Author: Nathan Gauër Date: 2026-03-25T16:07:35Z New Revision: 18250fd47bb65cc63f70b070e2a70c1668deb934
URL: https://github.com/llvm/llvm-project/commit/18250fd47bb65cc63f70b070e2a70c1668deb934 DIFF: https://github.com/llvm/llvm-project/commit/18250fd47bb65cc63f70b070e2a70c1668deb934.diff LOG: [HLSL][SPIR-V] Add vk::ext_builtin_output attribute (#188268) This attribute is similar to the already implemented ext_builtin_input attribute. One important bit is the `static` storage class: HLSL uses static differently than C/C++. This is a known weirdness: See https://github.com/microsoft/hlsl-specs/issues/350 In C/C++, when we declare a variable as 'extern', we often expect another module to declare the symbole. In HLSL, the pipeline will 'declare' the symbol. Hence in this case, we need to emit the global variable. Related WG-HLSL: https://github.com/llvm/wg-hlsl/blob/main/proposals/0031-semantics.md --------- Co-authored-by: Steven Perron <[email protected]> Added: clang/test/CodeGenHLSL/vk-output-builtin.hlsl clang/test/SemaHLSL/vk-ext-output-builtin.hlsl Modified: clang/include/clang/Basic/AddressSpaces.h clang/include/clang/Basic/Attr.td clang/include/clang/Basic/AttrDocs.td clang/include/clang/Sema/SemaHLSL.h clang/lib/AST/Type.cpp clang/lib/AST/TypePrinter.cpp clang/lib/Basic/TargetInfo.cpp clang/lib/Basic/Targets/AArch64.h clang/lib/Basic/Targets/AMDGPU.cpp clang/lib/Basic/Targets/DirectX.h clang/lib/Basic/Targets/NVPTX.h clang/lib/Basic/Targets/SPIR.h clang/lib/Basic/Targets/SystemZ.h clang/lib/Basic/Targets/TCE.h clang/lib/Basic/Targets/WebAssembly.h clang/lib/Basic/Targets/X86.h clang/lib/CodeGen/CGHLSLRuntime.cpp clang/lib/CodeGen/CodeGenModule.cpp clang/lib/Sema/SemaDeclAttr.cpp clang/lib/Sema/SemaHLSL.cpp clang/test/SemaTemplate/address_space-dependent.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/AddressSpaces.h b/clang/include/clang/Basic/AddressSpaces.h index 7280b8fc923d2..a941805423bca 100644 --- a/clang/include/clang/Basic/AddressSpaces.h +++ b/clang/include/clang/Basic/AddressSpaces.h @@ -62,6 +62,7 @@ enum class LangAS : unsigned { hlsl_private, hlsl_device, hlsl_input, + hlsl_output, hlsl_push_constant, // Wasm specific address spaces. diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td index f697262d603bf..5b0215f466e62 100644 --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -146,6 +146,12 @@ def HLSLInputBuiltin S->getType().isConstQualified()}], "static const globals">; +def HLSLOutputBuiltin + : SubsetSubject<Var, [{S->hasGlobalStorage() && + S->getStorageClass() == StorageClass::SC_Static && + !S->getType().isConstQualified()}], + "non-const static globals">; + def GlobalVar : SubsetSubject<Var, [{S->hasGlobalStorage()}], "global variables">; @@ -5217,6 +5223,14 @@ def HLSLVkExtBuiltinInput : InheritableAttr { let Documentation = [HLSLVkExtBuiltinInputDocs]; } +def HLSLVkExtBuiltinOutput : InheritableAttr { + let Spellings = [CXX11<"vk", "ext_builtin_output">]; + let Args = [UnsignedArgument<"BuiltIn">]; + let Subjects = SubjectList<[HLSLOutputBuiltin], ErrorDiag>; + let LangOpts = [HLSL]; + let Documentation = [HLSLVkExtBuiltinOutputDocs]; +} + def HLSLVkPushConstant : InheritableAttr { let Spellings = [CXX11<"vk", "push_constant">]; let Args = []; diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td index 555a54fd51a89..d93dcf5e9b2fd 100644 --- a/clang/include/clang/Basic/AttrDocs.td +++ b/clang/include/clang/Basic/AttrDocs.td @@ -8978,6 +8978,29 @@ https://github.com/microsoft/hlsl-specs/blob/main/proposals/0011-inline-spirv.md }]; } +def HLSLVkExtBuiltinOutputDocs : Documentation { + let Category = DocCatVariable; + let Content = [{ +Vulkan shaders have `Output` builtins. Those variables are externally +visible to the driver/pipeline, but each copy is private to the current +lane. + +Those builtins can be declared using the `[[vk::ext_builtin_output]]` +attribute like follows: + +.. code-block:: c++ + + [[vk::ext_builtin_output(/* Position */ 0)]] + static float4 position; + +This variable will be lowered into a module-level variable, with the `Output` +storage class, and the `BuiltIn 0` decoration. + +The full documentation for this inline SPIR-V attribute can be found here: +https://github.com/microsoft/hlsl-specs/blob/main/proposals/0011-inline-spirv.md + }]; +} + def HLSLVkPushConstantDocs : Documentation { let Category = DocCatVariable; let Content = [{ diff --git a/clang/include/clang/Sema/SemaHLSL.h b/clang/include/clang/Sema/SemaHLSL.h index cf9b8c39b109e..6f62fbc635d9c 100644 --- a/clang/include/clang/Sema/SemaHLSL.h +++ b/clang/include/clang/Sema/SemaHLSL.h @@ -190,6 +190,7 @@ class SemaHLSL : public SemaBase { void handleSemanticAttr(Decl *D, const ParsedAttr &AL); void handleVkExtBuiltinInputAttr(Decl *D, const ParsedAttr &AL); + void handleVkExtBuiltinOutputAttr(Decl *D, const ParsedAttr &AL); void handleVkPushConstantAttr(Decl *D, const ParsedAttr &AL); bool CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall); diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp index a351bc34af798..78524c205eb3d 100644 --- a/clang/lib/AST/Type.cpp +++ b/clang/lib/AST/Type.cpp @@ -101,6 +101,7 @@ bool Qualifiers::isTargetAddressSpaceSupersetOf(LangAS A, LangAS B, (A == LangAS::Default && B == LangAS::hlsl_private) || (A == LangAS::Default && B == LangAS::hlsl_device) || (A == LangAS::Default && B == LangAS::hlsl_input) || + (A == LangAS::Default && B == LangAS::hlsl_output) || (A == LangAS::Default && B == LangAS::hlsl_push_constant) || // Conversions from target specific address spaces may be legal // depending on the target information. diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp index 3375630827501..80f5b90ba35c4 100644 --- a/clang/lib/AST/TypePrinter.cpp +++ b/clang/lib/AST/TypePrinter.cpp @@ -2707,6 +2707,8 @@ std::string Qualifiers::getAddrSpaceAsString(LangAS AS) { return "hlsl_device"; case LangAS::hlsl_input: return "hlsl_input"; + case LangAS::hlsl_output: + return "hlsl_output"; case LangAS::hlsl_push_constant: return "hlsl_push_constant"; case LangAS::wasm_funcref: diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp index 38edc65801384..e6ae89e0948c5 100644 --- a/clang/lib/Basic/TargetInfo.cpp +++ b/clang/lib/Basic/TargetInfo.cpp @@ -52,7 +52,8 @@ static const LangASMap FakeAddrSpaceMap = { 15, // hlsl_private 16, // hlsl_device 17, // hlsl_input - 18, // hlsl_push_constant + 18, // hlsl_output + 19, // hlsl_push_constant 20, // wasm_funcref }; diff --git a/clang/lib/Basic/Targets/AArch64.h b/clang/lib/Basic/Targets/AArch64.h index f9dffed8769ef..0a29bad81939b 100644 --- a/clang/lib/Basic/Targets/AArch64.h +++ b/clang/lib/Basic/Targets/AArch64.h @@ -49,6 +49,7 @@ static const unsigned ARM64AddrSpaceMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp index c9cd01080fd0c..2c05b3c6512fb 100644 --- a/clang/lib/Basic/Targets/AMDGPU.cpp +++ b/clang/lib/Basic/Targets/AMDGPU.cpp @@ -53,6 +53,7 @@ const LangASMap AMDGPUTargetInfo::AMDGPUDefIsGenMap = { llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_private llvm::AMDGPUAS::GLOBAL_ADDRESS, // hlsl_device llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_input + llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_output llvm::AMDGPUAS::GLOBAL_ADDRESS, // hlsl_push_constant }; @@ -82,6 +83,7 @@ const LangASMap AMDGPUTargetInfo::AMDGPUDefIsPrivMap = { llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_private llvm::AMDGPUAS::GLOBAL_ADDRESS, // hlsl_device llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_input + llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_output llvm::AMDGPUAS::GLOBAL_ADDRESS, // hlsl_push_constant }; } // namespace targets diff --git a/clang/lib/Basic/Targets/DirectX.h b/clang/lib/Basic/Targets/DirectX.h index 3976238bede4a..8b21b86bac264 100644 --- a/clang/lib/Basic/Targets/DirectX.h +++ b/clang/lib/Basic/Targets/DirectX.h @@ -46,6 +46,7 @@ static const unsigned DirectXAddrSpaceMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. diff --git a/clang/lib/Basic/Targets/NVPTX.h b/clang/lib/Basic/Targets/NVPTX.h index 2e142cc95f9bb..69ee20f38343b 100644 --- a/clang/lib/Basic/Targets/NVPTX.h +++ b/clang/lib/Basic/Targets/NVPTX.h @@ -50,6 +50,7 @@ static const unsigned NVPTXAddrSpaceMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. diff --git a/clang/lib/Basic/Targets/SPIR.h b/clang/lib/Basic/Targets/SPIR.h index 11a45d17e4aa4..6f4154fcf311f 100644 --- a/clang/lib/Basic/Targets/SPIR.h +++ b/clang/lib/Basic/Targets/SPIR.h @@ -52,6 +52,7 @@ static const unsigned SPIRDefIsPrivMap[] = { 10, // hlsl_private 11, // hlsl_device 7, // hlsl_input + 8, // hlsl_output 13, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. @@ -89,6 +90,7 @@ static const unsigned SPIRDefIsGenMap[] = { 10, // hlsl_private 11, // hlsl_device 7, // hlsl_input + 8, // hlsl_output 13, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. diff --git a/clang/lib/Basic/Targets/SystemZ.h b/clang/lib/Basic/Targets/SystemZ.h index 2bcf75deb0a91..00f7d7a055b24 100644 --- a/clang/lib/Basic/Targets/SystemZ.h +++ b/clang/lib/Basic/Targets/SystemZ.h @@ -46,6 +46,7 @@ static const unsigned ZOSAddressMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant 0 // wasm_funcref }; diff --git a/clang/lib/Basic/Targets/TCE.h b/clang/lib/Basic/Targets/TCE.h index 161025378c471..2b22f4c4ec724 100644 --- a/clang/lib/Basic/Targets/TCE.h +++ b/clang/lib/Basic/Targets/TCE.h @@ -55,6 +55,7 @@ static const unsigned TCEOpenCLAddrSpaceMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. diff --git a/clang/lib/Basic/Targets/WebAssembly.h b/clang/lib/Basic/Targets/WebAssembly.h index 8128dd96068a0..808342485cad0 100644 --- a/clang/lib/Basic/Targets/WebAssembly.h +++ b/clang/lib/Basic/Targets/WebAssembly.h @@ -46,6 +46,7 @@ static const unsigned WebAssemblyAddrSpaceMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant 20, // wasm_funcref }; diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h index bd9127b2ec8b5..c7afcc7c86053 100644 --- a/clang/lib/Basic/Targets/X86.h +++ b/clang/lib/Basic/Targets/X86.h @@ -50,6 +50,7 @@ static const unsigned X86AddrSpaceMap[] = { 0, // hlsl_private 0, // hlsl_device 0, // hlsl_input + 0, // hlsl_output 0, // hlsl_push_constant // Wasm address space values for