1 //===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===//
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 contains code to emit Expr nodes with scalar LLVM types as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/Frontend/CodeGenOptions.h"
15 #include "CodeGenFunction.h"
16 #include "CGCXXABI.h"
17 #include "CGObjCRuntime.h"
18 #include "CodeGenModule.h"
19 #include "CGDebugInfo.h"
20 #include "clang/AST/ASTContext.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/RecordLayout.h"
23 #include "clang/AST/StmtVisitor.h"
24 #include "clang/Basic/TargetInfo.h"
25 #include "llvm/Constants.h"
26 #include "llvm/Function.h"
27 #include "llvm/GlobalVariable.h"
28 #include "llvm/Intrinsics.h"
29 #include "llvm/Module.h"
30 #include "llvm/Support/CFG.h"
31 #include "llvm/Target/TargetData.h"
32 #include <cstdarg>
33
34 using namespace clang;
35 using namespace CodeGen;
36 using llvm::Value;
37
38 //===----------------------------------------------------------------------===//
39 // Scalar Expression Emitter
40 //===----------------------------------------------------------------------===//
41
42 namespace {
43 struct BinOpInfo {
44 Value *LHS;
45 Value *RHS;
46 QualType Ty; // Computation Type.
47 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform
48 const Expr *E; // Entire expr, for error unsupported. May not be binop.
49 };
50
MustVisitNullValue(const Expr * E)51 static bool MustVisitNullValue(const Expr *E) {
52 // If a null pointer expression's type is the C++0x nullptr_t, then
53 // it's not necessarily a simple constant and it must be evaluated
54 // for its potential side effects.
55 return E->getType()->isNullPtrType();
56 }
57
58 class ScalarExprEmitter
59 : public StmtVisitor<ScalarExprEmitter, Value*> {
60 CodeGenFunction &CGF;
61 CGBuilderTy &Builder;
62 bool IgnoreResultAssign;
63 llvm::LLVMContext &VMContext;
64 public:
65
ScalarExprEmitter(CodeGenFunction & cgf,bool ira=false)66 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false)
67 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira),
68 VMContext(cgf.getLLVMContext()) {
69 }
70
71 //===--------------------------------------------------------------------===//
72 // Utilities
73 //===--------------------------------------------------------------------===//
74
TestAndClearIgnoreResultAssign()75 bool TestAndClearIgnoreResultAssign() {
76 bool I = IgnoreResultAssign;
77 IgnoreResultAssign = false;
78 return I;
79 }
80
ConvertType(QualType T)81 llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); }
EmitLValue(const Expr * E)82 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); }
EmitCheckedLValue(const Expr * E,CodeGenFunction::TypeCheckKind TCK)83 LValue EmitCheckedLValue(const Expr *E, CodeGenFunction::TypeCheckKind TCK) {
84 return CGF.EmitCheckedLValue(E, TCK);
85 }
86
EmitLoadOfLValue(LValue LV)87 Value *EmitLoadOfLValue(LValue LV) {
88 return CGF.EmitLoadOfLValue(LV).getScalarVal();
89 }
90
91 /// EmitLoadOfLValue - Given an expression with complex type that represents a
92 /// value l-value, this method emits the address of the l-value, then loads
93 /// and returns the result.
EmitLoadOfLValue(const Expr * E)94 Value *EmitLoadOfLValue(const Expr *E) {
95 return EmitLoadOfLValue(EmitCheckedLValue(E, CodeGenFunction::TCK_Load));
96 }
97
98 /// EmitConversionToBool - Convert the specified expression value to a
99 /// boolean (i1) truth value. This is equivalent to "Val != 0".
100 Value *EmitConversionToBool(Value *Src, QualType DstTy);
101
102 /// EmitScalarConversion - Emit a conversion from the specified type to the
103 /// specified destination type, both of which are LLVM scalar types.
104 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy);
105
106 /// EmitComplexToScalarConversion - Emit a conversion from the specified
107 /// complex type to the specified destination type, where the destination type
108 /// is an LLVM scalar type.
109 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
110 QualType SrcTy, QualType DstTy);
111
112 /// EmitNullValue - Emit a value that corresponds to null for the given type.
113 Value *EmitNullValue(QualType Ty);
114
115 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion.
EmitFloatToBoolConversion(Value * V)116 Value *EmitFloatToBoolConversion(Value *V) {
117 // Compare against 0.0 for fp scalars.
118 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType());
119 return Builder.CreateFCmpUNE(V, Zero, "tobool");
120 }
121
122 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion.
EmitPointerToBoolConversion(Value * V)123 Value *EmitPointerToBoolConversion(Value *V) {
124 Value *Zero = llvm::ConstantPointerNull::get(
125 cast<llvm::PointerType>(V->getType()));
126 return Builder.CreateICmpNE(V, Zero, "tobool");
127 }
128
EmitIntToBoolConversion(Value * V)129 Value *EmitIntToBoolConversion(Value *V) {
130 // Because of the type rules of C, we often end up computing a
131 // logical value, then zero extending it to int, then wanting it
132 // as a logical value again. Optimize this common case.
133 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) {
134 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) {
135 Value *Result = ZI->getOperand(0);
136 // If there aren't any more uses, zap the instruction to save space.
137 // Note that there can be more uses, for example if this
138 // is the result of an assignment.
139 if (ZI->use_empty())
140 ZI->eraseFromParent();
141 return Result;
142 }
143 }
144
145 return Builder.CreateIsNotNull(V, "tobool");
146 }
147
148 //===--------------------------------------------------------------------===//
149 // Visitor Methods
150 //===--------------------------------------------------------------------===//
151
Visit(Expr * E)152 Value *Visit(Expr *E) {
153 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
154 }
155
VisitStmt(Stmt * S)156 Value *VisitStmt(Stmt *S) {
157 S->dump(CGF.getContext().getSourceManager());
158 llvm_unreachable("Stmt can't have complex result type!");
159 }
160 Value *VisitExpr(Expr *S);
161
VisitParenExpr(ParenExpr * PE)162 Value *VisitParenExpr(ParenExpr *PE) {
163 return Visit(PE->getSubExpr());
164 }
VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr * E)165 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
166 return Visit(E->getReplacement());
167 }
VisitGenericSelectionExpr(GenericSelectionExpr * GE)168 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
169 return Visit(GE->getResultExpr());
170 }
171
172 // Leaves.
VisitIntegerLiteral(const IntegerLiteral * E)173 Value *VisitIntegerLiteral(const IntegerLiteral *E) {
174 return Builder.getInt(E->getValue());
175 }
VisitFloatingLiteral(const FloatingLiteral * E)176 Value *VisitFloatingLiteral(const FloatingLiteral *E) {
177 return llvm::ConstantFP::get(VMContext, E->getValue());
178 }
VisitCharacterLiteral(const CharacterLiteral * E)179 Value *VisitCharacterLiteral(const CharacterLiteral *E) {
180 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
181 }
VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr * E)182 Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
183 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
184 }
VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr * E)185 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
186 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
187 }
VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr * E)188 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
189 return EmitNullValue(E->getType());
190 }
VisitGNUNullExpr(const GNUNullExpr * E)191 Value *VisitGNUNullExpr(const GNUNullExpr *E) {
192 return EmitNullValue(E->getType());
193 }
194 Value *VisitOffsetOfExpr(OffsetOfExpr *E);
195 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
VisitAddrLabelExpr(const AddrLabelExpr * E)196 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
197 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel());
198 return Builder.CreateBitCast(V, ConvertType(E->getType()));
199 }
200
VisitSizeOfPackExpr(SizeOfPackExpr * E)201 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) {
202 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength());
203 }
204
VisitPseudoObjectExpr(PseudoObjectExpr * E)205 Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) {
206 return CGF.EmitPseudoObjectRValue(E).getScalarVal();
207 }
208
VisitOpaqueValueExpr(OpaqueValueExpr * E)209 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) {
210 if (E->isGLValue())
211 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
212
213 // Otherwise, assume the mapping is the scalar directly.
