[HLSL] [DXIL] Implement the AddUint64 HLSL function and the UAddc DXIL op

clang/include/clang/Basic/Builtins.td

@@ -4753,6 +4753,12 @@ def GetDeviceSideMangledName : LangBuiltin<"CUDA_LANG"> {
 }
 
 // HLSL
+def HLSLAddUint64: LangBuiltin<"HLSL_LANG"> {
+  let Spellings = ["__builtin_hlsl_adduint64"];
+  let Attributes = [NoThrow, Const];
+  let Prototype = "void(...)";
+}
+
 def HLSLResourceGetPointer : LangBuiltin<"HLSL_LANG"> {
   let Spellings = ["__builtin_hlsl_resource_getpointer"];
   let Attributes = [NoThrow];

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -10624,6 +10624,8 @@ def err_second_argument_to_cwsc_not_pointer : Error<
 
 def err_vector_incorrect_num_elements : Error<
   "%select{too many|too few}0 elements in vector %select{initialization|operand}3 (expected %1 elements, have %2)">;
+def err_invalid_even_odd_vector_element_count : Error<
+  "invalid element count of %0 in vector %select{initialization|operand}4 (expected an %select{even|odd}3 element count in the range of %1 and %2)">;
 def err_altivec_empty_initializer : Error<"expected initializer">;
 
 def err_invalid_neon_type_code : Error<

clang/lib/CodeGen/CGBuiltin.cpp

@@ -19105,6 +19105,51 @@ Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
     return nullptr;
 
   switch (BuiltinID) {
+  case Builtin::BI__builtin_hlsl_adduint64: {
+    Value *OpA = EmitScalarExpr(E->getArg(0));
+    Value *OpB = EmitScalarExpr(E->getArg(1));
+    assert(E->getArg(0)->getType()->hasIntegerRepresentation() &&
+           E->getArg(1)->getType()->hasIntegerRepresentation() &&
+           "AddUint64 operands must have an integer representation");
+    assert(((E->getArg(0)->getType()->castAs<VectorType>()->getNumElements() ==
+                 2 &&
+             E->getArg(1)->getType()->castAs<VectorType>()->getNumElements() ==
+                 2) ||
+            (E->getArg(0)->getType()->castAs<VectorType>()->getNumElements() ==
+                 4 &&
+             E->getArg(1)->getType()->castAs<VectorType>()->getNumElements() ==
+                 4)) &&
+           "input vectors must have 2 or 4 elements each");
+
+    llvm::Value *Result = PoisonValue::get(OpA->getType());
+    uint64_t NumElements =
+        E->getArg(0)->getType()->castAs<VectorType>()->getNumElements();
+    for (uint64_t i = 0; i < NumElements / 2; ++i) {
+
+      // Obtain low and high words of inputs A and B
+      llvm::Value *LowA = Builder.CreateExtractElement(OpA, 2 * i + 0);
+      llvm::Value *HighA = Builder.CreateExtractElement(OpA, 2 * i + 1);
+      llvm::Value *LowB = Builder.CreateExtractElement(OpB, 2 * i + 0);
+      llvm::Value *HighB = Builder.CreateExtractElement(OpB, 2 * i + 1);
+
+      // Use an uadd_with_overflow to compute the sum of low words and obtain a
+      // carry value
+      llvm::Value *Carry;
+      llvm::Value *LowSum = EmitOverflowIntrinsic(
+          *this, llvm::Intrinsic::uadd_with_overflow, LowA, LowB, Carry);
+      llvm::Value *ZExtCarry = Builder.CreateZExt(Carry, HighA->getType());
+
+      // Sum the high words and the carry
+      llvm::Value *HighSum = Builder.CreateAdd(HighA, HighB);
+      llvm::Value *HighSumPlusCarry = Builder.CreateAdd(HighSum, ZExtCarry);
+
+      // Insert the low and high word sums into the result vector
+      Result = Builder.CreateInsertElement(Result, LowSum, 2 * i + 0);
+      Result = Builder.CreateInsertElement(Result, HighSumPlusCarry, 2 * i + 1,
+                                           "hlsl.AddUint64");
+    }
+    return Result;
+  }
   case Builtin::BI__builtin_hlsl_resource_getpointer: {
     Value *HandleOp = EmitScalarExpr(E->getArg(0));
     Value *IndexOp = EmitScalarExpr(E->getArg(1));

clang/lib/Headers/hlsl/hlsl_intrinsics.h

@@ -138,6 +138,27 @@ _HLSL_BUILTIN_ALIAS(__builtin_elementwise_acos)
 float4 acos(float4);
 
