llvm · arsenm · Jan 5, 2026
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
@@ -1013,14 +1013,6 @@ class TargetInfo : public TransferrableTargetInfo,
     return ComplexLongDoubleUsesFP2Ret;
   }
 
-  /// Check whether llvm intrinsics such as llvm.convert.to.fp16 should be used
-  /// to convert to and from __fp16.
-  /// FIXME: This function should be removed once all targets stop using the
-  /// conversion intrinsics.
-  virtual bool useFP16ConversionIntrinsics() const {
-    return true;
-  }
-
   /// Specify if mangling based on address space map should be used or
   /// not for language specific address spaces
   bool useAddressSpaceMapMangling() const {

diff --git a/clang/lib/Basic/Targets/AArch64.h b/clang/lib/Basic/Targets/AArch64.h
@@ -154,10 +154,6 @@ class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public TargetInfo {
 
   llvm::APInt getFMVPriority(ArrayRef<StringRef> Features) const override;
 
-  bool useFP16ConversionIntrinsics() const override {
-    return false;
-  }
-
   void getTargetDefinesARMV81A(const LangOptions &Opts,
                                MacroBuilder &Builder) const;
   void getTargetDefinesARMV82A(const LangOptions &Opts,

diff --git a/clang/lib/Basic/Targets/AMDGPU.h b/clang/lib/Basic/Targets/AMDGPU.h
@@ -268,8 +268,6 @@ class LLVM_LIBRARY_VISIBILITY AMDGPUTargetInfo final : public TargetInfo {
 
   llvm::SmallVector<Builtin::InfosShard> getTargetBuiltins() const override;
 
-  bool useFP16ConversionIntrinsics() const override { return false; }
-
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 

diff --git a/clang/lib/Basic/Targets/ARM.h b/clang/lib/Basic/Targets/ARM.h
@@ -177,10 +177,6 @@ class LLVM_LIBRARY_VISIBILITY ARMTargetInfo : public TargetInfo {
 
   bool setFPMath(StringRef Name) override;
 
-  bool useFP16ConversionIntrinsics() const override {
-    return false;
-  }
-
   void getTargetDefinesARMV81A(const LangOptions &Opts,
                                MacroBuilder &Builder) const;
   void getTargetDefinesARMV82A(const LangOptions &Opts,

diff --git a/clang/lib/Basic/Targets/DirectX.h b/clang/lib/Basic/Targets/DirectX.h
@@ -68,7 +68,6 @@ class LLVM_LIBRARY_VISIBILITY DirectXTargetInfo : public TargetInfo {
     resetDataLayout();
     TheCXXABI.set(TargetCXXABI::GenericItanium);
   }
-  bool useFP16ConversionIntrinsics() const override { return false; }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 

diff --git a/clang/lib/Basic/Targets/LoongArch.h b/clang/lib/Basic/Targets/LoongArch.h
@@ -105,8 +105,6 @@ class LLVM_LIBRARY_VISIBILITY LoongArchTargetInfo : public TargetInfo {
 
   bool hasBFloat16Type() const override { return true; }
 
-  bool useFP16ConversionIntrinsics() const override { return false; }
-
   bool handleTargetFeatures(std::vector<std::string> &Features,
                             DiagnosticsEngine &Diags) override;
 

diff --git a/clang/lib/Basic/Targets/NVPTX.h b/clang/lib/Basic/Targets/NVPTX.h
@@ -81,8 +81,6 @@ class LLVM_LIBRARY_VISIBILITY NVPTXTargetInfo : public TargetInfo {
 
   llvm::SmallVector<Builtin::InfosShard> getTargetBuiltins() const override;
 
-  bool useFP16ConversionIntrinsics() const override { return false; }
-
   bool
   initFeatureMap(llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags,
                  StringRef CPU,

diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
@@ -113,10 +113,6 @@ class RISCVTargetInfo : public TargetInfo {
 
   CallingConvCheckResult checkCallingConvention(CallingConv CC) const override;
 
-  bool useFP16ConversionIntrinsics() const override {
-    return false;
-  }
-
   bool isValidCPUName(StringRef Name) const override;
   void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;
   bool isValidTuneCPUName(StringRef Name) const override;

diff --git a/clang/lib/Basic/Targets/SPIR.h b/clang/lib/Basic/Targets/SPIR.h
@@ -168,10 +168,6 @@ class LLVM_LIBRARY_VISIBILITY BaseSPIRTargetInfo : public TargetInfo {
   }
 
 public:
-  // SPIR supports the half type and the only llvm intrinsic allowed in SPIR is
-  // memcpy as per section 3 of the SPIR spec.
-  bool useFP16ConversionIntrinsics() const override { return false; }
-
   llvm::SmallVector<Builtin::InfosShard> getTargetBuiltins() const override {
     return {};
   }

diff --git a/clang/lib/Basic/Targets/SystemZ.h b/clang/lib/Basic/Targets/SystemZ.h
@@ -106,8 +106,6 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public TargetInfo {
 
   unsigned getMinGlobalAlign(uint64_t Size, bool HasNonWeakDef) const override;
 
