Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression

[dblaikie]

Summary

There is a version that just tests (also called
isIntegerConstantExpression) & whereas this version is specifically used
when the value is of interest (a few call sites were actually refactored
to calling the test-only version) so let's make the API look more like
it.

[dblaikie]

Ping

[dblaikie]

Ping

[dblaikie]

Ping

[aaron.ballman]

LGTM aside from the formatting nits. I think this is a nice cleanup, thanks!

clang/include/clang/AST/Expr.h

513–515

80-col issue, should clang-format the patch.

[sberg]

clang/include/clang/AST/Expr.h

513

I think the "Return the value..." description now matches getIntegerConstantExpr, not isIntegerConstantExpr

clang/include/clang/AST/Expr.h

public:
   ///
   /// \param Semantic If true, only return true for expressions that are known
   /// to be semantically boolean, which might not be true even for expressions
   /// that are known to evaluate to 0/1. For instance, reading an unsigned
   /// bit-field with width '1' will evaluate to 0/1, but doesn't necessarily
   /// semantically correspond to a bool.
   bool isKnownToHaveBooleanValue(bool Semantic = true) const;
 
-  /// isIntegerConstantExpr - Return true if this expression is a valid integer
-  /// constant expression, and, if so, return its value in Result.  If not a
-  /// valid i-c-e, return false and fill in Loc (if specified) with the location
-  /// of the invalid expression.
+  /// isIntegerConstantExpr - Return the value if this expression is a valid
+  /// integer constant expression.  If not a valid i-c-e, return None and fill
+  /// in Loc (if specified) with the location of the invalid expression.
   ///
   /// Note: This does not perform the implicit conversions required by C++11
   /// [expr.const]p5.
-  bool isIntegerConstantExpr(llvm::APSInt &Result, const ASTContext &Ctx,
+  Optional<llvm::APSInt> getIntegerConstantExpr(const ASTContext &Ctx,
                                                 SourceLocation *Loc = nullptr,
                                                 bool isEvaluated = true) const;
   bool isIntegerConstantExpr(const ASTContext &Ctx,
                              SourceLocation *Loc = nullptr) const;
 
   /// isCXX98IntegralConstantExpr - Return true if this expression is an
   /// integral constant expression in C++98. Can only be used in C++.
   bool isCXX98IntegralConstantExpr(const ASTContext &Ctx) const;
 
   /// isCXX11ConstantExpr - Return true if this expression is a constant

clang/lib/AST/ASTContext.cpp

case Type::ConstantArray:
 
     // If either side is a variable array, and both are complete, check whether
     // the current dimension is definite.
     if (LVAT || RVAT) {
       auto SizeFetch = [this](const VariableArrayType* VAT,
           const ConstantArrayType* CAT)
           -> std::pair<bool,llvm::APInt> {
         if (VAT) {
-          llvm::APSInt TheInt;
+          Optional<llvm::APSInt> TheInt;
           Expr *E = VAT->getSizeExpr();
-          if (E && E->isIntegerConstantExpr(TheInt, *this))
-            return std::make_pair(true, TheInt);
-          else
-            return std::make_pair(false, TheInt);
-        } else if (CAT) {
-            return std::make_pair(true, CAT->getSize());
-        } else {
-            return std::make_pair(false, llvm::APInt());
-        }
+          if (E && (TheInt = E->getIntegerConstantExpr(*this)))
+            return std::make_pair(true, *TheInt);
+          return std::make_pair(false, llvm::APSInt());
+        }
+        if (CAT)
       };
 
       bool HaveLSize, HaveRSize;
       llvm::APInt LSize, RSize;
       std::tie(HaveLSize, LSize) = SizeFetch(LVAT, LCAT);
       std::tie(HaveRSize, RSize) = SizeFetch(RVAT, RCAT);
       if (HaveLSize && HaveRSize && !llvm::APInt::isSameValue(LSize, RSize))
         return {}; // Definite, but unequal, array dimension

clang/lib/AST/ExprConstant.cpp

bool Expr::isIntegerConstantExpr(const ASTContext &Ctx,
   ICEDiag D = CheckICE(this, Ctx);
   if (D.Kind != IK_ICE) {
     if (Loc) *Loc = D.Loc;
     return false;
   }
   return true;
 }
 
-bool Expr::isIntegerConstantExpr(llvm::APSInt &Value, const ASTContext &Ctx,
-                                 SourceLocation *Loc, bool isEvaluated) const {
+Optional<llvm::APSInt> Expr::getIntegerConstantExpr(const ASTContext &Ctx,
+                                                    SourceLocation *Loc,
+                                                    bool isEvaluated) const {
   assert(!isValueDependent() &&
          "Expression evaluator can't be called on a dependent expression.");
 
-  if (Ctx.getLangOpts().CPlusPlus11)
-    return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc);
+  APSInt Value;
+
+  if (Ctx.getLangOpts().CPlusPlus11) {
+    if (EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc))
+      return Value;
+    return None;
+  }
 
   if (!isIntegerConstantExpr(Ctx, Loc))
-    return false;
+    return None;
 
   // The only possible side-effects here are due to UB discovered in the
   // evaluation (for instance, INT_MAX + 1). In such a case, we are still
   // required to treat the expression as an ICE, so we produce the folded
   // value.
   EvalResult ExprResult;
   Expr::EvalStatus Status;
   EvalInfo Info(Ctx, Status, EvalInfo::EM_IgnoreSideEffects);
   Info.InConstantContext = true;
 
   if (!::EvaluateAsInt(this, ExprResult, Ctx, SE_AllowSideEffects, Info))
     llvm_unreachable("ICE cannot be evaluated!");
 
-  Value = ExprResult.Val.getInt();
-  return true;
+  return ExprResult.Val.getInt();
 }
 
 bool Expr::isCXX98IntegralConstantExpr(const ASTContext &Ctx) const {
   assert(!isValueDependent() &&
          "Expression evaluator can't be called on a dependent expression.");
 
   return CheckICE(this, Ctx).Kind == IK_ICE;
 }

clang/lib/AST/MicrosoftMangle.cpp

void MicrosoftCXXNameMangler::mangleIntegerLiteral(const llvm::APSInt &Value,
   else if (Value.isSigned())
     mangleNumber(Value.getSExtValue());
   else
     mangleNumber(Value.getZExtValue());
 }
 
 void MicrosoftCXXNameMangler::mangleExpression(const Expr *E) {
   // See if this is a constant expression.
-  llvm::APSInt Value;
-  if (E->isIntegerConstantExpr(Value, Context.getASTContext())) {
-    mangleIntegerLiteral(Value, E->getType()->isBooleanType());
+  if (Optional<llvm::APSInt> Value =
+          E->getIntegerConstantExpr(Context.getASTContext())) {
+    mangleIntegerLiteral(*Value, E->getType()->isBooleanType());
     return;
   }
 
   // As bad as this diagnostic is, it's better than crashing.
   DiagnosticsEngine &Diags = Context.getDiags();
   unsigned DiagID = Diags.getCustomDiagID(
       DiagnosticsEngine::Error, "cannot yet mangle expression type %0");
   Diags.Report(E->getExprLoc(), DiagID) << E->getStmtClassName()

clang/lib/CodeGen/CGBuiltin.cpp

if (IntrinsicID != Intrinsic::not_intrinsic) {
     for (unsigned i = 0, e = E->getNumArgs(); i != e; ++i) {
       Value *ArgValue;
       // If this is a normal argument, just emit it as a scalar.
       if ((ICEArguments & (1 << i)) == 0) {
         ArgValue = EmitScalarExpr(E->getArg(i));
       } else {
         // If this is required to be a constant, constant fold it so that we
         // know that the generated intrinsic gets a ConstantInt.
-        llvm::APSInt Result;
-        bool IsConst = E->getArg(i)->isIntegerConstantExpr(Result,getContext());
-        assert(IsConst && "Constant arg isn't actually constant?");
-        (void)IsConst;
-        ArgValue = llvm::ConstantInt::get(getLLVMContext(), Result);
+        ArgValue = llvm::ConstantInt::get(
+            getLLVMContext(),
+            *E->getArg(i)->getIntegerConstantExpr(getContext()));
       }
 
       // If the intrinsic arg type is different from the builtin arg type
       // we need to do a bit cast.
       llvm::Type *PTy = FTy->getParamType(i);
       if (PTy != ArgValue->getType()) {
         // XXX - vector of pointers?
         if (auto *PtrTy = dyn_cast<llvm::PointerType>(PTy)) {

 }
 
 Value *CodeGenFunction::EmitCommonNeonBuiltinExpr(
     unsigned BuiltinID, unsigned LLVMIntrinsic, unsigned AltLLVMIntrinsic,
     const char *NameHint, unsigned Modifier, const CallExpr *E,
     SmallVectorImpl<llvm::Value *> &Ops, Address PtrOp0, Address PtrOp1,
     llvm::Triple::ArchType Arch) {
   // Get the last argument, which specifies the vector type.
-  llvm::APSInt NeonTypeConst;
   const Expr *Arg = E->getArg(E->getNumArgs() - 1);
-  if (!Arg->isIntegerConstantExpr(NeonTypeConst, getContext()))
+  Optional<llvm::APSInt> NeonTypeConst =
+      Arg->getIntegerConstantExpr(getContext());
+  if (!NeonTypeConst)
     return nullptr;
 
   // Determine the type of this overloaded NEON intrinsic.
-  NeonTypeFlags Type(NeonTypeConst.getZExtValue());
+  NeonTypeFlags Type(NeonTypeConst->getZExtValue());
   bool Usgn = Type.isUnsigned();
   bool Quad = Type.isQuad();
   const bool HasLegalHalfType = getTarget().hasLegalHalfType();
   const bool AllowBFloatArgsAndRet =
       getTargetHooks().getABIInfo().allowBFloatArgsAndRet();
 
   llvm::VectorType *VTy = GetNeonType(this, Type, HasLegalHalfType, false,
                                       AllowBFloatArgsAndRet);
if (i == 1) {
       }
     }
 
     if ((ICEArguments & (1 << i)) == 0) {
       Ops.push_back(EmitScalarExpr(E->getArg(i)));
     } else {
       // If this is required to be a constant, constant fold it so that we know
       // that the generated intrinsic gets a ConstantInt.
-      llvm::APSInt Result;
-      bool IsConst = E->getArg(i)->isIntegerConstantExpr(Result, getContext());
-      assert(IsConst && "Constant arg isn't actually constant?"); (void)IsConst;
-      Ops.push_back(llvm::ConstantInt::get(getLLVMContext(), Result));
+      Ops.push_back(llvm::ConstantInt::get(
+          getLLVMContext(),
+          *E->getArg(i)->getIntegerConstantExpr(getContext())));
     }
   }
 
   switch (BuiltinID) {
   default: break;
 
   case NEON::BI__builtin_neon_vget_lane_i8:
   case NEON::BI__builtin_neon_vget_lane_i16:
Value *CodeGenFunction::EmitARMBuiltinExpr(unsigned BuiltinID,
   case ARM::BI_InterlockedDecrement16_nf:
   case ARM::BI_InterlockedDecrement_nf:
   case ARM::BI_InterlockedDecrement64_nf:
     return EmitMSVCBuiltinExpr(MSVCIntrin::_InterlockedDecrement_nf, E);
   }
 
