https://github.com/jhuber6 updated
https://github.com/llvm/llvm-project/pull/145799
>From 904f4b8f5635b99fefa4b8a684b8ee2ae2362179 Mon Sep 17 00:00:00 2001
From: Joseph Huber <hube...@outlook.com>
Date: Wed, 25 Jun 2025 17:21:21 -0500
Subject: [PATCH] [Clang] Determine offloading architectures at Toolchain
creation
Summary:
Previously we had this weird disconnect where we would get some
offloading architectures beforehand and some later. This patch changes
it to where we just generate this information at Toolchain creation.
There's a few edge cases that will need to be cleaned up. Namely, we
don't handle the strange SPIR-V handling that mixes two separate
toolchains and we needed a pre-check to reject errors when inferring the
toolchain from `--offload-arch` in OpenMP.
Possible we could also use this information for some host defines if
needed.
---
clang/include/clang/Driver/Driver.h | 13 ++-
clang/lib/Driver/Driver.cpp | 132 +++++++++++++------------
clang/test/Driver/openmp-offload-gpu.c | 2 +-
3 files changed, 75 insertions(+), 72 deletions(-)
diff --git a/clang/include/clang/Driver/Driver.h
b/clang/include/clang/Driver/Driver.h
index 7ca848f11b561..d9e328fe918bc 100644
--- a/clang/include/clang/Driver/Driver.h
+++ b/clang/include/clang/Driver/Driver.h
@@ -367,10 +367,9 @@ class Driver {
/// stored in it, and will clean them up when torn down.
mutable llvm::StringMap<std::unique_ptr<ToolChain>> ToolChains;
- /// Cache of known offloading architectures for the ToolChain already
derived.
- /// This should only be modified when we first initialize the offloading
- /// toolchains.
- llvm::DenseMap<const ToolChain *, llvm::DenseSet<llvm::StringRef>>
KnownArchs;
+ /// The associated offloading architectures with each toolchain.
+ llvm::DenseMap<const ToolChain *, llvm::SmallVector<llvm::StringRef>>
+ OffloadArchs;
private:
/// TranslateInputArgs - Create a new derived argument list from the input
@@ -535,11 +534,11 @@ class Driver {
/// Returns the set of bound architectures active for this offload kind.
/// If there are no bound architctures we return a set containing only the
- /// empty string. The \p SuppressError option is used to suppress errors.
- llvm::DenseSet<StringRef>
+ /// empty string.
+ llvm::SmallVector<StringRef>
getOffloadArchs(Compilation &C, const llvm::opt::DerivedArgList &Args,
Action::OffloadKind Kind, const ToolChain *TC,
- bool SuppressError = false) const;
+ bool SpecificToolchain = true) const;
/// Check that the file referenced by Value exists. If it doesn't,
/// issue a diagnostic and return false.
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index b88f148b2f1ad..0c5503a66b8f0 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -988,6 +988,8 @@ void Driver::CreateOffloadingDeviceToolChains(Compilation
&C,
if (CudaInstallation.isValid())
CudaInstallation.WarnIfUnsupportedVersion();
C.addOffloadDeviceToolChain(&TC, Action::OFK_Cuda);
+ OffloadArchs[&TC] = getOffloadArchs(C, C.getArgs(), Action::OFK_Cuda, &TC,
+ /*SpecificToolchain=*/true);
} else if (IsHIP && !UseLLVMOffload) {
if (auto *OMPTargetArg =
C.getInputArgs().getLastArg(options::OPT_fopenmp_targets_EQ)) {
@@ -1004,6 +1006,12 @@ void
Driver::CreateOffloadingDeviceToolChains(Compilation &C,
getOffloadToolChain(C.getInputArgs(), Action::OFK_HIP, *HIPTriple,
C.getDefaultToolChain().getTriple());
C.addOffloadDeviceToolChain(&TC, Action::OFK_HIP);
+
+ // TODO: Fix 'amdgcnspirv' handling with the new driver.
