[clang] [HIP][SPIRV] Enable the SPIRV backend instead of the translator through an experimental flag. (PR #162282)
Manuel Carrasco via cfe-commits
cfe-commits at lists.llvm.org
Fri Oct 10 01:50:50 PDT 2025
https://github.com/mgcarrasco updated https://github.com/llvm/llvm-project/pull/162282
>From e89ce89521602f651495cf936e016d8f0c926974 Mon Sep 17 00:00:00 2001
From: Manuel Carrasco <Manuel.Carrasco at amd.com>
Date: Tue, 7 Oct 2025 06:05:21 -0700
Subject: [PATCH 1/2] [HIP][SPIRV] Enable the SPIRV backend instead of the
translator through an experimental flag.
MIME-Version: 1.0
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Co-authored-by: Juan Manuel Martinez Caamaño <juamarti at amd.com>
---
clang/include/clang/Driver/Options.td | 14 ++++++++
clang/lib/Driver/ToolChains/HIPAMD.cpp | 36 +++++++++++++++-----
clang/test/Driver/amdgpu-spirv-backend-opt.c | 12 +++++++
3 files changed, 53 insertions(+), 9 deletions(-)
create mode 100644 clang/test/Driver/amdgpu-spirv-backend-opt.c
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index ec38231f906eb..37dbb820ce22f 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -5483,6 +5483,20 @@ defm wavefrontsize64 : SimpleMFlag<"wavefrontsize64",
defm amdgpu_precise_memory_op
: SimpleMFlag<"amdgpu-precise-memory-op", "Enable", "Disable",
" precise memory mode (AMDGPU only)">;
+def amdgpu_use_experimental_spirv_backend
+ : Flag<["-"], "amdgpu-use-experimental-spirv-backend">,
+ Group<m_amdgpu_Features_Group>,
+ Flags<[HelpHidden]>,
+ Visibility<[ClangOption]>,
+ HelpText<"Use experimental SPIRV backend for AMDGPU compilation (AMDGPU "
+ "only)">;
+def no_amdgpu_use_experimental_spirv_backend
+ : Flag<["-"], "no-amdgpu-use-experimental-spirv-backend">,
+ Group<m_amdgpu_Features_Group>,
+ Flags<[HelpHidden]>,
+ Visibility<[ClangOption]>,
+ HelpText<"Do not use experimental SPIRV backend for AMDGPU compilation "
+ "(AMDGPU only)">;
def munsafe_fp_atomics : Flag<["-"], "munsafe-fp-atomics">,
Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>, Alias<fatomic_ignore_denormal_mode>;
diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index c0c8afec07264..aeccf381c7a63 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -175,15 +175,33 @@ void AMDGCN::Linker::constructLinkAndEmitSpirvCommand(
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);
+ bool UseSPIRVBackend = Args.hasFlag(
+ options::OPT_amdgpu_use_experimental_spirv_backend,
+ options::OPT_no_amdgpu_use_experimental_spirv_backend, /*Default=*/false);
+
+ // Emit SPIR-V binary either using the SPIRV backend or the translator.
+ if (UseSPIRVBackend) {
+ llvm::opt::ArgStringList CmdArgs;
+ const char *Triple =
+ C.getArgs().MakeArgString("-triple=spirv64-amd-amdhsa");
+ CmdArgs.append({"-cc1", Triple, "-emit-obj", LinkedBCFile.getFilename(),
+ "-o", Output.getFilename()});
+ const char *Exec = getToolChain().getDriver().getClangProgramPath();
+ C.addCommand(std::make_unique<Command>(JA, *this,
+ ResponseFileSupport::None(), Exec,
+ CmdArgs, LinkedBCFile, Output));
+ } else {
+ // Use the SPIRV translator for code gen.
+ 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/amdgpu-spirv-backend-opt.c b/clang/test/Driver/amdgpu-spirv-backend-opt.c
new file mode 100644
index 0000000000000..0435ad9dad6d1
--- /dev/null
+++ b/clang/test/Driver/amdgpu-spirv-backend-opt.c
@@ -0,0 +1,12 @@
+// COM: This test case validates the behavior of -amdgpu-use-experimental-spirv-backend
+
+// COM: Test that -amdgpu-use-experimental-spirv-backend calls clang -cc1 with the SPIRV triple.
+// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -amdgpu-use-experimental-spirv-backend -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-BACKEND
+// CHECK-SPIRV-BACKEND: "{{.*}}clang{{.*}}" "-cc1" "{{.*-triple=spirv64-amd-amdhsa}}"
+
+// COM: Test that -no-amdgpu-use-experimental-spirv-backend calls the SPIRV translator
+// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -no-amdgpu-use-experimental-spirv-backend -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TRANSLATOR
+// CHECK-SPIRV-TRANSLATOR: "{{.*llvm-spirv.*}}" "{{--spirv-max-version=[0-9]+\.[0-9]}}"
+
+// COM: Test that by default we use the translator
+// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TRANSLATOR
>From 8d56d95ebc8f5ce620b08eb7af516a645364af9c Mon Sep 17 00:00:00 2001
From: Manuel Carrasco <Manuel.Carrasco at amd.com>
Date: Fri, 10 Oct 2025 01:49:49 -0700
Subject: [PATCH 2/2] Switch to hip prefix for new flags.