   // Get the last argument, which specifies the vector type.
   assert(HasExtraArg);
-  llvm::APSInt Result;
   const Expr *Arg = E->getArg(E->getNumArgs()-1);
-  if (!Arg->isIntegerConstantExpr(Result, getContext()))
+  Optional<llvm::APSInt> Result = Arg->getIntegerConstantExpr(getContext());
+  if (!Result)
     return nullptr;
 
   if (BuiltinID == ARM::BI__builtin_arm_vcvtr_f ||
       BuiltinID == ARM::BI__builtin_arm_vcvtr_d) {
     // Determine the overloaded type of this builtin.
     llvm::Type *Ty;
     if (BuiltinID == ARM::BI__builtin_arm_vcvtr_f)
       Ty = FloatTy;
     else
       Ty = DoubleTy;
 
     // Determine whether this is an unsigned conversion or not.
-    bool usgn = Result.getZExtValue() == 1;
+    bool usgn = Result->getZExtValue() == 1;
     unsigned Int = usgn ? Intrinsic::arm_vcvtru : Intrinsic::arm_vcvtr;
 
     // Call the appropriate intrinsic.
     Function *F = CGM.getIntrinsic(Int, Ty);
     return Builder.CreateCall(F, Ops, "vcvtr");
   }
 
   // Determine the type of this overloaded NEON intrinsic.
-  NeonTypeFlags Type(Result.getZExtValue());
+  NeonTypeFlags Type = Result->getZExtValue();
   bool usgn = Type.isUnsigned();
   bool rightShift = false;
 
   llvm::VectorType *VTy = GetNeonType(this, Type,
                                       getTarget().hasLegalHalfType(),
                                       false,
                                       getTarget().hasBFloat16Type());
   llvm::Type *Ty = VTy;
Value *CodeGenFunction::EmitARMBuiltinExpr(unsigned BuiltinID,
   case NEON::BI__builtin_neon_vtbx4_v:
     return EmitNeonCall(CGM.getIntrinsic(Intrinsic::arm_neon_vtbx4),
                         Ops, "vtbx4");
   }
 }
 
 template<typename Integer>
 static Integer GetIntegerConstantValue(const Expr *E, ASTContext &Context) {
-  llvm::APSInt IntVal;
-  bool IsConst = E->isIntegerConstantExpr(IntVal, Context);
-  assert(IsConst && "Sema should have checked this was a constant");
-  (void)IsConst;
-  return IntVal.getExtValue();
+  return E->getIntegerConstantExpr(Context)->getExtValue();
 }
 
 static llvm::Value *SignOrZeroExtend(CGBuilderTy &Builder, llvm::Value *V,
                                      llvm::Type *T, bool Unsigned) {
   // Helper function called by Tablegen-constructed ARM MVE builtin codegen,
   // which finds it convenient to specify signed/unsigned as a boolean flag.
   return Unsigned ? Builder.CreateZExt(V, T) : Builder.CreateSExt(V, T);
 }
static Value *EmitAArch64TblBuiltinExpr(CodeGenFunction &CGF, unsigned BuiltinID,
   case NEON::BI__builtin_neon_vqtbx4_v:
   case NEON::BI__builtin_neon_vqtbx4q_v:
     break;
   }
 
   assert(E->getNumArgs() >= 3);
 
   // Get the last argument, which specifies the vector type.
-  llvm::APSInt Result;
   const Expr *Arg = E->getArg(E->getNumArgs() - 1);
-  if (!Arg->isIntegerConstantExpr(Result, CGF.getContext()))
+  Optional<llvm::APSInt> Result = Arg->getIntegerConstantExpr(CGF.getContext());
+  if (!Result)
     return nullptr;
 
   // Determine the type of this overloaded NEON intrinsic.
-  NeonTypeFlags Type(Result.getZExtValue());
+  NeonTypeFlags Type = Result->getZExtValue();
   llvm::VectorType *Ty = GetNeonType(&CGF, Type);
   if (!Ty)
     return nullptr;
 
   CodeGen::CGBuilderTy &Builder = CGF.Builder;
 
   // AArch64 scalar builtins are not overloaded, they do not have an extra
   // argument that specifies the vector type, need to handle each case.
if (i == 0) {
         continue;
       }
     }
     if ((ICEArguments & (1 << i)) == 0) {
       Ops.push_back(EmitScalarExpr(E->getArg(i)));
     } else {
       // If this is required to be a constant, constant fold it so that we know
       // that the generated intrinsic gets a ConstantInt.
-      llvm::APSInt Result;
-      bool IsConst = E->getArg(i)->isIntegerConstantExpr(Result, getContext());
-      assert(IsConst && "Constant arg isn't actually constant?");
-      (void)IsConst;
-      Ops.push_back(llvm::ConstantInt::get(getLLVMContext(), Result));
+      Ops.push_back(llvm::ConstantInt::get(
+          getLLVMContext(),
+          *E->getArg(i)->getIntegerConstantExpr(getContext())));
     }
   }
 
   auto SISDMap = makeArrayRef(AArch64SISDIntrinsicMap);
   const ARMVectorIntrinsicInfo *Builtin = findARMVectorIntrinsicInMap(
       SISDMap, BuiltinID, AArch64SISDIntrinsicsProvenSorted);
 
   if (Builtin) {
     Ops.push_back(EmitScalarExpr(E->getArg(E->getNumArgs() - 1)));
     Value *Result = EmitCommonNeonSISDBuiltinExpr(*this, *Builtin, Ops, E);
     assert(Result && "SISD intrinsic should have been handled");
     return Result;
   }
 
-  llvm::APSInt Result;
   const Expr *Arg = E->getArg(E->getNumArgs()-1);
   NeonTypeFlags Type(0);
-  if (Arg->isIntegerConstantExpr(Result, getContext()))
+  if (Optional<llvm::APSInt> Result = Arg->getIntegerConstantExpr(getContext()))
     // Determine the type of this overloaded NEON intrinsic.
-    Type = NeonTypeFlags(Result.getZExtValue());
+    Type = NeonTypeFlags(Result->getZExtValue());
 
   bool usgn = Type.isUnsigned();
   bool quad = Type.isQuad();
 
   // Handle non-overloaded intrinsics first.
   switch (BuiltinID) {
   default: break;
   case NEON::BI__builtin_neon_vabsh_f16:
for (unsigned i = 0, e = E->getNumArgs(); i != e; i++) {
     // If this is a normal argument, just emit it as a scalar.
     if ((ICEArguments & (1 << i)) == 0) {
       Ops.push_back(EmitScalarExpr(E->getArg(i)));
       continue;
     }
 
     // If this is required to be a constant, constant fold it so that we know
     // that the generated intrinsic gets a ConstantInt.
-    llvm::APSInt Result;
-    bool IsConst = E->getArg(i)->isIntegerConstantExpr(Result, getContext());
-    assert(IsConst && "Constant arg isn't actually constant?"); (void)IsConst;
-    Ops.push_back(llvm::ConstantInt::get(getLLVMContext(), Result));
+    Ops.push_back(llvm::ConstantInt::get(
+        getLLVMContext(), *E->getArg(i)->getIntegerConstantExpr(getContext())));
   }
 
   // These exist so that the builtin that takes an immediate can be bounds
   // checked by clang to avoid passing bad immediates to the backend. Since
   // AVX has a larger immediate than SSE we would need separate builtins to
   // do the different bounds checking. Rather than create a clang specific
   // SSE only builtin, this implements eight separate builtins to match gcc
   // implementation.
case SystemZ::BI__builtin_s390_vflndb: {
     Function *F = CGM.getIntrinsic(Intrinsic::fabs, ResultType);
     return Builder.CreateFNeg(Builder.CreateCall(F, X), "neg");
   }
   case SystemZ::BI__builtin_s390_vfisb:
   case SystemZ::BI__builtin_s390_vfidb: {
     llvm::Type *ResultType = ConvertType(E->getType());
     Value *X = EmitScalarExpr(E->getArg(0));
     // Constant-fold the M4 and M5 mask arguments.
-    llvm::APSInt M4, M5;
-    bool IsConstM4 = E->getArg(1)->isIntegerConstantExpr(M4, getContext());
-    bool IsConstM5 = E->getArg(2)->isIntegerConstantExpr(M5, getContext());
-    assert(IsConstM4 && IsConstM5 && "Constant arg isn't actually constant?");
-    (void)IsConstM4; (void)IsConstM5;
+    llvm::APSInt M4 = *E->getArg(1)->getIntegerConstantExpr(getContext());
+    llvm::APSInt M5 = *E->getArg(2)->getIntegerConstantExpr(getContext());
     // Check whether this instance can be represented via a LLVM standard
     // intrinsic.  We only support some combinations of M4 and M5.
     Intrinsic::ID ID = Intrinsic::not_intrinsic;
     Intrinsic::ID CI;
     switch (M4.getZExtValue()) {
     default: break;
     case 0:  // IEEE-inexact exception allowed
       switch (M5.getZExtValue()) {
case SystemZ::BI__builtin_s390_vfidb: {
     return Builder.CreateCall(F, {X, M4Value, M5Value});
   }
   case SystemZ::BI__builtin_s390_vfmaxsb:
   case SystemZ::BI__builtin_s390_vfmaxdb: {
     llvm::Type *ResultType = ConvertType(E->getType());
     Value *X = EmitScalarExpr(E->getArg(0));
     Value *Y = EmitScalarExpr(E->getArg(1));
     // Constant-fold the M4 mask argument.
-    llvm::APSInt M4;
-    bool IsConstM4 = E->getArg(2)->isIntegerConstantExpr(M4, getContext());
-    assert(IsConstM4 && "Constant arg isn't actually constant?");
-    (void)IsConstM4;
+    llvm::APSInt M4 = *E->getArg(2)->getIntegerConstantExpr(getContext());
     // Check whether this instance can be represented via a LLVM standard
     // intrinsic.  We only support some values of M4.
     Intrinsic::ID ID = Intrinsic::not_intrinsic;
     Intrinsic::ID CI;
     switch (M4.getZExtValue()) {
     default: break;
     case 4: ID = Intrinsic::maxnum;
             CI = Intrinsic::experimental_constrained_maxnum; break;
case SystemZ::BI__builtin_s390_vfmaxdb: {
     return Builder.CreateCall(F, {X, Y, M4Value});
   }
   case SystemZ::BI__builtin_s390_vfminsb:
   case SystemZ::BI__builtin_s390_vfmindb: {
     llvm::Type *ResultType = ConvertType(E->getType());
     Value *X = EmitScalarExpr(E->getArg(0));
     Value *Y = EmitScalarExpr(E->getArg(1));
     // Constant-fold the M4 mask argument.
-    llvm::APSInt M4;
-    bool IsConstM4 = E->getArg(2)->isIntegerConstantExpr(M4, getContext());
-    assert(IsConstM4 && "Constant arg isn't actually constant?");
-    (void)IsConstM4;
+    llvm::APSInt M4 = *E->getArg(2)->getIntegerConstantExpr(getContext());
     // Check whether this instance can be represented via a LLVM standard
     // intrinsic.  We only support some values of M4.
     Intrinsic::ID ID = Intrinsic::not_intrinsic;
     Intrinsic::ID CI;
     switch (M4.getZExtValue()) {
     default: break;
     case 4: ID = Intrinsic::minnum;
             CI = Intrinsic::experimental_constrained_minnum; break;
CodeGenFunction::EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
   case NVPTX::BI__imma_m8n8k32_ld_c:
   case NVPTX::BI__bmma_m8n8k128_ld_a_b1:
   case NVPTX::BI__bmma_m8n8k128_ld_b_b1:
   case NVPTX::BI__bmma_m8n8k128_ld_c:
   {
     Address Dst = EmitPointerWithAlignment(E->getArg(0));
     Value *Src = EmitScalarExpr(E->getArg(1));
     Value *Ldm = EmitScalarExpr(E->getArg(2));
-    llvm::APSInt isColMajorArg;
-    if (!E->getArg(3)->isIntegerConstantExpr(isColMajorArg, getContext()))
+    Optional<llvm::APSInt> isColMajorArg =
+        E->getArg(3)->getIntegerConstantExpr(getContext());
+    if (!isColMajorArg)
       return nullptr;
-    bool isColMajor = isColMajorArg.getSExtValue();
+    bool isColMajor = isColMajorArg->getSExtValue();
     NVPTXMmaLdstInfo II = getNVPTXMmaLdstInfo(BuiltinID);
     unsigned IID = isColMajor ? II.IID_col : II.IID_row;
     if (IID == 0)
       return nullptr;
 