 //===----------------------------------------------------------------------===//
+// AddUint64 builtins
+//===----------------------------------------------------------------------===//
+
+/// \fn T AddUint64(T a, T b)
+/// \brief Implements unsigned 64-bit integer addition using pairs of unsigned
+/// 32-bit integers.
+/// \param x [in] The first unsigned 32-bit integer pair(s)
+/// \param y [in] The second unsigned 32-bit integer pair(s)
+///
+/// This function takes one or two pairs (low, high) of unsigned 32-bit integer
+/// values and returns pairs (low, high) of unsigned 32-bit integer
+/// values representing the result of unsigned 64-bit integer addition.
+
+_HLSL_AVAILABILITY(shadermodel, 6.0)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_adduint64)
+uint32_t2 AddUint64(uint32_t2, uint32_t2);
+_HLSL_AVAILABILITY(shadermodel, 6.0)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_adduint64)
+uint32_t4 AddUint64(uint32_t4, uint32_t4);
+
+// //===----------------------------------------------------------------------===//
 // all builtins
 //===----------------------------------------------------------------------===//
 

clang/lib/Sema/SemaHLSL.cpp

@@ -2023,6 +2023,18 @@ static bool CheckAllArgsHaveFloatRepresentation(Sema *S, CallExpr *TheCall) {
                                     checkAllFloatTypes);
 }
 
+static bool CheckUnsignedIntRepresentations(Sema *S, CallExpr *TheCall) {
+  auto checkUnsignedInteger = [](clang::QualType PassedType) -> bool {
+    clang::QualType BaseType =
+        PassedType->isVectorType()
+            ? PassedType->getAs<clang::VectorType>()->getElementType()
+            : PassedType;
+    return !BaseType->isUnsignedIntegerType();
+  };
+  return CheckAllArgTypesAreCorrect(S, TheCall, S->Context.UnsignedIntTy,
+                                    checkUnsignedInteger);
+}
+
 static bool CheckFloatOrHalfRepresentations(Sema *S, CallExpr *TheCall) {
   auto checkFloatorHalf = [](clang::QualType PassedType) -> bool {
     clang::QualType BaseType =
@@ -2214,6 +2226,41 @@ static bool CheckResourceHandle(
 // returning an ExprError
 bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   switch (BuiltinID) {
+  case Builtin::BI__builtin_hlsl_adduint64: {
+    if (SemaRef.checkArgCount(TheCall, 2))
+      return true;
+    if (CheckVectorElementCallArgs(&SemaRef, TheCall))
+      return true;
+    if (CheckUnsignedIntRepresentations(&SemaRef, TheCall))
+      return true;
+
+    // CheckVectorElementCallArgs(...) guarantees both args are the same type.
+    assert(TheCall->getArg(0)->getType() == TheCall->getArg(1)->getType() &&
+           "Both args must be of the same type");
+
+    // ensure both args are vectors
+    auto *VTy = TheCall->getArg(0)->getType()->getAs<VectorType>();
+    if (!VTy) {
+      SemaRef.Diag(TheCall->getBeginLoc(), diag::err_vec_builtin_non_vector)
+          << "AddUint64" << /*all*/ 1;
+      return true;
+    }
+
+    // ensure both args have 2 elements, or both args have 4 elements
+    int NumElementsArg = VTy->getNumElements();
+    if (NumElementsArg != 2 && NumElementsArg != 4) {
+      SemaRef.Diag(TheCall->getBeginLoc(),
+                   diag::err_invalid_even_odd_vector_element_count)
+          << NumElementsArg << 2 << 4 << /*even*/ 0 << /*operand*/ 1;
+      return true;
+    }
+
+    ExprResult A = TheCall->getArg(0);
+    QualType ArgTyA = A.get()->getType();
+    // return type is the same as the input type
+    TheCall->setType(ArgTyA);
+    break;
+  }
   case Builtin::BI__builtin_hlsl_resource_getpointer: {
     if (SemaRef.checkArgCount(TheCall, 2) ||
         CheckResourceHandle(&SemaRef, TheCall, 0) ||

