE: @c_decl_tgt_link_ptr = common global i32* null
+// DEVICE: @c_decl_tgt_ref_ptr = common global i32* null
 // HOST: [[SIZES:@.+]] = private unnamed_addr constant [2 x i64] [i64 4, i64 4]
 // HOST: [[MAPTYPES:@.+]] = private unnamed_addr constant [2 x i64] [i64 35, i64 531]
-// HOST: @.omp_offloading.entry_name{{.*}} = internal unnamed_addr constant [{{[0-9]+}} x i8] c"c_decl_tgt_link_ptr\00"
-// HOST: @.omp_offloading.entry.c_decl_tgt_link_ptr = weak constant %struct.__tgt_offload_entry { i8* bitcast (i32** @c_decl_tgt_link_ptr to i8*), i8* getelementptr inbounds ([{{[0-9]+}} x i8], [{{[0-9]+}} x i8]* @.omp_offloading.entry_name, i32 0, i32 0), i64 8, i32 1, i32 0 }, section ".omp_offloading.entries", align 1
-// DEVICE-NOT: internal unnamed_addr constant [{{[0-9]+}} x i8] c"c_decl_tgt_link_ptr\00"
-// CHECK: @llvm.used = appending global [1 x i8*] [i8* bitcast (i32** @c_decl_tgt_link_ptr to i8*)]
+// HOST: @.omp_offloading.entry_name{{.*}} = internal unnamed_addr constant [{{[0-9]+}} x i8] c"c_decl_tgt_ref_ptr\00"
+// HOST: @.omp_offloading.entry.c_decl_tgt_ref_ptr = weak constant %struct.__tgt_offload_entry { i8* bitcast (i32** @c_decl_tgt_ref_ptr to i8*), i8* getelementptr inbounds ([{{[0-9]+}} x i8], [{{[0-9]+}} x i8]* @.omp_offloading.entry_name, i32 0, i32 0), i64 8, i32 1, i32 0 }, section ".omp_offloading.entries", align 1
+// DEVICE-NOT: internal unnamed_addr constant [{{[0-9]+}} x i8] c"c_decl_tgt_ref_ptr\00"
+// CHECK: @llvm.used = appending global [1 x i8*] [i8* bitcast (i32** @c_decl_tgt_ref_ptr to i8*)]
 
 extern int c;
 #pragma omp declare target link(c)
@@ -44,7 +44,7 @@ int maini1() {
 }
 
 // DEVICE: define weak void @__omp_offloading_{{.*}}_{{.*}}maini1{{.*}}_l[[@LINE-10]](i32* dereferenceable{{[^,]*}}
-// DEVICE: [[C_REF:%.+]] = load i32*, i32** @c_decl_tgt_link_ptr,
+// DEVICE: [[C_REF:%.+]] = load i32*, i32** @c_decl_tgt_ref_ptr,
 // DEVICE: [[C:%.+]] = load i32, i32* [[C_REF]],
 // DEVICE: store i32 [[C]], i32* %
 
@@ -55,7 +55,7 @@ int maini1() {
 // HOST: getelementptr inbounds [2 x i8*], [2 x i8*]* [[PTRS]], i{{[0-9]+}} 0, i{{[0-9]+}} 0
 // HOST: [[BP1:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[BASEPTRS]], i{{[0-9]+}} 0, i{{[0-9]+}} 1
 // HOST: [[BP1_CAST:%.+]] = bitcast i8** [[BP1]] to i32***
-// HOST: store i32** @c_decl_tgt_link_ptr, i32*** [[BP1_CAST]],
+// HOST: store i32** @c_decl_tgt_ref_ptr, i32*** [[BP1_CAST]],
 // HOST: [[P1:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[PTRS]], i{{[0-9]+}} 0, i{{[0-9]+}} 1
 // HOST: [[P1_CAST:%.+]] = bitcast i8** [[P1]] to i32**
 // HOST: store i32* @c, i32** [[P1_CAST]],
@@ -69,5 +69,5 @@ int maini1() {
 // HOST: [[C:%.*]] = load i32, i32* @c,
 // HOST: store i32 [[C]], i32* %
 