     Value *Result =
         Builder.CreateCall(CGM.getIntrinsic(IID, Src->getType()), {Src, Ldm});
 
CodeGenFunction::EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
   case NVPTX::BI__imma_m16n16k16_st_c_i32:
   case NVPTX::BI__imma_m32n8k16_st_c_i32:
   case NVPTX::BI__imma_m8n32k16_st_c_i32:
   case NVPTX::BI__imma_m8n8k32_st_c_i32:
   case NVPTX::BI__bmma_m8n8k128_st_c_i32: {
     Value *Dst = EmitScalarExpr(E->getArg(0));
     Address Src = EmitPointerWithAlignment(E->getArg(1));
     Value *Ldm = EmitScalarExpr(E->getArg(2));
-    llvm::APSInt isColMajorArg;
-    if (!E->getArg(3)->isIntegerConstantExpr(isColMajorArg, getContext()))
+    Optional<llvm::APSInt> isColMajorArg =
+        E->getArg(3)->getIntegerConstantExpr(getContext());
+    if (!isColMajorArg)
       return nullptr;
-    bool isColMajor = isColMajorArg.getSExtValue();
+    bool isColMajor = isColMajorArg->getSExtValue();
     NVPTXMmaLdstInfo II = getNVPTXMmaLdstInfo(BuiltinID);
     unsigned IID = isColMajor ? II.IID_col : II.IID_row;
     if (IID == 0)
       return nullptr;
     Function *Intrinsic =
         CGM.getIntrinsic(IID, Dst->getType());
     llvm::Type *ParamType = Intrinsic->getFunctionType()->getParamType(1);
     SmallVector<Value *, 10> Values = {Dst};
CodeGenFunction::EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
   case NVPTX::BI__imma_m8n32k16_mma_u8:
   case NVPTX::BI__imma_m8n8k32_mma_s4:
   case NVPTX::BI__imma_m8n8k32_mma_u4:
   case NVPTX::BI__bmma_m8n8k128_mma_xor_popc_b1: {
     Address Dst = EmitPointerWithAlignment(E->getArg(0));
     Address SrcA = EmitPointerWithAlignment(E->getArg(1));
     Address SrcB = EmitPointerWithAlignment(E->getArg(2));
     Address SrcC = EmitPointerWithAlignment(E->getArg(3));
-    llvm::APSInt LayoutArg;
-    if (!E->getArg(4)->isIntegerConstantExpr(LayoutArg, getContext()))
+    Optional<llvm::APSInt> LayoutArg =
+        E->getArg(4)->getIntegerConstantExpr(getContext());
+    if (!LayoutArg)
       return nullptr;
-    int Layout = LayoutArg.getSExtValue();
+    int Layout = LayoutArg->getSExtValue();
     if (Layout < 0 || Layout > 3)
       return nullptr;
     llvm::APSInt SatfArg;
     if (BuiltinID == NVPTX::BI__bmma_m8n8k128_mma_xor_popc_b1)
       SatfArg = 0;  // .b1 does not have satf argument.
-    else if (!E->getArg(5)->isIntegerConstantExpr(SatfArg, getContext()))
+    else if (Optional<llvm::APSInt> OptSatfArg =
+                 E->getArg(5)->getIntegerConstantExpr(getContext()))
+      SatfArg = *OptSatfArg;
+    else
       return nullptr;
     bool Satf = SatfArg.getSExtValue();
     NVPTXMmaInfo MI = getNVPTXMmaInfo(BuiltinID);
     unsigned IID = MI.getMMAIntrinsic(Layout, Satf);
     if (IID == 0)  // Unsupported combination of Layout/Satf.
       return nullptr;
 
     SmallVector<Value *, 24> Values;
Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
   case WebAssembly::BI__builtin_wasm_extract_lane_s_i8x16:
   case WebAssembly::BI__builtin_wasm_extract_lane_u_i8x16:
   case WebAssembly::BI__builtin_wasm_extract_lane_s_i16x8:
   case WebAssembly::BI__builtin_wasm_extract_lane_u_i16x8:
   case WebAssembly::BI__builtin_wasm_extract_lane_i32x4:
   case WebAssembly::BI__builtin_wasm_extract_lane_i64x2:
   case WebAssembly::BI__builtin_wasm_extract_lane_f32x4:
   case WebAssembly::BI__builtin_wasm_extract_lane_f64x2: {
-    llvm::APSInt LaneConst;
-    if (!E->getArg(1)->isIntegerConstantExpr(LaneConst, getContext()))
-      llvm_unreachable("Constant arg isn't actually constant?");
+    llvm::APSInt LaneConst =
+        *E->getArg(1)->getIntegerConstantExpr(getContext());
     Value *Vec = EmitScalarExpr(E->getArg(0));
     Value *Lane = llvm::ConstantInt::get(getLLVMContext(), LaneConst);
     Value *Extract = Builder.CreateExtractElement(Vec, Lane);
     switch (BuiltinID) {
     case WebAssembly::BI__builtin_wasm_extract_lane_s_i8x16:
     case WebAssembly::BI__builtin_wasm_extract_lane_s_i16x8:
       return Builder.CreateSExt(Extract, ConvertType(E->getType()));
     case WebAssembly::BI__builtin_wasm_extract_lane_u_i8x16:
case WebAssembly::BI__builtin_wasm_extract_lane_f64x2: {
     }
   }
   case WebAssembly::BI__builtin_wasm_replace_lane_i8x16:
   case WebAssembly::BI__builtin_wasm_replace_lane_i16x8:
   case WebAssembly::BI__builtin_wasm_replace_lane_i32x4:
   case WebAssembly::BI__builtin_wasm_replace_lane_i64x2:
   case WebAssembly::BI__builtin_wasm_replace_lane_f32x4:
   case WebAssembly::BI__builtin_wasm_replace_lane_f64x2: {
-    llvm::APSInt LaneConst;
-    if (!E->getArg(1)->isIntegerConstantExpr(LaneConst, getContext()))
-      llvm_unreachable("Constant arg isn't actually constant?");
+    llvm::APSInt LaneConst =
+        *E->getArg(1)->getIntegerConstantExpr(getContext());
     Value *Vec = EmitScalarExpr(E->getArg(0));
     Value *Lane = llvm::ConstantInt::get(getLLVMContext(), LaneConst);
     Value *Val = EmitScalarExpr(E->getArg(2));
     switch (BuiltinID) {
     case WebAssembly::BI__builtin_wasm_replace_lane_i8x16:
     case WebAssembly::BI__builtin_wasm_replace_lane_i16x8: {
       llvm::Type *ElemType =
           cast<llvm::VectorType>(ConvertType(E->getType()))->getElementType();

clang/lib/CodeGen/CGExpr.cpp

if (IsLowerBound || E->getColonLocFirst().isInvalid()) {
     // Try to emit length or lower bound as constant. If this is possible, 1
     // is subtracted from constant length or lower bound. Otherwise, emit LLVM
     // IR (LB + Len) - 1.
     auto &C = CGM.getContext();
     auto *Length = E->getLength();
     llvm::APSInt ConstLength;
     if (Length) {
       // Idx = LowerBound + Length - 1;
-      if (Length->isIntegerConstantExpr(ConstLength, C)) {
-        ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
+      if (Optional<llvm::APSInt> CL = Length->getIntegerConstantExpr(C)) {
+        ConstLength = CL->zextOrTrunc(PointerWidthInBits);
         Length = nullptr;
       }
       auto *LowerBound = E->getLowerBound();
       llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
-      if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
-        ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
+      if (LowerBound) {
+        if (Optional<llvm::APSInt> LB = LowerBound->getIntegerConstantExpr(C)) {
+          ConstLowerBound = LB->zextOrTrunc(PointerWidthInBits);
           LowerBound = nullptr;
         }
+      }
       if (!Length)
         --ConstLength;
       else if (!LowerBound)
         --ConstLowerBound;
 
       if (Length || LowerBound) {
         auto *LowerBoundVal =
             LowerBound
if (Length) {
         Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
     } else {
       // Idx = ArraySize - 1;
       QualType ArrayTy = BaseTy->isPointerType()
                              ? E->getBase()->IgnoreParenImpCasts()->getType()
                              : BaseTy;
       if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
         Length = VAT->getSizeExpr();
-        if (Length->isIntegerConstantExpr(ConstLength, C))
+        if (Optional<llvm::APSInt> L = Length->getIntegerConstantExpr(C)) {
+          ConstLength = *L;
           Length = nullptr;
+        }
       } else {
         auto *CAT = C.getAsConstantArrayType(ArrayTy);
         ConstLength = CAT->getSize();
       }
       if (Length) {
         auto *LengthVal = Builder.CreateIntCast(
             EmitScalarExpr(Length), IntPtrTy,
             Length->getType()->hasSignedIntegerRepresentation());

clang/lib/Sema/SemaAttr.cpp

 
 void Sema::ActOnPragmaPack(SourceLocation PragmaLoc, PragmaMsStackAction Action,
                            StringRef SlotLabel, Expr *alignment) {
   Expr *Alignment = static_cast<Expr *>(alignment);
 