214 return CGF.getOpaqueRValueMapping(E).getScalarVal();
215 }
216
217 // l-values.
VisitDeclRefExpr(DeclRefExpr * E)218 Value *VisitDeclRefExpr(DeclRefExpr *E) {
219 if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
220 if (result.isReference())
221 return EmitLoadOfLValue(result.getReferenceLValue(CGF, E));
222 return result.getValue();
223 }
224 return EmitLoadOfLValue(E);
225 }
226
VisitObjCSelectorExpr(ObjCSelectorExpr * E)227 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {
228 return CGF.EmitObjCSelectorExpr(E);
229 }
VisitObjCProtocolExpr(ObjCProtocolExpr * E)230 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
231 return CGF.EmitObjCProtocolExpr(E);
232 }
VisitObjCIvarRefExpr(ObjCIvarRefExpr * E)233 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
234 return EmitLoadOfLValue(E);
235 }
VisitObjCMessageExpr(ObjCMessageExpr * E)236 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
237 if (E->getMethodDecl() &&
238 E->getMethodDecl()->getResultType()->isReferenceType())
239 return EmitLoadOfLValue(E);
240 return CGF.EmitObjCMessageExpr(E).getScalarVal();
241 }
242
VisitObjCIsaExpr(ObjCIsaExpr * E)243 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
244 LValue LV = CGF.EmitObjCIsaExpr(E);
245 Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal();
246 return V;
247 }
248
249 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
250 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
251 Value *VisitMemberExpr(MemberExpr *E);
VisitExtVectorElementExpr(Expr * E)252 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
VisitCompoundLiteralExpr(CompoundLiteralExpr * E)253 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
254 return EmitLoadOfLValue(E);
255 }
256
257 Value *VisitInitListExpr(InitListExpr *E);
258
VisitImplicitValueInitExpr(const ImplicitValueInitExpr * E)259 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
260 return CGF.CGM.EmitNullConstant(E->getType());
261 }
VisitExplicitCastExpr(ExplicitCastExpr * E)262 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) {
263 if (E->getType()->isVariablyModifiedType())
264 CGF.EmitVariablyModifiedType(E->getType());
265 return VisitCastExpr(E);
266 }
267 Value *VisitCastExpr(CastExpr *E);
268
VisitCallExpr(const CallExpr * E)269 Value *VisitCallExpr(const CallExpr *E) {
270 if (E->getCallReturnType()->isReferenceType())
271 return EmitLoadOfLValue(E);
272
273 return CGF.EmitCallExpr(E).getScalarVal();
274 }
275
276 Value *VisitStmtExpr(const StmtExpr *E);
277
278 // Unary Operators.
VisitUnaryPostDec(const UnaryOperator * E)279 Value *VisitUnaryPostDec(const UnaryOperator *E) {
280 LValue LV = EmitLValue(E->getSubExpr());
281 return EmitScalarPrePostIncDec(E, LV, false, false);
282 }
VisitUnaryPostInc(const UnaryOperator * E)283 Value *VisitUnaryPostInc(const UnaryOperator *E) {
284 LValue LV = EmitLValue(E->getSubExpr());
285 return EmitScalarPrePostIncDec(E, LV, true, false);
286 }
VisitUnaryPreDec(const UnaryOperator * E)287 Value *VisitUnaryPreDec(const UnaryOperator *E) {
288 LValue LV = EmitLValue(E->getSubExpr());
289 return EmitScalarPrePostIncDec(E, LV, false, true);
290 }
VisitUnaryPreInc(const UnaryOperator * E)291 Value *VisitUnaryPreInc(const UnaryOperator *E) {
292 LValue LV = EmitLValue(E->getSubExpr());
293 return EmitScalarPrePostIncDec(E, LV, true, true);
294 }
295
296 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E,
297 llvm::Value *InVal,
298 llvm::Value *NextVal,
299 bool IsInc);
300
301 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
302 bool isInc, bool isPre);
303
304
VisitUnaryAddrOf(const UnaryOperator * E)305 Value *VisitUnaryAddrOf(const UnaryOperator *E) {
306 if (isa<MemberPointerType>(E->getType())) // never sugared
307 return CGF.CGM.getMemberPointerConstant(E);
308
309 return EmitLValue(E->getSubExpr()).getAddress();
310 }
VisitUnaryDeref(const UnaryOperator * E)311 Value *VisitUnaryDeref(const UnaryOperator *E) {
312 if (E->getType()->isVoidType())
313 return Visit(E->getSubExpr()); // the actual value should be unused
314 return EmitLoadOfLValue(E);
315 }
VisitUnaryPlus(const UnaryOperator * E)316 Value *VisitUnaryPlus(const UnaryOperator *E) {
317 // This differs from gcc, though, most likely due to a bug in gcc.
318 TestAndClearIgnoreResultAssign();
319 return Visit(E->getSubExpr());
320 }
321 Value *VisitUnaryMinus (const UnaryOperator *E);
322 Value *VisitUnaryNot (const UnaryOperator *E);
323 Value *VisitUnaryLNot (const UnaryOperator *E);
324 Value *VisitUnaryReal (const UnaryOperator *E);
325 Value *VisitUnaryImag (const UnaryOperator *E);
VisitUnaryExtension(const UnaryOperator * E)326 Value *VisitUnaryExtension(const UnaryOperator *E) {
327 return Visit(E->getSubExpr());
328 }
329
330 // C++
VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr * E)331 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) {
332 return EmitLoadOfLValue(E);
333 }
334
VisitCXXDefaultArgExpr(CXXDefaultArgExpr * DAE)335 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
336 return Visit(DAE->getExpr());
337 }
VisitCXXThisExpr(CXXThisExpr * TE)338 Value *VisitCXXThisExpr(CXXThisExpr *TE) {
339 return CGF.LoadCXXThis();
340 }
341
VisitExprWithCleanups(ExprWithCleanups * E)342 Value *VisitExprWithCleanups(ExprWithCleanups *E) {
343 CGF.enterFullExpression(E);
344 CodeGenFunction::RunCleanupsScope Scope(CGF);
345 return Visit(E->getSubExpr());
346 }
VisitCXXNewExpr(const CXXNewExpr * E)347 Value *VisitCXXNewExpr(const CXXNewExpr *E) {
348 return CGF.EmitCXXNewExpr(E);
349 }
VisitCXXDeleteExpr(const CXXDeleteExpr * E)350 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
351 CGF.EmitCXXDeleteExpr(E);
352 return 0;
353 }
VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr * E)354 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) {
355 return Builder.getInt1(E->getValue());
356 }
357
VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr * E)358 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) {
359 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
360 }
361
VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr * E)362 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
363 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue());
364 }
365
VisitExpressionTraitExpr(const ExpressionTraitExpr * E)366 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
367 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue());
368 }
369
VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr * E)370 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
371 // C++ [expr.pseudo]p1:
372 // The result shall only be used as the operand for the function call
373 // operator (), and the result of such a call has type void. The only
374 // effect is the evaluation of the postfix-expression before the dot or
375 // arrow.
376 CGF.EmitScalarExpr(E->getBase());
377 return 0;
378 }
379
VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr * E)380 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
381 return EmitNullValue(E->getType());
382 }
383
VisitCXXThrowExpr(const CXXThrowExpr * E)384 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) {
385 CGF.EmitCXXThrowExpr(E);
386 return 0;
387 }
388
VisitCXXNoexceptExpr(const CXXNoexceptExpr * E)389 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
390 return Builder.getInt1(E->getValue());
391 }
392
393 // Binary Operators.
EmitMul(const BinOpInfo & Ops)394 Value *EmitMul(const BinOpInfo &Ops) {
395 if (Ops.Ty->isSignedIntegerOrEnumerationType()) {
396 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) {
397 case LangOptions::SOB_Defined:
398 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
399 case LangOptions::SOB_Undefined:
400 if (!CGF.CatchUndefined)
401 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
402 // Fall through.
