Default to new driver and default device linker pipeline

Change-Id: I64c952c9f198dfe62dc8a10275b29de3a0fadc4e

Author: doru1004

clang/lib/Driver/ToolChains/AMDGPUOpenMP.cpp

@@ -435,11 +435,6 @@ void AMDGPUOpenMPToolChain::addClangTargetOptions(
                          options::OPT_fno_gpu_allow_device_init, false))
     CC1Args.push_back("-fgpu-allow-device-init");
 
-  // TODO: check if flag is needed for the opaque linker case
-  const char *UseLinkerWrapper = std::getenv("CLANG_USE_LINKER_WRAPPER");
-  if (!UseLinkerWrapper || atoi(UseLinkerWrapper) == 0)
-    CC1Args.push_back("-fcuda-allow-variadic-functions");
-
   // Default to "hidden" visibility, as object level linking will not be
   // supported for the foreseeable future.
   if (!DriverArgs.hasArg(options::OPT_fvisibility_EQ,

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9664,11 +9664,9 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
   }
 
   // Overwrite the default driver choice using an env var:
-  // CLANG_USE_LINKER_WRAPPER which can be 0 or 1.
   bool UseOpaqueOffloadLinker = isAMDGPU;
   if (isAMDGPU)
-    if (const char *UseLinkerWrapper = std::getenv("CLANG_USE_LINKER_WRAPPER"))
-      UseOpaqueOffloadLinker = !(atoi(UseLinkerWrapper) == 1);
+    UseOpaqueOffloadLinker = 0;
 
   if (!OpenMPTCs.empty() && Args.hasFlag(options::OPT_opaque_offload_linker,
                                          options::OPT_no_opaque_offload_linker,
@@ -9714,6 +9712,12 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
       OOpt = "0";
     if (!OOpt.empty())
       CmdArgs.push_back(Args.MakeArgString(Twine("--opt-level=O") + OOpt));
+
+    // Ensure we default to default linking pipeline when linking on AMD GPUs:
+    if (!D.IsFlangMode() && isAMDGPU && OOpt != "0")
+      CmdArgs.push_back(Args.MakeArgString(
+          Twine("--device-linker=--lto-newpm-passes=default<O") + OOpt +
+          Twine(">")));
   }
 
   CmdArgs.push_back(

clang/test/Driver/amdgpu-openmp-toolchain.c

@@ -114,10 +114,30 @@
 // LIBCXX-NOT: include/amdgcn-amd-amdhsa/c++/v1
 
 // RUN: %clang -### --save-temps -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a:xnack+ -mamdgpu-precise-memory-op \
-// RUN:   -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES
+// RUN:   -nogpulib %s --opaque-offload-linker 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES
 // CHECK-TARGET-FEATURES: clang-offload-packager{{.*}} "-o" {{.*}}.out" "--image=file={{.*}}.bc,triple=amdgcn-amd-amdhsa,arch=gfx90a:xnack+,kind=openmp"
 // CHECK-TARGET-FEATURES: clang-offload-packager"{{.*}}.o" "--image=file={{.*}}.bc,triple=amdgcn-amd-amdhsa,arch=gfx90a:xnack+,kind=openmp"
 // CHECK-TARGET-FEATURES: opt{{.*}} "-mtriple=amdgcn-amd-amdhsa" "-o" {{.*}}.bc" "-mcpu=gfx90a" "-mattr=+xnack,+precise-memory"
 // CHECK-TARGET-FEATURES: llc{{.*}} "-mtriple=amdgcn-amd-amdhsa" "-filetype=asm" "-o" {{.*}}.s" "{{.*}}.bc" "-mcpu=gfx90a" "-mattr=+xnack,+precise-memory"
 // CHECK-TARGET-FEATURES: llc{{.*}} "-mtriple=amdgcn-amd-amdhsa" "-filetype=obj" "-o" {{.*}}.o" "{{.*}}.bc" "-mcpu=gfx90a" "-mattr=+xnack,+precise-memory"
 // CHECK-TARGET-FEATURES: lld{{.*}} "-flavor" "gnu" "--no-undefined" "-shared" {{.*}}.o" "-plugin-opt=mcpu=gfx90a" "-plugin-opt=-mattr=+xnack,+precise-memory" "-o" {{.*}}.out"
+
+// RUN: %clang -### --save-temps -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a:xnack+ -mamdgpu-precise-memory-op \
+// RUN:   -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES-LW
+// CHECK-TARGET-FEATURES-LW: clang-linker-wrapper
+
+// RUN: %clang -### --save-temps -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a:xnack+ -mamdgpu-precise-memory-op \
+// RUN:   -nogpulib %s -O3 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES-LW3
+// CHECK-TARGET-FEATURES-LW3: clang-linker-wrapper{{.*}} "--device-linker=--lto-newpm-passes=default<O3>"
+
+// RUN: %clang -### --save-temps -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a:xnack+ -mamdgpu-precise-memory-op \
+// RUN:   -nogpulib %s -O2 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES-LW2
+// CHECK-TARGET-FEATURES-LW2: clang-linker-wrapper{{.*}} "--device-linker=--lto-newpm-passes=default<O2>"
+
+// RUN: %clang -### --save-temps -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a:xnack+ -mamdgpu-precise-memory-op \
+// RUN:   -nogpulib %s -O1 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES-LW1
+// CHECK-TARGET-FEATURES-LW1: clang-linker-wrapper{{.*}} "--device-linker=--lto-newpm-passes=default<O1>"
+
+// RUN: %clang -### --save-temps -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a:xnack+ -mamdgpu-precise-memory-op \
+// RUN:   -nogpulib %s -O0 2>&1 | FileCheck %s --check-prefix=CHECK-TARGET-FEATURES-LW0
+// CHECK-TARGET-FEATURES-LW0-NOT: clang-linker-wrapper{{.*}} "--device-linker=--lto-newpm-passes=default<O0>"

offload/test/lit.cfg

@@ -34,11 +34,6 @@ if 'OMP_TARGET_OFFLOAD' in os.environ:
 if 'HSA_ENABLE_SDMA' in os.environ:
     config.environment['HSA_ENABLE_SDMA'] = os.environ['HSA_ENABLE_SDMA']
 
-if 'CLANG_USE_LINKER_WRAPPER' in os.environ:
-    config.environment['CLANG_USE_LINKER_WRAPPER'] = os.environ['CLANG_USE_LINKER_WRAPPER']
-else:
-    config.environment['CLANG_USE_LINKER_WRAPPER'] = "1"
-
 # Architectures like gfx942 may or may not be APUs so an additional environment
 # variable is required as some tests can be APU specific.
 if 'IS_APU' in os.environ: