Reland "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #169637

mgcarrasco · 2025-11-26T11:16:42Z

This relands "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #167543. The only changes introduced now fix an issue for the multicall driver that is fixed with this commit. We were not forwarding Driver.getPrependArg().

…67543) For HIP, the SPIR-V backend can be optionally activated with the -use-spirv-backend flag. This option uses the SPIR-V BE instead of the SPIR-V translator. These changes also ensure that -use-spirv-backend does not require external dependencies, such as spirv-as and spirv-link

…ng Driver.getPrependArg().

llvmbot · 2025-11-26T11:17:15Z

@llvm/pr-subscribers-clang-driver

Author: Manuel Carrasco (mgcarrasco)

Changes

This relands "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #167543. The only changes introduced now are to fix an issue for the multicall driver that is fixed with this commit. We were not forwarding Driver.getPrependArg().

Patch is 25.67 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/169637.diff

7 Files Affected:

(modified) clang/include/clang/Options/Options.td (+10)
(modified) clang/lib/Driver/Driver.cpp (+41-3)
(modified) clang/lib/Driver/ToolChains/Clang.cpp (+9-1)
(modified) clang/lib/Driver/ToolChains/HIPAMD.cpp (+36-13)
(added) clang/test/Driver/hip-spirv-backend-bindings.c (+57)
(added) clang/test/Driver/hip-spirv-backend-opt.c (+61)
(added) clang/test/Driver/hip-spirv-backend-phases.c (+80)

diff --git a/clang/include/clang/Options/Options.td b/clang/include/clang/Options/Options.td
index a8fc1c4326cc5..00200055cce7e 100644
--- a/clang/include/clang/Options/Options.td
+++ b/clang/include/clang/Options/Options.td
@@ -1427,6 +1427,16 @@ def fhip_emit_relocatable : Flag<["-"], "fhip-emit-relocatable">,
   HelpText<"Compile HIP source to relocatable">;
 def fno_hip_emit_relocatable : Flag<["-"], "fno-hip-emit-relocatable">,
   HelpText<"Do not override toolchain to compile HIP source to relocatable">;
+def use_spirv_backend
+    : Flag<["-"], "use-spirv-backend">,
+      Group<hip_Group>,
+      Flags<[HelpHidden]>,
+      HelpText<"Use the SPIRV backend for compilation ">;
+def no_use_spirv_backend
+    : Flag<["-"], "no-use-spirv-backend">,
+      Group<hip_Group>,
+      Flags<[HelpHidden]>,
+      HelpText<"Do not use the SPIRV backend for compilation ">;
 }
 