+ if (C.getInputArgs().hasFlag(options::OPT_offload_new_driver,
+ options::OPT_no_offload_new_driver, false))
+ OffloadArchs[&TC] = getOffloadArchs(C, C.getArgs(), Action::OFK_HIP, &TC,
+ /*SpecificToolchain=*/true);
}
if (IsCuda || IsHIP)
@@ -1069,40 +1077,43 @@ void
Driver::CreateOffloadingDeviceToolChains(Compilation &C,
auto &TC = getOffloadToolChain(C.getInputArgs(), Action::OFK_OpenMP,
TT,
C.getDefaultToolChain().getTriple());
C.addOffloadDeviceToolChain(&TC, Action::OFK_OpenMP);
+ OffloadArchs[&TC] =
+ getOffloadArchs(C, C.getArgs(), Action::OFK_OpenMP, &TC,
+ /*SpecificToolchain=*/true);
}
} else if (C.getInputArgs().hasArg(options::OPT_offload_arch_EQ) &&
((!IsHIP && !IsCuda) || UseLLVMOffload)) {
llvm::Triple AMDTriple("amdgcn-amd-amdhsa");
llvm::Triple NVPTXTriple("nvptx64-nvidia-cuda");
- // Attempt to deduce the offloading triple from the set of architectures.
- // We can only correctly deduce NVPTX / AMDGPU triples currently.
- for (const llvm::Triple &TT : {AMDTriple, NVPTXTriple}) {
- auto &TC = getOffloadToolChain(C.getInputArgs(), Action::OFK_OpenMP,
TT,
- C.getDefaultToolChain().getTriple());
-
- llvm::DenseSet<StringRef> Archs =
- getOffloadArchs(C, C.getArgs(), Action::OFK_OpenMP, &TC, true);
- llvm::DenseSet<StringRef> ArchsForTarget;
- for (StringRef Arch : Archs) {
+ for (StringRef A :
+ C.getInputArgs().getAllArgValues(options::OPT_offload_arch_EQ)) {
+ for (StringRef Arch : llvm::split(A, ",")) {
bool IsNVPTX = IsNVIDIAOffloadArch(
StringToOffloadArch(getProcessorFromTargetID(NVPTXTriple,
Arch)));
bool IsAMDGPU = IsAMDOffloadArch(
StringToOffloadArch(getProcessorFromTargetID(AMDTriple, Arch)));
- if (!IsNVPTX && !IsAMDGPU && !Arch.equals_insensitive("native")) {
+ if (!IsNVPTX && !IsAMDGPU && !Arch.empty() &&
+ !Arch.equals_insensitive("native")) {
Diag(clang::diag::err_drv_failed_to_deduce_target_from_arch)
<< Arch;
return;
}
-
- if (TT.isNVPTX() && IsNVPTX)
- ArchsForTarget.insert(Arch);
- else if (TT.isAMDGPU() && IsAMDGPU)
- ArchsForTarget.insert(Arch);
}
- if (!ArchsForTarget.empty()) {
+ }
+
+ // Attempt to deduce the offloading triple from the set of architectures.
+ // We can only correctly deduce NVPTX / AMDGPU triples currently.
+ for (const llvm::Triple &TT : {AMDTriple, NVPTXTriple}) {
+ auto &TC = getOffloadToolChain(C.getInputArgs(), Action::OFK_OpenMP,
TT,
+ C.getDefaultToolChain().getTriple());
+
+ llvm::SmallVector<StringRef> Archs =
+ getOffloadArchs(C, C.getArgs(), Action::OFK_OpenMP, &TC,
+ /*SpecificToolchain=*/false);
+ if (!Archs.empty()) {
C.addOffloadDeviceToolChain(&TC, Action::OFK_OpenMP);
- KnownArchs[&TC] = ArchsForTarget;
+ OffloadArchs[&TC] = Archs;
}
}
@@ -1143,9 +1154,11 @@ void
Driver::CreateOffloadingDeviceToolChains(Compilation &C,
// going to create will depend on both.
const ToolChain *HostTC = C.getSingleOffloadToolChain<Action::OFK_Host>();
for (const auto &TT : UniqueSYCLTriplesVec) {
- auto SYCLTC = &getOffloadToolChain(C.getInputArgs(), Action::OFK_SYCL,
TT,
- HostTC->getTriple());
- C.addOffloadDeviceToolChain(SYCLTC, Action::OFK_SYCL);
+ auto &TC = getOffloadToolChain(C.getInputArgs(), Action::OFK_SYCL, TT,
+ HostTC->getTriple());
+ C.addOffloadDeviceToolChain(&TC, Action::OFK_SYCL);
+ OffloadArchs[&TC] = getOffloadArchs(C, C.getArgs(), Action::OFK_SYCL,
&TC,
+ /*SpecificToolchain=*/true);
}
}
@@ -4703,20 +4716,22 @@ static StringRef getCanonicalArchString(Compilation &C,
const llvm::opt::DerivedArgList &Args,
StringRef ArchStr,
const llvm::Triple &Triple,
- bool SuppressError = false) {
+ bool SpecificToolchain) {
// Lookup the CUDA / HIP architecture string. Only report an error if we were
// expecting the triple to be only NVPTX / AMDGPU.