-  bool useFP16ConversionIntrinsics() const override { return false; }
-
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 

diff --git a/clang/lib/Basic/Targets/WebAssembly.h b/clang/lib/Basic/Targets/WebAssembly.h
@@ -110,7 +110,6 @@ class LLVM_LIBRARY_VISIBILITY WebAssemblyTargetInfo : public TargetInfo {
 
   StringRef getABI() const override;
   bool setABI(const std::string &Name) override;
-  bool useFP16ConversionIntrinsics() const override { return !HasFP16; }
 
 protected:
   void getTargetDefines(const LangOptions &Opts,

diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
@@ -325,10 +325,6 @@ class LLVM_LIBRARY_VISIBILITY X86TargetInfo : public TargetInfo {
     return "";
   }
 
-  bool useFP16ConversionIntrinsics() const override {
-    return false;
-  }
-
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 

@@ -1793,18 +1793,10 @@ mlir::Attribute ConstantEmitter::tryEmitPrivate(const APValue &value,
     return cir::IntAttr::get(ty, value.getInt());
   }
   case APValue::Float: {
-    const llvm::APFloat &init = value.getFloat();
-    if (&init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
-        !cgm.getASTContext().getLangOpts().NativeHalfType &&
-        cgm.getASTContext().getTargetInfo().useFP16ConversionIntrinsics()) {
-      cgm.errorNYI("ConstExprEmitter::tryEmitPrivate half");
-      return {};
-    }
-
     mlir::Type ty = cgm.convertType(destType);
     assert(mlir::isa<cir::FPTypeInterface>(ty) &&
            "expected floating-point type");
-    return cir::FPAttr::get(ty, init);
+    return cir::FPAttr::get(ty, value.getFloat());
   }
   case APValue::Array: {
     const ArrayType *arrayTy = cgm.getASTContext().getAsArrayType(destType);

@@ -924,19 +924,12 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
     if (srcType->isHalfType() &&
         !cgf.getContext().getLangOpts().NativeHalfType) {
       // Cast to FP using the intrinsic if the half type itself isn't supported.
-      if (mlir::isa<cir::FPTypeInterface>(mlirDstType)) {
-        if (cgf.getContext().getTargetInfo().useFP16ConversionIntrinsics())
-          cgf.getCIRGenModule().errorNYI(loc,
-                                         "cast via llvm.convert.from.fp16");
-      } else {
-        // Cast to other types through float, using either the intrinsic or
-        // FPExt, depending on whether the half type itself is supported (as
-        // opposed to operations on half, available with NativeHalfType).
-        if (cgf.getContext().getTargetInfo().useFP16ConversionIntrinsics())
-          cgf.getCIRGenModule().errorNYI(loc,
-                                         "cast via llvm.convert.from.fp16");
-        // FIXME(cir): For now lets pretend we shouldn't use the conversion
-        // intrinsics and insert a cast here unconditionally.
+      if (!mlir::isa<cir::FPTypeInterface>(mlirDstType)) {
+        // Cast to other types through float, using FPExt, depending on whether
+        // the half type itself is supported (as opposed to operations on half,
+        // available with NativeHalfType).  FIXME(cir): For now lets pretend we
+        // shouldn't use the conversion intrinsics and insert a cast here
+        // unconditionally.
         src = builder.createCast(cgf.getLoc(loc), cir::CastKind::floating, src,
                                  cgf.floatTy);
         srcType = cgf.getContext().FloatTy;
@@ -994,11 +987,6 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
     res = emitScalarCast(src, srcType, dstType, mlirSrcType, mlirDstType, opts);
 
     if (mlirDstType != resTy) {
-      if (cgf.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
-        cgf.getCIRGenModule().errorNYI(loc, "cast via llvm.convert.to.fp16");
-      }
-      // FIXME(cir): For now we never use FP16 conversion intrinsics even if
-      // required by the target. Change that once this is implemented
       res = builder.createCast(cgf.getLoc(loc), cir::CastKind::floating, res,
                                resTy);
     }

