[AMDGPU] Teach the driver to infer a libclc library to link with #153162
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This commit introduces a new compiler option which lets the target infer the name of the libclc builtins library to link with. This is contrasted with the previous option where the user explicitly provides a namespec. For the AMDGPU target, the general form of libclc libraries is gfxXYZ-amdgcn--.bc or gfxXYZ-amdgcn-mesa-mesa3d.bc. The target will try to link with either of these libraries, based on the triple and GPU architecture. Note that this patch doesn't guarantee that a library will necessary be found for all CPUs or GFX architectures. For example, some libclc libraries use another naming scheme, for example 'tonga' instead of 'gfx802'. These are not accounted for. If an inferred library isn't found then the compiler will error as if the user had provided the path themselves. Future patches will focus on libclc and standardize the naming system to reduce the likelihood of this happening.
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@llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-driver Author: Fraser Cormack (frasercrmck) ChangesThis commit introduces a new compiler option which lets the target infer the name of the libclc builtins library to link with. This is contrasted with the previous option where the user explicitly provides a namespec. For the AMDGPU target, the general form of libclc libraries is gfxXYZ-amdgcn--.bc or gfxXYZ-amdgcn-mesa-mesa3d.bc. The target will try to link with either of these libraries, based on the triple and GPU architecture. Note that this patch doesn't guarantee that a library will necessary be found for all CPUs or GFX architectures. For example, some libclc libraries use another naming scheme, for example 'tonga' instead of 'gfx802'. These are not accounted for. If an inferred library isn't found then the compiler will error as if the user had provided the path themselves. Future patches will focus on libclc and standardize the naming system to reduce the likelihood of this happening. Full diff: https://github.com/llvm/llvm-project/pull/153162.diff 5 Files Affected:
diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index 0f17f4aa761ea..adbfbfed12da5 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -395,6 +395,8 @@ def warn_drv_fraw_string_literals_in_cxx11 : Warning<
InGroup<UnusedCommandLineArgument>;
def err_drv_libclc_not_found : Error<"no libclc library '%0' found in the clang resource directory">;
+def err_drv_libclc_not_inferred : Error<
+ "could not infer a libclc library for this target; try providing a namespec or full path">;
def err_drv_invalid_malign_branch_EQ : Error<
"invalid argument '%0' to -malign-branch=; each element must be one of: %1">;
diff --git a/clang/include/clang/Driver/CommonArgs.h b/clang/include/clang/Driver/CommonArgs.h
index 1464ce4e1b31b..ea4b73082623a 100644
--- a/clang/include/clang/Driver/CommonArgs.h
+++ b/clang/include/clang/Driver/CommonArgs.h
@@ -218,7 +218,8 @@ void addOpenMPDeviceRTL(const Driver &D, const llvm::opt::ArgList &DriverArgs,
const ToolChain &HostTC);
void addOpenCLBuiltinsLib(const Driver &D, const llvm::opt::ArgList &DriverArgs,
- llvm::opt::ArgStringList &CC1Args);
+ llvm::opt::ArgStringList &CC1Args,
+ const StringRef InferredLibclcLibName = "");
void addOutlineAtomicsArgs(const Driver &D, const ToolChain &TC,
const llvm::opt::ArgList &Args,
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6aab43c9ed57f..1dc688d25b9b3 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1435,6 +1435,8 @@ def openacc_macro_override_EQ
// End Clang specific/exclusive options for OpenACC.