clang/test/CodeGenHLSL/builtins/AddUint64.hlsl

@@ -0,0 +1,71 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.3-library %s \
+// RUN:  -emit-llvm -disable-llvm-passes -o - | \
+// RUN:  FileCheck %s --check-prefixes=CHECK
+
+
+// CHECK-LABEL: define noundef <2 x i32> @_Z20test_AddUint64_uint2Dv2_jS_(
+// CHECK-SAME: <2 x i32> noundef [[A:%.*]], <2 x i32> noundef [[B:%.*]]) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[A_ADDR:%.*]] = alloca <2 x i32>, align 8
+// CHECK-NEXT:    [[B_ADDR:%.*]] = alloca <2 x i32>, align 8
+// CHECK-NEXT:    store <2 x i32> [[A]], ptr [[A_ADDR]], align 8
+// CHECK-NEXT:    store <2 x i32> [[B]], ptr [[B_ADDR]], align 8
+// CHECK-NEXT:    [[A_LOAD:%.*]] = load <2 x i32>, ptr [[A_ADDR]], align 8
+// CHECK-NEXT:    [[B_LOAD:%.*]] = load <2 x i32>, ptr [[B_ADDR]], align 8
+// CHECK-NEXT:    [[LowA:%.*]] = extractelement <2 x i32> [[A_LOAD]], i64 0
+// CHECK-NEXT:    [[HighA:%.*]] = extractelement <2 x i32> [[A_LOAD]], i64 1
+// CHECK-NEXT:    [[LowB:%.*]] = extractelement <2 x i32> [[B_LOAD]], i64 0
+// CHECK-NEXT:    [[HighB:%.*]] = extractelement <2 x i32> [[B_LOAD]], i64 1
+// CHECK-NEXT:    [[UAddc:%.*]] = call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[LowA]], i32 [[LowB]])
+// CHECK-NEXT:    [[Carry:%.*]] = extractvalue { i32, i1 } [[UAddc]], 1
+// CHECK-NEXT:    [[LowSum:%.*]] = extractvalue { i32, i1 } [[UAddc]], 0
+// CHECK-NEXT:    [[CarryZExt:%.*]] = zext i1 [[Carry]] to i32
+// CHECK-NEXT:    [[HighSum:%.*]] = add i32 [[HighA]], [[HighB]]
+// CHECK-NEXT:    [[HighSumPlusCarry:%.*]] = add i32 [[HighSum]], [[CarryZExt]]
+// CHECK-NEXT:    [[HLSL_ADDUINT64_UPTO0:%.*]] = insertelement <2 x i32> poison, i32 [[LowSum]], i64 0
+// CHECK-NEXT:    [[HLSL_ADDUINT64:%.*]] = insertelement <2 x i32> [[HLSL_ADDUINT64_UPTO0]], i32 [[HighSumPlusCarry]], i64 1
+// CHECK-NEXT:    ret <2 x i32> [[HLSL_ADDUINT64]]
+//
+uint2 test_AddUint64_uint2(uint2 a, uint2 b) {
+  return AddUint64(a, b);
+}
+
+// CHECK-LABEL: define noundef <4 x i32> @_Z20test_AddUint64_uint4Dv4_jS_(
+// CHECK-SAME: <4 x i32> noundef [[A:%.*]], <4 x i32> noundef [[B:%.*]]) #[[ATTR0]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[A_ADDR:%.*]] = alloca <4 x i32>, align 16
+// CHECK-NEXT:    [[B_ADDR:%.*]] = alloca <4 x i32>, align 16