@@ -396,13 +396,7 @@ mlir::Type CIRGenTypes::convertType(QualType type) {
       resultType = cgm.fP16Ty;
       break;
     case BuiltinType::Half:
-      if (astContext.getLangOpts().NativeHalfType ||
-          !astContext.getTargetInfo().useFP16ConversionIntrinsics()) {
-        resultType = cgm.fP16Ty;
-      } else {
-        cgm.errorNYI(SourceLocation(), "processing of built-in type", type);
-        resultType = cgm.sInt32Ty;
-      }
+      resultType = cgm.fP16Ty;
       break;
     case BuiltinType::BFloat16:
       resultType = cgm.bFloat16Ty;

diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -2469,16 +2469,8 @@ ConstantEmitter::tryEmitPrivate(const APValue &Value, QualType DestType,
         llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
     return llvm::ConstantStruct::get(STy, Complex);
   }
-  case APValue::Float: {
-    const llvm::APFloat &Init = Value.getFloat();
-    if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
-        !CGM.getContext().getLangOpts().NativeHalfType &&
-        CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics())
-      return llvm::ConstantInt::get(CGM.getLLVMContext(),
-                                    Init.bitcastToAPInt());
-    else
-      return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
-  }
+  case APValue::Float:
+    return llvm::ConstantFP::get(CGM.getLLVMContext(), Value.getFloat());
   case APValue::ComplexFloat: {
     llvm::Constant *Complex[2];
 

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1596,23 +1596,11 @@ Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
   // Cast from half through float if half isn't a native type.
   if (SrcType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
     // Cast to FP using the intrinsic if the half type itself isn't supported.
-    if (DstTy->isFloatingPointTy()) {
-      if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics())
-        return Builder.CreateCall(
-            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16, DstTy),
-            Src);
-    } else {
+    if (!DstTy->isFloatingPointTy()) {
       // Cast to other types through float, using either the intrinsic or FPExt,
       // depending on whether the half type itself is supported
       // (as opposed to operations on half, available with NativeHalfType).
-      if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
-        Src = Builder.CreateCall(
-            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16,
-                                 CGF.CGM.FloatTy),
-            Src);
-      } else {
-        Src = Builder.CreateFPExt(Src, CGF.CGM.FloatTy, "conv");
-      }
+      Src = Builder.CreateFPExt(Src, CGF.CGM.FloatTy, "conv");
       SrcType = CGF.getContext().FloatTy;
       SrcTy = CGF.FloatTy;
     }
@@ -1723,11 +1711,6 @@ Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
   if (DstType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
     // Make sure we cast in a single step if from another FP type.
     if (SrcTy->isFloatingPointTy()) {
-      // Use the intrinsic if the half type itself isn't supported
-      // (as opposed to operations on half, available with NativeHalfType).
-      if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics())
-        return Builder.CreateCall(
-            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16, SrcTy), Src);
       // If the half type is supported, just use an fptrunc.
       return Builder.CreateFPTrunc(Src, DstTy);
     }
@@ -1737,14 +1720,7 @@ Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
   Res = EmitScalarCast(Src, SrcType, DstType, SrcTy, DstTy, Opts);
 
   if (DstTy != ResTy) {
-    if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
-      assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion");
-      Res = Builder.CreateCall(
-        CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16, CGF.CGM.FloatTy),
-        Res);
-    } else {
-      Res = Builder.CreateFPTrunc(Res, ResTy, "conv");
-    }
+    Res = Builder.CreateFPTrunc(Res, ResTy, "conv");
   }
 
   if (Opts.EmitImplicitIntegerTruncationChecks)
@@ -3399,14 +3375,7 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
 
     if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
       // Another special case: half FP increment should be done via float
-      if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
-        value = Builder.CreateCall(
-            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16,
-                                 CGF.CGM.FloatTy),
-            input, "incdec.conv");
-      } else {
-        value = Builder.CreateFPExt(input, CGF.CGM.FloatTy, "incdec.conv");
-      }
+      value = Builder.CreateFPExt(input, CGF.CGM.FloatTy, "incdec.conv");
     }
 
     if (value->getType()->isFloatTy())
@@ -3439,14 +3408,7 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
     value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec");
 
     if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
-      if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
-        value = Builder.CreateCall(
-            CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16,
-                                 CGF.CGM.FloatTy),
-            value, "incdec.conv");
-      } else {
-        value = Builder.CreateFPTrunc(value, input->getType(), "incdec.conv");
-      }
+      value = Builder.CreateFPTrunc(value, input->getType(), "incdec.conv");
     }
 
   // Fixed-point types.

diff --git a/clang/lib/CodeGen/CodeGenTypes.cpp b/clang/lib/CodeGen/CodeGenTypes.cpp
@@ -471,10 +471,8 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) {
 
     case BuiltinType::Half:
       // Half FP can either be storage-only (lowered to i16) or native.
-      ResultType = getTypeForFormat(
-          getLLVMContext(), Context.getFloatTypeSemantics(T),
-          Context.getLangOpts().NativeHalfType ||
-              !Context.getTargetInfo().useFP16ConversionIntrinsics());
+      ResultType = getTypeForFormat(getLLVMContext(),
+                                    Context.getFloatTypeSemantics(T), true);
       break;
     case BuiltinType::LongDouble:
       LongDoubleReferenced = true;

diff --git a/clang/lib/CodeGen/TargetBuiltins/NVPTX.cpp b/clang/lib/CodeGen/TargetBuiltins/NVPTX.cpp
@@ -375,23 +375,8 @@ static Value *MakeCpAsync(unsigned IntrinsicID, unsigned IntrinsicIDS,
                                        CGF.EmitScalarExpr(E->getArg(1))});
 }
 
-static bool EnsureNativeHalfSupport(unsigned BuiltinID, const CallExpr *E,
-                                    CodeGenFunction &CGF) {
-  auto &C = CGF.CGM.getContext();
-  if (!C.getLangOpts().NativeHalfType &&
-      C.getTargetInfo().useFP16ConversionIntrinsics()) {
-    CGF.CGM.Error(E->getExprLoc(), C.BuiltinInfo.getQuotedName(BuiltinID) +
-                                       " requires native half type support.");
-    return false;
-  }
-  return true;
-}
-
 static Value *MakeHalfType(Function *Intrinsic, unsigned BuiltinID,
                            const CallExpr *E, CodeGenFunction &CGF) {
-  if (!EnsureNativeHalfSupport(BuiltinID, E, CGF))
-    return nullptr;
-
   SmallVector<Value *, 16> Args;
   auto *FTy = Intrinsic->getFunctionType();
   unsigned ICEArguments = 0;
@@ -1069,13 +1054,10 @@ Value *CodeGenFunction::EmitNVPTXBuiltinExpr(unsigned BuiltinID,
                                         EmitScalarExpr(E->getArg(0)));
   case NVPTX::BI__nvvm_ldg_h:
   case NVPTX::BI__nvvm_ldg_h2:
-    return EnsureNativeHalfSupport(BuiltinID, E, *this) ? MakeLdg(*this, E)
-                                                        : nullptr;
+    return MakeLdg(*this, E);
   case NVPTX::BI__nvvm_ldu_h:
   case NVPTX::BI__nvvm_ldu_h2:
-    return EnsureNativeHalfSupport(BuiltinID, E, *this)
-               ? MakeLdu(Intrinsic::nvvm_ldu_global_f, *this, E)
-               : nullptr;
+    return MakeLdu(Intrinsic::nvvm_ldu_global_f, *this, E);
   case NVPTX::BI__nvvm_cp_async_ca_shared_global_4:
     return MakeCpAsync(Intrinsic::nvvm_cp_async_ca_shared_global_4,
                        Intrinsic::nvvm_cp_async_ca_shared_global_4_s, *this, E,

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
@@ -5763,22 +5763,12 @@ bool Sema::BuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs,
   if (OrigArg->isTypeDependent())
     return false;
 
-  // Usual Unary Conversions will convert half to float, which we want for
-  // machines that use fp16 conversion intrinsics. Else, we wnat to leave the
-  // type how it is, but do normal L->Rvalue conversions.
-  if (Context.getTargetInfo().useFP16ConversionIntrinsics()) {
-    ExprResult Res = UsualUnaryConversions(OrigArg);
-
-    if (!Res.isUsable())
-      return true;
-    OrigArg = Res.get();
-  } else {
-    ExprResult Res = DefaultFunctionArrayLvalueConversion(OrigArg);
+  // We want to leave the type how it is, but do normal L->Rvalue conversions.
+  ExprResult Res = DefaultFunctionArrayLvalueConversion(OrigArg);
+  if (!Res.isUsable())
+    return true;
+  OrigArg = Res.get();
 
-    if (!Res.isUsable())
-      return true;
-    OrigArg = Res.get();
-  }
   TheCall->setArg(FPArgNo, OrigArg);
 
   QualType VectorResultTy;

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
@@ -15213,8 +15213,7 @@ static ExprResult convertHalfVecBinOp(Sema &S, ExprResult LHS, ExprResult RHS,
 /// is needed.
 static bool needsConversionOfHalfVec(bool OpRequiresConversion, ASTContext &Ctx,
                                      Expr *E0, Expr *E1 = nullptr) {
-  if (!OpRequiresConversion || Ctx.getLangOpts().NativeHalfType ||
-      Ctx.getTargetInfo().useFP16ConversionIntrinsics())
+  if (!OpRequiresConversion || Ctx.getLangOpts().NativeHalfType)
     return false;
 
   auto HasVectorOfHalfType = [&Ctx](Expr *E) {