   // If specified then alignment must be a "small" power of two.
   unsigned AlignmentVal = 0;
   if (Alignment) {
-    llvm::APSInt Val;
+    Optional<llvm::APSInt> Val;
 
     // pack(0) is like pack(), which just works out since that is what
     // we use 0 for in PackAttr.
-    if (Alignment->isTypeDependent() ||
-        Alignment->isValueDependent() ||
-        !Alignment->isIntegerConstantExpr(Val, Context) ||
-        !(Val == 0 || Val.isPowerOf2()) ||
-        Val.getZExtValue() > 16) {
+    if (Alignment->isTypeDependent() || Alignment->isValueDependent() ||
+        !(Val = Alignment->getIntegerConstantExpr(Context)) ||
+        !(*Val == 0 || Val->isPowerOf2()) || Val->getZExtValue() > 16) {
       Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment);
       return; // Ignore
     }
 
-    AlignmentVal = (unsigned) Val.getZExtValue();
+    AlignmentVal = (unsigned)Val->getZExtValue();
   }
   if (Action == Sema::PSK_Show) {
     // Show the current alignment, making sure to show the right value
     // for the default.
     // FIXME: This should come from the target.
     AlignmentVal = PackStack.CurrentValue;
     if (AlignmentVal == 0)
       AlignmentVal = 8;

clang/lib/Sema/SemaChecking.cpp

bool Sema::CheckARMCoprocessorImmediate(const TargetInfo &TI,
                                         const Expr *CoprocArg, bool WantCDE) {
   if (isConstantEvaluated())
     return false;
 
   // We can't check the value of a dependent argument.
   if (CoprocArg->isTypeDependent() || CoprocArg->isValueDependent())
     return false;
 
-  llvm::APSInt CoprocNoAP;
-  bool IsICE = CoprocArg->isIntegerConstantExpr(CoprocNoAP, Context);
-  (void)IsICE;
-  assert(IsICE && "Coprocossor immediate is not a constant expression");
+  llvm::APSInt CoprocNoAP = *CoprocArg->getIntegerConstantExpr(Context);
   int64_t CoprocNo = CoprocNoAP.getExtValue();
   assert(CoprocNo >= 0 && "Coprocessor immediate must be non-negative");
 
   uint32_t CDECoprocMask = TI.getARMCDECoprocMask();
   bool IsCDECoproc = CoprocNo <= 7 && (CDECoprocMask & (1 << CoprocNo));
 
   if (IsCDECoproc != WantCDE)
     return Diag(CoprocArg->getBeginLoc(), diag::err_arm_invalid_coproc)
if (Arg->getType()->getAsPlaceholderType() ||
        !dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()))) {
     Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_field)
         << 1 << Arg->getSourceRange();
     return true;
   }
 
   // The second argument needs to be a constant int
   Arg = TheCall->getArg(1);
-  llvm::APSInt Value;
-  if (!Arg->isIntegerConstantExpr(Value, Context)) {
+  if (!Arg->isIntegerConstantExpr(Context)) {
     Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_const)
         << 2 << Arg->getSourceRange();
     return true;
   }
 
   TheCall->setType(Context.UnsignedIntTy);
   return false;
 }
bool Sema::CheckAMDGCNBuiltinFunctionCall(unsigned BuiltinID,
 
   return false;
 }
 
 bool Sema::CheckSystemZBuiltinFunctionCall(unsigned BuiltinID,
                                            CallExpr *TheCall) {
   if (BuiltinID == SystemZ::BI__builtin_tabort) {
     Expr *Arg = TheCall->getArg(0);
-    llvm::APSInt AbortCode(32);
-    if (Arg->isIntegerConstantExpr(AbortCode, Context) &&
-        AbortCode.getSExtValue() >= 0 && AbortCode.getSExtValue() < 256)
+    if (Optional<llvm::APSInt> AbortCode = Arg->getIntegerConstantExpr(Context))
+      if (AbortCode->getSExtValue() >= 0 && AbortCode->getSExtValue() < 256)
         return Diag(Arg->getBeginLoc(), diag::err_systemz_invalid_tabort_code)
                << Arg->getSourceRange();
   }
 
   // For intrinsics which take an immediate value as part of the instruction,
   // range check them here.
   unsigned i = 0, l = 0, u = 0;
   switch (BuiltinID) {
   default: return false;
   case SystemZ::BI__builtin_s390_lcbb: i = 1; l = 0; u = 15; break;
case GNUCmpXchg:
     SubExprs.push_back(APIOrderedArgs[1]); // Val1
     SubExprs.push_back(APIOrderedArgs[5]); // OrderFail
     SubExprs.push_back(APIOrderedArgs[2]); // Val2
     SubExprs.push_back(APIOrderedArgs[3]); // Weak
     break;
   }
 
   if (SubExprs.size() >= 2 && Form != Init) {
-    llvm::APSInt Result(32);
-    if (SubExprs[1]->isIntegerConstantExpr(Result, Context) &&
-        !isValidOrderingForOp(Result.getSExtValue(), Op))
+    if (Optional<llvm::APSInt> Result =
+            SubExprs[1]->getIntegerConstantExpr(Context))
+      if (!isValidOrderingForOp(Result->getSExtValue(), Op))
         Diag(SubExprs[1]->getBeginLoc(),
              diag::warn_atomic_op_has_invalid_memory_order)
             << SubExprs[1]->getSourceRange();
   }
 
   if (auto ScopeModel = AtomicExpr::getScopeModel(Op)) {
     auto *Scope = Args[Args.size() - 1];
-    llvm::APSInt Result(32);
-    if (Scope->isIntegerConstantExpr(Result, Context) &&
-        !ScopeModel->isValid(Result.getZExtValue())) {
+    if (Optional<llvm::APSInt> Result =
+            Scope->getIntegerConstantExpr(Context)) {
+      if (!ScopeModel->isValid(Result->getZExtValue()))
         Diag(Scope->getBeginLoc(), diag::err_atomic_op_has_invalid_synch_scope)
             << Scope->getSourceRange();
     }
     SubExprs.push_back(Scope);
   }
 
   AtomicExpr *AE = new (Context)
       AtomicExpr(ExprRange.getBegin(), SubExprs, ResultType, Op, RParenLoc);
 
   if ((Op == AtomicExpr::AO__c11_atomic_load ||
bool Sema::SemaBuiltinVSX(CallExpr *TheCall) {
 
   if (TheCall->getNumArgs() > ExpectedNumArgs)
     return Diag(TheCall->getEndLoc(),
                 diag::err_typecheck_call_too_many_args_at_most)
            << 0 /*function call*/ << ExpectedNumArgs << TheCall->getNumArgs()
            << TheCall->getSourceRange();
 
   // Check the third argument is a compile time constant
-  llvm::APSInt Value;
-  if(!TheCall->getArg(2)->isIntegerConstantExpr(Value, Context))
+  if (!TheCall->getArg(2)->isIntegerConstantExpr(Context))
     return Diag(TheCall->getBeginLoc(),
                 diag::err_vsx_builtin_nonconstant_argument)
            << 3 /* argument index */ << TheCall->getDirectCallee()
            << SourceRange(TheCall->getArg(2)->getBeginLoc(),
                           TheCall->getArg(2)->getEndLoc());
 
   QualType Arg1Ty = TheCall->getArg(0)->getType();
   QualType Arg2Ty = TheCall->getArg(1)->getType();
if (!TheCall->getArg(0)->isTypeDependent() &&
     }
   }
 
   for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
     if (TheCall->getArg(i)->isTypeDependent() ||
         TheCall->getArg(i)->isValueDependent())
       continue;
 
-    llvm::APSInt Result(32);
-    if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
+    Optional<llvm::APSInt> Result;
+    if (!(Result = TheCall->getArg(i)->getIntegerConstantExpr(Context)))
       return ExprError(Diag(TheCall->getBeginLoc(),
                             diag::err_shufflevector_nonconstant_argument)
                        << TheCall->getArg(i)->getSourceRange());
 
     // Allow -1 which will be translated to undef in the IR.
-    if (Result.isSigned() && Result.isAllOnesValue())
+    if (Result->isSigned() && Result->isAllOnesValue())
       continue;
 
-    if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
+    if (Result->getActiveBits() > 64 ||
+        Result->getZExtValue() >= numElements * 2)
       return ExprError(Diag(TheCall->getBeginLoc(),
                             diag::err_shufflevector_argument_too_large)
                        << TheCall->getArg(i)->getSourceRange());
   }
 
   SmallVector<Expr*, 32> exprs;
 
   for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {

 bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
                                   llvm::APSInt &Result) {
   Expr *Arg = TheCall->getArg(ArgNum);
   DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
   FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
 
   if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
 
-  if (!Arg->isIntegerConstantExpr(Result, Context))
+  Optional<llvm::APSInt> R;
+  if (!(R = Arg->getIntegerConstantExpr(Context)))
     return Diag(TheCall->getBeginLoc(), diag::err_constant_integer_arg_type)
            << FDecl->getDeclName() << Arg->getSourceRange();
-
+  Result = *R;
   return false;
 }
 
 /// SemaBuiltinConstantArgRange - Handle a check if argument ArgNum of CallExpr
 /// TheCall is a constant expression in the range [Low, High].
 bool Sema::SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum,
                                        int Low, int High, bool RangeIsError) {
   if (isConstantEvaluated())
if (const auto *BO = dyn_cast<BinaryOperator>(E)) {
 
     // Right shift by a constant can narrow its left argument.
     case BO_Shr:
     case BO_ShrAssign: {
       IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth, InConstantContext);
 
       // If the shift amount is a positive constant, drop the width by
       // that much.
-      llvm::APSInt shift;
-      if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
-          shift.isNonNegative()) {
-        unsigned zext = shift.getZExtValue();
+      if (Optional<llvm::APSInt> shift =
+              BO->getRHS()->getIntegerConstantExpr(C)) {
+        if (shift->isNonNegative()) {
+          unsigned zext = shift->getZExtValue();
           if (zext >= L.Width)
             L.Width = (L.NonNegative ? 0 : 1);
           else
             L.Width -= zext;
         }
+      }
 
       return L;
     }
 
     // Comma acts as its right operand.
     case BO_Comma:
       return GetExprRange(C, BO->getRHS(), MaxWidth, InConstantContext);
 
     // Black-list pointer subtractions.
     case BO_Sub:
       if (BO->getLHS()->getType()->isPointerType())
         return IntRange::forValueOfType(C, GetExprType(E));
       break;
 
