[SPIRV] Add Target Builtins using Distance ext as an example (#121598)

- Update pr labeler so new SPIRV files get properly labeled.
- Add distance target builtin to BuiltinsSPIRV.td.
- Update TargetBuiltins.h to account for spirv builtins.
- Update clang basic CMakeLists.txt to build spirv builtin tablegen.
- Hook up sema for SPIRV in Sema.h|cpp, SemaSPIRV.h|cpp, and
SemaChecking.cpp.
- Hookup sprv target builtins to SPIR.h|SPIR.cpp target.
- Update GBuiltin.cpp to emit spirv intrinsics when we get the expected
spirv target builtin.

Consensus was reach in this RFC to add both target builtins and pattern
matching:
https://discourse.llvm.org/t/rfc-add-targetbuiltins-for-spirv-to-support-hlsl/83329.

pattern matching will come in a separate pr this one just sets up the
groundwork to do target builtins for spirv.

partially resolves
[#99107](#99107)

Author: farzonl

.github/new-prs-labeler.yml

@@ -661,6 +661,11 @@ backend:DirectX:
 
 backend:SPIR-V:
   - clang/lib/Driver/ToolChains/SPIRV.*
+  - clang/lib/Sema/SemaSPIRV.cpp
+  - clang/include/clang/Sema/SemaSPIRV.h
+  - clang/include/clang/Basic/BuiltinsSPIRV.td
+  - clang/test/CodeGenSPIRV/**
+  - clang/test/SemaSPIRV/**
   - llvm/lib/Target/SPIRV/**
   - llvm/test/CodeGen/SPIRV/**
   - llvm/test/Frontend/HLSL/**

clang/include/clang/Basic/BuiltinsSPIRV.td

@@ -0,0 +1,15 @@
+//===--- BuiltinsSPIRV.td - SPIRV Builtin function database ---------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+include "clang/Basic/BuiltinsBase.td"
+
+def HLSLDistance : Builtin {
+  let Spellings = ["__builtin_spirv_distance"];
+  let Attributes = [NoThrow, Const];
+  let Prototype = "void(...)";
+}

clang/include/clang/Basic/CMakeLists.txt

@@ -60,6 +60,10 @@ clang_tablegen(BuiltinsRISCV.inc -gen-clang-builtins
   SOURCE BuiltinsRISCV.td
   TARGET ClangBuiltinsRISCV)
 
+clang_tablegen(BuiltinsSPIRV.inc -gen-clang-builtins
+  SOURCE BuiltinsSPIRV.td
+  TARGET ClangBuiltinsSPIRV)
+
 clang_tablegen(BuiltinsX86.inc -gen-clang-builtins
   SOURCE BuiltinsX86.td
   TARGET ClangBuiltinsX86)

clang/include/clang/Basic/TargetBuiltins.h

@@ -119,6 +119,16 @@ namespace clang {
   };
   }
 
+  /// SPIRV builtins
+  namespace SPIRV {
+  enum {
+    LastTIBuiltin = clang::Builtin::FirstTSBuiltin - 1,
+#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
+#include "clang/Basic/BuiltinsSPIRV.inc"
+    LastTSBuiltin
+  };
+  } // namespace SPIRV
+
   /// X86 builtins
   namespace X86 {
   enum {

clang/include/clang/Sema/Sema.h

@@ -173,6 +173,7 @@ class SemaOpenMP;
 class SemaPPC;
 class SemaPseudoObject;
 class SemaRISCV;
+class SemaSPIRV;
 class SemaSYCL;
 class SemaSwift;
 class SemaSystemZ;
@@ -1142,6 +1143,11 @@ class Sema final : public SemaBase {
     return *RISCVPtr;
   }
 
+  SemaSPIRV &SPIRV() {
+    assert(SPIRVPtr);
+    return *SPIRVPtr;
+  }
+
   SemaSYCL &SYCL() {
     assert(SYCLPtr);
     return *SYCLPtr;
@@ -1219,6 +1225,7 @@ class Sema final : public SemaBase {
   std::unique_ptr<SemaPPC> PPCPtr;
   std::unique_ptr<SemaPseudoObject> PseudoObjectPtr;
   std::unique_ptr<SemaRISCV> RISCVPtr;
+  std::unique_ptr<SemaSPIRV> SPIRVPtr;
   std::unique_ptr<SemaSYCL> SYCLPtr;
   std::unique_ptr<SemaSwift> SwiftPtr;
   std::unique_ptr<SemaSystemZ> SystemZPtr;

