[clang] 22c477f - [HLSL] Initial codegen for SV_GroupIndex
Chris Bieneman via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 25 09:20:25 PDT 2022
Author: Chris Bieneman
Date: 2022-08-25T11:17:54-05:00
New Revision: 22c477f934c4d1fa3f7d782d32a3e151f581c686
URL: https://github.com/llvm/llvm-project/commit/22c477f934c4d1fa3f7d782d32a3e151f581c686
DIFF: https://github.com/llvm/llvm-project/commit/22c477f934c4d1fa3f7d782d32a3e151f581c686.diff
LOG: [HLSL] Initial codegen for SV_GroupIndex
Semantic parameters aren't passed as actual parameters, instead they are
populated from intrinsics which are generally lowered to reads from
dedicated hardware registers.
This change modifies clang CodeGen to emit the intrinsic calls and
populate the parameter's LValue with the result of the intrinsic call
for SV_GroupIndex.
The result of this is to make the actual passed argument ignored, which
will make it easy to clean up later in an IR pass.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D131203
Added:
clang/test/CodeGenHLSL/semantics/GroupIndex-codegen.hlsl
Modified:
clang/lib/AST/Mangle.cpp
clang/lib/CodeGen/CGHLSLRuntime.cpp
clang/lib/CodeGen/CGHLSLRuntime.h
clang/lib/CodeGen/CodeGenFunction.cpp
clang/lib/CodeGen/CodeGenModule.cpp
Removed:
################################################################################
diff --git a/clang/lib/AST/Mangle.cpp b/clang/lib/AST/Mangle.cpp
index cb9a35cb0e7da..7ea569c63d9e4 100644
--- a/clang/lib/AST/Mangle.cpp
+++ b/clang/lib/AST/Mangle.cpp
@@ -133,10 +133,6 @@ bool MangleContext::shouldMangleDeclName(const NamedDecl *D) {
if (isa<MSGuidDecl>(D))
return true;
- // HLSL shader entry function never need to be mangled.
- if (getASTContext().getLangOpts().HLSL && D->hasAttr<HLSLShaderAttr>())
- return false;
-
return shouldMangleCXXName(D);
}
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index 5c3930869864c..fa7bab9121b7a 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -14,7 +14,9 @@
#include "CGHLSLRuntime.h"
#include "CodeGenModule.h"
+#include "clang/AST/Decl.h"
#include "clang/Basic/TargetOptions.h"
+#include "llvm/IR/IntrinsicsDirectX.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
@@ -87,11 +89,55 @@ void CGHLSLRuntime::annotateHLSLResource(const VarDecl *D, GlobalVariable *GV) {
ConstantAsMetadata::get(B.getInt32(Counter))}));
}
-void clang::CodeGen::CGHLSLRuntime::setHLSLFunctionAttributes(
- llvm::Function *F, const FunctionDecl *FD) {
- if (HLSLShaderAttr *ShaderAttr = FD->getAttr<HLSLShaderAttr>()) {
- const StringRef ShaderAttrKindStr = "hlsl.shader";
- F->addFnAttr(ShaderAttrKindStr,
- ShaderAttr->ConvertShaderTypeToStr(ShaderAttr->getType()));
+void clang::CodeGen::CGHLSLRuntime::setHLSLEntryAttributes(
+ const FunctionDecl *FD, llvm::Function *Fn) {
+ const auto *ShaderAttr = FD->getAttr<HLSLShaderAttr>();
+ assert(ShaderAttr && "All entry functions must have a HLSLShaderAttr");
+ const StringRef ShaderAttrKindStr = "hlsl.shader";
+ Fn->addFnAttr(ShaderAttrKindStr,
+ ShaderAttr->ConvertShaderTypeToStr(ShaderAttr->getType()));
+}
+
+llvm::Value *CGHLSLRuntime::emitInputSemantic(IRBuilder<> &B,
+ const ParmVarDecl &D) {
+ assert(D.hasAttrs() && "Entry parameter missing annotation attribute!");
+ if (D.hasAttr<HLSLSV_GroupIndexAttr>()) {
+ llvm::Function *DxGroupIndex =
+ CGM.getIntrinsic(Intrinsic::dx_flattened_thread_id_in_group);
+ return B.CreateCall(FunctionCallee(DxGroupIndex));
+ }
+ assert(false && "Unhandled parameter attribute");
+ return nullptr;
+}
+
+void CGHLSLRuntime::emitEntryFunction(const FunctionDecl *FD,
+ llvm::Function *Fn) {
+ llvm::Module &M = CGM.getModule();
+ llvm::LLVMContext &Ctx = M.getContext();
+ auto *EntryTy = llvm::FunctionType::get(llvm::Type::getVoidTy(Ctx), false);
+ Function *EntryFn =
+ Function::Create(EntryTy, Function::ExternalLinkage, FD->getName(), &M);
+
+ // Copy function attributes over, we have no argument or return attributes
+ // that can be valid on the real entry.
+ AttributeList NewAttrs = AttributeList::get(Ctx, AttributeList::FunctionIndex,
+ Fn->getAttributes().getFnAttrs());
+ EntryFn->setAttributes(NewAttrs);
+ setHLSLEntryAttributes(FD, EntryFn);
+
+ // Set the called function as internal linkage.