     // The width of a division result is mostly determined by the size
     // of the LHS.
     case BO_Div: {
       // Don't 'pre-truncate' the operands.
       unsigned opWidth = C.getIntWidth(GetExprType(E));
       IntRange L = GetExprRange(C, BO->getLHS(), opWidth, InConstantContext);
 
       // If the divisor is constant, use that.
-      llvm::APSInt divisor;
-      if (BO->getRHS()->isIntegerConstantExpr(divisor, C)) {
-        unsigned log2 = divisor.logBase2(); // floor(log_2(divisor))
+      if (Optional<llvm::APSInt> divisor =
+              BO->getRHS()->getIntegerConstantExpr(C)) {
+        unsigned log2 = divisor->logBase2(); // floor(log_2(divisor))
         if (log2 >= L.Width)
           L.Width = (L.NonNegative ? 0 : 1);
         else
           L.Width = std::min(L.Width - log2, MaxWidth);
         return L;
       }
 
       // Otherwise, just use the LHS's width.
static void AnalyzeComparison(Sema &S, BinaryOperator *E) {
   // Don't analyze value-dependent comparisons directly.
   if (E->isValueDependent())
     return AnalyzeImpConvsInComparison(S, E);
 
   Expr *LHS = E->getLHS();
   Expr *RHS = E->getRHS();
 
   if (T->isIntegralType(S.Context)) {
-    llvm::APSInt RHSValue;
-    llvm::APSInt LHSValue;
-
-    bool IsRHSIntegralLiteral = RHS->isIntegerConstantExpr(RHSValue, S.Context);
-    bool IsLHSIntegralLiteral = LHS->isIntegerConstantExpr(LHSValue, S.Context);
+    Optional<llvm::APSInt> RHSValue = RHS->getIntegerConstantExpr(S.Context);
+    Optional<llvm::APSInt> LHSValue = LHS->getIntegerConstantExpr(S.Context);
 
     // We don't care about expressions whose result is a constant.
-    if (IsRHSIntegralLiteral && IsLHSIntegralLiteral)
+    if (RHSValue && LHSValue)
       return AnalyzeImpConvsInComparison(S, E);
 
     // We only care about expressions where just one side is literal
-    if (IsRHSIntegralLiteral ^ IsLHSIntegralLiteral) {
+    if ((bool)RHSValue ^ (bool)LHSValue) {
       // Is the constant on the RHS or LHS?
-      const bool RhsConstant = IsRHSIntegralLiteral;
+      const bool RhsConstant = (bool)RHSValue;
       Expr *Const = RhsConstant ? RHS : LHS;
       Expr *Other = RhsConstant ? LHS : RHS;
-      const llvm::APSInt &Value = RhsConstant ? RHSValue : LHSValue;
+      const llvm::APSInt &Value = RhsConstant ? *RHSValue : *LHSValue;
 
       // Check whether an integer constant comparison results in a value
       // of 'true' or 'false'.
       if (CheckTautologicalComparison(S, E, Const, Other, Value, RhsConstant))
         return AnalyzeImpConvsInComparison(S, E);
     }
   }
 
if (SourceBT && TargetBT && SourceBT->isIntegerType() &&
     // Determine the number of precision bits in the
     // target floating point type.
     unsigned int TargetPrecision = llvm::APFloatBase::semanticsPrecision(
         S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)));
 
     if (SourcePrecision > 0 && TargetPrecision > 0 &&
         SourcePrecision > TargetPrecision) {
 
-      llvm::APSInt SourceInt;
-      if (E->isIntegerConstantExpr(SourceInt, S.Context)) {
+      if (Optional<llvm::APSInt> SourceInt =
+              E->getIntegerConstantExpr(S.Context)) {
         // If the source integer is a constant, convert it to the target
         // floating point type. Issue a warning if the value changes
         // during the whole conversion.
         llvm::APFloat TargetFloatValue(
             S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)));
         llvm::APFloat::opStatus ConversionStatus =
             TargetFloatValue.convertFromAPInt(
-                SourceInt, SourceBT->isSignedInteger(),
+                *SourceInt, SourceBT->isSignedInteger(),
                 llvm::APFloat::rmNearestTiesToEven);
 
         if (ConversionStatus != llvm::APFloat::opOK) {
-          std::string PrettySourceValue = SourceInt.toString(10);
+          std::string PrettySourceValue = SourceInt->toString(10);
           SmallString<32> PrettyTargetValue;
           TargetFloatValue.toString(PrettyTargetValue, TargetPrecision);
 
           S.DiagRuntimeBehavior(
               E->getExprLoc(), E,
               S.PDiag(diag::warn_impcast_integer_float_precision_constant)
                   << PrettySourceValue << PrettyTargetValue << E->getType() << T
                   << E->getSourceRange() << clang::SourceRange(CC));
void VisitBinaryOperator(BinaryOperator *BinOp) {
       if (!Variable || VarWillBeReased || BinOp->getOpcode() != BO_Assign)
         return;
       Expr *LHS = BinOp->getLHS();
       if (const DeclRefExpr *DRE = dyn_cast_or_null<DeclRefExpr>(LHS)) {
         if (DRE->getDecl() != Variable)
           return;
         if (Expr *RHS = BinOp->getRHS()) {
           RHS = RHS->IgnoreParenCasts();
-          llvm::APSInt Value;
+          Optional<llvm::APSInt> Value;
           VarWillBeReased =
-            (RHS && RHS->isIntegerConstantExpr(Value, Context) && Value == 0);
+              (RHS && (Value = RHS->getIntegerConstantExpr(Context)) &&
+               *Value == 0);
         }
       }
     }
   };
 
 } // namespace
 
 /// Check whether the given argument is a block which captures a

clang/lib/Sema/SemaDecl.cpp

if (!VD->hasAttr<TypeTagForDatatypeAttr>() ||
       !VD->getType()->isIntegralOrEnumerationType())
     return;
 
   for (const auto *I : ThisDecl->specific_attrs<TypeTagForDatatypeAttr>()) {
     const Expr *MagicValueExpr = VD->getInit();
     if (!MagicValueExpr) {
       continue;
     }
-    llvm::APSInt MagicValueInt;
-    if (!MagicValueExpr->isIntegerConstantExpr(MagicValueInt, Context)) {
+    Optional<llvm::APSInt> MagicValueInt;
+    if (!(MagicValueInt = MagicValueExpr->getIntegerConstantExpr(Context))) {
       Diag(I->getRange().getBegin(),
            diag::err_type_tag_for_datatype_not_ice)
         << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
       continue;
     }
-    if (MagicValueInt.getActiveBits() > 64) {
+    if (MagicValueInt->getActiveBits() > 64) {
       Diag(I->getRange().getBegin(),
            diag::err_type_tag_for_datatype_too_large)
         << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
       continue;
     }
-    uint64_t MagicValue = MagicValueInt.getZExtValue();
+    uint64_t MagicValue = MagicValueInt->getZExtValue();
     RegisterTypeTagForDatatype(I->getArgumentKind(),
                                MagicValue,
                                I->getMatchingCType(),
                                I->getLayoutCompatible(),
                                I->getMustBeNull());
   }
 }
 

clang/lib/Sema/SemaDeclAttr.cpp

 /// expression and return success or failure. May output an error.
 ///
 /// Negative argument is implicitly converted to unsigned, unless
 /// \p StrictlyUnsigned is true.
 template <typename AttrInfo>
 static bool checkUInt32Argument(Sema &S, const AttrInfo &AI, const Expr *Expr,
                                 uint32_t &Val, unsigned Idx = UINT_MAX,
                                 bool StrictlyUnsigned = false) {
-  llvm::APSInt I(32);
+  Optional<llvm::APSInt> I = llvm::APSInt(32);
   if (Expr->isTypeDependent() || Expr->isValueDependent() ||
-      !Expr->isIntegerConstantExpr(I, S.Context)) {
+      !(I = Expr->getIntegerConstantExpr(S.Context))) {
     if (Idx != UINT_MAX)
       S.Diag(getAttrLoc(AI), diag::err_attribute_argument_n_type)
           << &AI << Idx << AANT_ArgumentIntegerConstant
           << Expr->getSourceRange();
     else
       S.Diag(getAttrLoc(AI), diag::err_attribute_argument_type)
           << &AI << AANT_ArgumentIntegerConstant << Expr->getSourceRange();
     return false;
   }
 
-  if (!I.isIntN(32)) {
+  if (!I->isIntN(32)) {
     S.Diag(Expr->getExprLoc(), diag::err_ice_too_large)
-        << I.toString(10, false) << 32 << /* Unsigned */ 1;
+        << I->toString(10, false) << 32 << /* Unsigned */ 1;
     return false;
   }
 
-  if (StrictlyUnsigned && I.isSigned() && I.isNegative()) {
+  if (StrictlyUnsigned && I->isSigned() && I->isNegative()) {
     S.Diag(getAttrLoc(AI), diag::err_attribute_requires_positive_integer)
         << &AI << /*non-negative*/ 1;
     return false;
   }
 
-  Val = (uint32_t)I.getZExtValue();
+  Val = (uint32_t)I->getZExtValue();
   return true;
 }
 
 /// Wrapper around checkUInt32Argument, with an extra check to be sure
 /// that the result will fit into a regular (signed) int. All args have the same
 /// purpose as they do in checkUInt32Argument.
 template <typename AttrInfo>
 static bool checkPositiveIntArgument(Sema &S, const AttrInfo &AI, const Expr *Expr,
static bool checkFunctionOrMethodParameterIndex(
   // In C++ the implicit 'this' function parameter also counts.
   // Parameters are counted from one.
   bool HP = hasFunctionProto(D);
   bool HasImplicitThisParam = isInstanceMethod(D);
   bool IV = HP && isFunctionOrMethodVariadic(D);
   unsigned NumParams =
       (HP ? getFunctionOrMethodNumParams(D) : 0) + HasImplicitThisParam;
 
-  llvm::APSInt IdxInt;
+  Optional<llvm::APSInt> IdxInt;
   if (IdxExpr->isTypeDependent() || IdxExpr->isValueDependent() ||
-      !IdxExpr->isIntegerConstantExpr(IdxInt, S.Context)) {
+      !(IdxInt = IdxExpr->getIntegerConstantExpr(S.Context))) {
     S.Diag(getAttrLoc(AI), diag::err_attribute_argument_n_type)
         << &AI << AttrArgNum << AANT_ArgumentIntegerConstant
         << IdxExpr->getSourceRange();
     return false;
   }
 