 // Clang specific/exclusive options for OpenACC.
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index de8d4601210ae..c66ba73fc1f47 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -5024,15 +5024,24 @@ Action *Driver::BuildOffloadingActions(Compilation &C,
     // Compiling HIP in device-only non-RDC mode requires linking each action
     // individually.
     for (Action *&A : DeviceActions) {
-      // Special handling for the HIP SPIR-V toolchain because it doesn't use
-      // the SPIR-V backend yet doesn't report the output as an object.
       bool IsAMDGCNSPIRV = A->getOffloadingToolChain() &&
                            A->getOffloadingToolChain()->getTriple().getOS() ==
                                llvm::Triple::OSType::AMDHSA &&
                            A->getOffloadingToolChain()->getTriple().isSPIRV();
+      bool UseSPIRVBackend = Args.hasFlag(options::OPT_use_spirv_backend,
+                                          options::OPT_no_use_spirv_backend,
+                                          /*Default=*/false);
+
+      // Special handling for the HIP SPIR-V toolchain in device-only.
+      // The translator path has a linking step, whereas the SPIR-V backend path
+      // does not to avoid any external dependency such as spirv-link. The
+      // linking step is skipped for the SPIR-V backend path.
+      bool IsAMDGCNSPIRVWithBackend = IsAMDGCNSPIRV && UseSPIRVBackend;
+
       if ((A->getType() != types::TY_Object && !IsAMDGCNSPIRV &&
            A->getType() != types::TY_LTO_BC) ||
-          HIPRelocatableObj || !HIPNoRDC || !offloadDeviceOnly())
+          HIPRelocatableObj || !HIPNoRDC || !offloadDeviceOnly() ||
+          (IsAMDGCNSPIRVWithBackend && offloadDeviceOnly()))
         continue;
       ActionList LinkerInput = {A};
       A = C.MakeAction<LinkJobAction>(LinkerInput, types::TY_Image);
@@ -5258,12 +5267,28 @@ Action *Driver::ConstructPhaseAction(
           Args.hasArg(options::OPT_S) ? types::TY_LTO_IR : types::TY_LTO_BC;
       return C.MakeAction<BackendJobAction>(Input, Output);
     }
+    bool UseSPIRVBackend = Args.hasFlag(options::OPT_use_spirv_backend,
+                                        options::OPT_no_use_spirv_backend,
+                                        /*Default=*/false);
+
+    auto OffloadingToolChain = Input->getOffloadingToolChain();
+    // For AMD SPIRV, if offloadDeviceOnly(), we call the SPIRV backend unless
+    // LLVM bitcode was requested explicitly or RDC is set. If
+    // !offloadDeviceOnly, we emit LLVM bitcode, and clang-linker-wrapper will
+    // compile it to SPIRV.
+    bool UseSPIRVBackendForHipDeviceOnlyNoRDC =
+        TargetDeviceOffloadKind == Action::OFK_HIP && OffloadingToolChain &&
+        OffloadingToolChain->getTriple().isSPIRV() && UseSPIRVBackend &&
+        offloadDeviceOnly() &&
+        !Args.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc, false);
+
     if (Args.hasArg(options::OPT_emit_llvm) ||
         TargetDeviceOffloadKind == Action::OFK_SYCL ||
         (((Input->getOffloadingToolChain() &&
            Input->getOffloadingToolChain()->getTriple().isAMDGPU() &&
            TargetDeviceOffloadKind != Action::OFK_None) ||
           TargetDeviceOffloadKind == Action::OFK_HIP) &&
+         !UseSPIRVBackendForHipDeviceOnlyNoRDC &&
          ((Args.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc,
                         false) ||
            (Args.hasFlag(options::OPT_offload_new_driver,
@@ -5285,6 +5310,19 @@ Action *Driver::ConstructPhaseAction(
               : types::TY_LLVM_BC;
       return C.MakeAction<BackendJobAction>(Input, Output);
     }
+
+    // The SPIRV backend compilation path for HIP must avoid external
+    // dependencies. The default compilation path assembles and links its
+    // output, but the SPIRV assembler and linker are external tools. This code
+    // ensures the backend emits binary SPIRV directly to bypass those steps and
+    // avoid failures. Without -save-temps, the compiler may already skip
+    // assembling and linking. With -save-temps, these steps must be explicitly
+    // disabled, as done here. We also force skipping these steps regardless of
+    // -save-temps to avoid relying on optimizations (unless -S is set).
+    // The current HIP bundling expects the type to be types::TY_Image
+    if (UseSPIRVBackendForHipDeviceOnlyNoRDC && !Args.hasArg(options::OPT_S))
+      return C.MakeAction<BackendJobAction>(Input, types::TY_Image);
+
     return C.MakeAction<BackendJobAction>(Input, types::TY_PP_Asm);
   }
   case phases::Assemble:
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index c5d40c9825fab..03796c7d0fe4a 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5057,6 +5057,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     Args.ClaimAllArgs(options::OPT_femit_dwarf_unwind_EQ);
   }
 
+  bool IsAMDSPIRVForHIPDevice =
+      IsHIPDevice && getToolChain().getTriple().isSPIRV() &&
+      getToolChain().getTriple().getVendor() == llvm::Triple::AMD;
+
   if (isa<AnalyzeJobAction>(JA)) {
     assert(JA.getType() == types::TY_Plist && "Invalid output type.");
     CmdArgs.push_back("-analyze");
@@ -5154,6 +5158,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       rewriteKind = RK_Fragile;
     } else if (JA.getType() == types::TY_CIR) {
       CmdArgs.push_back("-emit-cir");
+    } else if (JA.getType() == types::TY_Image && IsAMDSPIRVForHIPDevice) {
+      CmdArgs.push_back("-emit-obj");
     } else {
       assert(JA.getType() == types::TY_PP_Asm && "Unexpected output type!");
     }
@@ -9084,7 +9090,9 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
       OPT_fno_lto,
       OPT_flto,
       OPT_flto_partitions_EQ,
-      OPT_flto_EQ};
+      OPT_flto_EQ,
+      OPT_use_spirv_backend};
+
   const llvm::DenseSet<unsigned> LinkerOptions{OPT_mllvm, OPT_Zlinker_input};
   auto ShouldForwardForToolChain = [&](Arg *A, const ToolChain &TC) {
     // Don't forward -mllvm to toolchains that don't support LLVM.
diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index 231a38c2d3717..f2f64922cb404 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -159,10 +159,9 @@ void AMDGCN::Linker::constructLldCommand(Compilation &C, const JobAction &JA,
 