+// CHECK-NEXT:    store <4 x i32> [[A]], ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    store <4 x i32> [[B]], ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[A_LOAD:%.*]] = load <4 x i32>, ptr [[A_ADDR]], align 16
+// CHECK-NEXT:    [[B_LOAD:%.*]] = load <4 x i32>, ptr [[B_ADDR]], align 16
+// CHECK-NEXT:    [[LowA:%.*]] = extractelement <4 x i32> [[A_LOAD]], i64 0
+// CHECK-NEXT:    [[HighA:%.*]] = extractelement <4 x i32> [[A_LOAD]], i64 1
+// CHECK-NEXT:    [[LowB:%.*]] = extractelement <4 x i32> [[B_LOAD]], i64 0
+// CHECK-NEXT:    [[HighB:%.*]] = extractelement <4 x i32> [[B_LOAD]], i64 1
+// CHECK-NEXT:    [[UAddc:%.*]] = call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[LowA]], i32 [[LowB]])
+// CHECK-NEXT:    [[Carry:%.*]] = extractvalue { i32, i1 } [[UAddc]], 1
+// CHECK-NEXT:    [[LowSum:%.*]] = extractvalue { i32, i1 } [[UAddc]], 0
+// CHECK-NEXT:    [[CarryZExt:%.*]] = zext i1 [[Carry]] to i32
+// CHECK-NEXT:    [[HighSum:%.*]] = add i32 [[HighA]], [[HighB]]
+// CHECK-NEXT:    [[HighSumPlusCarry:%.*]] = add i32 [[HighSum]], [[CarryZExt]]
+// CHECK-NEXT:    [[HLSL_ADDUINT64_UPTO0:%.*]] = insertelement <4 x i32> poison, i32 [[LowSum]], i64 0
+// CHECK-NEXT:    [[HLSL_ADDUINT64_UPTO1:%.*]] = insertelement <4 x i32> [[HLSL_ADDUINT64_UPTO0]], i32 [[HighSumPlusCarry]], i64 1
+// CHECK-NEXT:    [[LowA1:%.*]] = extractelement <4 x i32> [[A_LOAD]], i64 2
+// CHECK-NEXT:    [[HighA1:%.*]] = extractelement <4 x i32> [[A_LOAD]], i64 3
+// CHECK-NEXT:    [[LowB1:%.*]] = extractelement <4 x i32> [[B_LOAD]], i64 2
+// CHECK-NEXT:    [[HighB1:%.*]] = extractelement <4 x i32> [[B_LOAD]], i64 3
+// CHECK-NEXT:    [[UAddc1:%.*]] = call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[LowA1]], i32 [[LowB1]])
+// CHECK-NEXT:    [[Carry1:%.*]] = extractvalue { i32, i1 } [[UAddc1]], 1
+// CHECK-NEXT:    [[LowSum1:%.*]] = extractvalue { i32, i1 } [[UAddc1]], 0
+// CHECK-NEXT:    [[CarryZExt1:%.*]] = zext i1 [[Carry1]] to i32
+// CHECK-NEXT:    [[HighSum1:%.*]] = add i32 [[HighA1]], [[HighB1]]
+// CHECK-NEXT:    [[HighSumPlusCarry1:%.*]] = add i32 [[HighSum1]], [[CarryZExt1]]
+// CHECK-NEXT:    [[HLSL_ADDUINT64_UPTO2:%.*]] = insertelement <4 x i32> [[HLSL_ADDUINT64_UPTO1]], i32 [[LowSum1]], i64 2
+// CHECK-NEXT:    [[HLSL_ADDUINT64:%.*]] = insertelement <4 x i32> [[HLSL_ADDUINT64_UPTO2]], i32 [[HighSumPlusCarry1]], i64 3
+// CHECK-NEXT:    ret <4 x i32> [[HLSL_ADDUINT64]]
+//
+uint4 test_AddUint64_uint4(uint4 a, uint4 b) {
+  return AddUint64(a, b);
+}

