[AMDGPU][OpenMP] Emit textual IR for -emit-llvm -S

[pdhaliwal]

Summary

Previously clang would print a binary blob into the bundled file
for amdgcn. With this patch, it will instead print textual IR as
expected.

[JonChesterfield]

clang/lib/Driver/ToolChains/Clang.cpp

4397–4403

Does unconditionally using emit-llvm here achieve the same result?

[pdhaliwal]

clang/lib/Driver/ToolChains/Clang.cpp

4397–4403

Nope, it would start producing textual IR even when there was no -emit-llvm -S. This could be problematic since we always have been producing .bc files including our libraries.

[JonChesterfield]

Ah, yes. Thanks!

[pdhaliwal]

This is not working as expected. And has resulted in broken libomptarget tests. Reverting this until I find a different fix.

[pdhaliwal]

Fixed the if-else logic

[pdhaliwal]

Tested on gfx906. The libomptarget tests are working as expected.

clang/lib/Driver/ToolChains/Clang.cpp

assert((isa<CompileJobAction>(JA) || isa<BackendJobAction>(JA)) &&
            "Invalid action for clang tool.");
     if (JA.getType() == types::TY_Nothing) {
       CmdArgs.push_back("-fsyntax-only");
     } else if (JA.getType() == types::TY_LLVM_IR ||
                JA.getType() == types::TY_LTO_IR) {
       CmdArgs.push_back("-emit-llvm");
     } else if (JA.getType() == types::TY_LLVM_BC ||
                JA.getType() == types::TY_LTO_BC) {
+      // Emit textual llvm IR for AMDGPU offloading for -emit-llvm -S
+      if (Triple.isAMDGCN() && IsOpenMPDevice && Args.hasArg(options::OPT_S) &&
+          Args.hasArg(options::OPT_emit_llvm)) {
+        CmdArgs.push_back("-emit-llvm");
+      } else {
         CmdArgs.push_back("-emit-llvm-bc");
+      }
     } else if (JA.getType() == types::TY_IFS ||
                JA.getType() == types::TY_IFS_CPP) {
       StringRef ArgStr =
           Args.hasArg(options::OPT_interface_stub_version_EQ)
               ? Args.getLastArgValue(options::OPT_interface_stub_version_EQ)
               : "experimental-ifs-v2";
       CmdArgs.push_back("-emit-interface-stubs");
       CmdArgs.push_back(

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

 // REQUIRES: x86-registered-target
 // REQUIRES: amdgpu-registered-target
 // RUN:   env LIBRARY_PATH=%S/Inputs/hip_dev_lib %clang -### --target=x86_64-unknown-linux-gnu -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx906 %s 2>&1 \
 // RUN:   | FileCheck %s
 
 // verify the tools invocations
 // CHECK: clang{{.*}}"-cc1" "-triple" "x86_64-unknown-linux-gnu"{{.*}}"-x" "c"{{.*}}
 // CHECK: clang{{.*}}"-cc1" "-triple" "x86_64-unknown-linux-gnu"{{.*}}"-x" "ir"{{.*}}
-// CHECK: clang{{.*}}"-cc1"{{.*}}"-triple" "amdgcn-amd-amdhsa"{{.*}}"-target-cpu" "gfx906" "-fcuda-is-device" "-mlink-builtin-bitcode"{{.*}}libomptarget-amdgcn-gfx906.bc"{{.*}}
+// CHECK: clang{{.*}}"-cc1"{{.*}}"-triple" "amdgcn-amd-amdhsa"{{.*}}"-emit-llvm-bc"{{.*}}"-target-cpu" "gfx906" "-fcuda-is-device"{{.*}}"-mlink-builtin-bitcode"{{.*}}libomptarget-amdgcn-gfx906.bc"{{.*}}
 // CHECK: llvm-link{{.*}}"-o" "{{.*}}amdgpu-openmp-toolchain-{{.*}}-gfx906-linked-{{.*}}.bc"
 // CHECK: llc{{.*}}amdgpu-openmp-toolchain-{{.*}}-gfx906-linked-{{.*}}.bc" "-mtriple=amdgcn-amd-amdhsa" "-mcpu=gfx906" "-filetype=obj" "-o"{{.*}}amdgpu-openmp-toolchain-{{.*}}-gfx906-{{.*}}.o"
 // CHECK: lld{{.*}}"-flavor" "gnu" "--no-undefined" "-shared" "-o"{{.*}}amdgpu-openmp-toolchain-{{.*}}.out" "{{.*}}amdgpu-openmp-toolchain-{{.*}}-gfx906-{{.*}}.o"
 // CHECK: clang-offload-wrapper{{.*}}"-target" "x86_64-unknown-linux-gnu" "-o" "{{.*}}a-{{.*}}.bc" {{.*}}amdgpu-openmp-toolchain-{{.*}}.out"
 // CHECK: clang{{.*}}"-cc1" "-triple" "x86_64-unknown-linux-gnu"{{.*}}"-o" "{{.*}}a-{{.*}}.o" "-x" "ir" "{{.*}}a-{{.*}}.bc"
 // CHECK: ld{{.*}}"-o" "a.out"{{.*}}"{{.*}}amdgpu-openmp-toolchain-{{.*}}.o" "{{.*}}a-{{.*}}.o" "-lomp" "-lomptarget"
 
 // RUN:   %clang -ccc-print-phases --target=x86_64-unknown-linux-gnu -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx906 %s 2>&1 \

 // RUN:   | FileCheck %s --check-prefix=CHECK-C
 // CHECK-C: "x86_64-unknown-linux-gnu" - "clang",
 // CHECK-C: "x86_64-unknown-linux-gnu" - "clang",{{.*}}output: "[[HOST_BC:.*]]"
 // CHECK-C: "amdgcn-amd-amdhsa" - "clang",{{.*}}output: "[[DEVICE_I:.*]]"
 // CHECK-C: "amdgcn-amd-amdhsa" - "clang", inputs: ["[[DEVICE_I]]", "[[HOST_BC]]"]
 // CHECK-C: "x86_64-unknown-linux-gnu" - "clang"
 // CHECK-C: "x86_64-unknown-linux-gnu" - "clang::as"
 // CHECK-C: "x86_64-unknown-linux-gnu" - "offload bundler"
+
+// RUN:   %clang -### --target=x86_64-unknown-linux-gnu -emit-llvm -S -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx803 -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-EMIT-LLVM-IR
+// CHECK-EMIT-LLVM-IR: clang{{.*}}"-cc1"{{.*}}"-triple" "amdgcn-amd-amdhsa"{{.*}}"-emit-llvm"