 // For SPIR-V the inputs for the job are device AMDGCN SPIR-V flavoured bitcode
 // and the output is either a compiled SPIR-V binary or bitcode (-emit-llvm). It
-// calls llvm-link and then the llvm-spirv translator. Once the SPIR-V BE will
-// be promoted from experimental, we will switch to using that. TODO: consider
-// if we want to run any targeted optimisations over IR here, over generic
-// SPIR-V.
+// calls llvm-link and then the llvm-spirv translator or the SPIR-V BE.
+// TODO: consider if we want to run any targeted optimisations over IR here,
+// over generic SPIR-V.
 void AMDGCN::Linker::constructLinkAndEmitSpirvCommand(
     Compilation &C, const JobAction &JA, const InputInfoList &Inputs,
     const InputInfo &Output, const llvm::opt::ArgList &Args) const {
@@ -173,17 +172,41 @@ void AMDGCN::Linker::constructLinkAndEmitSpirvCommand(
   const char *LinkedBCFilePath = HIP::getTempFile(C, LinkedBCFilePrefix, "bc");
   InputInfo LinkedBCFile(&JA, LinkedBCFilePath, Output.getBaseInput());
 
+  bool UseSPIRVBackend =
+      Args.hasFlag(options::OPT_use_spirv_backend,
+                   options::OPT_no_use_spirv_backend, /*Default=*/false);
+
   constructLlvmLinkCommand(C, JA, Inputs, LinkedBCFile, Args);
 
-  // Emit SPIR-V binary.
-  llvm::opt::ArgStringList TrArgs{
-      "--spirv-max-version=1.6",
-      "--spirv-ext=+all",
-      "--spirv-allow-unknown-intrinsics",
-      "--spirv-lower-const-expr",
-      "--spirv-preserve-auxdata",
-      "--spirv-debug-info-version=nonsemantic-shader-200"};
-  SPIRV::constructTranslateCommand(C, *this, JA, Output, LinkedBCFile, TrArgs);
+  if (UseSPIRVBackend) {
+    // This code handles the case in the new driver when --offload-device-only
+    // is unset and clang-linker-wrapper forwards the bitcode that must be
+    // compiled to SPIR-V.
+
+    llvm::opt::ArgStringList CmdArgs;
+    const char *Triple =
+        C.getArgs().MakeArgString("-triple=spirv64-amd-amdhsa");
+
+    CmdArgs.append({"-cc1", Triple, "-emit-obj", "-disable-llvm-optzns",
+                    LinkedBCFile.getFilename(), "-o", Output.getFilename()});
+
+    const Driver &Driver = getToolChain().getDriver();
+    const char *Exec = Driver.getClangProgramPath();
+    C.addCommand(std::make_unique<Command>(
+        JA, *this, ResponseFileSupport::None(), Exec, CmdArgs, LinkedBCFile,
+        Output, Driver.getPrependArg()));
+  } else {
+    // Emit SPIR-V binary using the translator
+    llvm::opt::ArgStringList TrArgs{
+        "--spirv-max-version=1.6",
+        "--spirv-ext=+all",
+        "--spirv-allow-unknown-intrinsics",
+        "--spirv-lower-const-expr",
+        "--spirv-preserve-auxdata",
+        "--spirv-debug-info-version=nonsemantic-shader-200"};
+    SPIRV::constructTranslateCommand(C, *this, JA, Output, LinkedBCFile,
+                                     TrArgs);
+  }
 }
 