clang/test/SemaHLSL/BuiltIns/AddUint64-errors.hlsl

@@ -0,0 +1,41 @@
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm-only -disable-llvm-passes -verify
+
+uint2 test_too_few_arg() {
+  return __builtin_hlsl_adduint64();
+  // expected-error@-1 {{too few arguments to function call, expected 2, have 0}}
+}
+
+uint4 test_too_many_arg(uint4 a) {
+  return __builtin_hlsl_adduint64(a, a, a);
+  // expected-error@-1 {{too many arguments to function call, expected 2, have 3}}
+}
+
+uint2 test_mismatched_arg_types(uint2 a, uint4 b) {
+  return __builtin_hlsl_adduint64(a, b);
+  // expected-error@-1 {{all arguments to '__builtin_hlsl_adduint64' must have the same type}}
+}
+
+uint2 test_bad_num_arg_elements(uint3 a, uint3 b) {
+  return __builtin_hlsl_adduint64(a, b);
+  // expected-error@-1 {{invalid element count of 3 in vector operand (expected an even element count in the range of 2 and 4)}}
+}
+
+uint2 test_scalar_arg_type(uint a) {
+  return __builtin_hlsl_adduint64(a, a);
+  // expected-error@-1 {{all arguments to AddUint64 must be vectors}}
+}
+
+uint2 test_signed_integer_args(int2 a, int2 b) {
+  return __builtin_hlsl_adduint64(a, b);
+// expected-error@-1 {{passing 'int2' (aka 'vector<int, 2>') to parameter of incompatible type '__attribute__((__vector_size__(2 * sizeof(unsigned int)))) unsigned int' (vector of 2 'unsigned int' values)}}
+}
+
+struct S {
+  uint2 a;
+};
+
+uint2 test_incorrect_arg_type(S a) {
+  return __builtin_hlsl_adduint64(a, a);
+  // expected-error@-1 {{passing 'S' to parameter of incompatible type 'unsigned int'}}
+}
+

llvm/lib/Target/DirectX/DXIL.td

@@ -50,6 +50,7 @@ def HandleTy : DXILOpParamType;
 def ResBindTy : DXILOpParamType;
 def ResPropsTy : DXILOpParamType;
 def SplitDoubleTy : DXILOpParamType;
+def BinaryWithCarryTy : DXILOpParamType;
 
 class DXILOpClass;
 
@@ -738,6 +739,18 @@ def UMin : DXILOp<40, binary> {
   let attributes = [Attributes<DXIL1_0, [ReadNone]>];
 }
 
+def UAddc : DXILOp<44, binaryWithCarryOrBorrow > {
+  let Doc = "Unsigned 32-bit integer arithmetic add with carry. uaddc(a,b) = (a+b, a+b overflowed ? 1 : 0)";
+  // TODO: This `let intrinsics = ...` line may be uncommented when 
+  // https://github.com/llvm/llvm-project/issues/113192 is fixed
+  // let intrinsics = [IntrinSelect<int_uadd_with_overflow>];
+  let arguments = [OverloadTy, OverloadTy];
+  let result = BinaryWithCarryTy;
+  let overloads = [Overloads<DXIL1_0, [Int32Ty]>];
+  let stages = [Stages<DXIL1_0, [all_stages]>];
+  let attributes = [Attributes<DXIL1_0, [ReadNone]>];
+}
+
 def FMad : DXILOp<46, tertiary> {
   let Doc = "Floating point arithmetic multiply/add operation. fmad(m,a,b) = m "
             "* a + b.";

llvm/lib/Target/DirectX/DXILOpBuilder.cpp

@@ -230,6 +230,14 @@ static StructType *getSplitDoubleType(LLVMContext &Context) {
   return StructType::create({Int32Ty, Int32Ty}, "dx.types.splitdouble");
 }
 