-// CHECK: !{i32 1, !"c_decl_tgt_link_ptr", i32 1, i32 {{[0-9]+}}}
+// CHECK: !{i32 1, !"c_decl_tgt_ref_ptr", i32 1, i32 {{[0-9]+}}}
 #endif // HEADER
diff --git a/clang/test/OpenMP/nvptx_target_requires_unified_shared_memory.cpp b/clang/test/OpenMP/nvptx_target_requires_unified_shared_memory.cpp
index 8349649f6af..578df532254 100644
--- a/clang/test/OpenMP/nvptx_target_requires_unified_shared_memory.cpp
+++ b/clang/test/OpenMP/nvptx_target_requires_unified_shared_memory.cpp
@@ -1,5 +1,10 @@
 // Test declare target link under unified memory requirement.
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -x c++ -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -o - | FileCheck %s --check-prefix CHECK
+
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -x c++ -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -o - | FileCheck %s --check-prefix CHECK-HOST
+
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=45 -fopenmp-cuda-mode -x c++ -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm-bc %s -o %t-ppc-host.bc
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=45 -fopenmp-cuda-mode -x c++ -triple nvptx64-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -target-cpu sm_70 -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-ppc-host.bc -o - | FileCheck %s --check-prefix CHECK-DEVICE
+
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -8,53 +13,74 @@
 #define N 1000
 
 double var = 10.0;
+double to_var = 20.0;
 
 #pragma omp requires unified_shared_memory
 #pragma omp declare target link(var)
+#pragma omp declare target to(to_var)
 
 int bar(int n){
   double sum = 0;
 
 #pragma omp target
   for(int i = 0; i < n; i++) {
-    sum += var;
+    sum += var + to_var;
   }
 
   return sum;
 }
 
-// CHECK: [[VAR:@.+]] = global double 1.000000e+01
-// CHECK: [[VAR_DECL_TGT_LINK_PTR:@.+]] = global double* [[VAR]]
+// CHECK-HOST: [[VAR:@.+]] = global double 1.000000e+01
+// CHECK-HOST: [[VAR_DECL_TGT_LINK_PTR:@.+]] = global double* [[VAR]]
+
+// CHECK-HOST: [[TO_VAR:@.+]] = global double 2.000000e+01
+// CHECK-HOST: [[VAR_DECL_TGT_TO_PTR:@.+]] = global double* [[TO_VAR]]
+
+// CHECK-HOST: [[OFFLOAD_SIZES:@.+]] = private unnamed_addr constant [2 x i64] [i64 4, i64 8]
+// CHECK-HOST: [[OFFLOAD_MAPTYPES:@.+]] = private unnamed_addr constant [2 x i64] [i64 800, i64 800]
+
+// CHECK-HOST: [[OMP_OFFLOAD_ENTRY_LINK_VAR_PTR_NAME:@.+]] = internal unnamed_addr constant [21 x i8]
+// CHECK-HOST: [[OMP_OFFLOAD_ENTRY_LINK_VAR_PTR:@.+]] = weak constant %struct.__tgt_offload_entry { i8* bitcast (double** [[VAR_DECL_TGT_LINK_PTR]] to i8*), i8* getelementptr inbounds ([21 x i8], [21 x i8]* [[OMP_OFFLOAD_ENTRY_LINK_VAR_PTR_NAME]], i32 0, i32 0), i64 8, i32 1, i32 0 }, section ".omp_offloading.entries"
+
+// CHECK-HOST: [[OMP_OFFLOAD_ENTRY_TO_VAR_PTR_NAME:@.+]] = internal unnamed_addr constant [24 x i8]
+// CHECK-HOST: [[OMP_OFFLOAD_ENTRY_TO_VAR_PTR:@.+]] = weak constant %struct.__tgt_offload_entry { i8* bitcast (double** [[VAR_DECL_TGT_TO_PTR]] to i8*), i8* getelementptr inbounds ([24 x i8], [24 x i8]* [[OMP_OFFLOAD_ENTRY_TO_VAR_PTR_NAME]], i32 0, i32 0), i64 8, i32 0, i32 0 }, section ".omp_offloading.entries"
+
+// CHECK-HOST: @llvm.used = appending global [2 x i8*] [i8* bitcast (double** [[VAR_DECL_TGT_LINK_PTR]] to i8*), i8* bitcast (double** [[VAR_DECL_TGT_TO_PTR]] to i8*)], section "llvm.metadata"
+
+// CHECK-HOST: [[N_CASTED:%.+]] = alloca i64
+// CHECK-HOST: [[SUM_CASTED:%.+]] = alloca i64
+
+// CHECK-HOST: [[OFFLOAD_BASEPTRS:%.+]] = alloca [2 x i8*]
+// CHECK-HOST: [[OFFLOAD_PTRS:%.+]] = alloca [2 x i8*]
 
-// CHECK: [[OFFLOAD_SIZES:@.+]] = private unnamed_addr constant [2 x i64] [i64 4, i64 8]
-// CHECK: [[OFFLOAD_MAPTYPES:@.+]] = private unnamed_addr constant [2 x i64] [i64 800, i64 800]
+// CHECK-HOST: [[LOAD1:%.+]] = load i64, i64* [[N_CASTED]]
+// CHECK-HOST: [[LOAD2:%.+]] = load i64, i64* [[SUM_CASTED]]
 