+def libclc_lib : Joined<["--"], "libclc-lib">, Group<opencl_Group>,
+ HelpText<"Link with the libclc OpenCL bitcode library">;
def libclc_lib_EQ : Joined<["--"], "libclc-lib=">, Group<opencl_Group>,
HelpText<"Namespec of libclc OpenCL bitcode library to link">;
def libomptarget_amdgpu_bc_path_EQ : Joined<["--"], "libomptarget-amdgpu-bc-path=">, Group<i_Group>,
diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp
index 5e463b9c98687..f1bcfd47831a3 100644
--- a/clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -858,8 +858,19 @@ void AMDGPUToolChain::addClangTargetOptions(
CC1Args.push_back("-fapply-global-visibility-to-externs");
}
- if (DeviceOffloadingKind == Action::OFK_None)
- addOpenCLBuiltinsLib(getDriver(), DriverArgs, CC1Args);
+ if (DeviceOffloadingKind == Action::OFK_None) {
+ auto GpuArch = getGPUArch(DriverArgs);
+ auto Kind = llvm::AMDGPU::parseArchAMDGCN(GpuArch);
+ const StringRef CanonArch = llvm::AMDGPU::getArchNameAMDGCN(Kind);
+ SmallString<128> InferredLibclcLibName(CanonArch);
+ if (getTriple().getOS() != llvm::Triple::Mesa3D)
+ InferredLibclcLibName += "-amdgcn--";
+ else
+ InferredLibclcLibName += "-amdgcn-mesa-mesa3d";
+ InferredLibclcLibName += ".bc";
+ addOpenCLBuiltinsLib(getDriver(), DriverArgs, CC1Args,
+ InferredLibclcLibName);
+ }
}
void AMDGPUToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index eb88f7bd4b469..5be3babc100d2 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -2999,27 +2999,42 @@ void tools::addHIPRuntimeLibArgs(const ToolChain &TC, Compilation &C,
void tools::addOpenCLBuiltinsLib(const Driver &D,
const llvm::opt::ArgList &DriverArgs,
- llvm::opt::ArgStringList &CC1Args) {
+ llvm::opt::ArgStringList &CC1Args,
+ const StringRef InferredLibclcLibName) {
// Check whether user specifies a libclc bytecode library
- const Arg *A = DriverArgs.getLastArg(options::OPT_libclc_lib_EQ);
+ const Arg *A = DriverArgs.getLastArg(options::OPT_libclc_lib,
+ options::OPT_libclc_lib_EQ);
if (!A)
return;
+ bool IsEQOpt = A->getOption().matches(options::OPT_libclc_lib_EQ);
+
// Find device libraries in <LLVM_DIR>/lib/clang/<ver>/lib/libclc/
SmallString<128> LibclcPath(D.ResourceDir);
llvm::sys::path::append(LibclcPath, "lib", "libclc");
// If the namespec is of the form :filename, search for that file.
- StringRef LibclcNamespec(A->getValue());
- bool FilenameSearch = LibclcNamespec.consume_front(":");
- SmallString<128> LibclcTargetFile(LibclcNamespec);
+ bool FilenameSearch = false;
+ SmallString<128> LibclcTargetFile;
+
+ if (IsEQOpt) {
+ StringRef LibclcNamespec(A->getValue());
+ FilenameSearch = LibclcNamespec.consume_front(":");
+ LibclcTargetFile = LibclcNamespec;
+ } else {
+ if (InferredLibclcLibName.empty()) {
+ D.Diag(diag::err_drv_libclc_not_inferred);
+ return;
+ }
+ LibclcTargetFile = InferredLibclcLibName;
+ }
if (FilenameSearch && llvm::sys::fs::exists(LibclcTargetFile)) {
CC1Args.push_back("-mlink-builtin-bitcode");
CC1Args.push_back(DriverArgs.MakeArgString(LibclcTargetFile));
} else {
// Search the library paths for the file
- if (!FilenameSearch)
+ if (!FilenameSearch && IsEQOpt)
LibclcTargetFile += ".bc";
llvm::sys::path::append(LibclcPath, LibclcTargetFile);
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@llvm/pr-subscribers-backend-amdgpu Author: Fraser Cormack (frasercrmck) ChangesThis commit introduces a new compiler option which lets the target infer the name of the libclc builtins library to link with. This is contrasted with the previous option where the user explicitly provides a namespec. For the AMDGPU target, the general form of libclc libraries is gfxXYZ-amdgcn--.bc or gfxXYZ-amdgcn-mesa-mesa3d.bc. The target will try to link with either of these libraries, based on the triple and GPU architecture. Note that this patch doesn't guarantee that a library will necessary be found for all CPUs or GFX architectures. For example, some libclc libraries use another naming scheme, for example 'tonga' instead of 'gfx802'. These are not accounted for. If an inferred library isn't found then the compiler will error as if the user had provided the path themselves. Future patches will focus on libclc and standardize the naming system to reduce the likelihood of this happening. Full diff: https://github.com/llvm/llvm-project/pull/153162.diff 5 Files Affected:
diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index 0f17f4aa761ea..adbfbfed12da5 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -395,6 +395,8 @@ def warn_drv_fraw_string_literals_in_cxx11 : Warning<
InGroup<UnusedCommandLineArgument>;
def err_drv_libclc_not_found : Error<"no libclc library '%0' found in the clang resource directory">;
+def err_drv_libclc_not_inferred : Error<
+ "could not infer a libclc library for this target; try providing a namespec or full path">;
def err_drv_invalid_malign_branch_EQ : Error<
"invalid argument '%0' to -malign-branch=; each element must be one of: %1">;
diff --git a/clang/include/clang/Driver/CommonArgs.h b/clang/include/clang/Driver/CommonArgs.h
index 1464ce4e1b31b..ea4b73082623a 100644
--- a/clang/include/clang/Driver/CommonArgs.h
+++ b/clang/include/clang/Driver/CommonArgs.h
@@ -218,7 +218,8 @@ void addOpenMPDeviceRTL(const Driver &D, const llvm::opt::ArgList &DriverArgs,
const ToolChain &HostTC);
void addOpenCLBuiltinsLib(const Driver &D, const llvm::opt::ArgList &DriverArgs,
- llvm::opt::ArgStringList &CC1Args);
+ llvm::opt::ArgStringList &CC1Args,
+ const StringRef InferredLibclcLibName = "");
void addOutlineAtomicsArgs(const Driver &D, const ToolChain &TC,
const llvm::opt::ArgList &Args,
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6aab43c9ed57f..1dc688d25b9b3 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1435,6 +1435,8 @@ def openacc_macro_override_EQ
// End Clang specific/exclusive options for OpenACC.
+def libclc_lib : Joined<["--"], "libclc-lib">, Group<opencl_Group>,
+ HelpText<"Link with the libclc OpenCL bitcode library">;
def libclc_lib_EQ : Joined<["--"], "libclc-lib=">, Group<opencl_Group>,
HelpText<"Namespec of libclc OpenCL bitcode library to link">;
def libomptarget_amdgpu_bc_path_EQ : Joined<["--"], "libomptarget-amdgpu-bc-path=">, Group<i_Group>,
diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp
index 5e463b9c98687..f1bcfd47831a3 100644
--- a/clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -858,8 +858,19 @@ void AMDGPUToolChain::addClangTargetOptions(
CC1Args.push_back("-fapply-global-visibility-to-externs");
}
- if (DeviceOffloadingKind == Action::OFK_None)
- addOpenCLBuiltinsLib(getDriver(), DriverArgs, CC1Args);
+ if (DeviceOffloadingKind == Action::OFK_None) {
+ auto GpuArch = getGPUArch(DriverArgs);
+ auto Kind = llvm::AMDGPU::parseArchAMDGCN(GpuArch);
+ const StringRef CanonArch = llvm::AMDGPU::getArchNameAMDGCN(Kind);
+ SmallString<128> InferredLibclcLibName(CanonArch);
+ if (getTriple().getOS() != llvm::Triple::Mesa3D)
+ InferredLibclcLibName += "-amdgcn--";
+ else
+ InferredLibclcLibName += "-amdgcn-mesa-mesa3d";
+ InferredLibclcLibName += ".bc";
+ addOpenCLBuiltinsLib(getDriver(), DriverArgs, CC1Args,
+ InferredLibclcLibName);
+ }
}
void AMDGPUToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index eb88f7bd4b469..5be3babc100d2 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -2999,27 +2999,42 @@ void tools::addHIPRuntimeLibArgs(const ToolChain &TC, Compilation &C,
void tools::addOpenCLBuiltinsLib(const Driver &D,
const llvm::opt::ArgList &DriverArgs,
- llvm::opt::ArgStringList &CC1Args) {
+ llvm::opt::ArgStringList &CC1Args,
+ const StringRef InferredLibclcLibName) {
// Check whether user specifies a libclc bytecode library
- const Arg *A = DriverArgs.getLastArg(options::OPT_libclc_lib_EQ);
+ const Arg *A = DriverArgs.getLastArg(options::OPT_libclc_lib,
+ options::OPT_libclc_lib_EQ);
if (!A)
return;
+ bool IsEQOpt = A->getOption().matches(options::OPT_libclc_lib_EQ);
+
// Find device libraries in <LLVM_DIR>/lib/clang/<ver>/lib/libclc/
SmallString<128> LibclcPath(D.ResourceDir);
llvm::sys::path::append(LibclcPath, "lib", "libclc");
// If the namespec is of the form :filename, search for that file.