clang/include/clang/Sema/SemaSPIRV.h

@@ -0,0 +1,28 @@
+//===----- SemaSPIRV.h ----- Semantic Analysis for SPIRV constructs--------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares semantic analysis for SPIRV constructs.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SEMA_SEMASPIRV_H
+#define LLVM_CLANG_SEMA_SEMASPIRV_H
+
+#include "clang/AST/ASTFwd.h"
+#include "clang/Sema/SemaBase.h"
+
+namespace clang {
+class SemaSPIRV : public SemaBase {
+public:
+  SemaSPIRV(Sema &S);
+
+  bool CheckSPIRVBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
+};
+} // namespace clang
+
+#endif // LLVM_CLANG_SEMA_SEMASPIRV_H

clang/lib/Basic/Targets/SPIR.cpp

@@ -13,11 +13,24 @@
 #include "SPIR.h"
 #include "AMDGPU.h"
 #include "Targets.h"
+#include "clang/Basic/MacroBuilder.h"
+#include "clang/Basic/TargetBuiltins.h"
 #include "llvm/TargetParser/TargetParser.h"
 
 using namespace clang;
 using namespace clang::targets;
 
+static constexpr Builtin::Info BuiltinInfo[] = {
+#define BUILTIN(ID, TYPE, ATTRS)                                               \
+  {#ID, TYPE, ATTRS, nullptr, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
+#include "clang/Basic/BuiltinsSPIRV.inc"
+};
+
+ArrayRef<Builtin::Info> SPIRVTargetInfo::getTargetBuiltins() const {
+  return llvm::ArrayRef(BuiltinInfo,
+                        clang::SPIRV::LastTSBuiltin - Builtin::FirstTSBuiltin);
+}
+
 void SPIRTargetInfo::getTargetDefines(const LangOptions &Opts,
                                       MacroBuilder &Builder) const {
   DefineStd(Builder, "SPIR", Opts);

clang/lib/Basic/Targets/SPIR.h

@@ -313,7 +313,7 @@ class LLVM_LIBRARY_VISIBILITY SPIRVTargetInfo : public BaseSPIRVTargetInfo {
     resetDataLayout("e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-"
                     "v256:256-v512:512-v1024:1024-n8:16:32:64-G1");
   }
-
+  ArrayRef<Builtin::Info> getTargetBuiltins() const override;
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 };

clang/lib/CodeGen/CGBuiltin.cpp

@@ -6797,6 +6797,8 @@ static Value *EmitTargetArchBuiltinExpr(CodeGenFunction *CGF,
   case llvm::Triple::riscv32:
   case llvm::Triple::riscv64:
     return CGF->EmitRISCVBuiltinExpr(BuiltinID, E, ReturnValue);
+  case llvm::Triple::spirv:
+    return CGF->EmitSPIRVBuiltinExpr(BuiltinID, E);
   case llvm::Triple::spirv64:
     if (CGF->getTarget().getTriple().getOS() != llvm::Triple::OSType::AMDHSA)
       return nullptr;
@@ -20480,6 +20482,26 @@ Value *CodeGenFunction::EmitAMDGPUBuiltinExpr(unsigned BuiltinID,
   }
 }
 
+Value *CodeGenFunction::EmitSPIRVBuiltinExpr(unsigned BuiltinID,
+                                             const CallExpr *E) {
+  switch (BuiltinID) {
+  case SPIRV::BI__builtin_spirv_distance: {
+    Value *X = EmitScalarExpr(E->getArg(0));
+    Value *Y = EmitScalarExpr(E->getArg(1));
+    assert(E->getArg(0)->getType()->hasFloatingRepresentation() &&
+           E->getArg(1)->getType()->hasFloatingRepresentation() &&
+           "Distance operands must have a float representation");
+    assert(E->getArg(0)->getType()->isVectorType() &&
+           E->getArg(1)->getType()->isVectorType() &&
+           "Distance operands must be a vector");
+    return Builder.CreateIntrinsic(
+        /*ReturnType=*/X->getType()->getScalarType(), Intrinsic::spv_distance,
+        ArrayRef<Value *>{X, Y}, nullptr, "spv.distance");
+  }
+  }
+  return nullptr;
+}
+
 /// Handle a SystemZ function in which the final argument is a pointer
 /// to an int that receives the post-instruction CC value.  At the LLVM level
 /// this is represented as a function that returns a {result, cc} pair.

clang/lib/CodeGen/CodeGenFunction.h

@@ -4756,6 +4756,7 @@ class CodeGenFunction : public CodeGenTypeCache {
   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitHLSLBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
                                    ReturnValueSlot ReturnValue);
+  llvm::Value *EmitSPIRVBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitScalarOrConstFoldImmArg(unsigned ICEArguments, unsigned Idx,
                                            const CallExpr *E);
   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);