Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 1 | //===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===// |
Anders Carlsson | c44eec6 | 2008-07-03 04:20:39 +0000 | [diff] [blame] | 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file implements the Expr constant evaluator. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "clang/AST/APValue.h" |
| 15 | #include "clang/AST/ASTContext.h" |
Seo Sanghyeon | 0fe52e1 | 2008-07-08 07:23:12 +0000 | [diff] [blame] | 16 | #include "clang/AST/StmtVisitor.h" |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 17 | #include "clang/Basic/Diagnostic.h" |
Anders Carlsson | 06a3675 | 2008-07-08 05:49:43 +0000 | [diff] [blame] | 18 | #include "clang/Basic/TargetInfo.h" |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 19 | #include "llvm/Support/Compiler.h" |
Anders Carlsson | c44eec6 | 2008-07-03 04:20:39 +0000 | [diff] [blame] | 20 | using namespace clang; |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 21 | using llvm::APSInt; |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 22 | using llvm::APFloat; |
Anders Carlsson | c44eec6 | 2008-07-03 04:20:39 +0000 | [diff] [blame] | 23 | |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 24 | /// EvalInfo - This is a private struct used by the evaluator to capture |
| 25 | /// information about a subexpression as it is folded. It retains information |
| 26 | /// about the AST context, but also maintains information about the folded |
| 27 | /// expression. |
| 28 | /// |
| 29 | /// If an expression could be evaluated, it is still possible it is not a C |
| 30 | /// "integer constant expression" or constant expression. If not, this struct |
| 31 | /// captures information about how and why not. |
| 32 | /// |
| 33 | /// One bit of information passed *into* the request for constant folding |
| 34 | /// indicates whether the subexpression is "evaluated" or not according to C |
| 35 | /// rules. For example, the RHS of (0 && foo()) is not evaluated. We can |
| 36 | /// evaluate the expression regardless of what the RHS is, but C only allows |
| 37 | /// certain things in certain situations. |
| 38 | struct EvalInfo { |
| 39 | ASTContext &Ctx; |
| 40 | |
| 41 | /// isEvaluated - True if the subexpression is required to be evaluated, false |
| 42 | /// if it is short-circuited (according to C rules). |
| 43 | bool isEvaluated; |
| 44 | |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 45 | /// ICEDiag - If the expression is unfoldable, then ICEDiag contains the |
| 46 | /// error diagnostic indicating why it is not foldable and DiagLoc indicates a |
| 47 | /// caret position for the error. If it is foldable, but the expression is |
| 48 | /// not an integer constant expression, ICEDiag contains the extension |
| 49 | /// diagnostic to emit which describes why it isn't an integer constant |
| 50 | /// expression. If this expression *is* an integer-constant-expr, then |
| 51 | /// ICEDiag is zero. |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 52 | /// |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 53 | /// The caller can choose to emit this diagnostic or not, depending on whether |
| 54 | /// they require an i-c-e or a constant or not. DiagLoc indicates the caret |
| 55 | /// position for the report. |
| 56 | /// |
| 57 | /// If ICEDiag is zero, then this expression is an i-c-e. |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 58 | unsigned ICEDiag; |
| 59 | SourceLocation DiagLoc; |
| 60 | |
| 61 | EvalInfo(ASTContext &ctx) : Ctx(ctx), isEvaluated(true), ICEDiag(0) {} |
| 62 | }; |
| 63 | |
| 64 | |
| 65 | static bool EvaluatePointer(const Expr *E, APValue &Result, EvalInfo &Info); |
| 66 | static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info); |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 67 | static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info); |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 68 | |
| 69 | //===----------------------------------------------------------------------===// |
| 70 | // Pointer Evaluation |
| 71 | //===----------------------------------------------------------------------===// |
| 72 | |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 73 | namespace { |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 74 | class VISIBILITY_HIDDEN PointerExprEvaluator |
| 75 | : public StmtVisitor<PointerExprEvaluator, APValue> { |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 76 | EvalInfo &Info; |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 77 | public: |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 78 | |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 79 | PointerExprEvaluator(EvalInfo &info) : Info(info) {} |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 80 | |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 81 | APValue VisitStmt(Stmt *S) { |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 82 | return APValue(); |
| 83 | } |
| 84 | |
| 85 | APValue VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| 86 | |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 87 | APValue VisitBinaryOperator(const BinaryOperator *E); |
| 88 | APValue VisitCastExpr(const CastExpr* E); |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 89 | }; |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 90 | } // end anonymous namespace |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 91 | |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 92 | static bool EvaluatePointer(const Expr* E, APValue& Result, EvalInfo &Info) { |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 93 | if (!E->getType()->isPointerType()) |
| 94 | return false; |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 95 | Result = PointerExprEvaluator(Info).Visit(const_cast<Expr*>(E)); |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 96 | return Result.isLValue(); |
| 97 | } |
| 98 | |
| 99 | APValue PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
| 100 | if (E->getOpcode() != BinaryOperator::Add && |
| 101 | E->getOpcode() != BinaryOperator::Sub) |
| 102 | return APValue(); |
| 103 | |
| 104 | const Expr *PExp = E->getLHS(); |
| 105 | const Expr *IExp = E->getRHS(); |
| 106 | if (IExp->getType()->isPointerType()) |
| 107 | std::swap(PExp, IExp); |
| 108 | |
| 109 | APValue ResultLValue; |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 110 | if (!EvaluatePointer(PExp, ResultLValue, Info)) |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 111 | return APValue(); |
| 112 | |
| 113 | llvm::APSInt AdditionalOffset(32); |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 114 | if (!EvaluateInteger(IExp, AdditionalOffset, Info)) |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 115 | return APValue(); |
| 116 | |
| 117 | uint64_t Offset = ResultLValue.getLValueOffset(); |
| 118 | if (E->getOpcode() == BinaryOperator::Add) |
| 119 | Offset += AdditionalOffset.getZExtValue(); |
| 120 | else |
| 121 | Offset -= AdditionalOffset.getZExtValue(); |
| 122 | |
| 123 | return APValue(ResultLValue.getLValueBase(), Offset); |
| 124 | } |
| 125 | |
| 126 | |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 127 | APValue PointerExprEvaluator::VisitCastExpr(const CastExpr* E) { |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 128 | const Expr* SubExpr = E->getSubExpr(); |
| 129 | |
| 130 | // Check for pointer->pointer cast |
| 131 | if (SubExpr->getType()->isPointerType()) { |
| 132 | APValue Result; |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 133 | if (EvaluatePointer(SubExpr, Result, Info)) |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 134 | return Result; |
| 135 | return APValue(); |
| 136 | } |
| 137 | |
Eli Friedman | d9f4bcd | 2008-07-27 05:46:18 +0000 | [diff] [blame] | 138 | if (SubExpr->getType()->isIntegralType()) { |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 139 | llvm::APSInt Result(32); |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 140 | if (EvaluateInteger(SubExpr, Result, Info)) { |
| 141 | Result.extOrTrunc((unsigned)Info.Ctx.getTypeSize(E->getType())); |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 142 | return APValue(0, Result.getZExtValue()); |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | assert(0 && "Unhandled cast"); |
| 147 | return APValue(); |
| 148 | } |
| 149 | |
| 150 | |
| 151 | //===----------------------------------------------------------------------===// |
| 152 | // Integer Evaluation |
| 153 | //===----------------------------------------------------------------------===// |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 154 | |
| 155 | namespace { |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 156 | class VISIBILITY_HIDDEN IntExprEvaluator |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 157 | : public StmtVisitor<IntExprEvaluator, bool> { |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 158 | EvalInfo &Info; |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 159 | APSInt &Result; |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 160 | public: |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 161 | IntExprEvaluator(EvalInfo &info, APSInt &result) |
| 162 | : Info(info), Result(result) {} |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 163 | |
Chris Lattner | 7a76778 | 2008-07-11 19:24:49 +0000 | [diff] [blame] | 164 | unsigned getIntTypeSizeInBits(QualType T) const { |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 165 | return (unsigned)Info.Ctx.getIntWidth(T); |
| 166 | } |
| 167 | |
| 168 | bool Extension(SourceLocation L, diag::kind D) { |
| 169 | Info.DiagLoc = L; |
| 170 | Info.ICEDiag = D; |
| 171 | return true; // still a constant. |
| 172 | } |
| 173 | |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 174 | bool Error(SourceLocation L, diag::kind D, QualType ExprTy) { |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 175 | // If this is in an unevaluated portion of the subexpression, ignore the |
| 176 | // error. |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 177 | if (!Info.isEvaluated) { |
| 178 | // If error is ignored because the value isn't evaluated, get the real |
| 179 | // type at least to prevent errors downstream. |
| 180 | Result.zextOrTrunc(getIntTypeSizeInBits(ExprTy)); |
| 181 | Result.setIsUnsigned(ExprTy->isUnsignedIntegerType()); |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 182 | return true; |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 183 | } |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 184 | |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 185 | // Take the first error. |
| 186 | if (Info.ICEDiag == 0) { |
| 187 | Info.DiagLoc = L; |
| 188 | Info.ICEDiag = D; |
| 189 | } |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 190 | return false; |
Chris Lattner | 7a76778 | 2008-07-11 19:24:49 +0000 | [diff] [blame] | 191 | } |
| 192 | |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 193 | //===--------------------------------------------------------------------===// |
| 194 | // Visitor Methods |
| 195 | //===--------------------------------------------------------------------===// |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 196 | |
| 197 | bool VisitStmt(Stmt *) { |
| 198 | assert(0 && "This should be called on integers, stmts are not integers"); |
| 199 | return false; |
| 200 | } |
Chris Lattner | 7a76778 | 2008-07-11 19:24:49 +0000 | [diff] [blame] | 201 | |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 202 | bool VisitExpr(Expr *E) { |
| 203 | return Error(E->getLocStart(), diag::err_expr_not_constant, E->getType()); |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 204 | } |
| 205 | |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 206 | bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
Anders Carlsson | c754aa6 | 2008-07-08 05:13:58 +0000 | [diff] [blame] | 207 | |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 208 | bool VisitIntegerLiteral(const IntegerLiteral *E) { |
| 209 | Result = E->getValue(); |
| 210 | Result.setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
| 211 | return true; |
| 212 | } |
| 213 | bool VisitCharacterLiteral(const CharacterLiteral *E) { |
| 214 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 215 | Result = E->getValue(); |
| 216 | Result.setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
| 217 | return true; |
| 218 | } |
| 219 | bool VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { |
| 220 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
Daniel Dunbar | ac620de | 2008-10-24 08:07:57 +0000 | [diff] [blame] | 221 | // Per gcc docs "this built-in function ignores top level |
| 222 | // qualifiers". We need to use the canonical version to properly |
| 223 | // be able to strip CRV qualifiers from the type. |
| 224 | QualType T0 = Info.Ctx.getCanonicalType(E->getArgType1()); |
| 225 | QualType T1 = Info.Ctx.getCanonicalType(E->getArgType2()); |
| 226 | Result = Info.Ctx.typesAreCompatible(T0.getUnqualifiedType(), |
| 227 | T1.getUnqualifiedType()); |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 228 | return true; |
| 229 | } |
| 230 | bool VisitDeclRefExpr(const DeclRefExpr *E); |
| 231 | bool VisitCallExpr(const CallExpr *E); |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 232 | bool VisitBinaryOperator(const BinaryOperator *E); |
| 233 | bool VisitUnaryOperator(const UnaryOperator *E); |
Anders Carlsson | 06a3675 | 2008-07-08 05:49:43 +0000 | [diff] [blame] | 234 | |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 235 | bool VisitCastExpr(CastExpr* E) { |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 236 | return HandleCast(E->getLocStart(), E->getSubExpr(), E->getType()); |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 237 | } |
Sebastian Redl | 0518999 | 2008-11-11 17:56:53 +0000 | [diff] [blame] | 238 | bool VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); |
| 239 | |
Chris Lattner | fcee001 | 2008-07-11 21:24:13 +0000 | [diff] [blame] | 240 | private: |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 241 | bool HandleCast(SourceLocation CastLoc, Expr *SubExpr, QualType DestType); |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 242 | }; |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 243 | } // end anonymous namespace |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 244 | |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 245 | static bool EvaluateInteger(const Expr* E, APSInt &Result, EvalInfo &Info) { |
| 246 | return IntExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 247 | } |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 248 | |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 249 | bool IntExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) { |
| 250 | // Enums are integer constant exprs. |
| 251 | if (const EnumConstantDecl *D = dyn_cast<EnumConstantDecl>(E->getDecl())) { |
| 252 | Result = D->getInitVal(); |
| 253 | return true; |
| 254 | } |
| 255 | |
| 256 | // Otherwise, random variable references are not constants. |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 257 | return Error(E->getLocStart(), diag::err_expr_not_constant, E->getType()); |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 258 | } |
| 259 | |
Chris Lattner | a4d55d8 | 2008-10-06 06:40:35 +0000 | [diff] [blame] | 260 | /// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way |
| 261 | /// as GCC. |
| 262 | static int EvaluateBuiltinClassifyType(const CallExpr *E) { |
| 263 | // The following enum mimics the values returned by GCC. |
| 264 | enum gcc_type_class { |
| 265 | no_type_class = -1, |
| 266 | void_type_class, integer_type_class, char_type_class, |
| 267 | enumeral_type_class, boolean_type_class, |
| 268 | pointer_type_class, reference_type_class, offset_type_class, |
| 269 | real_type_class, complex_type_class, |
| 270 | function_type_class, method_type_class, |
| 271 | record_type_class, union_type_class, |
| 272 | array_type_class, string_type_class, |
| 273 | lang_type_class |
| 274 | }; |
| 275 | |
| 276 | // If no argument was supplied, default to "no_type_class". This isn't |
| 277 | // ideal, however it is what gcc does. |
| 278 | if (E->getNumArgs() == 0) |
| 279 | return no_type_class; |
| 280 | |
| 281 | QualType ArgTy = E->getArg(0)->getType(); |
| 282 | if (ArgTy->isVoidType()) |
| 283 | return void_type_class; |
| 284 | else if (ArgTy->isEnumeralType()) |
| 285 | return enumeral_type_class; |
| 286 | else if (ArgTy->isBooleanType()) |
| 287 | return boolean_type_class; |
| 288 | else if (ArgTy->isCharType()) |
| 289 | return string_type_class; // gcc doesn't appear to use char_type_class |
| 290 | else if (ArgTy->isIntegerType()) |
| 291 | return integer_type_class; |
| 292 | else if (ArgTy->isPointerType()) |
| 293 | return pointer_type_class; |
| 294 | else if (ArgTy->isReferenceType()) |
| 295 | return reference_type_class; |
| 296 | else if (ArgTy->isRealType()) |
| 297 | return real_type_class; |
| 298 | else if (ArgTy->isComplexType()) |
| 299 | return complex_type_class; |
| 300 | else if (ArgTy->isFunctionType()) |
| 301 | return function_type_class; |
| 302 | else if (ArgTy->isStructureType()) |
| 303 | return record_type_class; |
| 304 | else if (ArgTy->isUnionType()) |
| 305 | return union_type_class; |
| 306 | else if (ArgTy->isArrayType()) |
| 307 | return array_type_class; |
| 308 | else if (ArgTy->isUnionType()) |
| 309 | return union_type_class; |
| 310 | else // FIXME: offset_type_class, method_type_class, & lang_type_class? |
| 311 | assert(0 && "CallExpr::isBuiltinClassifyType(): unimplemented type"); |
| 312 | return -1; |
| 313 | } |
| 314 | |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 315 | bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) { |
| 316 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 317 | |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 318 | switch (E->isBuiltinCall()) { |
| 319 | default: |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 320 | return Error(E->getLocStart(), diag::err_expr_not_constant, E->getType()); |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 321 | case Builtin::BI__builtin_classify_type: |
Chris Lattner | a4d55d8 | 2008-10-06 06:40:35 +0000 | [diff] [blame] | 322 | Result.setIsSigned(true); |
| 323 | Result = EvaluateBuiltinClassifyType(E); |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 324 | return true; |
| 325 | |
| 326 | case Builtin::BI__builtin_constant_p: { |
| 327 | // __builtin_constant_p always has one operand: it returns true if that |
| 328 | // operand can be folded, false otherwise. |
| 329 | APValue Res; |
| 330 | Result = E->getArg(0)->tryEvaluate(Res, Info.Ctx); |
| 331 | return true; |
| 332 | } |
| 333 | } |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 334 | } |
Anders Carlsson | 650c92f | 2008-07-08 15:34:11 +0000 | [diff] [blame] | 335 | |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 336 | bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 337 | // The LHS of a constant expr is always evaluated and needed. |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 338 | llvm::APSInt RHS(32); |
Chris Lattner | c8cc9cc | 2008-11-12 07:04:29 +0000 | [diff] [blame] | 339 | if (!Visit(E->getLHS())) { |
| 340 | // If the LHS is unfoldable, we generally can't fold this. However, if this |
| 341 | // is a logical operator like &&/||, and if we know that the RHS determines |
| 342 | // the outcome of the result (e.g. X && 0), return the outcome. |
| 343 | if (!E->isLogicalOp()) |
| 344 | return false; |
| 345 | |
| 346 | // If this is a logical op, see if the RHS determines the outcome. |
| 347 | EvalInfo Info2(Info.Ctx); |
| 348 | if (!EvaluateInteger(E->getRHS(), RHS, Info2)) |
| 349 | return false; |
| 350 | |
| 351 | // X && 0 -> 0, X || 1 -> 1. |
| 352 | if (E->getOpcode() == BinaryOperator::LAnd && RHS == 0 || |
| 353 | E->getOpcode() == BinaryOperator::LOr && RHS != 0) { |
| 354 | Result = RHS != 0; |
| 355 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 356 | Result.setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
Chris Lattner | c8cc9cc | 2008-11-12 07:04:29 +0000 | [diff] [blame] | 357 | return true; |
| 358 | } |
| 359 | |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 360 | return false; // error in subexpression. |
Chris Lattner | c8cc9cc | 2008-11-12 07:04:29 +0000 | [diff] [blame] | 361 | } |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 362 | |
| 363 | bool OldEval = Info.isEvaluated; |
| 364 | |
| 365 | // The short-circuiting &&/|| operators don't necessarily evaluate their |
| 366 | // RHS. Make sure to pass isEvaluated down correctly. |
| 367 | if ((E->getOpcode() == BinaryOperator::LAnd && Result == 0) || |
| 368 | (E->getOpcode() == BinaryOperator::LOr && Result != 0)) |
| 369 | Info.isEvaluated = false; |
Eli Friedman | d9f4bcd | 2008-07-27 05:46:18 +0000 | [diff] [blame] | 370 | |
| 371 | // FIXME: Handle pointer subtraction |
| 372 | |
| 373 | // FIXME Maybe we want to succeed even where we can't evaluate the |
| 374 | // right side of LAnd/LOr? |
| 375 | // For example, see http://llvm.org/bugs/show_bug.cgi?id=2525 |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 376 | if (!EvaluateInteger(E->getRHS(), RHS, Info)) |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 377 | return false; |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 378 | Info.isEvaluated = OldEval; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 379 | |
| 380 | switch (E->getOpcode()) { |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 381 | default: |
| 382 | return Error(E->getOperatorLoc(), diag::err_expr_not_constant,E->getType()); |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 383 | case BinaryOperator::Mul: Result *= RHS; return true; |
| 384 | case BinaryOperator::Add: Result += RHS; return true; |
| 385 | case BinaryOperator::Sub: Result -= RHS; return true; |
| 386 | case BinaryOperator::And: Result &= RHS; return true; |
| 387 | case BinaryOperator::Xor: Result ^= RHS; return true; |
| 388 | case BinaryOperator::Or: Result |= RHS; return true; |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 389 | case BinaryOperator::Div: |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 390 | if (RHS == 0) |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 391 | return Error(E->getOperatorLoc(), diag::err_expr_divide_by_zero, |
| 392 | E->getType()); |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 393 | Result /= RHS; |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 394 | break; |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 395 | case BinaryOperator::Rem: |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 396 | if (RHS == 0) |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 397 | return Error(E->getOperatorLoc(), diag::err_expr_divide_by_zero, |
| 398 | E->getType()); |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 399 | Result %= RHS; |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 400 | break; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 401 | case BinaryOperator::Shl: |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 402 | // FIXME: Warn about out of range shift amounts! |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 403 | Result <<= (unsigned)RHS.getLimitedValue(Result.getBitWidth()-1); |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 404 | break; |
| 405 | case BinaryOperator::Shr: |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 406 | Result >>= (unsigned)RHS.getLimitedValue(Result.getBitWidth()-1); |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 407 | break; |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 408 | |
Chris Lattner | ac7cb60 | 2008-07-11 19:29:32 +0000 | [diff] [blame] | 409 | case BinaryOperator::LT: |
| 410 | Result = Result < RHS; |
| 411 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 412 | break; |
| 413 | case BinaryOperator::GT: |
| 414 | Result = Result > RHS; |
| 415 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 416 | break; |
| 417 | case BinaryOperator::LE: |
| 418 | Result = Result <= RHS; |
| 419 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 420 | break; |
| 421 | case BinaryOperator::GE: |
| 422 | Result = Result >= RHS; |
| 423 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 424 | break; |
| 425 | case BinaryOperator::EQ: |
| 426 | Result = Result == RHS; |
| 427 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 428 | break; |
| 429 | case BinaryOperator::NE: |
| 430 | Result = Result != RHS; |
| 431 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 432 | break; |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 433 | case BinaryOperator::LAnd: |
| 434 | Result = Result != 0 && RHS != 0; |
| 435 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 436 | break; |
| 437 | case BinaryOperator::LOr: |
| 438 | Result = Result != 0 || RHS != 0; |
| 439 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 440 | break; |
| 441 | |
Anders Carlsson | 06a3675 | 2008-07-08 05:49:43 +0000 | [diff] [blame] | 442 | |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 443 | case BinaryOperator::Comma: |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 444 | // Result of the comma is just the result of the RHS. |
| 445 | Result = RHS; |
| 446 | |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 447 | // C99 6.6p3: "shall not contain assignment, ..., or comma operators, |
| 448 | // *except* when they are contained within a subexpression that is not |
| 449 | // evaluated". Note that Assignment can never happen due to constraints |
| 450 | // on the LHS subexpr, so we don't need to check it here. |
Chris Lattner | 54176fd | 2008-07-12 00:14:42 +0000 | [diff] [blame] | 451 | if (!Info.isEvaluated) |
| 452 | return true; |
| 453 | |
| 454 | // If the value is evaluated, we can accept it as an extension. |
| 455 | return Extension(E->getOperatorLoc(), diag::ext_comma_in_constant_expr); |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 456 | } |
| 457 | |
| 458 | Result.setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 459 | return true; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 460 | } |
| 461 | |
Sebastian Redl | 0518999 | 2008-11-11 17:56:53 +0000 | [diff] [blame] | 462 | /// VisitSizeAlignOfExpr - Evaluate a sizeof or alignof with a result as the |
| 463 | /// expression's type. |
| 464 | bool IntExprEvaluator::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { |
| 465 | QualType DstTy = E->getType(); |
Chris Lattner | fcee001 | 2008-07-11 21:24:13 +0000 | [diff] [blame] | 466 | // Return the result in the right width. |
| 467 | Result.zextOrTrunc(getIntTypeSizeInBits(DstTy)); |
| 468 | Result.setIsUnsigned(DstTy->isUnsignedIntegerType()); |
| 469 | |
Sebastian Redl | 0518999 | 2008-11-11 17:56:53 +0000 | [diff] [blame] | 470 | QualType SrcTy = E->getTypeOfArgument(); |
| 471 | |
Chris Lattner | fcee001 | 2008-07-11 21:24:13 +0000 | [diff] [blame] | 472 | // sizeof(void) and __alignof__(void) = 1 as a gcc extension. |
| 473 | if (SrcTy->isVoidType()) |
| 474 | Result = 1; |
| 475 | |
| 476 | // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2. |
| 477 | if (!SrcTy->isConstantSizeType()) { |
| 478 | // FIXME: Should we attempt to evaluate this? |
| 479 | return false; |
| 480 | } |
Sebastian Redl | 0518999 | 2008-11-11 17:56:53 +0000 | [diff] [blame] | 481 | |
| 482 | bool isSizeOf = E->isSizeOf(); |
Chris Lattner | fcee001 | 2008-07-11 21:24:13 +0000 | [diff] [blame] | 483 | |
| 484 | // GCC extension: sizeof(function) = 1. |
| 485 | if (SrcTy->isFunctionType()) { |
| 486 | // FIXME: AlignOf shouldn't be unconditionally 4! |
| 487 | Result = isSizeOf ? 1 : 4; |
| 488 | return true; |
| 489 | } |
| 490 | |
| 491 | // Get information about the size or align. |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 492 | unsigned CharSize = Info.Ctx.Target.getCharWidth(); |
Chris Lattner | fcee001 | 2008-07-11 21:24:13 +0000 | [diff] [blame] | 493 | if (isSizeOf) |
| 494 | Result = getIntTypeSizeInBits(SrcTy) / CharSize; |
| 495 | else |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 496 | Result = Info.Ctx.getTypeAlign(SrcTy) / CharSize; |
Chris Lattner | fcee001 | 2008-07-11 21:24:13 +0000 | [diff] [blame] | 497 | return true; |
| 498 | } |
| 499 | |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 500 | bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) { |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 501 | // Special case unary operators that do not need their subexpression |
| 502 | // evaluated. offsetof/sizeof/alignof are all special. |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 503 | if (E->isOffsetOfOp()) { |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 504 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 505 | Result = E->evaluateOffsetOf(Info.Ctx); |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 506 | Result.setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
| 507 | return true; |
| 508 | } |
| 509 | |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 510 | // Get the operand value into 'Result'. |
| 511 | if (!Visit(E->getSubExpr())) |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 512 | return false; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 513 | |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 514 | switch (E->getOpcode()) { |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 515 | default: |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 516 | // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. |
| 517 | // See C99 6.6p3. |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 518 | return Error(E->getOperatorLoc(), diag::err_expr_not_constant, |
| 519 | E->getType()); |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 520 | case UnaryOperator::LNot: { |
| 521 | bool Val = Result == 0; |
| 522 | Result.zextOrTrunc(getIntTypeSizeInBits(E->getType())); |
| 523 | Result = Val; |
| 524 | break; |
| 525 | } |
| 526 | case UnaryOperator::Extension: |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 527 | // FIXME: Should extension allow i-c-e extension expressions in its scope? |
| 528 | // If so, we could clear the diagnostic ID. |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 529 | case UnaryOperator::Plus: |
Chris Lattner | 4c4867e | 2008-07-12 00:38:25 +0000 | [diff] [blame] | 530 | // The result is always just the subexpr. |
Chris Lattner | 75a4881 | 2008-07-11 22:15:16 +0000 | [diff] [blame] | 531 | break; |
| 532 | case UnaryOperator::Minus: |
| 533 | Result = -Result; |
| 534 | break; |
| 535 | case UnaryOperator::Not: |
| 536 | Result = ~Result; |
| 537 | break; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 538 | } |
| 539 | |
| 540 | Result.setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 541 | return true; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 542 | } |
| 543 | |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 544 | /// HandleCast - This is used to evaluate implicit or explicit casts where the |
| 545 | /// result type is integer. |
| 546 | bool IntExprEvaluator::HandleCast(SourceLocation CastLoc, |
| 547 | Expr *SubExpr, QualType DestType) { |
Chris Lattner | 7a76778 | 2008-07-11 19:24:49 +0000 | [diff] [blame] | 548 | unsigned DestWidth = getIntTypeSizeInBits(DestType); |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 549 | |
| 550 | // Handle simple integer->integer casts. |
| 551 | if (SubExpr->getType()->isIntegerType()) { |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 552 | if (!Visit(SubExpr)) |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 553 | return false; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 554 | |
| 555 | // Figure out if this is a truncate, extend or noop cast. |
| 556 | // If the input is signed, do a sign extend, noop, or truncate. |
| 557 | if (DestType->isBooleanType()) { |
| 558 | // Conversion to bool compares against zero. |
| 559 | Result = Result != 0; |
| 560 | Result.zextOrTrunc(DestWidth); |
Chris Lattner | 7a76778 | 2008-07-11 19:24:49 +0000 | [diff] [blame] | 561 | } else |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 562 | Result.extOrTrunc(DestWidth); |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 563 | Result.setIsUnsigned(DestType->isUnsignedIntegerType()); |
| 564 | return true; |
| 565 | } |
| 566 | |
| 567 | // FIXME: Clean this up! |
| 568 | if (SubExpr->getType()->isPointerType()) { |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 569 | APValue LV; |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 570 | if (!EvaluatePointer(SubExpr, LV, Info)) |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 571 | return false; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 572 | if (LV.getLValueBase()) |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 573 | return false; |
Anders Carlsson | 06a3675 | 2008-07-08 05:49:43 +0000 | [diff] [blame] | 574 | |
Anders Carlsson | 559e56b | 2008-07-08 16:49:00 +0000 | [diff] [blame] | 575 | Result.extOrTrunc(DestWidth); |
| 576 | Result = LV.getLValueOffset(); |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 577 | Result.setIsUnsigned(DestType->isUnsignedIntegerType()); |
| 578 | return true; |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 579 | } |
| 580 | |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 581 | if (!SubExpr->getType()->isRealFloatingType()) |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 582 | return Error(CastLoc, diag::err_expr_not_constant, DestType); |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 583 | |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 584 | APFloat F(0.0); |
| 585 | if (!EvaluateFloat(SubExpr, F, Info)) |
Chris Lattner | 32fea9d | 2008-11-12 07:43:42 +0000 | [diff] [blame^] | 586 | return Error(CastLoc, diag::err_expr_not_constant, DestType); |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 587 | |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 588 | // If the destination is boolean, compare against zero. |
| 589 | if (DestType->isBooleanType()) { |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 590 | Result = !F.isZero(); |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 591 | Result.zextOrTrunc(DestWidth); |
| 592 | Result.setIsUnsigned(DestType->isUnsignedIntegerType()); |
| 593 | return true; |
| 594 | } |
| 595 | |
| 596 | // Determine whether we are converting to unsigned or signed. |
| 597 | bool DestSigned = DestType->isSignedIntegerType(); |
| 598 | |
| 599 | // FIXME: Warning for overflow. |
Dale Johannesen | ee5a700 | 2008-10-09 23:02:32 +0000 | [diff] [blame] | 600 | uint64_t Space[4]; |
| 601 | bool ignored; |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 602 | (void)F.convertToInteger(Space, DestWidth, DestSigned, |
Dale Johannesen | ee5a700 | 2008-10-09 23:02:32 +0000 | [diff] [blame] | 603 | llvm::APFloat::rmTowardZero, &ignored); |
Chris Lattner | 732b223 | 2008-07-12 01:15:53 +0000 | [diff] [blame] | 604 | Result = llvm::APInt(DestWidth, 4, Space); |
| 605 | Result.setIsUnsigned(!DestSigned); |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 606 | return true; |
Anders Carlsson | a25ae3d | 2008-07-08 14:35:21 +0000 | [diff] [blame] | 607 | } |
Anders Carlsson | 2bad168 | 2008-07-08 14:30:00 +0000 | [diff] [blame] | 608 | |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 609 | //===----------------------------------------------------------------------===// |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 610 | // Float Evaluation |
| 611 | //===----------------------------------------------------------------------===// |
| 612 | |
| 613 | namespace { |
| 614 | class VISIBILITY_HIDDEN FloatExprEvaluator |
| 615 | : public StmtVisitor<FloatExprEvaluator, bool> { |
| 616 | EvalInfo &Info; |
| 617 | APFloat &Result; |
| 618 | public: |
| 619 | FloatExprEvaluator(EvalInfo &info, APFloat &result) |
| 620 | : Info(info), Result(result) {} |
| 621 | |
| 622 | bool VisitStmt(Stmt *S) { |
| 623 | return false; |
| 624 | } |
| 625 | |
| 626 | bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 627 | bool VisitCallExpr(const CallExpr *E); |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 628 | |
Daniel Dunbar | 5db4b3f | 2008-10-16 03:51:50 +0000 | [diff] [blame] | 629 | bool VisitUnaryOperator(const UnaryOperator *E); |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 630 | bool VisitBinaryOperator(const BinaryOperator *E); |
| 631 | bool VisitFloatingLiteral(const FloatingLiteral *E); |
| 632 | }; |
| 633 | } // end anonymous namespace |
| 634 | |
| 635 | static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) { |
| 636 | return FloatExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
| 637 | } |
| 638 | |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 639 | bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) { |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 640 | switch (E->isBuiltinCall()) { |
Chris Lattner | 34a74ab | 2008-10-06 05:53:16 +0000 | [diff] [blame] | 641 | default: return false; |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 642 | case Builtin::BI__builtin_huge_val: |
| 643 | case Builtin::BI__builtin_huge_valf: |
| 644 | case Builtin::BI__builtin_huge_vall: |
| 645 | case Builtin::BI__builtin_inf: |
| 646 | case Builtin::BI__builtin_inff: |
Daniel Dunbar | 7cbed03 | 2008-10-14 05:41:12 +0000 | [diff] [blame] | 647 | case Builtin::BI__builtin_infl: { |
| 648 | const llvm::fltSemantics &Sem = |
| 649 | Info.Ctx.getFloatTypeSemantics(E->getType()); |
Chris Lattner | 34a74ab | 2008-10-06 05:53:16 +0000 | [diff] [blame] | 650 | Result = llvm::APFloat::getInf(Sem); |
| 651 | return true; |
Daniel Dunbar | 7cbed03 | 2008-10-14 05:41:12 +0000 | [diff] [blame] | 652 | } |
Chris Lattner | 9e62171 | 2008-10-06 06:31:58 +0000 | [diff] [blame] | 653 | |
| 654 | case Builtin::BI__builtin_nan: |
| 655 | case Builtin::BI__builtin_nanf: |
| 656 | case Builtin::BI__builtin_nanl: |
| 657 | // If this is __builtin_nan("") turn this into a simple nan, otherwise we |
| 658 | // can't constant fold it. |
| 659 | if (const StringLiteral *S = |
| 660 | dyn_cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts())) { |
| 661 | if (!S->isWide() && S->getByteLength() == 0) { // empty string. |
Daniel Dunbar | 7cbed03 | 2008-10-14 05:41:12 +0000 | [diff] [blame] | 662 | const llvm::fltSemantics &Sem = |
| 663 | Info.Ctx.getFloatTypeSemantics(E->getType()); |
Chris Lattner | 9e62171 | 2008-10-06 06:31:58 +0000 | [diff] [blame] | 664 | Result = llvm::APFloat::getNaN(Sem); |
| 665 | return true; |
| 666 | } |
| 667 | } |
| 668 | return false; |
Daniel Dunbar | 5db4b3f | 2008-10-16 03:51:50 +0000 | [diff] [blame] | 669 | |
| 670 | case Builtin::BI__builtin_fabs: |
| 671 | case Builtin::BI__builtin_fabsf: |
| 672 | case Builtin::BI__builtin_fabsl: |
| 673 | if (!EvaluateFloat(E->getArg(0), Result, Info)) |
| 674 | return false; |
| 675 | |
| 676 | if (Result.isNegative()) |
| 677 | Result.changeSign(); |
| 678 | return true; |
| 679 | |
| 680 | case Builtin::BI__builtin_copysign: |
| 681 | case Builtin::BI__builtin_copysignf: |
| 682 | case Builtin::BI__builtin_copysignl: { |
| 683 | APFloat RHS(0.); |
| 684 | if (!EvaluateFloat(E->getArg(0), Result, Info) || |
| 685 | !EvaluateFloat(E->getArg(1), RHS, Info)) |
| 686 | return false; |
| 687 | Result.copySign(RHS); |
| 688 | return true; |
| 689 | } |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 690 | } |
| 691 | } |
| 692 | |
Daniel Dunbar | 5db4b3f | 2008-10-16 03:51:50 +0000 | [diff] [blame] | 693 | bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) { |
| 694 | if (!EvaluateFloat(E->getSubExpr(), Result, Info)) |
| 695 | return false; |
| 696 | |
| 697 | switch (E->getOpcode()) { |
| 698 | default: return false; |
| 699 | case UnaryOperator::Plus: |
| 700 | return true; |
| 701 | case UnaryOperator::Minus: |
| 702 | Result.changeSign(); |
| 703 | return true; |
| 704 | } |
| 705 | } |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 706 | |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 707 | bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
| 708 | // FIXME: Diagnostics? I really don't understand how the warnings |
| 709 | // and errors are supposed to work. |
Daniel Dunbar | 5db4b3f | 2008-10-16 03:51:50 +0000 | [diff] [blame] | 710 | APFloat RHS(0.0); |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 711 | if (!EvaluateFloat(E->getLHS(), Result, Info)) |
| 712 | return false; |
| 713 | if (!EvaluateFloat(E->getRHS(), RHS, Info)) |
| 714 | return false; |
| 715 | |
| 716 | switch (E->getOpcode()) { |
| 717 | default: return false; |
| 718 | case BinaryOperator::Mul: |
| 719 | Result.multiply(RHS, APFloat::rmNearestTiesToEven); |
| 720 | return true; |
| 721 | case BinaryOperator::Add: |
| 722 | Result.add(RHS, APFloat::rmNearestTiesToEven); |
| 723 | return true; |
| 724 | case BinaryOperator::Sub: |
| 725 | Result.subtract(RHS, APFloat::rmNearestTiesToEven); |
| 726 | return true; |
| 727 | case BinaryOperator::Div: |
| 728 | Result.divide(RHS, APFloat::rmNearestTiesToEven); |
| 729 | return true; |
| 730 | case BinaryOperator::Rem: |
| 731 | Result.mod(RHS, APFloat::rmNearestTiesToEven); |
| 732 | return true; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) { |
| 737 | Result = E->getValue(); |
| 738 | return true; |
| 739 | } |
| 740 | |
| 741 | //===----------------------------------------------------------------------===// |
Chris Lattner | f5eeb05 | 2008-07-11 18:11:29 +0000 | [diff] [blame] | 742 | // Top level TryEvaluate. |
| 743 | //===----------------------------------------------------------------------===// |
| 744 | |
Chris Lattner | 019f4e8 | 2008-10-06 05:28:25 +0000 | [diff] [blame] | 745 | /// tryEvaluate - Return true if this is a constant which we can fold using |
| 746 | /// any crazy technique (that has nothing to do with language standards) that |
| 747 | /// we want to. If this function returns true, it returns the folded constant |
| 748 | /// in Result. |
Chris Lattner | b542afe | 2008-07-11 19:10:17 +0000 | [diff] [blame] | 749 | bool Expr::tryEvaluate(APValue &Result, ASTContext &Ctx) const { |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 750 | EvalInfo Info(Ctx); |
Anders Carlsson | 06a3675 | 2008-07-08 05:49:43 +0000 | [diff] [blame] | 751 | if (getType()->isIntegerType()) { |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 752 | llvm::APSInt sInt(32); |
Chris Lattner | 87eae5e | 2008-07-11 22:52:41 +0000 | [diff] [blame] | 753 | if (EvaluateInteger(this, sInt, Info)) { |
Anders Carlsson | 06a3675 | 2008-07-08 05:49:43 +0000 | [diff] [blame] | 754 | Result = APValue(sInt); |
| 755 | return true; |
| 756 | } |
Eli Friedman | d8bfe7f | 2008-08-22 00:06:13 +0000 | [diff] [blame] | 757 | } else if (getType()->isPointerType()) { |
| 758 | if (EvaluatePointer(this, Result, Info)) { |
| 759 | return true; |
| 760 | } |
| 761 | } else if (getType()->isRealFloatingType()) { |
| 762 | llvm::APFloat f(0.0); |
| 763 | if (EvaluateFloat(this, f, Info)) { |
| 764 | Result = APValue(f); |
| 765 | return true; |
| 766 | } |
| 767 | } |
Anders Carlsson | 165a70f | 2008-08-10 17:03:01 +0000 | [diff] [blame] | 768 | |
Anders Carlsson | c44eec6 | 2008-07-03 04:20:39 +0000 | [diff] [blame] | 769 | return false; |
| 770 | } |
Chris Lattner | 45b6b9d | 2008-10-06 06:49:02 +0000 | [diff] [blame] | 771 | |
| 772 | /// isEvaluatable - Call tryEvaluate to see if this expression can be constant |
| 773 | /// folded, but discard the result. |
| 774 | bool Expr::isEvaluatable(ASTContext &Ctx) const { |
| 775 | APValue V; |
| 776 | return tryEvaluate(V, Ctx); |
| 777 | } |