-// CHECK: [[N_CASTED:%.+]] = alloca i64
-// CHECK: [[SUM_CASTED:%.+]] = alloca i64
+// CHECK-HOST: [[BPTR1:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_BASEPTRS]], i32 0, i32 0
+// CHECK-HOST: [[BCAST1:%.+]] = bitcast i8** [[BPTR1]] to i64*
+// CHECK-HOST: store i64 [[LOAD1]], i64* [[BCAST1]]
+// CHECK-HOST: [[BPTR2:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_PTRS]], i32 0, i32 0
+// CHECK-HOST: [[BCAST2:%.+]] = bitcast i8** [[BPTR2]] to i64*
+// CHECK-HOST: store i64 [[LOAD1]], i64* [[BCAST2]]
 
-// CHECK: [[OFFLOAD_BASEPTRS:%.+]] = alloca [2 x i8*]
-// CHECK: [[OFFLOAD_PTRS:%.+]] = alloca [2 x i8*]
+// CHECK-HOST: [[BPTR3:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_BASEPTRS]], i32 0, i32 1
+// CHECK-HOST: [[BCAST3:%.+]] = bitcast i8** [[BPTR3]] to i64*
+// CHECK-HOST: store i64 [[LOAD2]], i64* [[BCAST3]]
+// CHECK-HOST: [[BPTR4:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_PTRS]], i32 0, i32 1
+// CHECK-HOST: [[BCAST4:%.+]] = bitcast i8** [[BPTR4]] to i64*
+// CHECK-HOST: store i64 [[LOAD2]], i64* [[BCAST4]]
 
-// CHECK: [[LOAD1:%.+]] = load i64, i64* [[N_CASTED]]
-// CHECK: [[LOAD2:%.+]] = load i64, i64* [[SUM_CASTED]]
+// CHECK-HOST: [[BPTR7:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_BASEPTRS]], i32 0, i32 0
+// CHECK-HOST: [[BPTR8:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_PTRS]], i32 0, i32 0
 
-// CHECK: [[BPTR1:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_BASEPTRS]], i32 0, i32 0
-// CHECK: [[BCAST1:%.+]] = bitcast i8** [[BPTR1]] to i64*
-// CHECK: store i64 [[LOAD1]], i64* [[BCAST1]]
-// CHECK: [[BPTR2:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_PTRS]], i32 0, i32 0
-// CHECK: [[BCAST2:%.+]] = bitcast i8** [[BPTR2]] to i64*
-// CHECK: store i64 [[LOAD1]], i64* [[BCAST2]]
+// CHECK-HOST: call i32 @__tgt_target(i64 -1, i8* @{{.*}}.region_id, i32 2, i8** [[BPTR7]], i8** [[BPTR8]], i64* getelementptr inbounds ([2 x i64], [2 x i64]* [[OFFLOAD_SIZES]], i32 0, i32 0), i64* getelementptr inbounds ([2 x i64], [2 x i64]* [[OFFLOAD_MAPTYPES]], i32 0, i32 0))
 
-// CHECK: [[BPTR3:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_BASEPTRS]], i32 0, i32 1
-// CHECK: [[BCAST3:%.+]] = bitcast i8** [[BPTR3]] to i64*
-// CHECK: store i64 [[LOAD2]], i64* [[BCAST3]]
-// CHECK: [[BPTR4:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_PTRS]], i32 0, i32 1
-// CHECK: [[BCAST4:%.+]] = bitcast i8** [[BPTR4]] to i64*
-// CHECK: store i64 [[LOAD2]], i64* [[BCAST4]]
+// CHECK-DEVICE: [[VAR_LINK:@.+]] = common global double* null
+// CHECK-DEVICE: [[VAR_TO:@.+]] = common global double* null
 
-// CHECK: [[BPTR7:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_BASEPTRS]], i32 0, i32 0
-// CHECK: [[BPTR8:%.+]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[OFFLOAD_PTRS]], i32 0, i32 0
+// CHECK-DEVICE: @llvm.used = appending global [2 x i8*] [i8* bitcast (double** [[VAR_LINK]] to i8*), i8* bitcast (double** [[VAR_TO]] to i8*)], section "llvm.metadata"
 
-// CHECK: call i32 @__tgt_target(i64 -1, i8* @{{.*}}.region_id, i32 2, i8** [[BPTR7]], i8** [[BPTR8]], i64* getelementptr inbounds ([2 x i64], [2 x i64]* [[OFFLOAD_SIZES]], i32 0, i32 0), i64* getelementptr inbounds ([2 x i64], [2 x i64]* [[OFFLOAD_MAPTYPES]], i32 0, i32 0))
+// CHECK-DEVICE: [[VAR_TO_PTR:%.+]] = load double*, double** [[VAR_TO]]
+// CHECK-DEVICE: load double, double* [[VAR_TO_PTR]]
 
 #endif