this target are dummy values, // as it is only enabled for Wasm targets. diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp index c8a0ab34ae848..4e6f853890c83 100644 --- a/clang/lib/CodeGen/CGHLSLRuntime.cpp +++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp @@ -1163,6 +1163,8 @@ void CGHLSLRuntime::handleGlobalVarDefinition(const VarDecl *VD, llvm::GlobalVariable *GV) { if (auto Attr = VD->getAttr<HLSLVkExtBuiltinInputAttr>()) addSPIRVBuiltinDecoration(GV, Attr->getBuiltIn()); + if (auto Attr = VD->getAttr<HLSLVkExtBuiltinOutputAttr>()) + addSPIRVBuiltinDecoration(GV, Attr->getBuiltIn()); } llvm::Instruction *CGHLSLRuntime::getConvergenceToken(BasicBlock &BB) { diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 3fcd6f5f904db..ed517d244f9a8 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -4441,6 +4441,17 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) { return; } } + + // HLSL extern globals can be read/written to by the pipeline. Those + // are declared, but never defined. + if (LangOpts.HLSL) { + if (VD->getStorageClass() == SC_Extern) { + auto GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(VD)); + getHLSLRuntime().handleGlobalVarDefinition(VD, GV); + return; + } + } + // If this declaration may have caused an inline variable definition to // change linkage, make sure that it's emitted. if (Context.getInlineVariableDefinitionKind(VD) == diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index 3c1e00c206dc3..131559f2cf786 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -7953,6 +7953,9 @@ ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D, const ParsedAttr &AL, case ParsedAttr::AT_HLSLVkExtBuiltinInput: S.HLSL().handleVkExtBuiltinInputAttr(D, AL); break; + case ParsedAttr::AT_HLSLVkExtBuiltinOutput: + S.HLSL().handleVkExtBuiltinOutputAttr(D, AL); + break; case ParsedAttr::AT_HLSLVkPushConstant: S.HLSL().handleVkPushConstantAttr(D, AL); break; diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp index 823d312df296e..1fe5b62afc073 100644 --- a/clang/lib/Sema/SemaHLSL.cpp +++ b/clang/lib/Sema/SemaHLSL.cpp @@ -1842,6 +1842,14 @@ void SemaHLSL::handleVkExtBuiltinInputAttr(Decl *D, const ParsedAttr &AL) { HLSLVkExtBuiltinInputAttr(getASTContext(), AL, ID)); } +void SemaHLSL::handleVkExtBuiltinOutputAttr(Decl *D, const ParsedAttr &AL) { + uint32_t ID; + if (!SemaRef.checkUInt32Argument(AL, AL.getArgAsExpr(0), ID)) + return; + D->addAttr(::new (getASTContext()) + HLSLVkExtBuiltinOutputAttr(getASTContext(), AL, ID)); +} + void SemaHLSL::handleVkPushConstantAttr(Decl *D, const ParsedAttr &AL) { D->addAttr(::new (getASTContext()) HLSLVkPushConstantAttr(getASTContext(), AL)); @@ -4857,6 +4865,19 @@ void SemaHLSL::deduceAddressSpace(VarDecl *Decl) { return; } + if (Decl->hasAttr<HLSLVkExtBuiltinOutputAttr>()) { + LangAS ImplAS = LangAS::hlsl_output; + Type = SemaRef.getASTContext().getAddrSpaceQualType(Type, ImplAS); + Decl->setType(Type); + + // HLSL uses `static` diff erently than C++. For BuiltIn output, the static + // does not imply private to the module scope. + // Marking it as external to reflect the semantic this attribute brings. + // See https://github.com/microsoft/hlsl-specs/issues/350 + Decl->setStorageClass(SC_Extern); + return; + } + bool IsVulkan = getASTContext().getTargetInfo().getTriple().getOS() == llvm::Triple::Vulkan; if (IsVulkan && Decl->hasAttr<HLSLVkPushConstantAttr>()) { diff --git a/clang/test/CodeGenHLSL/vk-output-builtin.hlsl b/clang/test/CodeGenHLSL/vk-output-builtin.hlsl new file mode 100644 index 0000000000000..df521113476eb --- /dev/null +++ b/clang/test/CodeGenHLSL/vk-output-builtin.hlsl @@ -0,0 +1,15 @@ +// RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \ +// RUN: spirv-unknown-vulkan1.3-vertex %s -emit-llvm -O3 -o - | FileCheck %s + +[[vk::ext_builtin_output(/* Position */ 0)]] +static float4 position; +// CHECK: @position = external hidden local_unnamed_addr addrspace(8) global <4 x float>, align 16, !spirv.Decorations [[META0:![0-9]+]] + +RWStructuredBuffer<float4> input : register(u1, space0); + +void main() { + position = input[0]; + // CHECK: store <4 x float> %[[#]], ptr addrspace(8) @position, align 16 +} +// CHECK: [[META0]] = !{[[META1:![0-9]+]]} +// CHECK: [[META1]] = !{i32 11, i32 0} diff --git a/clang/test/SemaHLSL/vk-ext-output-builtin.hlsl b/clang/test/SemaHLSL/vk-ext-output-builtin.hlsl new file mode 100644 index 0000000000000..bfe0ce3067043 --- /dev/null +++ b/clang/test/SemaHLSL/vk-ext-output-builtin.hlsl @@ -0,0 +1,27 @@ +// RUN: %clang_cc1 -triple spirv-unknown-vulkan1.3-compute -x hlsl -hlsl-entry foo -finclude-default-header -o - %s -verify + +// expected-error@+1 {{'vk::ext_builtin_output' attribute only applies to non-const static globals}} +[[vk::ext_builtin_output(/* Position */ 0)]] +float4 position0; + +// expected-error@+1 {{'vk::ext_builtin_output' attribute only applies to non-const static globals}} +[[vk::ext_builtin_output(/* Position */ 0)]] +// expected-error@+1 {{default initialization of an object of const type 'const hlsl_private float4' (aka 'const hlsl_private vector<float, 4>')}} +static const float4 position1; + +// expected-error@+1 {{'vk::ext_builtin_output' attribute takes one argument}} +[[vk::ext_builtin_output()]] +static float4 position2; + +// expected-error@+1 {{'vk::ext_builtin_output' attribute requires an integer constant}} +[[vk::ext_builtin_output(0.4f)]] +static float4 position3; + +// expected-error@+1 {{'vk::ext_builtin_output' attribute only applies to non-const static globals}} +[[vk::ext_builtin_output(0)]] +void some_function() { +} + +[numthreads(1,1,1)] +void foo() { +} diff --git a/clang/test/SemaTemplate/address_space-dependent.cpp b/clang/test/SemaTemplate/address_space-dependent.cpp index cba21b416bb48..3fdccb2c71a76 100644 --- a/clang/test/SemaTemplate/address_space-dependent.cpp +++ b/clang/test/SemaTemplate/address_space-dependent.cpp @@ -43,7 +43,7 @@ void neg() { template <long int I> void tooBig() { - __attribute__((address_space(I))) int *bounds; // expected-error {{address space is larger than the maximum supported (8388581)}} + __attribute__((address_space(I))) int *bounds; // expected-error {{address space is larger than the maximum supported (8388580)}} } template <long int I> @@ -101,7 +101,7 @@ int main() { car<1, 2, 3>(); // expected-note {{in instantiation of function template specialization 'car<1, 2, 3>' requested here}} HasASTemplateFields<1> HASTF; neg<-1>(); // expected-note {{in instantiation of function template specialization 'neg<-1>' requested here}} - correct<0x7FFFE5>(); + correct<0x7FFFE4>(); tooBig<8388650>(); // expected-note {{in instantiation of function template specialization 'tooBig<8388650L>' requested here}} __attribute__((address_space(1))) char *x; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