-  unsigned IdxSource = IdxInt.getLimitedValue(UINT_MAX);
+  unsigned IdxSource = IdxInt->getLimitedValue(UINT_MAX);
   if (IdxSource < 1 || (!IV && IdxSource > NumParams)) {
     S.Diag(getAttrLoc(AI), diag::err_attribute_argument_out_of_bounds)
         << &AI << AttrArgNum << IdxExpr->getSourceRange();
     return false;
   }
   if (HasImplicitThisParam && !CanIndexImplicitThis) {
     if (IdxSource == 1) {
       S.Diag(getAttrLoc(AI), diag::err_attribute_invalid_implicit_this_argument)
void Sema::AddAssumeAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E,
 
   if (!isValidPointerAttrType(ResultType, /* RefOkay */ true)) {
     Diag(AttrLoc, diag::warn_attribute_return_pointers_refs_only)
         << &TmpAttr << TmpAttr.getRange() << SR;
     return;
   }
 
   if (!E->isValueDependent()) {
-    llvm::APSInt I(64);
-    if (!E->isIntegerConstantExpr(I, Context)) {
+    Optional<llvm::APSInt> I = llvm::APSInt(64);
+    if (!(I = E->getIntegerConstantExpr(Context))) {
       if (OE)
         Diag(AttrLoc, diag::err_attribute_argument_n_type)
           << &TmpAttr << 1 << AANT_ArgumentIntegerConstant
           << E->getSourceRange();
       else
         Diag(AttrLoc, diag::err_attribute_argument_type)
           << &TmpAttr << AANT_ArgumentIntegerConstant
           << E->getSourceRange();
       return;
     }
 
-    if (!I.isPowerOf2()) {
+    if (!I->isPowerOf2()) {
       Diag(AttrLoc, diag::err_alignment_not_power_of_two)
         << E->getSourceRange();
       return;
     }
 
-    if (I > Sema::MaximumAlignment)
+    if (*I > Sema::MaximumAlignment)
       Diag(CI.getLoc(), diag::warn_assume_aligned_too_great)
           << CI.getRange() << Sema::MaximumAlignment;
   }
 
-  if (OE) {
-    if (!OE->isValueDependent()) {
-      llvm::APSInt I(64);
-      if (!OE->isIntegerConstantExpr(I, Context)) {
-        Diag(AttrLoc, diag::err_attribute_argument_n_type)
-          << &TmpAttr << 2 << AANT_ArgumentIntegerConstant
-          << OE->getSourceRange();
-        return;
-      }
-    }
-  }
+  if (OE && !OE->isValueDependent() && !OE->isIntegerConstantExpr(Context)) {
 
   D->addAttr(::new (Context) AssumeAlignedAttr(Context, CI, E, OE));
 }
 
 void Sema::AddAllocAlignAttr(Decl *D, const AttributeCommonInfo &CI,
                              Expr *ParamExpr) {
   QualType ResultType = getFunctionOrMethodResultType(D);
 
static void handleBlocksAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
   D->addAttr(::new (S.Context) BlocksAttr(S.Context, AL, type));
 }
 
 static void handleSentinelAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   unsigned sentinel = (unsigned)SentinelAttr::DefaultSentinel;
   if (AL.getNumArgs() > 0) {
     Expr *E = AL.getArgAsExpr(0);
-    llvm::APSInt Idx(32);
+    Optional<llvm::APSInt> Idx = llvm::APSInt(32);
     if (E->isTypeDependent() || E->isValueDependent() ||
-        !E->isIntegerConstantExpr(Idx, S.Context)) {
+        !(Idx = E->getIntegerConstantExpr(S.Context))) {
       S.Diag(AL.getLoc(), diag::err_attribute_argument_n_type)
           << AL << 1 << AANT_ArgumentIntegerConstant << E->getSourceRange();
       return;
     }
 
-    if (Idx.isSigned() && Idx.isNegative()) {
+    if (Idx->isSigned() && Idx->isNegative()) {
       S.Diag(AL.getLoc(), diag::err_attribute_sentinel_less_than_zero)
         << E->getSourceRange();
       return;
     }
 
-    sentinel = Idx.getZExtValue();
+    sentinel = Idx->getZExtValue();
   }
 
   unsigned nullPos = (unsigned)SentinelAttr::DefaultNullPos;
   if (AL.getNumArgs() > 1) {
     Expr *E = AL.getArgAsExpr(1);
-    llvm::APSInt Idx(32);
+    Optional<llvm::APSInt> Idx = llvm::APSInt(32);
     if (E->isTypeDependent() || E->isValueDependent() ||
-        !E->isIntegerConstantExpr(Idx, S.Context)) {
+        !(Idx = E->getIntegerConstantExpr(S.Context))) {
       S.Diag(AL.getLoc(), diag::err_attribute_argument_n_type)
           << AL << 2 << AANT_ArgumentIntegerConstant << E->getSourceRange();
       return;
     }
-    nullPos = Idx.getZExtValue();
+    nullPos = Idx->getZExtValue();
 
-    if ((Idx.isSigned() && Idx.isNegative()) || nullPos > 1) {
+    if ((Idx->isSigned() && Idx->isNegative()) || nullPos > 1) {
       // FIXME: This error message could be improved, it would be nice
       // to say what the bounds actually are.
       S.Diag(AL.getLoc(), diag::err_attribute_sentinel_not_zero_or_one)
         << E->getSourceRange();
       return;
     }
   }
 
static Expr *makeLaunchBoundsArgExpr(Sema &S, Expr *E,
   if (S.DiagnoseUnexpandedParameterPack(E))
     return nullptr;
 
   // Accept template arguments for now as they depend on something else.
   // We'll get to check them when they eventually get instantiated.
   if (E->isValueDependent())
     return E;
 
-  llvm::APSInt I(64);
-  if (!E->isIntegerConstantExpr(I, S.Context)) {
+  Optional<llvm::APSInt> I = llvm::APSInt(64);
+  if (!(I = E->getIntegerConstantExpr(S.Context))) {
     S.Diag(E->getExprLoc(), diag::err_attribute_argument_n_type)
         << &AL << Idx << AANT_ArgumentIntegerConstant << E->getSourceRange();
     return nullptr;
   }
   // Make sure we can fit it in 32 bits.
-  if (!I.isIntN(32)) {
-    S.Diag(E->getExprLoc(), diag::err_ice_too_large) << I.toString(10, false)
-                                                     << 32 << /* Unsigned */ 1;
+  if (!I->isIntN(32)) {
+    S.Diag(E->getExprLoc(), diag::err_ice_too_large)
+        << I->toString(10, false) << 32 << /* Unsigned */ 1;
     return nullptr;
   }
-  if (I < 0)
+  if (*I < 0)
     S.Diag(E->getExprLoc(), diag::warn_attribute_argument_n_negative)
         << &AL << Idx << E->getSourceRange();
 
   // We may need to perform implicit conversion of the argument.
   InitializedEntity Entity = InitializedEntity::InitializeParameter(
       S.Context, S.Context.getConstType(S.Context.IntTy), /*consume*/ false);
   ExprResult ValArg = S.PerformCopyInitialization(Entity, SourceLocation(), E);
   assert(!ValArg.isInvalid() &&
static void handleMSP430InterruptAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
   if (!AL.isArgExpr(0)) {
     S.Diag(AL.getLoc(), diag::err_attribute_argument_type)
         << AL << AANT_ArgumentIntegerConstant;
     return;
   }
 
   Expr *NumParamsExpr = static_cast<Expr *>(AL.getArgAsExpr(0));
-  llvm::APSInt NumParams(32);
-  if (!NumParamsExpr->isIntegerConstantExpr(NumParams, S.Context)) {
+  Optional<llvm::APSInt> NumParams = llvm::APSInt(32);
+  if (!(NumParams = NumParamsExpr->getIntegerConstantExpr(S.Context))) {
     S.Diag(AL.getLoc(), diag::err_attribute_argument_type)
         << AL << AANT_ArgumentIntegerConstant
         << NumParamsExpr->getSourceRange();
     return;
   }
   // The argument should be in range 0..63.
-  unsigned Num = NumParams.getLimitedValue(255);
+  unsigned Num = NumParams->getLimitedValue(255);
   if (Num > 63) {
     S.Diag(AL.getLoc(), diag::err_attribute_argument_out_of_bounds)
-        << AL << (int)NumParams.getSExtValue()
+        << AL << (int)NumParams->getSExtValue()
         << NumParamsExpr->getSourceRange();
     return;
   }
 
   D->addAttr(::new (S.Context) MSP430InterruptAttr(S.Context, AL, Num));
   D->addAttr(UsedAttr::CreateImplicit(S.Context));
 }
 

clang/lib/Sema/SemaExprCXX.cpp

if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) {
     // C++98 [expr.new]p7:
     //   The expression in a direct-new-declarator shall have integral type
     //   with a non-negative value.
     //
     // Let's see if this is a constant < 0. If so, we reject it out of hand,
     // per CWG1464. Otherwise, if it's not a constant, we must have an
     // unparenthesized array type.
     if (!(*ArraySize)->isValueDependent()) {
-      llvm::APSInt Value;
       // We've already performed any required implicit conversion to integer or
       // unscoped enumeration type.
       // FIXME: Per CWG1464, we are required to check the value prior to
       // converting to size_t. This will never find a negative array size in
       // C++14 onwards, because Value is always unsigned here!
-      if ((*ArraySize)->isIntegerConstantExpr(Value, Context)) {
-        if (Value.isSigned() && Value.isNegative()) {
+      if (Optional<llvm::APSInt> Value =
+              (*ArraySize)->getIntegerConstantExpr(Context)) {
+        if (Value->isSigned() && Value->isNegative()) {
           return ExprError(Diag((*ArraySize)->getBeginLoc(),
                                 diag::err_typecheck_negative_array_size)
                            << (*ArraySize)->getSourceRange());
         }
 
         if (!AllocType->isDependentType()) {
-          unsigned ActiveSizeBits =
-            ConstantArrayType::getNumAddressingBits(Context, AllocType, Value);
+          unsigned ActiveSizeBits = ConstantArrayType::getNumAddressingBits(
+              Context, AllocType, *Value);
           if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
             return ExprError(
                 Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large)
-                << Value.toString(10) << (*ArraySize)->getSourceRange());
+                << Value->toString(10) << (*ArraySize)->getSourceRange());
         }
 
-        KnownArraySize = Value.getZExtValue();
+        KnownArraySize = Value->getZExtValue();
       } else if (TypeIdParens.isValid()) {
         // Can't have dynamic array size when the type-id is in parentheses.
         Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst)
             << (*ArraySize)->getSourceRange()
             << FixItHint::CreateRemoval(TypeIdParens.getBegin())
             << FixItHint::CreateRemoval(TypeIdParens.getEnd());
 
         TypeIdParens = SourceRange();

clang/lib/Sema/SemaOpenMP.cpp

Sema::checkOpenMPDeclareVariantFunction(Sema::DeclGroupPtrTy DG,
   // Do not check templates, wait until instantiation.
   if (FD->isDependentContext() || ShouldDelayChecks(VariantRef, false) ||
       TI.anyScoreOrCondition(ShouldDelayChecks))
     return std::make_pair(FD, VariantRef);
 