403 case LangOptions::SOB_Trapping:
404 return EmitOverflowCheckedBinOp(Ops);
405 }
406 }
407
408 if (Ops.LHS->getType()->isFPOrFPVectorTy())
409 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
410 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
411 }
isTrapvOverflowBehavior()412 bool isTrapvOverflowBehavior() {
413 return CGF.getContext().getLangOpts().getSignedOverflowBehavior()
414 == LangOptions::SOB_Trapping || CGF.CatchUndefined;
415 }
416 /// Create a binary op that checks for overflow.
417 /// Currently only supports +, - and *.
418 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
419
420 // Check for undefined division and modulus behaviors.
421 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops,
422 llvm::Value *Zero,bool isDiv);
423 Value *EmitDiv(const BinOpInfo &Ops);
424 Value *EmitRem(const BinOpInfo &Ops);
425 Value *EmitAdd(const BinOpInfo &Ops);
426 Value *EmitSub(const BinOpInfo &Ops);
427 Value *EmitShl(const BinOpInfo &Ops);
428 Value *EmitShr(const BinOpInfo &Ops);
EmitAnd(const BinOpInfo & Ops)429 Value *EmitAnd(const BinOpInfo &Ops) {
430 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and");
431 }
EmitXor(const BinOpInfo & Ops)432 Value *EmitXor(const BinOpInfo &Ops) {
433 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor");
434 }
EmitOr(const BinOpInfo & Ops)435 Value *EmitOr (const BinOpInfo &Ops) {
436 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or");
437 }
438
439 BinOpInfo EmitBinOps(const BinaryOperator *E);
440 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
441 Value *(ScalarExprEmitter::*F)(const BinOpInfo &),
442 Value *&Result);
443
444 Value *EmitCompoundAssign(const CompoundAssignOperator *E,
445 Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
446
447 // Binary operators and binary compound assignment operators.
448 #define HANDLEBINOP(OP) \
449 Value *VisitBin ## OP(const BinaryOperator *E) { \
450 return Emit ## OP(EmitBinOps(E)); \
451 } \
452 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \
453 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \
454 }
455 HANDLEBINOP(Mul)
456 HANDLEBINOP(Div)
457 HANDLEBINOP(Rem)
458 HANDLEBINOP(Add)
459 HANDLEBINOP(Sub)
460 HANDLEBINOP(Shl)
461 HANDLEBINOP(Shr)
462 HANDLEBINOP(And)
463 HANDLEBINOP(Xor)
464 HANDLEBINOP(Or)
465 #undef HANDLEBINOP
466
467 // Comparisons.
468 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc,
469 unsigned SICmpOpc, unsigned FCmpOpc);
470 #define VISITCOMP(CODE, UI, SI, FP) \
471 Value *VisitBin##CODE(const BinaryOperator *E) { \
472 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \
473 llvm::FCmpInst::FP); }
474 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT)
475 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT)
476 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE)
477 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE)
478 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ)
479 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE)
480 #undef VISITCOMP
481
482 Value *VisitBinAssign (const BinaryOperator *E);
483
484 Value *VisitBinLAnd (const BinaryOperator *E);
485 Value *VisitBinLOr (const BinaryOperator *E);
486 Value *VisitBinComma (const BinaryOperator *E);
487
VisitBinPtrMemD(const Expr * E)488 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); }
VisitBinPtrMemI(const Expr * E)489 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); }
490
491 // Other Operators.
492 Value *VisitBlockExpr(const BlockExpr *BE);
493 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *);
494 Value *VisitChooseExpr(ChooseExpr *CE);
495 Value *VisitVAArgExpr(VAArgExpr *VE);
VisitObjCStringLiteral(const ObjCStringLiteral * E)496 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) {
497 return CGF.EmitObjCStringLiteral(E);
498 }
VisitObjCBoxedExpr(ObjCBoxedExpr * E)499 Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) {
500 return CGF.EmitObjCBoxedExpr(E);
501 }
VisitObjCArrayLiteral(ObjCArrayLiteral * E)502 Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) {
503 return CGF.EmitObjCArrayLiteral(E);
504 }
VisitObjCDictionaryLiteral(ObjCDictionaryLiteral * E)505 Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) {
506 return CGF.EmitObjCDictionaryLiteral(E);
507 }
508 Value *VisitAsTypeExpr(AsTypeExpr *CE);
509 Value *VisitAtomicExpr(AtomicExpr *AE);
510 };
511 } // end anonymous namespace.
512
513 //===----------------------------------------------------------------------===//
514 // Utilities
515 //===----------------------------------------------------------------------===//
516
517 /// EmitConversionToBool - Convert the specified expression value to a
518 /// boolean (i1) truth value. This is equivalent to "Val != 0".
EmitConversionToBool(Value * Src,QualType SrcType)519 Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) {
520 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs");
521
522 if (SrcType->isRealFloatingType())
523 return EmitFloatToBoolConversion(Src);
524
525 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType))
526 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT);
527
528 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) &&
529 "Unknown scalar type to convert");
530
531 if (isa<llvm::IntegerType>(Src->getType()))
532 return EmitIntToBoolConversion(Src);
533
534 assert(isa<llvm::PointerType>(Src->getType()));
535 return EmitPointerToBoolConversion(Src);
536 }
537
538 /// EmitScalarConversion - Emit a conversion from the specified type to the
539 /// specified destination type, both of which are LLVM scalar types.
EmitScalarConversion(Value * Src,QualType SrcType,QualType DstType)540 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
541 QualType DstType) {
542 SrcType = CGF.getContext().getCanonicalType(SrcType);
543 DstType = CGF.getContext().getCanonicalType(DstType);
544 if (SrcType == DstType) return Src;
545
546 if (DstType->isVoidType()) return 0;
547
548 llvm::Type *SrcTy = Src->getType();
549
550 // Floating casts might be a bit special: if we're doing casts to / from half
551 // FP, we should go via special intrinsics.
552 if (SrcType->isHalfType()) {
553 Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src);
554 SrcType = CGF.getContext().FloatTy;
555 SrcTy = CGF.FloatTy;
556 }
557
558 // Handle conversions to bool first, they are special: comparisons against 0.
559 if (DstType->isBooleanType())
560 return EmitConversionToBool(Src, SrcType);
561
562 llvm::Type *DstTy = ConvertType(DstType);
563
564 // Ignore conversions like int -> uint.
565 if (SrcTy == DstTy)
566 return Src;
567
568 // Handle pointer conversions next: pointers can only be converted to/from
569 // other pointers and integers. Check for pointer types in terms of LLVM, as
570 // some native types (like Obj-C id) may map to a pointer type.
571 if (isa<llvm::PointerType>(DstTy)) {
572 // The source value may be an integer, or a pointer.
573 if (isa<llvm::PointerType>(SrcTy))
574 return Builder.CreateBitCast(Src, DstTy, "conv");
575
576 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
577 // First, convert to the correct width so that we control the kind of
578 // extension.
579 llvm::Type *MiddleTy = CGF.IntPtrTy;
580 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
581 llvm::Value* IntResult =
582 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
583 // Then, cast to pointer.
584 return Builder.CreateIntToPtr(IntResult, DstTy, "conv");
585 }
586
587 if (isa<llvm::PointerType>(SrcTy)) {
588 // Must be an ptr to int cast.
589 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
590 return Builder.CreatePtrToInt(Src, DstTy, "conv");
591 }
592
593 // A scalar can be splatted to an extended vector of the same element type
594 if (DstType->isExtVectorType() && !SrcType->isVectorType()) {
595 // Cast the scalar to element type
596 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType();
597 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy);
598
599 // Insert the element in element zero of an undef vector
600 llvm::Value *UnV = llvm::UndefValue::get(DstTy);
601 llvm::Value *Idx = Builder.getInt32(0);
602 UnV = Builder.CreateInsertElement(UnV, Elt, Idx);
603
604 // Splat the element across to all elements
605 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
606 llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements,
607 Builder.getInt32(0));
608 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
609 return Yay;
610 }
611
612 // Allow bitcast from vector to integer/fp of the same size.
613 if (isa<llvm::VectorType>(SrcTy) ||
614 isa<llvm::VectorType>(DstTy))
615 return Builder.CreateBitCast(Src, DstTy, "conv");
616
617 // Finally, we have the arithmetic types: real int/float.
618 Value *Res = NULL;
619 llvm::Type *ResTy = DstTy;
620
621 // Cast to half via float
622 if (DstType->isHalfType())
623 DstTy = CGF.FloatTy;
624
625 if (isa<llvm::IntegerType>(SrcTy)) {
626 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
627 if (isa<llvm::IntegerType>(DstTy))
628 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
629 else if (InputSigned)
630 Res = Builder.CreateSIToFP(Src, DstTy, "conv");
631 else
632 Res = Builder.CreateUIToFP(Src, DstTy, "conv");
633 } else if (isa<llvm::IntegerType>(DstTy)) {
634 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion");
635 if (DstType->isSignedIntegerOrEnumerationType())
636 Res = Builder.CreateFPToSI(Src, DstTy, "conv");
637 else
638 Res = Builder.CreateFPToUI(Src, DstTy, "conv");
639 } else {
640 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() &&
641 "Unknown real conversion");
642 if (DstTy->getTypeID() < SrcTy->getTypeID())
643 Res = Builder.CreateFPTrunc(Src, DstTy, "conv");
644 else
645 Res = Builder.CreateFPExt(Src, DstTy, "conv");
646 }
647
648 if (DstTy != ResTy) {
649 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion");
650 Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res);
651 }
652
653 return Res;
654 }
655
656 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex
657 /// type to the specified destination type, where the destination type is an
658 /// LLVM scalar type.
659 Value *ScalarExprEmitter::
EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,QualType SrcTy,QualType DstTy)660 EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
661 QualType SrcTy, QualType DstTy) {
662 // Get the source element type.
663 SrcTy = SrcTy->getAs<ComplexType>()->getElementType();
664
665 // Handle conversions to bool first, they are special: comparisons against 0.
666 if (DstTy->isBooleanType()) {
667 // Complex != 0 -> (Real != 0) | (Imag != 0)
668 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy);
669 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy);
670 return Builder.CreateOr(Src.first, Src.second, "tobool");
671 }
672
673 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type,
674 // the imaginary part of the complex value is discarded and the value of the
675 // real part is converted according to the conversion rules for the
676 // corresponding real type.
677 return EmitScalarConversion(Src.first, SrcTy, DstTy);
678 }
679
EmitNullValue(QualType Ty)680 Value *ScalarExprEmitter::EmitNullValue(QualType Ty) {
681 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>())
682 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT);
683
684 return llvm::Constant::getNullValue(ConvertType(Ty));
685 }
686
687 //===----------------------------------------------------------------------===//
688 // Visitor Methods
689 //===----------------------------------------------------------------------===//
690
VisitExpr(Expr * E)691 Value *ScalarExprEmitter::VisitExpr(Expr *E) {
692 CGF.ErrorUnsupported(E, "scalar expression");
693 if (E->getType()->isVoidType())
694 return 0;
695 return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
696 }
697
VisitShuffleVectorExpr(ShuffleVectorExpr * E)698 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
699 // Vector Mask Case
700 if (E->getNumSubExprs() == 2 ||
701 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) {
702 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0));
703 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1));
704 Value *Mask;
705
706 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType());
707 unsigned LHSElts = LTy->getNumElements();
708
709 if (E->getNumSubExprs() == 3) {
710 Mask = CGF.EmitScalarExpr(E->getExpr(2));
711
712 // Shuffle LHS & RHS into one input vector.
713 SmallVector<llvm::Constant*, 32> concat;
714 for (unsigned i = 0; i != LHSElts; ++i) {
715 concat.push_back(Builder.getInt32(2*i));
716 concat.push_back(Builder.getInt32(2*i+1));
717 }
718
719 Value* CV = llvm::ConstantVector::get(concat);
720 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat");
721 LHSElts *= 2;
722 } else {
723 Mask = RHS;
724 }
725
726 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType());
727 llvm::Constant* EltMask;
728
729 // Treat vec3 like vec4.
730 if ((LHSElts == 6) && (E->getNumSubExprs() == 3))
731 EltMask = llvm::ConstantInt::get(MTy->getElementType(),
732 (1 << llvm::Log2_32(LHSElts+2))-1);
733 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2))
734 EltMask = llvm::ConstantInt::get(MTy->getElementType(),
735 (1 << llvm::Log2_32(LHSElts+1))-1);
736 else
737 EltMask = llvm::ConstantInt::get(MTy->getElementType(),
738 (1 << llvm::Log2_32(LHSElts))-1);
739
740 // Mask off the high bits of each shuffle index.
741 Value *MaskBits = llvm::ConstantVector::getSplat(MTy->getNumElements(),
742 EltMask);
743 Mask = Builder.CreateAnd(Mask, MaskBits, "mask");
744
745 // newv = undef
746 // mask = mask & maskbits
747 // for each elt
748 // n = extract mask i
749 // x = extract val n
750 // newv = insert newv, x, i
751 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(),
752 MTy->getNumElements());
753 Value* NewV = llvm::UndefValue::get(RTy);
754 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) {
755 Value *IIndx = Builder.getInt32(i);
756 Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx");
757 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext");
758
759 // Handle vec3 special since the index will be off by one for the RHS.
760 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) {
761 Value *cmpIndx, *newIndx;
762 cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3),
763 "cmp_shuf_idx");
764 newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj");
765 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx");
766 }
767 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt");
768 NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins");
769 }
770 return NewV;
771 }
772
773 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
774 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
775
776 // Handle vec3 special since the index will be off by one for the RHS.
777 llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType());
778 SmallVector<llvm::Constant*, 32> indices;
779 for (unsigned i = 2; i < E->getNumSubExprs(); i++) {
780 unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2);
781 if (VTy->getNumElements() == 3 && Idx > 3)
782 Idx -= 1;
783 indices.push_back(Builder.getInt32(Idx));
784 }
785
786 Value *SV = llvm::ConstantVector::get(indices);
787 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
788 }
VisitMemberExpr(MemberExpr * E)789 Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) {
790 llvm::APSInt Value;
791 if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) {
792 if (E->isArrow())
793 CGF.EmitScalarExpr(E->getBase());
794 else
795 EmitLValue(E->getBase());
796 return Builder.getInt(Value);
797 }
798
799 // Emit debug info for aggregate now, if it was delayed to reduce
800 // debug info size.
801 CGDebugInfo *DI = CGF.getDebugInfo();
802 if (DI &&
803 CGF.CGM.getCodeGenOpts().DebugInfo == CodeGenOptions::LimitedDebugInfo) {
804 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType();
805 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy))
806 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl()))
807 DI->getOrCreateRecordType(PTy->getPointeeType(),
808 M->getParent()->getLocation());
809 }
810 return EmitLoadOfLValue(E);
811 }
812
VisitArraySubscriptExpr(ArraySubscriptExpr * E)813 Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
814 TestAndClearIgnoreResultAssign();
815
816 // Emit subscript expressions in rvalue context's. For most cases, this just
817 // loads the lvalue formed by the subscript expr. However, we have to be
818 // careful, because the base of a vector subscript is occasionally an rvalue,
819 // so we can't get it as an lvalue.
820 if (!E->getBase()->getType()->isVectorType())
821 return EmitLoadOfLValue(E);
822
823 // Handle the vector case. The base must be a vector, the index must be an
824 // integer value.
825 Value *Base = Visit(E->getBase());
826 Value *Idx = Visit(E->getIdx());
827 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerOrEnumerationType();
828 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast");
829 return Builder.CreateExtractElement(Base, Idx, "vecext");
830 }
831
getMaskElt(llvm::ShuffleVectorInst * SVI,unsigned Idx,unsigned Off,llvm::Type * I32Ty)832 static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx,
833 unsigned Off, llvm::Type *I32Ty) {
834 int MV = SVI->getMaskValue(Idx);
835 if (MV == -1)
836 return llvm::UndefValue::get(I32Ty);
837 return llvm::ConstantInt::get(I32Ty, Off+MV);
838 }
839
VisitInitListExpr(InitListExpr * E)840 Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
841 bool Ignore = TestAndClearIgnoreResultAssign();
842 (void)Ignore;
843 assert (Ignore == false && "init list ignored");
844 unsigned NumInitElements = E->getNumInits();
845
846 if (E->hadArrayRangeDesignator())
847 CGF.ErrorUnsupported(E, "GNU array range designator extension");
848
849 llvm::VectorType *VType =
850 dyn_cast<llvm::VectorType>(ConvertType(E->getType()));
851
852 if (!VType) {
853 if (NumInitElements == 0) {
854 // C++11 value-initialization for the scalar.
855 return EmitNullValue(E->getType());
856 }
857 // We have a scalar in braces. Just use the first element.
858 return Visit(E->getInit(0));
859 }
860
861 unsigned ResElts = VType->getNumElements();
862
863 // Loop over initializers collecting the Value for each, and remembering
864 // whether the source was swizzle (ExtVectorElementExpr). This will allow
865 // us to fold the shuffle for the swizzle into the shuffle for the vector
866 // initializer, since LLVM optimizers generally do not want to touch
867 // shuffles.
868 unsigned CurIdx = 0;
869 bool VIsUndefShuffle = false;
870 llvm::Value *V = llvm::UndefValue::get(VType);
871 for (unsigned i = 0; i != NumInitElements; ++i) {
872 Expr *IE = E->getInit(i);
873 Value *Init = Visit(IE);
874 SmallVector<llvm::Constant*, 16> Args;
875
876 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType());
877
878 // Handle scalar elements. If the scalar initializer is actually one
879 // element of a different vector of the same width, use shuffle instead of
880 // extract+insert.
881 if (!VVT) {
882 if (isa<ExtVectorElementExpr>(IE)) {
883 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init);
884
885 if (EI->getVectorOperandType()->getNumElements() == ResElts) {
886 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand());
887 Value *LHS = 0, *RHS = 0;
888 if (CurIdx == 0) {
889 // insert into undef -> shuffle (src, undef)
890 Args.push_back(C);
891 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
892
893 LHS = EI->getVectorOperand();
894 RHS = V;
895 VIsUndefShuffle = true;
896 } else if (VIsUndefShuffle) {
897 // insert into undefshuffle && size match -> shuffle (v, src)
898 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V);
899 for (unsigned j = 0; j != CurIdx; ++j)
900 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty));
901 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue()));
902 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
903
904 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
905 RHS = EI->getVectorOperand();
906 VIsUndefShuffle = false;
907 }
908 if (!Args.empty()) {
909 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
910 V = Builder.CreateShuffleVector(LHS, RHS, Mask);
911 ++CurIdx;
912 continue;
913 }
914 }
915 }
916 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx),
917 "vecinit");
918 VIsUndefShuffle = false;
919 ++CurIdx;
920 continue;
921 }
922
923 unsigned InitElts = VVT->getNumElements();
924
925 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's
926 // input is the same width as the vector being constructed, generate an
927 // optimized shuffle of the swizzle input into the result.
928 unsigned Offset = (CurIdx == 0) ? 0 : ResElts;
929 if (isa<ExtVectorElementExpr>(IE)) {
930 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init);
931 Value *SVOp = SVI->getOperand(0);
932 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType());
933
934 if (OpTy->getNumElements() == ResElts) {
935 for (unsigned j = 0; j != CurIdx; ++j) {
936 // If the current vector initializer is a shuffle with undef, merge
937 // this shuffle directly into it.
938 if (VIsUndefShuffle) {
939 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0,
940 CGF.Int32Ty));
941 } else {
942 Args.push_back(Builder.getInt32(j));
943 }
944 }
945 for (unsigned j = 0, je = InitElts; j != je; ++j)
946 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty));
947 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
948
949 if (VIsUndefShuffle)
950 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
951
952 Init = SVOp;
953 }
954 }
955
956 // Extend init to result vector length, and then shuffle its contribution
957 // to the vector initializer into V.
958 if (Args.empty()) {
959 for (unsigned j = 0; j != InitElts; ++j)
960 Args.push_back(Builder.getInt32(j));
961 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
962 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
963 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
964 Mask, "vext");
965
966 Args.clear();
967 for (unsigned j = 0; j != CurIdx; ++j)
968 Args.push_back(Builder.getInt32(j));
969 for (unsigned j = 0; j != InitElts; ++j)
970 Args.push_back(Builder.getInt32(j+Offset));
971 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
972 }
973
974 // If V is undef, make sure it ends up on the RHS of the shuffle to aid
975 // merging subsequent shuffles into this one.
976 if (CurIdx == 0)
977 std::swap(V, Init);
978 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
979 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit");
980 VIsUndefShuffle = isa<llvm::UndefValue>(Init);
981 CurIdx += InitElts;
982 }
983
984 // FIXME: evaluate codegen vs. shuffling against constant null vector.
985 // Emit remaining default initializers.
986 llvm::Type *EltTy = VType->getElementType();
987
988 // Emit remaining default initializers
989 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) {
990 Value *Idx = Builder.getInt32(CurIdx);
991 llvm::Value *Init = llvm::Constant::getNullValue(EltTy);
992 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
993 }
994 return V;
995 }
996
ShouldNullCheckClassCastValue(const CastExpr * CE)997 static bool ShouldNullCheckClassCastValue(const CastExpr *CE) {
998 const Expr *E = CE->getSubExpr();
999
1000 if (CE->getCastKind() == CK_UncheckedDerivedToBase)
1001 return false;
1002
1003 if (isa<CXXThisExpr>(E)) {
1004 // We always assume that 'this' is never null.
1005 return false;
1006 }
1007
1008 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) {
1009 // And that glvalue casts are never null.
1010 if (ICE->getValueKind() != VK_RValue)
1011 return false;
1012 }
1013
1014 return true;
1015 }
1016
1017 // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts
1018 // have to handle a more broad range of conversions than explicit casts, as they
1019 // handle things like function to ptr-to-function decay etc.
VisitCastExpr(CastExpr * CE)1020 Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
1021 Expr *E = CE->getSubExpr();
1022 QualType DestTy = CE->getType();
1023 CastKind Kind = CE->getCastKind();
1024
1025 if (!DestTy->isVoidType())
1026 TestAndClearIgnoreResultAssign();
1027
1028 // Since almost all cast kinds apply to scalars, this switch doesn't have
1029 // a default case, so the compiler will warn on a missing case. The cases
1030 // are in the same order as in the CastKind enum.
1031 switch (Kind) {
1032 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
1033 case CK_BuiltinFnToFnPtr:
1034 llvm_unreachable("builtin functions are handled elsewhere");
1035
1036 case CK_LValueBitCast:
1037 case CK_ObjCObjectLValueCast: {
1038 Value *V = EmitLValue(E).getAddress();
1039 V = Builder.CreateBitCast(V,
1040 ConvertType(CGF.getContext().getPointerType(DestTy)));
1041 return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(V, DestTy));
1042 }
1043
1044 case CK_CPointerToObjCPointerCast:
1045 case CK_BlockPointerToObjCPointerCast:
1046 case CK_AnyPointerToBlockPointerCast:
1047 case CK_BitCast: {
1048 Value *Src = Visit(const_cast<Expr*>(E));
1049 return Builder.CreateBitCast(Src, ConvertType(DestTy));
1050 }
1051 case CK_AtomicToNonAtomic:
1052 case CK_NonAtomicToAtomic:
1053 case CK_NoOp:
1054 case CK_UserDefinedConversion:
1055 return Visit(const_cast<Expr*>(E));
1056
1057 case CK_BaseToDerived: {
1058 const CXXRecordDecl *DerivedClassDecl =
1059 DestTy->getCXXRecordDeclForPointerType();
1060
1061 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl,
1062 CE->path_begin(), CE->path_end(),
1063 ShouldNullCheckClassCastValue(CE));
1064 }
1065 case CK_UncheckedDerivedToBase:
1066 case CK_DerivedToBase: {
1067 const RecordType *DerivedClassTy =
1068 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>();
1069 CXXRecordDecl *DerivedClassDecl =
1070 cast<CXXRecordDecl>(DerivedClassTy->getDecl());
1071
1072 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl,
1073 CE->path_begin(), CE->path_end(),
1074 ShouldNullCheckClassCastValue(CE));
1075 }
1076 case CK_Dynamic: {
1077 Value *V = Visit(const_cast<Expr*>(E));
1078 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
1079 return CGF.EmitDynamicCast(V, DCE);
1080 }
1081
1082 case CK_ArrayToPointerDecay: {
1083 assert(E->getType()->isArrayType() &&
1084 "Array to pointer decay must have array source type!");
1085
1086 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays.
1087
1088 // Note that VLA pointers are always decayed, so we don't need to do
1089 // anything here.
1090 if (!E->getType()->isVariableArrayType()) {
1091 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer");
1092 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType())
1093 ->getElementType()) &&
1094 "Expected pointer to array");
1095 V = Builder.CreateStructGEP(V, 0, "arraydecay");
1096 }
1097
1098 // Make sure the array decay ends up being the right type. This matters if
1099 // the array type was of an incomplete type.
1100 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType()));
1101 }
1102 case CK_FunctionToPointerDecay:
1103 return EmitLValue(E).getAddress();
1104
1105 case CK_NullToPointer:
1106 if (MustVisitNullValue(E))
1107 (void) Visit(E);
1108
1109 return llvm::ConstantPointerNull::get(
1110 cast<llvm::PointerType>(ConvertType(DestTy)));
1111
1112 case CK_NullToMemberPointer: {
1113 if (MustVisitNullValue(E))
1114 (void) Visit(E);
1115
1116 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>();
1117 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT);
1118 }
1119
1120 case CK_ReinterpretMemberPointer:
1121 case CK_BaseToDerivedMemberPointer:
1122 case CK_DerivedToBaseMemberPointer: {
1123 Value *Src = Visit(E);
1124
1125 // Note that the AST doesn't distinguish between checked and
1126 // unchecked member pointer conversions, so we always have to
1127 // implement checked conversions here. This is inefficient when
1128 // actual control flow may be required in order to perform the
1129 // check, which it is for data member pointers (but not member
1130 // function pointers on Itanium and ARM).
1131 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src);
1132 }
1133
1134 case CK_ARCProduceObject:
1135 return CGF.EmitARCRetainScalarExpr(E);
1136 case CK_ARCConsumeObject:
1137 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E));
1138 case CK_ARCReclaimReturnedObject: {
1139 llvm::Value *value = Visit(E);
1140 value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
1141 return CGF.EmitObjCConsumeObject(E->getType(), value);
1142 }
1143 case CK_ARCExtendBlockObject:
1144 return CGF.EmitARCExtendBlockObject(E);
1145
1146 case CK_CopyAndAutoreleaseBlockObject:
1147 return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType());
1148
1149 case CK_FloatingRealToComplex:
1150 case CK_FloatingComplexCast:
1151 case CK_IntegralRealToComplex:
1152 case CK_IntegralComplexCast:
1153 case CK_IntegralComplexToFloatingComplex:
1154 case CK_FloatingComplexToIntegralComplex:
1155 case CK_ConstructorConversion:
1156 case CK_ToUnion:
1157 llvm_unreachable("scalar cast to non-scalar value");
1158
1159 case CK_LValueToRValue:
1160 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy));
1161 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!");
1162 return Visit(const_cast<Expr*>(E));
1163
1164 case CK_IntegralToPointer: {
1165 Value *Src = Visit(const_cast<Expr*>(E));
1166
1167 // First, convert to the correct width so that we control the kind of
1168 // extension.
1169 llvm::Type *MiddleTy = CGF.IntPtrTy;
1170 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType();
1171 llvm::Value* IntResult =
1172 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
1173
1174 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy));
1175 }
1176 case CK_PointerToIntegral:
1177 assert(!DestTy->isBooleanType() && "bool should use PointerToBool");
1178 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy));
1179
1180 case CK_ToVoid: {
1181 CGF.EmitIgnoredExpr(E);
1182 return 0;
1183 }
1184 case CK_VectorSplat: {
1185 llvm::Type *DstTy = ConvertType(DestTy);
1186 Value *Elt = Visit(const_cast<Expr*>(E));
1187 Elt = EmitScalarConversion(Elt, E->getType(),
1188 DestTy->getAs<VectorType>()->getElementType());
1189
1190 // Insert the element in element zero of an undef vector
1191 llvm::Value *UnV = llvm::UndefValue::get(DstTy);
1192 llvm::Value *Idx = Builder.getInt32(0);
1193 UnV = Builder.CreateInsertElement(UnV, Elt, Idx);
1194
1195 // Splat the element across to all elements
1196 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
1197 llvm::Constant *Zero = Builder.getInt32(0);
1198 llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, Zero);
1199 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
1200 return Yay;
1201 }
1202
1203 case CK_IntegralCast:
1204 case CK_IntegralToFloating:
1205 case CK_FloatingToIntegral:
1206 case CK_FloatingCast:
1207 return EmitScalarConversion(Visit(E), E->getType(), DestTy);
1208 case CK_IntegralToBoolean:
1209 return EmitIntToBoolConversion(Visit(E));
1210 case CK_PointerToBoolean:
1211 return EmitPointerToBoolConversion(Visit(E));
1212 case CK_FloatingToBoolean:
1213 return EmitFloatToBoolConversion(Visit(E));
1214 case CK_MemberPointerToBoolean: {
1215 llvm::Value *MemPtr = Visit(E);
1216 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>();
1217 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT);
1218 }
1219
1220 case CK_FloatingComplexToReal:
1221 case CK_IntegralComplexToReal:
1222 return CGF.EmitComplexExpr(E, false, true).first;
1223
1224 case CK_FloatingComplexToBoolean:
1225 case CK_IntegralComplexToBoolean: {
1226 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E);
1227
1228 // TODO: kill this function off, inline appropriate case here
1229 return EmitComplexToScalarConversion(V, E->getType(), DestTy);
1230 }
1231
1232 }
1233
1234 llvm_unreachable("unknown scalar cast");
1235 }
1236
VisitStmtExpr(const StmtExpr * E)1237 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
1238 CodeGenFunction::StmtExprEvaluation eval(CGF);
1239 return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType())
1240 .getScalarVal();
1241 }
1242
1243 //===----------------------------------------------------------------------===//
1244 // Unary Operators
1245 //===----------------------------------------------------------------------===//
1246
1247 llvm::Value *ScalarExprEmitter::
EmitAddConsiderOverflowBehavior(const UnaryOperator * E,llvm::Value * InVal,llvm::Value * NextVal,bool IsInc)1248 EmitAddConsiderOverflowBehavior(const UnaryOperator *E,
1249 llvm::Value *InVal,
1250 llvm::Value *NextVal, bool IsInc) {
1251 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) {
1252 case LangOptions::SOB_Defined:
1253 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec");
1254 case LangOptions::SOB_Undefined:
1255 if (!CGF.CatchUndefined)
1256 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec");
1257 // Fall through.
1258 case LangOptions::SOB_Trapping:
1259 BinOpInfo BinOp;
1260 BinOp.LHS = InVal;
1261 BinOp.RHS = NextVal;
1262 BinOp.Ty = E->getType();
1263 BinOp.Opcode = BO_Add;
1264 BinOp.E = E;
1265 return EmitOverflowCheckedBinOp(BinOp);
1266 }
1267 llvm_unreachable("Unknown SignedOverflowBehaviorTy");
1268 }
1269
1270 llvm::Value *
EmitScalarPrePostIncDec(const UnaryOperator * E,LValue LV,bool isInc,bool isPre)1271 ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
1272 bool isInc, bool isPre) {
1273
1274 QualType type = E->getSubExpr()->getType();
1275 llvm::Value *value = EmitLoadOfLValue(LV);
1276 llvm::Value *input = value;
1277 llvm::PHINode *atomicPHI = 0;
1278
1279 int amount = (isInc ? 1 : -1);
1280
1281 if (const AtomicType *atomicTy = type->getAs<AtomicType>()) {
1282 llvm::BasicBlock *startBB = Builder.GetInsertBlock();
1283 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
1284 Builder.CreateBr(opBB);
1285 Builder.SetInsertPoint(opBB);
1286 atomicPHI = Builder.CreatePHI(value->getType(), 2);
1287 atomicPHI->addIncoming(value, startBB);
1288 type = atomicTy->getValueType();
1289 value = atomicPHI;
1290 }
1291
1292 // Special case of integer increment that we have to check first: bool++.
1293 // Due to promotion rules, we get:
1294 // bool++ -> bool = bool + 1
1295 // -> bool = (int)bool + 1
1296 // -> bool = ((int)bool + 1 != 0)
1297 // An interesting aspect of this is that increment is always true.
1298 // Decrement does not have this property.
1299 if (isInc && type->isBooleanType()) {
1300 value = Builder.getTrue();
1301
1302 // Most common case by far: integer increment.
1303 } else if (type->isIntegerType()) {
1304
1305 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true);
1306
1307 // Note that signed integer inc/dec with width less than int can't
1308 // overflow because of promotion rules; we're just eliding a few steps here.
1309 if (type->isSignedIntegerOrEnumerationType() &&
1310 value->getType()->getPrimitiveSizeInBits() >=
1311 CGF.IntTy->getBitWidth())
1312 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc);
1313 else
1314 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
1315
1316 // Next most common: pointer increment.
1317 } else if (const PointerType *ptr = type->getAs<PointerType>()) {
1318 QualType type = ptr->getPointeeType();
1319
1320 // VLA types don't have constant size.
1321 if (const VariableArrayType *vla
1322 = CGF.getContext().getAsVariableArrayType(type)) {
1323 llvm::Value *numElts = CGF.getVLASize(vla).first;
1324 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize");
1325 if (CGF.getContext().getLangOpts().isSignedOverflowDefined())
1326 value = Builder.CreateGEP(value, numElts, "vla.inc");
1327 else
1328 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc");
1329
1330 // Arithmetic on function pointers (!) is just +-1.
1331 } else if (type->isFunctionType()) {
1332 llvm::Value *amt = Builder.getInt32(amount);
1333
1334 value = CGF.EmitCastToVoidPtr(value);
1335 if (CGF.getContext().getLangOpts().isSignedOverflowDefined())
1336 value = Builder.CreateGEP(value, amt, "incdec.funcptr");
1337 else
1338 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr");
1339 value = Builder.CreateBitCast(value, input->getType());
1340
1341 // For everything else, we can just do a simple increment.
1342 } else {
1343 llvm::Value *amt = Builder.getInt32(amount);
1344 if (CGF.getContext().getLangOpts().isSignedOverflowDefined())
1345 value = Builder.CreateGEP(value, amt, "incdec.ptr");
1346 else
1347 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr");
1348 }
1349
1350 // Vector increment/decrement.
1351 } else if (type->isVectorType()) {
1352 if (type->hasIntegerRepresentation()) {
1353 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount);
1354
1355 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
1356 } else {
1357 value = Builder.CreateFAdd(
1358 value,
1359 llvm::ConstantFP::get(value->getType(), amount),
1360 isInc ? "inc" : "dec");
1361 }
1362
1363 // Floating point.
1364 } else if (type->isRealFloatingType()) {
1365 // Add the inc/dec to the real part.
1366 llvm::Value *amt;
1367
1368 if (type->isHalfType()) {
1369 // Another special case: half FP increment should be done via float
1370 value =
1371 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16),
1372 input);
1373 }
1374
1375 if (value->getType()->isFloatTy())
1376 amt = llvm::ConstantFP::get(VMContext,
1377 llvm::APFloat(static_cast<float>(amount)));
1378 else if (value->getType()->isDoubleTy())
1379 amt = llvm::ConstantFP::get(VMContext,
1380 llvm::APFloat(static_cast<double>(amount)));
1381 else {
1382 llvm::APFloat F(static_cast<float>(amount));
1383 bool ignored;
1384 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero,
1385 &ignored);
1386 amt = llvm::ConstantFP::get(VMContext, F);
1387 }
1388 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec");
1389
1390 if (type->isHalfType())
1391 value =
1392 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16),
1393 value);
1394
1395 // Objective-C pointer types.
1396 } else {
1397 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>();
1398 value = CGF.EmitCastToVoidPtr(value);
1399
1400 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType());
1401 if (!isInc) size = -size;
1402 llvm::Value *sizeValue =
1403 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity());
1404
1405 if (CGF.getContext().getLangOpts().isSignedOverflowDefined())
1406 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr");
1407 else
1408 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr");
1409 value = Builder.CreateBitCast(value, input->getType());
1410 }
1411
1412 if (atomicPHI) {
1413 llvm::BasicBlock *opBB = Builder.GetInsertBlock();
1414 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
1415 llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI,
1416 value, llvm::SequentiallyConsistent);
1417 atomicPHI->addIncoming(old, opBB);
1418 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI);
1419 Builder.CreateCondBr(success, contBB, opBB);
1420 Builder.SetInsertPoint(contBB);
1421 return isPre ? value : input;
1422 }
1423
1424 // Store the updated result through the lvalue.
1425 if (LV.isBitField())
1426 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value);
1427 else
1428 CGF.EmitStoreThroughLValue(RValue::get(value), LV);
1429
1430 // If this is a postinc, return the value read from memory, otherwise use the
1431 // updated value.
1432 return isPre ? value : input;
1433 }
1434
1435
1436
VisitUnaryMinus(const UnaryOperator * E)1437 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
1438 TestAndClearIgnoreResultAssign();
1439 // Emit unary minus with EmitSub so we handle overflow cases etc.
1440 BinOpInfo BinOp;
1441 BinOp.RHS = Visit(E->getSubExpr());
1442
1443 if (BinOp.RHS->getType()->isFPOrFPVectorTy())
1444 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType());
1445 else
1446 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
1447 BinOp.Ty = E->getType();
1448 BinOp.Opcode = BO_Sub;
1449 BinOp.E = E;
1450 return EmitSub(BinOp);
1451 }
1452
VisitUnaryNot(const UnaryOperator * E)1453 Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
1454 TestAndClearIgnoreResultAssign();
1455 Value *Op = Visit(E->getSubExpr());
1456 return Builder.CreateNot(Op, "neg");
1457 }
1458
VisitUnaryLNot(const UnaryOperator * E)1459 Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) {
1460
1461 // Perform vector logical not on comparison with zero vector.
1462 if (E->getType()->isExtVectorType()) {
1463 Value *Oper = Visit(E->getSubExpr());
1464 Value *Zero = llvm::Constant::getNullValue(Oper->getType());
1465 Value *Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp");
1466 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
1467 }
1468
1469 // Compare operand to zero.
1470 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr());
1471
1472 // Invert value.
1473 // TODO: Could dynamically modify easy computations here. For example, if
1474 // the operand is an icmp ne, turn into icmp eq.
1475 BoolVal = Builder.CreateNot(BoolVal, "lnot");
1476
1477 // ZExt result to the expr type.
1478 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext");
1479 }
1480
VisitOffsetOfExpr(OffsetOfExpr * E)1481 Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) {
1482 // Try folding the offsetof to a constant.
1483 llvm::APSInt Value;
1484 if (E->EvaluateAsInt(Value, CGF.getContext()))
1485 return Builder.getInt(Value);
1486
1487 // Loop over the components of the offsetof to compute the value.
