changing implementation of asuint to use bit_cast

Author: joaosaffran-zz

clang/include/clang/Basic/Builtins.td

@@ -4763,12 +4763,6 @@ def HLSLSaturate : LangBuiltin<"HLSL_LANG"> {
   let Prototype = "void(...)";
 }
 
-def HLSLBitCast32 : LangBuiltin<"HLSL_LANG"> {
-  let Spellings = ["__builtin_hlsl_bit_cast_32"];
-  let Attributes = [NoThrow, Const];
-  let Prototype = "void(...)";
-}
-
 def HLSLSelect : LangBuiltin<"HLSL_LANG"> {
   let Spellings = ["__builtin_hlsl_select"];
   let Attributes = [NoThrow, Const];

clang/lib/CodeGen/CGBuiltin.cpp

@@ -18870,25 +18870,6 @@ case Builtin::BI__builtin_hlsl_elementwise_isinf: {
     Intrinsic::ID ID = CGM.getHLSLRuntime().getWaveIsFirstLaneIntrinsic();
     return EmitRuntimeCall(Intrinsic::getDeclaration(&CGM.getModule(), ID));
   }
-  case Builtin::BI__builtin_hlsl_bit_cast_32: {
-    Value *Op = EmitScalarExpr(E->getArg(0));
-
-    llvm::Type *DestTy = ConvertType(E->getCallReturnType(getContext()));
-
-    if (DestTy->isVectorTy()) {
-      const VectorType *VecTy =
-          E->getCallReturnType(getContext())->getAs<VectorType>();
-      DestTy = ConvertType(VecTy->getElementType());
-    }
-
-    if (Op->getType()->isVectorTy()) {
-      const VectorType *VecTy = E->getArg(0)->getType()->getAs<VectorType>();
-      DestTy = llvm::VectorType::get(
-          DestTy, ElementCount::getFixed(VecTy->getNumElements()));
-    }
-
-    return Builder.CreateBitCast(Op, DestTy);
-  }
   case Builtin::BI__builtin_hlsl_elementwise_sign: {
     Value *Op0 = EmitScalarExpr(E->getArg(0));
     llvm::Type *Xty = Op0->getType();

clang/lib/Headers/CMakeLists.txt

@@ -87,6 +87,7 @@ set(hlsl_h
 set(hlsl_subdir_files
   hlsl/hlsl_basic_types.h
   hlsl/hlsl_intrinsics.h
+  hlsl/hlsl_details.h
   )
 set(hlsl_files
   ${hlsl_h}

clang/lib/Headers/hlsl/hlsl_details.h

@@ -0,0 +1,42 @@
+//===----- hlsl_intrinsics.h - HLSL definitions for intrinsics ----------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+
+#ifndef _HLSL_HLSL_DETAILS_H_
+#define _HLSL_HLSL_DETAILS_H_
+
+namespace __details {
+#define HLSL_BUILTIN_ATTRIBUTES\
+  __attribute__((__always_inline__, __nodebug__)) static inline
+
+template<bool B, typename T>
+struct enable_if { };
+
+template<typename T>
+struct enable_if<true, T> {
+  using Type = T;
+};
+
+template<bool B, typename T=void>
+using enable_if_t = typename enable_if<B,T>::Type;
+
+template<typename U, typename T, int N>
+HLSL_BUILTIN_ATTRIBUTES vector<U, N> bit_cast(vector<T, N> V) {
+  _Static_assert(sizeof(U) == sizeof(T), "casting types must be same bit size.");
+  return __builtin_bit_cast(vector<U, N>, V);
+}
+
+template<typename U, typename T>
+HLSL_BUILTIN_ATTRIBUTES U bit_cast(T F) {
+  _Static_assert(sizeof(U) == sizeof(T), "casting types must be same bit size.");
+  return __builtin_bit_cast(U, F);
+}
+
+} // namespace hlsl
+
+#endif //_HLSL_HLSL_DETAILS_H_

clang/lib/Headers/hlsl/hlsl_intrinsics.h

@@ -10,6 +10,7 @@
 #define _HLSL_HLSL_INTRINSICS_H_
 
 namespace hlsl {
+#include "hlsl_details.h"
 
 // Note: Functions in this file are sorted alphabetically, then grouped by base
 // element type, and the element types are sorted by size, then singed integer,
@@ -395,32 +396,16 @@ float4 asin(float4);
 /// \brief Interprets the bit pattern of x as an unsigned integer.
 /// \param Val The input value.
 
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint asuint(int);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint2 asuint(int2);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint3 asuint(int3);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint4 asuint(int4);
-
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint asuint(uint);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint2 asuint(uint2);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint3 asuint(uint3);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint4 asuint(uint4);
-
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint asuint(float);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint2 asuint(float2);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint3 asuint(float3);
-_HLSL_BUILTIN_ALIAS(__builtin_hlsl_bit_cast_32)
-uint4 asuint(float4);
+template <typename T, int N>
+HLSL_BUILTIN_ATTRIBUTES vector<uint, N>
+asuint(vector<T, N> V) {
+   return __details::bit_cast<uint, T, N>(V);
+}
+
+template <typename T>
+HLSL_BUILTIN_ATTRIBUTES uint asuint(T F) {
+  return __details::bit_cast<uint, T>(F);
+}
 
 //===----------------------------------------------------------------------===//
 // atan builtins

clang/lib/Sema/SemaHLSL.cpp

@@ -1497,18 +1497,6 @@ bool CheckAllArgsHaveFloatRepresentation(Sema *S, CallExpr *TheCall) {
                                   checkAllFloatTypes);
 }
 
-bool CheckNotFloatAndInt(Sema *S, CallExpr *TheCall) {
-  auto checkFloat = [](clang::QualType PassedType) -> bool {
-    clang::QualType BaseType =
-        PassedType->isVectorType()
-            ? PassedType->getAs<clang::VectorType>()->getElementType()
-            : PassedType;
-    return !(BaseType->isFloat32Type() || BaseType->isIntegerType());
-  };
-
-  return CheckArgsTypesAreCorrect(S, TheCall, S->Context.FloatTy, checkFloat);
-}
-
 bool CheckFloatOrHalfRepresentations(Sema *S, CallExpr *TheCall) {
   auto checkFloatorHalf = [](clang::QualType PassedType) -> bool {
     clang::QualType BaseType =
@@ -1766,14 +1754,6 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
       return true;
     break;
   }
-  case Builtin::BI__builtin_hlsl_bit_cast_32: {
-    if (SemaRef.checkArgCount(TheCall, 1))
-      return true;
-
-    if (CheckNotFloatAndInt(&SemaRef, TheCall))
-      return true;
-    break;
-  }
   case Builtin::BI__builtin_elementwise_acos:
   case Builtin::BI__builtin_elementwise_asin:
   case Builtin::BI__builtin_elementwise_atan:

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

@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm-only -disable-llvm-passes -verify -verify-ignore-unexpected
+
+
+uint4 test_asuint_too_many_arg(float p0, float p1) {
+  return asuint(p0, p1);
+  // expected-error@-1 {{no matching function for call to 'asuint'}}
+}
+
+uint test_asuint_double(double p1) {
+    return asuint(p1);
+    // expected-error@-1{clang/20/include/hlsl/hlsl_details.h} {{static assertion failed due to requirement 'sizeof(unsigned int) == sizeof(double)'}}
+}
+
+
+uint test_asuint_half(half p1) {
+    return asuint(p1);
+    // expected-error@-1{clang/20/include/hlsl/hlsl_details.h} {{static assertion failed due to requirement 'sizeof(unsigned int) == sizeof(half)'}}
+}