+static StructType *getBinaryWithCarryType(LLVMContext &Context) {
+  if (auto *ST = StructType::getTypeByName(Context, "dx.types.i32c"))
+    return ST;
+  Type *Int32Ty = Type::getInt32Ty(Context);
+  Type *Int1Ty = Type::getInt1Ty(Context);
+  return StructType::create({Int32Ty, Int1Ty}, "dx.types.i32c");
+}
+
 static Type *getTypeFromOpParamType(OpParamType Kind, LLVMContext &Ctx,
                                     Type *OverloadTy) {
   switch (Kind) {
@@ -273,6 +281,8 @@ static Type *getTypeFromOpParamType(OpParamType Kind, LLVMContext &Ctx,
     return getResPropsType(Ctx);
   case OpParamType::SplitDoubleTy:
     return getSplitDoubleType(Ctx);
+  case OpParamType::BinaryWithCarryTy:
+    return getBinaryWithCarryType(Ctx);
   }
   llvm_unreachable("Invalid parameter kind");
   return nullptr;
@@ -539,6 +549,10 @@ StructType *DXILOpBuilder::getSplitDoubleType(LLVMContext &Context) {
   return ::getSplitDoubleType(Context);
 }
 
+StructType *DXILOpBuilder::getBinaryWithCarryType(LLVMContext &Context) {
+  return ::getBinaryWithCarryType(Context);
+}
+
 StructType *DXILOpBuilder::getHandleType() {
   return ::getHandleType(IRB.getContext());
 }

llvm/lib/Target/DirectX/DXILOpBuilder.h

@@ -53,6 +53,9 @@ class DXILOpBuilder {
   /// Get the `%dx.types.splitdouble` type.
   StructType *getSplitDoubleType(LLVMContext &Context);
 
+  /// Get the `%dx.types.i32c` type.
+  StructType *getBinaryWithCarryType(LLVMContext &Context);
+
   /// Get the `%dx.types.Handle` type.
   StructType *getHandleType();
 

llvm/lib/Target/DirectX/DXILOpLowering.cpp

@@ -359,17 +359,16 @@ class OpLowerer {
     return lowerToBindAndAnnotateHandle(F);
   }
 
-  Error replaceSplitDoubleCallUsages(CallInst *Intrin, CallInst *Op) {
+  Error replaceAggregateTypeOfCallUsages(CallInst *Intrin, CallInst *Op) {
     for (Use &U : make_early_inc_range(Intrin->uses())) {
       if (auto *EVI = dyn_cast<ExtractValueInst>(U.getUser())) {
-
-        if (EVI->getNumIndices() != 1)
-          return createStringError(std::errc::invalid_argument,
-                                   "Splitdouble has only 2 elements");
         EVI->setOperand(0, Op);
+      } else if (auto *IVI = dyn_cast<InsertValueInst>(U.getUser())) {
+        IVI->setOperand(0, Op);
       } else {
         return make_error<StringError>(
-            "Splitdouble use is not ExtractValueInst",
+            (Intrin->getCalledFunction()->getName() +
+             " use is not a ExtractValueInst or InsertValueInst"),
             inconvertibleErrorCode());
       }
     }
@@ -821,7 +820,16 @@ class OpLowerer {
             F, OpCode::SplitDouble,
             OpBuilder.getSplitDoubleType(M.getContext()),
             [&](CallInst *CI, CallInst *Op) {
-              return replaceSplitDoubleCallUsages(CI, Op);
+              return replaceAggregateTypeOfCallUsages(CI, Op);
+            });
+        break;
+      // TODO: this can be removed when
+      // https://github.com/llvm/llvm-project/issues/113192 is fixed
+      case Intrinsic::uadd_with_overflow:
+        HasErrors |= replaceFunctionWithNamedStructOp(
+            F, OpCode::UAddc, OpBuilder.getBinaryWithCarryType(M.getContext()),
+            [&](CallInst *CI, CallInst *Op) {
+              return replaceAggregateTypeOfCallUsages(CI, Op);
             });
         break;
       case Intrinsic::ctpop: