[clang] d50dacd - [Clang] Only emit textual LLVM-IR in device only mode

[Joseph Huber via cfe-commits]

Author: Joseph Huber
Date: 2023-01-24T15:11:30-06:00
New Revision: d50dacd7c3c2ce489df6ed1ccde71bba390fe5e2

URL: https://github.com/llvm/llvm-project/commit/d50dacd7c3c2ce489df6ed1ccde71bba390fe5e2
DIFF: https://github.com/llvm/llvm-project/commit/d50dacd7c3c2ce489df6ed1ccde71bba390fe5e2.diff

LOG: [Clang] Only emit textual LLVM-IR in device only mode

Currently, we embed device code into the host to perform
multi-architecture linking and handling of device code. If the user
specified `-S -emit-llvm` then the embedded output will be textual
LLVM-IR. This is a problem because it can't be used by the LTO backend
and it makes reading the file confusing.

This patch changes the behaviour to only emit textual device IR if we
are in device only mode, that is, if the device code is presented
directly to the user instead of being embedded. Otherwise we should
always embed device bitcode instead.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D141717

Added: 
    

Modified: 
    clang/lib/Driver/Driver.cpp
    clang/test/Driver/openmp-offload-gpu.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 49faa193fb7b1..661d9977fbc51 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -4634,7 +4634,14 @@ Action *Driver::ConstructPhaseAction(
                        false) ||
           TargetDeviceOffloadKind == Action::OFK_OpenMP))) {
       types::ID Output =
-          Args.hasArg(options::OPT_S) ? types::TY_LLVM_IR : types::TY_LLVM_BC;
+          Args.hasArg(options::OPT_S) &&
+                  (TargetDeviceOffloadKind == Action::OFK_None ||
+                   offloadDeviceOnly() ||
+                   (TargetDeviceOffloadKind == Action::OFK_HIP &&
+                    !Args.hasFlag(options::OPT_offload_new_driver,
+                                  options::OPT_no_offload_new_driver, false)))
+              ? types::TY_LLVM_IR
+              : types::TY_LLVM_BC;
       return C.MakeAction<BackendJobAction>(Input, Output);
     }
     return C.MakeAction<BackendJobAction>(Input, types::TY_PP_Asm);

diff  --git a/clang/test/Driver/openmp-offload-gpu.c b/clang/test/Driver/openmp-offload-gpu.c
index 9a05dafc16e96..b1e1954a93594 100644
--- a/clang/test/Driver/openmp-offload-gpu.c
+++ b/clang/test/Driver/openmp-offload-gpu.c
@@ -304,9 +304,16 @@
 // CHECK-IR: "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[INPUT_IR:.+]]"], output: "[[OBJECT:.+]]"
 // CHECK-IR: "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[OBJECT]]"], output: "a.out"
 
-// RUN:   %clang -### --target=x86_64-unknown-linux-gnu -emit-llvm -S -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda -Xopenmp-target=nvptx64-nvidia-cuda -march=sm_52 -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-EMIT-LLVM-IR
+// RUN:   %clang -### --target=x86_64-unknown-linux-gnu -emit-llvm -S -fopenmp=libomp --offload-device-only \
+// RUN:     -fopenmp-targets=nvptx64-nvidia-cuda -Xopenmp-target=nvptx64-nvidia-cuda -march=sm_52 -nogpulib %s 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-EMIT-LLVM-IR
 // CHECK-EMIT-LLVM-IR: "-cc1"{{.*}}"-triple" "nvptx64-nvidia-cuda"{{.*}}"-emit-llvm"
 
+// RUN:   %clang -### --target=x86_64-unknown-linux-gnu -emit-llvm -S -fopenmp=libomp \
+// RUN:     -fopenmp-targets=nvptx64-nvidia-cuda -Xopenmp-target=nvptx64-nvidia-cuda -march=sm_52 -nogpulib %s 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-EMIT-LLVM-IR-BC
+// CHECK-EMIT-LLVM-IR-BC: "-cc1"{{.*}}"-triple" "nvptx64-nvidia-cuda"{{.*}}"-emit-llvm-bc"
+
 // RUN:   %clang -### -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda -Xopenmp-target=nvptx64-nvida-cuda -march=sm_70 \
 // RUN:          --libomptarget-nvptx-bc-path=%S/Inputs/libomptarget/libomptarget-new-nvptx-test.bc \
 // RUN:          -nogpulib %s -o openmp-offload-gpu 2>&1 \