 // For amdgcn the inputs of the linker job are device bitcode and output is
diff --git a/clang/test/Driver/hip-spirv-backend-bindings.c b/clang/test/Driver/hip-spirv-backend-bindings.c
new file mode 100644
index 0000000000000..59b3f4fb54d4c
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-bindings.c
@@ -0,0 +1,57 @@
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-BASE,CHECK-SPIRV
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend -fgpu-rdc -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-BASE,CHECK-SPIRV-RDC
+
+// CHECK-SPIRV-BASE: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-BASE: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV: # "spirv64-amd-amdhsa" - "Offload::Packager", inputs: ["[[SPV_BC]]"], output: "[[HIP_OUT:.+\.out]]"
+// CHECK-SPIRV: # "spirv64-amd-amdhsa" - "Offload::Linker", inputs: ["[[HIP_OUT]]"], output: "[[HIPFB:.+\.hipfb]]"
+// CHECK-SPIRV-RDC: # "x86_64-unknown-linux-gnu" - "Offload::Packager", inputs: ["[[SPV_BC]]"], output: "[[HIP_OUT:.+\.out]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[INPUT]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[HIPI]]", "[[HIPFB]]"], output: "[[x86_BC:.+\.bc]]"
+// CHECK-SPIRV-RDC: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[HIPI]]", "[[HIP_OUT]]"], output: "[[x86_BC:.+\.bc]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[x86_BC]]"], output: "[[x86_S:.+\.s]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "clang::as", inputs: ["[[x86_S]]"], output: "[[x86_O:.+\.o]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[x86_O]]"], output: "{{.+\.out}}"
+
+// CHECK-SPIRV # "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[x86_O]]"], output: "[[x86_O:.+\.o]]"
+// CHECK-SPIRV # "x86_64-unknown-linux-gnu" - "GNU::Linker", inputs: ["[[x86_O]]"], output: "{{.+\.out}}"
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-OFFLOAD-DEVICE-ONLY
+
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[SPV_BC]]"], output: "[[SPV_OUT:.+\.out]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "AMDGCN::Linker", inputs: ["[[SPV_OUT]]"], output: "{{.+\.hipfb}}"
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -fgpu-rdc -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC
+
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[SPV_BC]]"], output: "{{.+}}"
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -S -fgpu-rdc -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -S -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY
+
+// CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[SPV_BC]]"], output: "{{.+\.s}}"
diff --git a/clang/test/Driver/hip-spirv-backend-opt.c b/clang/test/Driver/hip-spirv-backend-opt.c
new file mode 100644
index 0000000000000..88c4a848d5760
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-opt.c
@@ -0,0 +1,61 @@
+// This test case validates the behavior of -use-spirv-backend
+
+// --offload-device-only is always set --- testing interactions with -S and -fgpu-rdc
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend --offload-device-only -S \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-TEXTUAL
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend --offload-device-only \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BINARY
+
+// The new driver's behavior is to emit LLVM IR for --offload-device-only and -fgpu-rdc (independently of SPIR-V).
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -### -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -S -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-LL,CHECK-FGPU-RDC
+
+// The new driver's behavior is to emit LLVM IR for --offload-device-only and -fgpu-rdc (independently of SPIR-V).
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend --offload-device-only -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-FGPU-RDC
+
+// --offload-device-only is always unset --- testing interactions with -S and -fgpu-rdc
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend -S -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-FGPU-RDC
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend -S \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-CLANG-LINKER-WRAPPER
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-CLANG-LINKER-WRAPPER
+
+// RUN: %clang --no-offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-SPIRV-BACKEND-BINARY-EQ-TRIPLE
+
+// CHECK-SPIRV-TRANSLATOR-NOT: "{{.*llvm-spirv.*}}"
+// CHECK-SPIRV-BACKEND-TEXTUAL: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-S"
+// CHECK-SPIRV-BACKEND-BINARY: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-emit-obj"
+// CHECK-SPIRV-BACKEND-BC: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-emit-llvm-bc"
+// CHECK-SPIRV-BACKEND-LL: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-emit-llvm"
+// CHECK-SPIRV-BACKEND-BINARY-EQ-TRIPLE: "{{.*}}clang{{.*}}" "-cc1" {{.*}}"-triple=spirv64-amd-amdhsa" {{.*}}"-emit-obj"
+// CHECK-FGPU-RDC-SAME: {{.*}} "-fgpu-rdc"
+// CHECK-CLANG-LINKER-WRAPPER: "{{.*}}clang-linker-wrapper" "--should-extract=amdgcnspirv" {{.*}} "--device-compiler=spirv64-amd-amdhsa=-use-spirv-backend"
diff --git a/clang/test/Driver/hip-spirv-backend-phases.c b/clang/test/Driver/hip-spirv-backend-phases.c
new file mode 100644
index 0000000000000..d743b8cd50c40
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-phases.c
@@ -0,0 +1,80 @@
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend -ccc-print-phases \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-BINARY
+
+// CHECK-SPIRV-BINARY: [[P0:[0-9]+]]: input, "[[INPUT:.*]].c", hip, (host-hip)
+// CHECK-SPIRV-BINARY: [[P1:[0-9]+]]: preprocessor, {[[P0]]}, hip-cpp-output, (host-hip)
+// CHECK-S...
[truncated]

llvmbot · 2025-11-26T11:17:16Z

@llvm/pr-subscribers-clang

Author: Manuel Carrasco (mgcarrasco)

Changes

This relands "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #167543. The only changes introduced now are to fix an issue for the multicall driver that is fixed with this commit. We were not forwarding Driver.getPrependArg().

Patch is 25.67 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/169637.diff

7 Files Affected:

(modified) clang/include/clang/Options/Options.td (+10)
(modified) clang/lib/Driver/Driver.cpp (+41-3)
(modified) clang/lib/Driver/ToolChains/Clang.cpp (+9-1)
(modified) clang/lib/Driver/ToolChains/HIPAMD.cpp (+36-13)
(added) clang/test/Driver/hip-spirv-backend-bindings.c (+57)
(added) clang/test/Driver/hip-spirv-backend-opt.c (+61)
(added) clang/test/Driver/hip-spirv-backend-phases.c (+80)

diff --git a/clang/include/clang/Options/Options.td b/clang/include/clang/Options/Options.td
index a8fc1c4326cc5..00200055cce7e 100644
--- a/clang/include/clang/Options/Options.td
+++ b/clang/include/clang/Options/Options.td
@@ -1427,6 +1427,16 @@ def fhip_emit_relocatable : Flag<["-"], "fhip-emit-relocatable">,
   HelpText<"Compile HIP source to relocatable">;
 def fno_hip_emit_relocatable : Flag<["-"], "fno-hip-emit-relocatable">,
   HelpText<"Do not override toolchain to compile HIP source to relocatable">;
+def use_spirv_backend
+    : Flag<["-"], "use-spirv-backend">,
+      Group<hip_Group>,
+      Flags<[HelpHidden]>,
+      HelpText<"Use the SPIRV backend for compilation ">;
+def no_use_spirv_backend
+    : Flag<["-"], "no-use-spirv-backend">,
+      Group<hip_Group>,
+      Flags<[HelpHidden]>,
+      HelpText<"Do not use the SPIRV backend for compilation ">;
 }
 
 // Clang specific/exclusive options for OpenACC.
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index de8d4601210ae..c66ba73fc1f47 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -5024,15 +5024,24 @@ Action *Driver::BuildOffloadingActions(Compilation &C,
     // Compiling HIP in device-only non-RDC mode requires linking each action
     // individually.
     for (Action *&A : DeviceActions) {
-      // Special handling for the HIP SPIR-V toolchain because it doesn't use
-      // the SPIR-V backend yet doesn't report the output as an object.
       bool IsAMDGCNSPIRV = A->getOffloadingToolChain() &&
                            A->getOffloadingToolChain()->getTriple().getOS() ==
                                llvm::Triple::OSType::AMDHSA &&
                            A->getOffloadingToolChain()->getTriple().isSPIRV();
+      bool UseSPIRVBackend = Args.hasFlag(options::OPT_use_spirv_backend,
+                                          options::OPT_no_use_spirv_backend,
+                                          /*Default=*/false);
+
+      // Special handling for the HIP SPIR-V toolchain in device-only.
+      // The translator path has a linking step, whereas the SPIR-V backend path
+      // does not to avoid any external dependency such as spirv-link. The
+      // linking step is skipped for the SPIR-V backend path.
+      bool IsAMDGCNSPIRVWithBackend = IsAMDGCNSPIRV && UseSPIRVBackend;
+
       if ((A->getType() != types::TY_Object && !IsAMDGCNSPIRV &&
            A->getType() != types::TY_LTO_BC) ||
-          HIPRelocatableObj || !HIPNoRDC || !offloadDeviceOnly())
+          HIPRelocatableObj || !HIPNoRDC || !offloadDeviceOnly() ||
+          (IsAMDGCNSPIRVWithBackend && offloadDeviceOnly()))
         continue;
       ActionList LinkerInput = {A};
       A = C.MakeAction<LinkJobAction>(LinkerInput, types::TY_Image);
@@ -5258,12 +5267,28 @@ Action *Driver::ConstructPhaseAction(
           Args.hasArg(options::OPT_S) ? types::TY_LTO_IR : types::TY_LTO_BC;
       return C.MakeAction<BackendJobAction>(Input, Output);
     }
+    bool UseSPIRVBackend = Args.hasFlag(options::OPT_use_spirv_backend,
+                                        options::OPT_no_use_spirv_backend,
+                                        /*Default=*/false);
+
+    auto OffloadingToolChain = Input->getOffloadingToolChain();
+    // For AMD SPIRV, if offloadDeviceOnly(), we call the SPIRV backend unless
+    // LLVM bitcode was requested explicitly or RDC is set. If
+    // !offloadDeviceOnly, we emit LLVM bitcode, and clang-linker-wrapper will
+    // compile it to SPIRV.
+    bool UseSPIRVBackendForHipDeviceOnlyNoRDC =
+        TargetDeviceOffloadKind == Action::OFK_HIP && OffloadingToolChain &&
+        OffloadingToolChain->getTriple().isSPIRV() && UseSPIRVBackend &&
+        offloadDeviceOnly() &&
+        !Args.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc, false);
+
     if (Args.hasArg(options::OPT_emit_llvm) ||
         TargetDeviceOffloadKind == Action::OFK_SYCL ||
         (((Input->getOffloadingToolChain() &&
            Input->getOffloadingToolChain()->getTriple().isAMDGPU() &&
            TargetDeviceOffloadKind != Action::OFK_None) ||
           TargetDeviceOffloadKind == Action::OFK_HIP) &&
+         !UseSPIRVBackendForHipDeviceOnlyNoRDC &&
          ((Args.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc,
                         false) ||
            (Args.hasFlag(options::OPT_offload_new_driver,
@@ -5285,6 +5310,19 @@ Action *Driver::ConstructPhaseAction(
               : types::TY_LLVM_BC;
       return C.MakeAction<BackendJobAction>(Input, Output);
     }
+
+    // The SPIRV backend compilation path for HIP must avoid external
+    // dependencies. The default compilation path assembles and links its
+    // output, but the SPIRV assembler and linker are external tools. This code
+    // ensures the backend emits binary SPIRV directly to bypass those steps and
+    // avoid failures. Without -save-temps, the compiler may already skip
+    // assembling and linking. With -save-temps, these steps must be explicitly
+    // disabled, as done here. We also force skipping these steps regardless of
+    // -save-temps to avoid relying on optimizations (unless -S is set).
+    // The current HIP bundling expects the type to be types::TY_Image
+    if (UseSPIRVBackendForHipDeviceOnlyNoRDC && !Args.hasArg(options::OPT_S))
+      return C.MakeAction<BackendJobAction>(Input, types::TY_Image);
+
     return C.MakeAction<BackendJobAction>(Input, types::TY_PP_Asm);
   }
   case phases::Assemble:
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index c5d40c9825fab..03796c7d0fe4a 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5057,6 +5057,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     Args.ClaimAllArgs(options::OPT_femit_dwarf_unwind_EQ);
   }
 
+  bool IsAMDSPIRVForHIPDevice =
+      IsHIPDevice && getToolChain().getTriple().isSPIRV() &&
+      getToolChain().getTriple().getVendor() == llvm::Triple::AMD;
+
   if (isa<AnalyzeJobAction>(JA)) {
     assert(JA.getType() == types::TY_Plist && "Invalid output type.");
     CmdArgs.push_back("-analyze");
@@ -5154,6 +5158,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       rewriteKind = RK_Fragile;
     } else if (JA.getType() == types::TY_CIR) {
       CmdArgs.push_back("-emit-cir");
+    } else if (JA.getType() == types::TY_Image && IsAMDSPIRVForHIPDevice) {
+      CmdArgs.push_back("-emit-obj");
     } else {
       assert(JA.getType() == types::TY_PP_Asm && "Unexpected output type!");
     }
@@ -9084,7 +9090,9 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
       OPT_fno_lto,
       OPT_flto,
       OPT_flto_partitions_EQ,
-      OPT_flto_EQ};
+      OPT_flto_EQ,
+      OPT_use_spirv_backend};
+
   const llvm::DenseSet<unsigned> LinkerOptions{OPT_mllvm, OPT_Zlinker_input};
   auto ShouldForwardForToolChain = [&](Arg *A, const ToolChain &TC) {
     // Don't forward -mllvm to toolchains that don't support LLVM.
diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index 231a38c2d3717..f2f64922cb404 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -159,10 +159,9 @@ void AMDGCN::Linker::constructLldCommand(Compilation &C, const JobAction &JA,
 
 // For SPIR-V the inputs for the job are device AMDGCN SPIR-V flavoured bitcode
 // and the output is either a compiled SPIR-V binary or bitcode (-emit-llvm). It
-// calls llvm-link and then the llvm-spirv translator. Once the SPIR-V BE will
-// be promoted from experimental, we will switch to using that. TODO: consider
-// if we want to run any targeted optimisations over IR here, over generic
-// SPIR-V.
+// calls llvm-link and then the llvm-spirv translator or the SPIR-V BE.
+// TODO: consider if we want to run any targeted optimisations over IR here,
+// over generic SPIR-V.
 void AMDGCN::Linker::constructLinkAndEmitSpirvCommand(
     Compilation &C, const JobAction &JA, const InputInfoList &Inputs,
     const InputInfo &Output, const llvm::opt::ArgList &Args) const {
@@ -173,17 +172,41 @@ void AMDGCN::Linker::constructLinkAndEmitSpirvCommand(
   const char *LinkedBCFilePath = HIP::getTempFile(C, LinkedBCFilePrefix, "bc");
   InputInfo LinkedBCFile(&JA, LinkedBCFilePath, Output.getBaseInput());
 
+  bool UseSPIRVBackend =
+      Args.hasFlag(options::OPT_use_spirv_backend,
+                   options::OPT_no_use_spirv_backend, /*Default=*/false);
+
   constructLlvmLinkCommand(C, JA, Inputs, LinkedBCFile, Args);
 