---
clang/include/clang/Driver/Options.td | 26 +++++++++-----------
clang/lib/Driver/ToolChains/HIPAMD.cpp | 4 +--
clang/test/Driver/amdgpu-spirv-backend-opt.c | 12 ---------
clang/test/Driver/hip-spirv-backend-opt.c | 12 +++++++++
4 files changed, 26 insertions(+), 28 deletions(-)
delete mode 100644 clang/test/Driver/amdgpu-spirv-backend-opt.c
create mode 100644 clang/test/Driver/hip-spirv-backend-opt.c
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 37dbb820ce22f..7da478e5e71d6 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1421,6 +1421,18 @@ 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 hip_use_experimental_spirv_backend
+ : Flag<["-"], "hip-use-experimental-spirv-backend">,
+ Group<hip_Group>,
+ Flags<[HelpHidden]>,
+ HelpText<"Use experimental SPIRV backend for HIP compilation (HIP "
+ "only)">;
+def no_hip_use_experimental_spirv_backend
+ : Flag<["-"], "no-hip-use-experimental-spirv-backend">,
+ Group<hip_Group>,
+ Flags<[HelpHidden]>,
+ HelpText<"Do not use experimental SPIRV backend for HIP compilation "
+ "(HIP only)">;
}
// Clang specific/exclusive options for OpenACC.
@@ -5483,20 +5495,6 @@ defm wavefrontsize64 : SimpleMFlag<"wavefrontsize64",
defm amdgpu_precise_memory_op
: SimpleMFlag<"amdgpu-precise-memory-op", "Enable", "Disable",
" precise memory mode (AMDGPU only)">;
-def amdgpu_use_experimental_spirv_backend
- : Flag<["-"], "amdgpu-use-experimental-spirv-backend">,
- Group<m_amdgpu_Features_Group>,
- Flags<[HelpHidden]>,
- Visibility<[ClangOption]>,
- HelpText<"Use experimental SPIRV backend for AMDGPU compilation (AMDGPU "
- "only)">;
-def no_amdgpu_use_experimental_spirv_backend
- : Flag<["-"], "no-amdgpu-use-experimental-spirv-backend">,
- Group<m_amdgpu_Features_Group>,
- Flags<[HelpHidden]>,
- Visibility<[ClangOption]>,
- HelpText<"Do not use experimental SPIRV backend for AMDGPU compilation "
- "(AMDGPU only)">;
def munsafe_fp_atomics : Flag<["-"], "munsafe-fp-atomics">,
Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>, Alias<fatomic_ignore_denormal_mode>;
diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index aeccf381c7a63..1b8a9af197ff7 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -176,8 +176,8 @@ void AMDGCN::Linker::constructLinkAndEmitSpirvCommand(
constructLlvmLinkCommand(C, JA, Inputs, LinkedBCFile, Args);
bool UseSPIRVBackend = Args.hasFlag(
- options::OPT_amdgpu_use_experimental_spirv_backend,
- options::OPT_no_amdgpu_use_experimental_spirv_backend, /*Default=*/false);
+ options::OPT_hip_use_experimental_spirv_backend,
+ options::OPT_no_hip_use_experimental_spirv_backend, /*Default=*/false);
// Emit SPIR-V binary either using the SPIRV backend or the translator.
if (UseSPIRVBackend) {
diff --git a/clang/test/Driver/amdgpu-spirv-backend-opt.c b/clang/test/Driver/amdgpu-spirv-backend-opt.c
deleted file mode 100644
index 0435ad9dad6d1..0000000000000
--- a/clang/test/Driver/amdgpu-spirv-backend-opt.c
+++ /dev/null
@@ -1,12 +0,0 @@
-// COM: This test case validates the behavior of -amdgpu-use-experimental-spirv-backend
-
-// COM: Test that -amdgpu-use-experimental-spirv-backend calls clang -cc1 with the SPIRV triple.
-// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -amdgpu-use-experimental-spirv-backend -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-BACKEND
-// CHECK-SPIRV-BACKEND: "{{.*}}clang{{.*}}" "-cc1" "{{.*-triple=spirv64-amd-amdhsa}}"
-
-// COM: Test that -no-amdgpu-use-experimental-spirv-backend calls the SPIRV translator
-// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -no-amdgpu-use-experimental-spirv-backend -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TRANSLATOR
-// CHECK-SPIRV-TRANSLATOR: "{{.*llvm-spirv.*}}" "{{--spirv-max-version=[0-9]+\.[0-9]}}"
-
-// COM: Test that by default we use the translator
-// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TRANSLATOR
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..7fe9819514066
--- /dev/null
+++ b/clang/test/Driver/hip-spirv-backend-opt.c
@@ -0,0 +1,12 @@
+// COM: This test case validates the behavior of -hip-use-experimental-spirv-backend
+
+// COM: Test that -hip-use-experimental-spirv-backend calls clang -cc1 with the SPIRV triple.
+// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -hip-use-experimental-spirv-backend -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-BACKEND
+// CHECK-SPIRV-BACKEND: "{{.*}}clang{{.*}}" "-cc1" "{{.*-triple=spirv64-amd-amdhsa}}"
+
+// COM: Test that -no-hip-use-experimental-spirv-backend calls the SPIRV translator
+// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -no-hip-use-experimental-spirv-backend -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TRANSLATOR
+// CHECK-SPIRV-TRANSLATOR: "{{.*llvm-spirv.*}}" "{{--spirv-max-version=[0-9]+\.[0-9]}}"
+
+// COM: Test that by default we use the translator
+// RUN: %clang -x hip %s --cuda-device-only --offload-arch=amdgcnspirv -nogpuinc -nogpulib -### 2>&1 | FileCheck %s --check-prefix=CHECK-SPIRV-TRANSLATOR
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