OffloadArch Arch =
StringToOffloadArch(getProcessorFromTargetID(Triple, ArchStr));
- if (!SuppressError && Triple.isNVPTX() &&
+ if (Triple.isNVPTX() &&
(Arch == OffloadArch::UNKNOWN || !IsNVIDIAOffloadArch(Arch))) {
- C.getDriver().Diag(clang::diag::err_drv_offload_bad_gpu_arch)
- << "CUDA" << ArchStr;
+ if (SpecificToolchain)
+ C.getDriver().Diag(clang::diag::err_drv_offload_bad_gpu_arch)
+ << "CUDA" << ArchStr;
return StringRef();
- } else if (!SuppressError && Triple.isAMDGPU() &&
+ } else if (Triple.isAMDGPU() &&
(Arch == OffloadArch::UNKNOWN || !IsAMDOffloadArch(Arch))) {
- C.getDriver().Diag(clang::diag::err_drv_offload_bad_gpu_arch)
- << "HIP" << ArchStr;
+ if (SpecificToolchain)
+ C.getDriver().Diag(clang::diag::err_drv_offload_bad_gpu_arch)
+ << "HIP" << ArchStr;
return StringRef();
}
@@ -4725,13 +4740,9 @@ static StringRef getCanonicalArchString(Compilation &C,
if (IsAMDOffloadArch(Arch)) {
llvm::StringMap<bool> Features;
- auto HIPTriple = getHIPOffloadTargetTriple(C.getDriver(),
C.getInputArgs());
- if (!HIPTriple)
- return StringRef();
- auto Arch = parseTargetID(*HIPTriple, ArchStr, &Features);
+ std::optional<StringRef> Arch = parseTargetID(Triple, ArchStr, &Features);
if (!Arch) {
C.getDriver().Diag(clang::diag::err_drv_bad_target_id) << ArchStr;
- C.setContainsError();
return StringRef();
}
return Args.MakeArgStringRef(getCanonicalTargetID(*Arch, Features));
@@ -4754,10 +4765,10 @@ getConflictOffloadArchCombination(const
llvm::DenseSet<StringRef> &Archs,
return getConflictTargetIDCombination(ArchSet);
}
-llvm::DenseSet<StringRef>
+llvm::SmallVector<StringRef>
Driver::getOffloadArchs(Compilation &C, const llvm::opt::DerivedArgList &Args,
Action::OffloadKind Kind, const ToolChain *TC,
- bool SuppressError) const {
+ bool SpecificToolchain) const {
if (!TC)
TC = &C.getDefaultToolChain();
@@ -4772,9 +4783,6 @@ Driver::getOffloadArchs(Compilation &C, const
llvm::opt::DerivedArgList &Args,
: "--no-offload-arch");
}
- if (KnownArchs.contains(TC))
- return KnownArchs.lookup(TC);
-
llvm::DenseSet<StringRef> Archs;
for (auto *Arg : C.getArgsForToolChain(TC, /*BoundArch=*/"", Kind)) {
// Add or remove the seen architectures in order of appearance. If an
@@ -4784,7 +4792,7 @@ Driver::getOffloadArchs(Compilation &C, const
llvm::opt::DerivedArgList &Args,
if (Arch == "native" || Arch.empty()) {
auto GPUsOrErr = TC->getSystemGPUArchs(Args);
if (!GPUsOrErr) {
- if (SuppressError)
+ if (!SpecificToolchain)
llvm::consumeError(GPUsOrErr.takeError());
else
TC->getDriver().Diag(diag::err_drv_undetermined_gpu_arch)
@@ -4794,16 +4802,21 @@ Driver::getOffloadArchs(Compilation &C, const
llvm::opt::DerivedArgList &Args,
}
for (auto ArchStr : *GPUsOrErr) {
- Archs.insert(
+ StringRef CanonicalStr =
getCanonicalArchString(C, Args, Args.MakeArgString(ArchStr),
- TC->getTriple(), SuppressError));
+ TC->getTriple(), SpecificToolchain);
+ if (!CanonicalStr.empty())
+ Archs.insert(CanonicalStr);
+ else if (SpecificToolchain)
+ return llvm::SmallVector<StringRef>();
}
} else {
- StringRef ArchStr = getCanonicalArchString(
- C, Args, Arch, TC->getTriple(), SuppressError);
- if (ArchStr.empty())
- return Archs;
- Archs.insert(ArchStr);
+ StringRef CanonicalStr = getCanonicalArchString(
+ C, Args, Arch, TC->getTriple(), SpecificToolchain);
+ if (!CanonicalStr.empty())