-  // Emit SPIR-V binary.
-  llvm::opt::ArgStringList TrArgs{
-      "--spirv-max-version=1.6",
-      "--spirv-ext=+all",
-      "--spirv-allow-unknown-intrinsics",
-      "--spirv-lower-const-expr",
-      "--spirv-preserve-auxdata",
-      "--spirv-debug-info-version=nonsemantic-shader-200"};
-  SPIRV::constructTranslateCommand(C, *this, JA, Output, LinkedBCFile, TrArgs);
+  if (UseSPIRVBackend) {
+    // This code handles the case in the new driver when --offload-device-only
+    // is unset and clang-linker-wrapper forwards the bitcode that must be
+    // compiled to SPIR-V.
+
+    llvm::opt::ArgStringList CmdArgs;
+    const char *Triple =
+        C.getArgs().MakeArgString("-triple=spirv64-amd-amdhsa");
+
+    CmdArgs.append({"-cc1", Triple, "-emit-obj", "-disable-llvm-optzns",
+                    LinkedBCFile.getFilename(), "-o", Output.getFilename()});
+
+    const Driver &Driver = getToolChain().getDriver();
+    const char *Exec = Driver.getClangProgramPath();
+    C.addCommand(std::make_unique<Command>(
+        JA, *this, ResponseFileSupport::None(), Exec, CmdArgs, LinkedBCFile,
+        Output, Driver.getPrependArg()));
+  } else {
+    // Emit SPIR-V binary using the translator
+    llvm::opt::ArgStringList TrArgs{
+        "--spirv-max-version=1.6",
+        "--spirv-ext=+all",
+        "--spirv-allow-unknown-intrinsics",
+        "--spirv-lower-const-expr",
+        "--spirv-preserve-auxdata",
+        "--spirv-debug-info-version=nonsemantic-shader-200"};
+    SPIRV::constructTranslateCommand(C, *this, JA, Output, LinkedBCFile,
+                                     TrArgs);
+  }
 }
 