- StringRef LibclcNamespec(A->getValue());
- bool FilenameSearch = LibclcNamespec.consume_front(":");
- SmallString<128> LibclcTargetFile(LibclcNamespec);
+ bool FilenameSearch = false;
+ SmallString<128> LibclcTargetFile;
+
+ if (IsEQOpt) {
+ StringRef LibclcNamespec(A->getValue());
+ FilenameSearch = LibclcNamespec.consume_front(":");
+ LibclcTargetFile = LibclcNamespec;
+ } else {
+ if (InferredLibclcLibName.empty()) {
+ D.Diag(diag::err_drv_libclc_not_inferred);
+ return;
+ }
+ LibclcTargetFile = InferredLibclcLibName;
+ }
if (FilenameSearch && llvm::sys::fs::exists(LibclcTargetFile)) {
CC1Args.push_back("-mlink-builtin-bitcode");
CC1Args.push_back(DriverArgs.MakeArgString(LibclcTargetFile));
} else {
// Search the library paths for the file
- if (!FilenameSearch)
+ if (!FilenameSearch && IsEQOpt)
LibclcTargetFile += ".bc";
llvm::sys::path::append(LibclcPath, LibclcTargetFile);
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| if (getTriple().getOS() != llvm::Triple::Mesa3D) | ||
| InferredLibclcLibName += "-amdgcn--"; | ||
| else | ||
| InferredLibclcLibName += "-amdgcn-mesa-mesa3d"; |
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Should just directly take the triple value? In particular this ignores the amdhsa case
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That might be good. It would work for the Mesa3D case but the only amdhsa we have is amdgcn--amdhsa.bc, without any gfx prefixes.
I don't understand the various AMDGPU architectures nor the libclc naming scheme well enough, I'm afraid.
Is using a amdgcn-amd-amdhsa triple compatible with libclc?
The build currently creates a bunch of symlinks, and I don't think it currently tries to reproduce the ISA version checks device libs has (or maybe rather, those were ripped out in the distance past). The full amdgcn bitcode files we end up with appear to be: The tahiti prefixed ones are in fact infected with target-cpu=gfx600, so overall the build is pretty busted |
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Using bitcode without |
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I'm not aware of any ISA-specific logic in libclc, but I may well be missing some subtleties. The attribute pollution is unfortunate - we certainly don't want to be building libclc any more times than we need to. Downstream we have modified the libclc "prepare-builtins" utility to remove @jhuber6 this should indeed work without |
We've always had """generic""" bitcode, it's just required a little hand holding. The ROCm Device Libs generate IR that gets fed in through |
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Getting back to this, I tried removing Most notably, |
This commit introduces a new compiler option which lets the target infer the name of the libclc builtins library to link with. This is contrasted with the previous option where the user explicitly provides a namespec.
For the AMDGPU target, the general form of libclc libraries is gfxXYZ-amdgcn--.bc or gfxXYZ-amdgcn-mesa-mesa3d.bc. The target will try to link with either of these libraries, based on the triple and GPU architecture.
Note that this patch doesn't guarantee that a library will necessary be found for all CPUs or GFX architectures. For example, some libclc libraries use another naming scheme, for example 'tonga' instead of 'gfx802'. These are not accounted for. If an inferred library isn't found then the compiler will error as if the user had provided the path themselves. Future patches will focus on libclc and standardize the naming system to reduce the likelihood of this happening.