+ Archs.insert(CanonicalStr);
+ else if (SpecificToolchain)
+ return llvm::SmallVector<StringRef>();
}
}
} else if (Arg->getOption().matches(options::OPT_no_offload_arch_EQ)) {
@@ -4812,9 +4825,7 @@ Driver::getOffloadArchs(Compilation &C, const
llvm::opt::DerivedArgList &Args,
Archs.clear();
} else {
StringRef ArchStr = getCanonicalArchString(
- C, Args, Arch, TC->getTriple(), SuppressError);
- if (ArchStr.empty())
- return Archs;
+ C, Args, Arch, TC->getTriple(), SpecificToolchain);
Archs.erase(ArchStr);
}
}
@@ -4822,17 +4833,12 @@ Driver::getOffloadArchs(Compilation &C, const
llvm::opt::DerivedArgList &Args,
}
if (auto ConflictingArchs =
- getConflictOffloadArchCombination(Archs, TC->getTriple())) {
+ getConflictOffloadArchCombination(Archs, TC->getTriple()))
C.getDriver().Diag(clang::diag::err_drv_bad_offload_arch_combo)
<< ConflictingArchs->first << ConflictingArchs->second;
- C.setContainsError();
- }
// Skip filling defaults if we're just querying what is availible.
- if (SuppressError)
- return Archs;
-
- if (Archs.empty()) {
+ if (SpecificToolchain && Archs.empty()) {
if (Kind == Action::OFK_Cuda) {
Archs.insert(OffloadArchToString(OffloadArch::CudaDefault));
} else if (Kind == Action::OFK_HIP) {
@@ -4858,12 +4864,13 @@ Driver::getOffloadArchs(Compilation &C, const
llvm::opt::DerivedArgList &Args,
}
}
}
- } else {
- Args.ClaimAllArgs(options::OPT_offload_arch_EQ);
- Args.ClaimAllArgs(options::OPT_no_offload_arch_EQ);
}
+ Args.ClaimAllArgs(options::OPT_offload_arch_EQ);
+ Args.ClaimAllArgs(options::OPT_no_offload_arch_EQ);
- return Archs;
+ SmallVector<StringRef> Sorted(Archs.begin(), Archs.end());
+ llvm::sort(Sorted);
+ return Sorted;
}
Action *Driver::BuildOffloadingActions(Compilation &C,
@@ -4927,10 +4934,7 @@ Action *Driver::BuildOffloadingActions(Compilation &C,
// Get the product of all bound architectures and toolchains.
SmallVector<std::pair<const ToolChain *, StringRef>> TCAndArchs;
for (const ToolChain *TC : ToolChains) {
- llvm::DenseSet<StringRef> Arches = getOffloadArchs(C, Args, Kind, TC);
- SmallVector<StringRef, 0> Sorted(Arches.begin(), Arches.end());
- llvm::sort(Sorted);
- for (StringRef Arch : Sorted) {
+ for (StringRef Arch : OffloadArchs.lookup(TC)) {
TCAndArchs.push_back(std::make_pair(TC, Arch));
DeviceActions.push_back(
C.MakeAction<InputAction>(*InputArg, InputType, CUID));
diff --git a/clang/test/Driver/openmp-offload-gpu.c
b/clang/test/Driver/openmp-offload-gpu.c
index 2af3e2da3b21c..62e7c9588ce66 100644
--- a/clang/test/Driver/openmp-offload-gpu.c
+++ b/clang/test/Driver/openmp-offload-gpu.c
@@ -307,7 +307,7 @@
// DRIVER_EMBEDDING: -fembed-offload-object={{.*}}.out
// RUN: %clang -### --target=x86_64-unknown-linux-gnu -ccc-print-bindings
-fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda \
-// RUN: --offload-host-only -nogpulib %s 2>&1 | FileCheck %s
--check-prefix=CHECK-HOST-ONLY
+// RUN: -Xopenmp-target=nvptx64-nvidia-cuda -march=sm_52
--offload-host-only -nogpulib %s 2>&1 | FileCheck %s
--check-prefix=CHECK-HOST-ONLY
// CHECK-HOST-ONLY: "x86_64-unknown-linux-gnu" - "clang", inputs:
["[[INPUT:.*]]"], output: "[[OUTPUT:.*]]"
// CHECK-HOST-ONLY: "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs:
["[[OUTPUT]]"], output: "a.out"
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