+ Fn->setLinkage(GlobalValue::InternalLinkage);
+
+ BasicBlock *BB = BasicBlock::Create(Ctx, "entry", EntryFn);
+ IRBuilder<> B(BB);
+ llvm::SmallVector<Value *> Args;
+ // FIXME: support struct parameters where semantics are on members.
+ for (const auto *Param : FD->parameters()) {
+ Args.push_back(emitInputSemantic(B, *Param));
}
+
+ CallInst *CI = B.CreateCall(FunctionCallee(Fn), Args);
+ (void)CI;
+ // FIXME: Handle codegen for return type semantics.
+ B.CreateRetVoid();
}
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.h b/clang/lib/CodeGen/CGHLSLRuntime.h
index a7246f7f8919b..9bd698b325026 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.h
+++ b/clang/lib/CodeGen/CGHLSLRuntime.h
@@ -15,6 +15,8 @@
#ifndef LLVM_CLANG_LIB_CODEGEN_CGHLSLRUNTIME_H
#define LLVM_CLANG_LIB_CODEGEN_CGHLSLRUNTIME_H
+#include "llvm/IR/IRBuilder.h"
+
#include "clang/Basic/HLSLRuntime.h"
namespace llvm {
@@ -23,6 +25,7 @@ class Function;
} // namespace llvm
namespace clang {
class VarDecl;
+class ParmVarDecl;
class FunctionDecl;
@@ -36,6 +39,8 @@ class CGHLSLRuntime {
uint32_t ResourceCounters[static_cast<uint32_t>(
hlsl::ResourceClass::NumClasses)] = {0};
+ llvm::Value *emitInputSemantic(llvm::IRBuilder<> &B, const ParmVarDecl &D);
+
public:
CGHLSLRuntime(CodeGenModule &CGM) : CGM(CGM) {}
virtual ~CGHLSLRuntime() {}
@@ -44,7 +49,9 @@ class CGHLSLRuntime {
void finishCodeGen();
- void setHLSLFunctionAttributes(llvm::Function *, const FunctionDecl *);
+ void setHLSLEntryAttributes(const FunctionDecl *FD, llvm::Function *Fn);
+
+ void emitEntryFunction(const FunctionDecl *FD, llvm::Function *Fn);
};
} // namespace CodeGen
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 061e0bf14d8fa..81c687e4530f4 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -16,6 +16,7 @@
#include "CGCXXABI.h"
#include "CGCleanup.h"
#include "CGDebugInfo.h"
+#include "CGHLSLRuntime.h"
#include "CGOpenMPRuntime.h"
#include "CodeGenModule.h"
#include "CodeGenPGO.h"
@@ -1137,6 +1138,10 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
if (getLangOpts().OpenMP && CurCodeDecl)
CGM.getOpenMPRuntime().emitFunctionProlog(*this, CurCodeDecl);
+ // Handle emitting HLSL entry functions.
+ if (D && D->hasAttr<HLSLShaderAttr>())
+ CGM.getHLSLRuntime().emitEntryFunction(FD, Fn);
+
EmitFunctionProlog(*CurFnInfo, CurFn, Args);
if (isa_and_nonnull<CXXMethodDecl>(D) &&
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 9df1970566646..2ced1c5419813 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1703,10 +1703,6 @@ void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
/*AttrOnCallSite=*/false, IsThunk);
F->setAttributes(PAL);
F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
- if (getLangOpts().HLSL) {
- if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl()))
- getHLSLRuntime().setHLSLFunctionAttributes(F, FD);
- }
}
static void removeImageAccessQualifier(std::string& TyName) {
diff --git a/clang/test/CodeGenHLSL/semantics/GroupIndex-codegen.hlsl b/clang/test/CodeGenHLSL/semantics/GroupIndex-codegen.hlsl
new file mode 100644
index 0000000000000..b8514b0d13f11
--- /dev/null
+++ b/clang/test/CodeGenHLSL/semantics/GroupIndex-codegen.hlsl
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -emit-llvm -disable-llvm-passes -o - -hlsl-entry main %s
+
+[numthreads(1,1,1)]
+void main(unsigned GI : SV_GroupIndex) {
+ main(GI - 1);
+}
+
+// For HLSL entry functions, we are generating a C-export function that wraps
+// the C++-mangled entry function. The wrapper function can be used to populate
+// semantic parameters and provides the expected void(void) signature that
+// drivers expect for entry points.
+
+//CHECK: define void @main() #[[ENTRY_ATTR:#]]{
+//CHECK-NEXT: entry:
+//CHECK-NEXT: %0 = call i32 @llvm.dx.flattened.thread.id.in.group()
+//CHECK-NEXT: call void @"?main@@YAXI at Z"(i32 %0)
+//CHECK-NEXT: ret void
+//CHECK-NEXT: }
+
+// Verify that the entry had the expected dx.shader attribute
+
+//CHECK: attributes #[[ENTRY_ATTR]] = { {{.*}}"dx.shader"="compute"{{.*}} }
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