 // For amdgcn the inputs of the linker job are device bitcode and output is
diff --git a/clang/test/Driver/hip-spirv-backend-bindings.c b/clang/test/Driver/hip-spirv-backend-bindings.c
new file mode 100644
index 0000000000000..59b3f4fb54d4c
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-bindings.c
@@ -0,0 +1,57 @@
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-BASE,CHECK-SPIRV
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend -fgpu-rdc -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-BASE,CHECK-SPIRV-RDC
+
+// CHECK-SPIRV-BASE: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-BASE: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV: # "spirv64-amd-amdhsa" - "Offload::Packager", inputs: ["[[SPV_BC]]"], output: "[[HIP_OUT:.+\.out]]"
+// CHECK-SPIRV: # "spirv64-amd-amdhsa" - "Offload::Linker", inputs: ["[[HIP_OUT]]"], output: "[[HIPFB:.+\.hipfb]]"
+// CHECK-SPIRV-RDC: # "x86_64-unknown-linux-gnu" - "Offload::Packager", inputs: ["[[SPV_BC]]"], output: "[[HIP_OUT:.+\.out]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[INPUT]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[HIPI]]", "[[HIPFB]]"], output: "[[x86_BC:.+\.bc]]"
+// CHECK-SPIRV-RDC: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[HIPI]]", "[[HIP_OUT]]"], output: "[[x86_BC:.+\.bc]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "clang", inputs: ["[[x86_BC]]"], output: "[[x86_S:.+\.s]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "clang::as", inputs: ["[[x86_S]]"], output: "[[x86_O:.+\.o]]"
+// CHECK-SPIRV-BASE: # "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[x86_O]]"], output: "{{.+\.out}}"
+
+// CHECK-SPIRV # "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[x86_O]]"], output: "[[x86_O:.+\.o]]"
+// CHECK-SPIRV # "x86_64-unknown-linux-gnu" - "GNU::Linker", inputs: ["[[x86_O]]"], output: "{{.+\.out}}"
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-OFFLOAD-DEVICE-ONLY
+
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[SPV_BC]]"], output: "[[SPV_OUT:.+\.out]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "AMDGCN::Linker", inputs: ["[[SPV_OUT]]"], output: "{{.+\.hipfb}}"
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -fgpu-rdc -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC
+
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[SPV_BC]]"], output: "{{.+}}"
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -S -fgpu-rdc -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-OFFLOAD-DEVICE-ONLY-RDC
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -S -ccc-print-bindings \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY
+
+// CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[INPUT:.+]]"], output: "[[HIPI:.+\.hipi]]"
+// CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[HIPI]]"], output: "[[SPV_BC:.+\.bc]]"
+// CHECK-SPIRV-TEXTUAL-OFFLOAD-DEVICE-ONLY: # "spirv64-amd-amdhsa" - "clang", inputs: ["[[SPV_BC]]"], output: "{{.+\.s}}"
diff --git a/clang/test/Driver/hip-spirv-backend-opt.c b/clang/test/Driver/hip-spirv-backend-opt.c
new file mode 100644
index 0000000000000..88c4a848d5760
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-opt.c
@@ -0,0 +1,61 @@
+// This test case validates the behavior of -use-spirv-backend
+
+// --offload-device-only is always set --- testing interactions with -S and -fgpu-rdc
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend --offload-device-only -S \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-TEXTUAL
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend --offload-device-only \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BINARY
+
+// The new driver's behavior is to emit LLVM IR for --offload-device-only and -fgpu-rdc (independently of SPIR-V).
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -### -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend --offload-device-only -S -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-LL,CHECK-FGPU-RDC
+
+// The new driver's behavior is to emit LLVM IR for --offload-device-only and -fgpu-rdc (independently of SPIR-V).
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend --offload-device-only -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-FGPU-RDC
+
+// --offload-device-only is always unset --- testing interactions with -S and -fgpu-rdc
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend -S -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-FGPU-RDC
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend -S \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend -fgpu-rdc \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-CLANG-LINKER-WRAPPER
+
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-CLANG-LINKER-WRAPPER
+
+// RUN: %clang --no-offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -### -x hip %s -save-temps  \
+// RUN:         -use-spirv-backend \
+// RUN: 2>&1 | FileCheck %s --check-prefixes=CHECK-SPIRV-TRANSLATOR,CHECK-SPIRV-BACKEND-BC,CHECK-SPIRV-BACKEND-BINARY-EQ-TRIPLE
+
+// CHECK-SPIRV-TRANSLATOR-NOT: "{{.*llvm-spirv.*}}"
+// CHECK-SPIRV-BACKEND-TEXTUAL: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-S"
+// CHECK-SPIRV-BACKEND-BINARY: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-emit-obj"
+// CHECK-SPIRV-BACKEND-BC: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-emit-llvm-bc"
+// CHECK-SPIRV-BACKEND-LL: "{{.*}}clang{{.*}}" "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-emit-llvm"
+// CHECK-SPIRV-BACKEND-BINARY-EQ-TRIPLE: "{{.*}}clang{{.*}}" "-cc1" {{.*}}"-triple=spirv64-amd-amdhsa" {{.*}}"-emit-obj"
+// CHECK-FGPU-RDC-SAME: {{.*}} "-fgpu-rdc"
+// CHECK-CLANG-LINKER-WRAPPER: "{{.*}}clang-linker-wrapper" "--should-extract=amdgcnspirv" {{.*}} "--device-compiler=spirv64-amd-amdhsa=-use-spirv-backend"
diff --git a/clang/test/Driver/hip-spirv-backend-phases.c b/clang/test/Driver/hip-spirv-backend-phases.c
new file mode 100644
index 0000000000000..d743b8cd50c40
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-phases.c
@@ -0,0 +1,80 @@
+// RUN: %clang --offload-new-driver --target=x86_64-unknown-linux-gnu --offload-arch=amdgcnspirv \
+// RUN:         -nogpuinc -nogpulib -x hip %s -save-temps \
+// RUN:         -use-spirv-backend -ccc-print-phases \
+// RUN: 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-BINARY
+
+// CHECK-SPIRV-BINARY: [[P0:[0-9]+]]: input, "[[INPUT:.*]].c", hip, (host-hip)
+// CHECK-SPIRV-BINARY: [[P1:[0-9]+]]: preprocessor, {[[P0]]}, hip-cpp-output, (host-hip)
+// CHECK-S...
[truncated]

jmmartinez

LGTM

… HIP" (llvm#169637) This relands "[clang][Driver] Support for the SPIR-V backend when compiling HIP" llvm#167543. The only new change is a small fix for the multicall driver. For HIP, the SPIR-V backend can be optionally activated with the -use-spirv-backend flag. This option uses the SPIR-V BE instead of the SPIR-V translator. These changes also ensure that -use-spirv-backend does not require external dependencies, such as spirv-as and spirv-link

mgcarrasco added 2 commits November 26, 2025 05:01

[clang][Driver] Fix issue for multicall driver caused by not forwardi…

0720ad9

…ng Driver.getPrependArg().

mgcarrasco requested a review from jmmartinez November 26, 2025 11:16

mgcarrasco self-assigned this Nov 26, 2025

llvmbot added clang Clang issues not falling into any other category clang:driver 'clang' and 'clang++' user-facing binaries. Not 'clang-cl' labels Nov 26, 2025

jmmartinez approved these changes Nov 26, 2025

View reviewed changes

mgcarrasco merged commit bbbe511 into main Nov 26, 2025
11 of 12 checks passed

mgcarrasco deleted the users/mgcarrasco/use-spirv-backend-hip branch November 26, 2025 12:43

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Reland "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #169637

Reland "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #169637

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mgcarrasco commented Nov 26, 2025 •

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Reland "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #169637

Reland "[clang][Driver] Support for the SPIR-V backend when compiling HIP" #169637

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mgcarrasco commented Nov 26, 2025 •

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