   // Deal with non-constant score and user condition expressions.
   auto HandleNonConstantScoresAndConditions = [this](Expr *&E,
                                                      bool IsScore) -> bool {
-    llvm::APSInt Result;
-    if (!E || E->isIntegerConstantExpr(Result, Context))
+    if (!E || E->isIntegerConstantExpr(Context))
       return false;
 
     if (IsScore) {
       // We warn on non-constant scores and pretend they were not present.
       Diag(E->getExprLoc(), diag::warn_omp_declare_variant_score_not_constant)
           << E;
       E = nullptr;
     } else {
if (!NewStep->isValueDependent()) {
     //  loop. If test-expr is of form var relational-op b and relational-op is
     //  > or >= then incr-expr must cause var to decrease on each iteration of
     //  the loop.
     //  If test-expr is of form b relational-op var and relational-op is < or
     //  <= then incr-expr must cause var to decrease on each iteration of the
     //  loop. If test-expr is of form b relational-op var and relational-op is
     //  > or >= then incr-expr must cause var to increase on each iteration of
     //  the loop.
-    llvm::APSInt Result;
-    bool IsConstant = NewStep->isIntegerConstantExpr(Result, SemaRef.Context);
+    Optional<llvm::APSInt> Result =
+        NewStep->getIntegerConstantExpr(SemaRef.Context);
     bool IsUnsigned = !NewStep->getType()->hasSignedIntegerRepresentation();
     bool IsConstNeg =
-        IsConstant && Result.isSigned() && (Subtract != Result.isNegative());
+        Result && Result->isSigned() && (Subtract != Result->isNegative());
     bool IsConstPos =
-        IsConstant && Result.isSigned() && (Subtract == Result.isNegative());
-    bool IsConstZero = IsConstant && !Result.getBoolValue();
+        Result && Result->isSigned() && (Subtract == Result->isNegative());
+    bool IsConstZero = Result && !Result->getBoolValue();
 
     // != with increment is treated as <; != with decrement is treated as >
     if (!TestIsLessOp.hasValue())
       TestIsLessOp = IsConstPos || (IsUnsigned && !Subtract);
     if (UB && (IsConstZero ||
                (TestIsLessOp.getValue() ?
                   (IsConstNeg || (IsUnsigned && Subtract)) :
                   (IsConstPos || (IsUnsigned && !Subtract))))) {
return SemaRef.PerformImplicitConversion(E, NewType, Sema::AA_Converting,
                                            true);
 }
 
 /// Check if the given expression \a E is a constant integer that fits
 /// into \a Bits bits.
 static bool fitsInto(unsigned Bits, bool Signed, const Expr *E, Sema &SemaRef) {
   if (E == nullptr)
     return false;
-  llvm::APSInt Result;
-  if (E->isIntegerConstantExpr(Result, SemaRef.Context))
-    return Signed ? Result.isSignedIntN(Bits) : Result.isIntN(Bits);
+  if (Optional<llvm::APSInt> Result =
+          E->getIntegerConstantExpr(SemaRef.Context))
+    return Signed ? Result->isSignedIntN(Bits) : Result->isIntN(Bits);
   return false;
 }
 
 /// Build preinits statement for the given declarations.
 static Stmt *buildPreInits(ASTContext &Context,
                            MutableArrayRef<Decl *> PreInits) {
   if (!PreInits.empty()) {
     return new (Context) DeclStmt(
LastIteration = SemaRef.BuildBinOp(
         LastIteration.get(),
         SemaRef.ActOnIntegerConstant(SourceLocation(), 1).get());
     if (!LastIteration.isUsable())
       return 0;
   }
 
   // Calculate the last iteration number beforehand instead of doing this on
   // each iteration. Do not do this if the number of iterations may be kfold-ed.
-  llvm::APSInt Result;
-  bool IsConstant =
-      LastIteration.get()->isIntegerConstantExpr(Result, SemaRef.Context);
+  bool IsConstant = LastIteration.get()->isIntegerConstantExpr(SemaRef.Context);
   ExprResult CalcLastIteration;
   if (!IsConstant) {
     ExprResult SaveRef =
         tryBuildCapture(SemaRef, LastIteration.get(), Captures);
     LastIteration = SaveRef;
 
     // Prepare SaveRef + 1.
     NumIterations = SemaRef.BuildBinOp(
if (!ValExpr->isTypeDependent() && !ValExpr->isValueDependent() &&
     SourceLocation Loc = ValExpr->getExprLoc();
     ExprResult Value =
         SemaRef.PerformOpenMPImplicitIntegerConversion(Loc, ValExpr);
     if (Value.isInvalid())
       return false;
 
     ValExpr = Value.get();
     // The expression must evaluate to a non-negative integer value.
-    llvm::APSInt Result;
-    if (ValExpr->isIntegerConstantExpr(Result, SemaRef.Context) &&
-        Result.isSigned() &&
-        !((!StrictlyPositive && Result.isNonNegative()) ||
-          (StrictlyPositive && Result.isStrictlyPositive()))) {
+    if (Optional<llvm::APSInt> Result =
+            ValExpr->getIntegerConstantExpr(SemaRef.Context)) {
+      if (Result->isSigned() &&
+          !((!StrictlyPositive && Result->isNonNegative()) ||
+            (StrictlyPositive && Result->isStrictlyPositive()))) {
         SemaRef.Diag(Loc, diag::err_omp_negative_expression_in_clause)
             << getOpenMPClauseName(CKind) << (StrictlyPositive ? 1 : 0)
             << ValExpr->getSourceRange();
         return false;
       }
+    }
     if (!BuildCapture)
       return true;
     *CaptureRegion =
         getOpenMPCaptureRegionForClause(DKind, CKind, SemaRef.LangOpts.OpenMP);
     if (*CaptureRegion != OMPD_unknown &&
         !SemaRef.CurContext->isDependentContext()) {
       ValExpr = SemaRef.MakeFullExpr(ValExpr).get();
       llvm::MapVector<const Expr *, DeclRefExpr *> Captures;
if (!ChunkSize->isValueDependent() && !ChunkSize->isTypeDependent() &&
       if (Val.isInvalid())
         return nullptr;
 
       ValExpr = Val.get();
 
       // OpenMP [2.7.1, Restrictions]
       //  chunk_size must be a loop invariant integer expression with a positive
       //  value.
-      llvm::APSInt Result;
-      if (ValExpr->isIntegerConstantExpr(Result, Context)) {
-        if (Result.isSigned() && !Result.isStrictlyPositive()) {
+      if (Optional<llvm::APSInt> Result =
+              ValExpr->getIntegerConstantExpr(Context)) {
+        if (Result->isSigned() && !Result->isStrictlyPositive()) {
           Diag(ChunkSizeLoc, diag::err_omp_negative_expression_in_clause)
               << "schedule" << 1 << ChunkSize->getSourceRange();
           return nullptr;
         }
       } else if (getOpenMPCaptureRegionForClause(
                      DSAStack->getCurrentDirective(), OMPC_schedule,
                      LangOpts.OpenMP) != OMPD_unknown &&
                  !CurContext->isDependentContext()) {
if (Step && !Step->isValueDependent() && !Step->isTypeDependent() &&
     ExprResult SaveRef =
         buildDeclRefExpr(*this, SaveVar, StepExpr->getType(), StepLoc);
     ExprResult CalcStep =
         BuildBinOp(CurScope, StepLoc, BO_Assign, SaveRef.get(), StepExpr);
     CalcStep = ActOnFinishFullExpr(CalcStep.get(), /*DiscardedValue*/ false);
 
     // Warn about zero linear step (it would be probably better specified as
     // making corresponding variables 'const').
-    llvm::APSInt Result;
-    bool IsConstant = StepExpr->isIntegerConstantExpr(Result, Context);
-    if (IsConstant && !Result.isNegative() && !Result.isStrictlyPositive())
-      Diag(StepLoc, diag::warn_omp_linear_step_zero) << Vars[0]
-                                                     << (Vars.size() > 1);
-    if (!IsConstant && CalcStep.isUsable()) {
+    if (Optional<llvm::APSInt> Result =
+            StepExpr->getIntegerConstantExpr(Context)) {
+      if (!Result->isNegative() && !Result->isStrictlyPositive())
+        Diag(StepLoc, diag::warn_omp_linear_step_zero)
+            << Vars[0] << (Vars.size() > 1);
+    } else if (CalcStep.isUsable()) {
       // Calculate the step beforehand instead of doing this on each iteration.
       // (This is not used if the number of iterations may be kfold-ed).
       CalcStepExpr = CalcStep.get();
     }
   }
 
   return OMPLinearClause::Create(Context, StartLoc, LParenLoc, LinKind, LinLoc,
                                  ColonLoc, EndLoc, Vars, Privates, Inits,
if (!ChunkSize->isValueDependent() && !ChunkSize->isTypeDependent() &&
       if (Val.isInvalid())
         return nullptr;
 
       ValExpr = Val.get();
 
       // OpenMP [2.7.1, Restrictions]
       //  chunk_size must be a loop invariant integer expression with a positive
       //  value.
-      llvm::APSInt Result;
-      if (ValExpr->isIntegerConstantExpr(Result, Context)) {
-        if (Result.isSigned() && !Result.isStrictlyPositive()) {
+      if (Optional<llvm::APSInt> Result =
+              ValExpr->getIntegerConstantExpr(Context)) {
+        if (Result->isSigned() && !Result->isStrictlyPositive()) {
           Diag(ChunkSizeLoc, diag::err_omp_negative_expression_in_clause)
               << "dist_schedule" << ChunkSize->getSourceRange();
           return nullptr;
         }
       } else if (getOpenMPCaptureRegionForClause(
                      DSAStack->getCurrentDirective(), OMPC_dist_schedule,
                      LangOpts.OpenMP) != OMPD_unknown &&
                  !CurContext->isDependentContext()) {

clang/lib/Sema/SemaOverload.cpp

NarrowingKind StandardConversionSequence::getNarrowingKind(
   case ICK_Floating_Integral:
   FloatingIntegralConversion:
     if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
       return NK_Type_Narrowing;
     } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
                ToType->isRealFloatingType()) {
       if (IgnoreFloatToIntegralConversion)
         return NK_Not_Narrowing;
-      llvm::APSInt IntConstantValue;
       const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
       assert(Initializer && "Unknown conversion expression");
 
       // If it's value-dependent, we can't tell whether it's narrowing.
       if (Initializer->isValueDependent())
         return NK_Dependent_Narrowing;
 
-      if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
+      if (Optional<llvm::APSInt> IntConstantValue =
+              Initializer->getIntegerConstantExpr(Ctx)) {
         // Convert the integer to the floating type.
         llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
-        Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
+        Result.convertFromAPInt(*IntConstantValue, IntConstantValue->isSigned(),
                                 llvm::APFloat::rmNearestTiesToEven);
         // And back.
-        llvm::APSInt ConvertedValue = IntConstantValue;
+        llvm::APSInt ConvertedValue = *IntConstantValue;
         bool ignored;
         Result.convertToInteger(ConvertedValue,
                                 llvm::APFloat::rmTowardZero, &ignored);
         // If the resulting value is different, this was a narrowing conversion.
-        if (IntConstantValue != ConvertedValue) {
-          ConstantValue = APValue(IntConstantValue);
+        if (*IntConstantValue != ConvertedValue) {
+          ConstantValue = APValue(*IntConstantValue);
           ConstantType = Initializer->getType();
           return NK_Constant_Narrowing;
         }
       } else {
         // Variables are always narrowings.
         return NK_Variable_Narrowing;
       }
     }
IntegralConversion: {
     const unsigned FromWidth = Ctx.getIntWidth(FromType);
     const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
     const unsigned ToWidth = Ctx.getIntWidth(ToType);
 
     if (FromWidth > ToWidth ||
         (FromWidth == ToWidth && FromSigned != ToSigned) ||
         (FromSigned && !ToSigned)) {
       // Not all values of FromType can be represented in ToType.
-      llvm::APSInt InitializerValue;
       const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
 
       // If it's value-dependent, we can't tell whether it's narrowing.
       if (Initializer->isValueDependent())
         return NK_Dependent_Narrowing;
 
-      if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
+      Optional<llvm::APSInt> OptInitializerValue;
+      if (!(OptInitializerValue = Initializer->getIntegerConstantExpr(Ctx))) {
         // Such conversions on variables are always narrowing.
         return NK_Variable_Narrowing;
       }
+      llvm::APSInt &InitializerValue = *OptInitializerValue;
       bool Narrowing = false;
       if (FromWidth < ToWidth) {
         // Negative -> unsigned is narrowing. Otherwise, more bits is never
         // narrowing.
         if (InitializerValue.isSigned() && InitializerValue.isNegative())
           Narrowing = true;
       } else {
         // Add a bit to the InitializerValue so we don't have to worry about
bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
   // conversion.
   //
   // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
   // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
   // bit-fields and those whose underlying type is larger than int) for GCC
   // compatibility.
   if (From) {
     if (FieldDecl *MemberDecl = From->getSourceBitField()) {
-      llvm::APSInt BitWidth;
+      Optional<llvm::APSInt> BitWidth;
       if (FromType->isIntegralType(Context) &&
-          MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
-        llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
+          (BitWidth =
+               MemberDecl->getBitWidth()->getIntegerConstantExpr(Context))) {
+        llvm::APSInt ToSize(BitWidth->getBitWidth(), BitWidth->isUnsigned());
         ToSize = Context.getTypeSize(ToType);
 
         // Are we promoting to an int from a bitfield that fits in an int?
-        if (BitWidth < ToSize ||
-            (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
+        if (*BitWidth < ToSize ||
+            (FromType->isSignedIntegerType() && *BitWidth <= ToSize)) {
           return To->getKind() == BuiltinType::Int;
         }
 
         // Are we promoting to an unsigned int from an unsigned bitfield
         // that fits into an unsigned int?
-        if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
+        if (FromType->isUnsignedIntegerType() && *BitWidth <= ToSize) {
           return To->getKind() == BuiltinType::UInt;
         }
 
         return false;
       }
     }
   }
 

clang/lib/Sema/SemaStmtAttr.cpp

if (NumArgs > 1) {
     S.Diag(A.getLoc(), diag::err_attribute_too_many_arguments) << A << 1;
     return nullptr;
   }
 
   unsigned UnrollFactor = 0;
 
   if (NumArgs == 1) {
     Expr *E = A.getArgAsExpr(0);
-    llvm::APSInt ArgVal(32);
+    Optional<llvm::APSInt> ArgVal;
 
-    if (!E->isIntegerConstantExpr(ArgVal, S.Context)) {
+    if (!(ArgVal = E->getIntegerConstantExpr(S.Context))) {
       S.Diag(A.getLoc(), diag::err_attribute_argument_type)
           << A << AANT_ArgumentIntegerConstant << E->getSourceRange();
       return nullptr;
     }
 
-    int Val = ArgVal.getSExtValue();
+    int Val = ArgVal->getSExtValue();
 
     if (Val <= 0) {
       S.Diag(A.getRange().getBegin(),
              diag::err_attribute_requires_positive_integer)
           << A << /* positive */ 0;
       return nullptr;
     }
     UnrollFactor = Val;

clang/lib/Sema/SemaType.cpp

if (!CurType->isDependentType() &&
     Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << CurType;
     return QualType();
   }
 
   if (SizeExpr->isTypeDependent() || SizeExpr->isValueDependent())
     return Context.getDependentVectorType(CurType, SizeExpr, AttrLoc,
                                                VectorType::GenericVector);
 
-  llvm::APSInt VecSize(32);
-  if (!SizeExpr->isIntegerConstantExpr(VecSize, Context)) {
+  Optional<llvm::APSInt> VecSize = SizeExpr->getIntegerConstantExpr(Context);
+  if (!VecSize) {
     Diag(AttrLoc, diag::err_attribute_argument_type)
         << "vector_size" << AANT_ArgumentIntegerConstant
         << SizeExpr->getSourceRange();
     return QualType();
   }
 
   if (CurType->isDependentType())
     return Context.getDependentVectorType(CurType, SizeExpr, AttrLoc,
                                                VectorType::GenericVector);
 
   // vecSize is specified in bytes - convert to bits.
-  if (!VecSize.isIntN(61)) {
+  if (!VecSize->isIntN(61)) {
     // Bit size will overflow uint64.
     Diag(AttrLoc, diag::err_attribute_size_too_large)
         << SizeExpr->getSourceRange() << "vector";
     return QualType();
   }
-  uint64_t VectorSizeBits = VecSize.getZExtValue() * 8;
+  uint64_t VectorSizeBits = VecSize->getZExtValue() * 8;
   unsigned TypeSize = static_cast<unsigned>(Context.getTypeSize(CurType));
 
   if (VectorSizeBits == 0) {
     Diag(AttrLoc, diag::err_attribute_zero_size)
         << SizeExpr->getSourceRange() << "vector";
     return QualType();
   }
 
QualType Sema::BuildExtVectorType(QualType T, Expr *ArraySize,
   if ((!T->isDependentType() && !T->isIntegerType() &&
        !T->isRealFloatingType()) ||
       T->isBooleanType()) {
     Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << T;
     return QualType();
   }
 
   if (!ArraySize->isTypeDependent() && !ArraySize->isValueDependent()) {
-    llvm::APSInt vecSize(32);
-    if (!ArraySize->isIntegerConstantExpr(vecSize, Context)) {
+    Optional<llvm::APSInt> vecSize = ArraySize->getIntegerConstantExpr(Context);
+    if (!vecSize) {
       Diag(AttrLoc, diag::err_attribute_argument_type)
         << "ext_vector_type" << AANT_ArgumentIntegerConstant
         << ArraySize->getSourceRange();
       return QualType();
     }
 
     if (!vecSize.isIntN(32)) {
       Diag(AttrLoc, diag::err_attribute_size_too_large)
           << ArraySize->getSourceRange() << "vector";
       return QualType();
     }
     // Unlike gcc's vector_size attribute, the size is specified as the
     // number of elements, not the number of bytes.
-    unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue());
+    unsigned vectorSize = static_cast<unsigned>(vecSize->getZExtValue());
 
     if (vectorSize == 0) {
       Diag(AttrLoc, diag::err_attribute_zero_size)
           << ArraySize->getSourceRange() << "vector";
       return QualType();
     }
 
     return Context.getExtVectorType(T, vectorSize);

 
 /// Build an AddressSpace index from a constant expression and diagnose any
 /// errors related to invalid address_spaces. Returns true on successfully
 /// building an AddressSpace index.
 static bool BuildAddressSpaceIndex(Sema &S, LangAS &ASIdx,
                                    const Expr *AddrSpace,
                                    SourceLocation AttrLoc) {
   if (!AddrSpace->isValueDependent()) {
-    llvm::APSInt addrSpace(32);
-    if (!AddrSpace->isIntegerConstantExpr(addrSpace, S.Context)) {
+    Optional<llvm::APSInt> OptAddrSpace =
+        AddrSpace->getIntegerConstantExpr(S.Context);
+    if (!OptAddrSpace) {
       S.Diag(AttrLoc, diag::err_attribute_argument_type)
           << "'address_space'" << AANT_ArgumentIntegerConstant
           << AddrSpace->getSourceRange();
       return false;
     }
+    llvm::APSInt &addrSpace = *OptAddrSpace;
 
     // Bounds checking.
     if (addrSpace.isSigned()) {
       if (addrSpace.isNegative()) {
         S.Diag(AttrLoc, diag::err_attribute_address_space_negative)
             << AddrSpace->getSourceRange();
         return false;
       }
static void HandleNeonVectorTypeAttr(QualType &CurType, const ParsedAttr &Attr,
   if (Attr.getNumArgs() != 1) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << Attr
                                                                       << 1;
     Attr.setInvalid();
     return;
   }
   // The number of elements must be an ICE.
   Expr *numEltsExpr = static_cast<Expr *>(Attr.getArgAsExpr(0));
-  llvm::APSInt numEltsInt(32);
+  Optional<llvm::APSInt> numEltsInt;
   if (numEltsExpr->isTypeDependent() || numEltsExpr->isValueDependent() ||
-      !numEltsExpr->isIntegerConstantExpr(numEltsInt, S.Context)) {
+      !(numEltsInt = numEltsExpr->getIntegerConstantExpr(S.Context))) {
     S.Diag(Attr.getLoc(), diag::err_attribute_argument_type)
         << Attr << AANT_ArgumentIntegerConstant
         << numEltsExpr->getSourceRange();
     Attr.setInvalid();
     return;
   }
   // Only certain element types are supported for Neon vectors.
   if (!isPermittedNeonBaseType(CurType, VecKind, S)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_invalid_vector_type) << CurType;
     Attr.setInvalid();
     return;
   }
 
   // The total size of the vector must be 64 or 128 bits.
   unsigned typeSize = static_cast<unsigned>(S.Context.getTypeSize(CurType));
-  unsigned numElts = static_cast<unsigned>(numEltsInt.getZExtValue());
+  unsigned numElts = static_cast<unsigned>(numEltsInt->getZExtValue());
   unsigned vecSize = typeSize * numElts;
   if (vecSize != 64 && vecSize != 128) {
     S.Diag(Attr.getLoc(), diag::err_attribute_bad_neon_vector_size) << CurType;
     Attr.setInvalid();
     return;
   }
 
   CurType = S.Context.getVectorType(CurType, numElts, VecKind);