1488 unsigned n = E->getNumComponents();
1489 llvm::Type* ResultType = ConvertType(E->getType());
1490 llvm::Value* Result = llvm::Constant::getNullValue(ResultType);
1491 QualType CurrentType = E->getTypeSourceInfo()->getType();
1492 for (unsigned i = 0; i != n; ++i) {
1493 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i);
1494 llvm::Value *Offset = 0;
1495 switch (ON.getKind()) {
1496 case OffsetOfExpr::OffsetOfNode::Array: {
1497 // Compute the index
1498 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex());
1499 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr);
1500 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType();
1501 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv");
1502
1503 // Save the element type
1504 CurrentType =
1505 CGF.getContext().getAsArrayType(CurrentType)->getElementType();
1506
1507 // Compute the element size
1508 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType,
1509 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity());
1510
1511 // Multiply out to compute the result
1512 Offset = Builder.CreateMul(Idx, ElemSize);
1513 break;
1514 }
1515
1516 case OffsetOfExpr::OffsetOfNode::Field: {
1517 FieldDecl *MemberDecl = ON.getField();
1518 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
1519 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
1520
1521 // Compute the index of the field in its parent.
1522 unsigned i = 0;
1523 // FIXME: It would be nice if we didn't have to loop here!
1524 for (RecordDecl::field_iterator Field = RD->field_begin(),
1525 FieldEnd = RD->field_end();
1526 Field != FieldEnd; ++Field, ++i) {
1527 if (*Field == MemberDecl)
1528 break;
1529 }
1530 assert(i < RL.getFieldCount() && "offsetof field in wrong type");
1531
1532 // Compute the offset to the field
1533 int64_t OffsetInt = RL.getFieldOffset(i) /
1534 CGF.getContext().getCharWidth();
1535 Offset = llvm::ConstantInt::get(ResultType, OffsetInt);
1536
1537 // Save the element type.
1538 CurrentType = MemberDecl->getType();
1539 break;
1540 }
1541
1542 case OffsetOfExpr::OffsetOfNode::Identifier:
1543 llvm_unreachable("dependent __builtin_offsetof");
1544
1545 case OffsetOfExpr::OffsetOfNode::Base: {
1546 if (ON.getBase()->isVirtual()) {
1547 CGF.ErrorUnsupported(E, "virtual base in offsetof");
1548 continue;
1549 }
1550
1551 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
1552 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
1553
1554 // Save the element type.
1555 CurrentType = ON.getBase()->getType();
1556
1557 // Compute the offset to the base.
1558 const RecordType *BaseRT = CurrentType->getAs<RecordType>();
1559 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
1560 CharUnits OffsetInt = RL.getBaseClassOffset(BaseRD);
1561 Offset = llvm::ConstantInt::get(ResultType, OffsetInt.getQuantity());
1562 break;
1563 }
1564 }
1565 Result = Builder.CreateAdd(Result, Offset);
1566 }
1567 return Result;
1568 }
1569
1570 /// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of
1571 /// argument of the sizeof expression as an integer.
1572 Value *
VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr * E)1573 ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr(
1574 const UnaryExprOrTypeTraitExpr *E) {
1575 QualType TypeToSize = E->getTypeOfArgument();
1576 if (E->getKind() == UETT_SizeOf) {
1577 if (const VariableArrayType *VAT =
1578 CGF.getContext().getAsVariableArrayType(TypeToSize)) {
1579 if (E->isArgumentType()) {
1580 // sizeof(type) - make sure to emit the VLA size.
1581 CGF.EmitVariablyModifiedType(TypeToSize);
1582 } else {
1583 // C99 6.5.3.4p2: If the argument is an expression of type
1584 // VLA, it is evaluated.
1585 CGF.EmitIgnoredExpr(E->getArgumentExpr());
1586 }
1587
1588 QualType eltType;
1589 llvm::Value *numElts;
1590 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT);
1591
1592 llvm::Value *size = numElts;
1593
1594 // Scale the number of non-VLA elements by the non-VLA element size.
1595 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
1596 if (!eltSize.isOne())
1597 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts);
1598
1599 return size;
1600 }
1601 }
1602
1603 // If this isn't sizeof(vla), the result must be constant; use the constant
1604 // folding logic so we don't have to duplicate it here.
1605 return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext()));
1606 }
1607
VisitUnaryReal(const UnaryOperator * E)1608 Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
1609 Expr *Op = E->getSubExpr();
1610 if (Op->getType()->isAnyComplexType()) {
1611 // If it's an l-value, load through the appropriate subobject l-value.
1612 // Note that we have to ask E because Op might be an l-value that
1613 // this won't work for, e.g. an Obj-C property.
1614 if (E->isGLValue())
1615 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal();
1616
1617 // Otherwise, calculate and project.
1618 return CGF.EmitComplexExpr(Op, false, true).first;
1619 }
1620
1621 return Visit(Op);
1622 }
1623
VisitUnaryImag(const UnaryOperator * E)1624 Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
1625 Expr *Op = E->getSubExpr();
1626 if (Op->getType()->isAnyComplexType()) {
1627 // If it's an l-value, load through the appropriate subobject l-value.
1628 // Note that we have to ask E because Op might be an l-value that
1629 // this won't work for, e.g. an Obj-C property.
1630 if (Op->isGLValue())
1631 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal();
1632
1633 // Otherwise, calculate and project.
1634 return CGF.EmitComplexExpr(Op, true, false).second;
1635 }
1636
1637 // __imag on a scalar returns zero. Emit the subexpr to ensure side
1638 // effects are evaluated, but not the actual value.
1639 if (Op->isGLValue())
1640 CGF.EmitLValue(Op);
1641 else
1642 CGF.EmitScalarExpr(Op, true);
1643 return llvm::Constant::getNullValue(ConvertType(E->getType()));
1644 }
1645
1646 //===----------------------------------------------------------------------===//
1647 // Binary Operators
1648 //===----------------------------------------------------------------------===//
1649
EmitBinOps(const BinaryOperator * E)1650 BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) {
1651 TestAndClearIgnoreResultAssign();
1652 BinOpInfo Result;
1653 Result.LHS = Visit(E->getLHS());
1654 Result.RHS = Visit(E->getRHS());
1655 Result.Ty = E->getType();
1656 Result.Opcode = E->getOpcode();
1657 Result.E = E;
1658 return Result;
1659 }
1660
EmitCompoundAssignLValue(const CompoundAssignOperator * E,Value * (ScalarExprEmitter::* Func)(const BinOpInfo &),Value * & Result)1661 LValue ScalarExprEmitter::EmitCompoundAssignLValue(
1662 const CompoundAssignOperator *E,
1663 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &),
1664 Value *&Result) {
1665 QualType LHSTy = E->getLHS()->getType();
1666 BinOpInfo OpInfo;
1667
1668 if (E->getComputationResultType()->isAnyComplexType()) {
1669 // This needs to go through the complex expression emitter, but it's a tad
1670 // complicated to do that... I'm leaving it out for now. (Note that we do
1671 // actually need the imaginary part of the RHS for multiplication and
1672 // division.)
1673 CGF.ErrorUnsupported(E, "complex compound assignment");
1674 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType()));
1675 return LValue();
1676 }
1677
1678 // Emit the RHS first. __block variables need to have the rhs evaluated
1679 // first, plus this should improve codegen a little.
1680 OpInfo.RHS = Visit(E->getRHS());
1681 OpInfo.Ty = E->getComputationResultType();
1682 OpInfo.Opcode = E->getOpcode();
1683 OpInfo.E = E;
1684 // Load/convert the LHS.
1685 LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
1686 OpInfo.LHS = EmitLoadOfLValue(LHSLV);
1687
1688 llvm::PHINode *atomicPHI = 0;
1689 if (LHSTy->isAtomicType()) {
1690 // FIXME: For floating point types, we should be saving and restoring the
1691 // floating point environment in the loop.
1692 llvm::BasicBlock *startBB = Builder.GetInsertBlock();
1693 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
1694 Builder.CreateBr(opBB);
1695 Builder.SetInsertPoint(opBB);
1696 atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2);
1697 atomicPHI->addIncoming(OpInfo.LHS, startBB);
1698 OpInfo.LHS = atomicPHI;
1699 }
1700
1701 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy,
1702 E->getComputationLHSType());
1703
1704 // Expand the binary operator.
1705 Result = (this->*Func)(OpInfo);
1706
1707 // Convert the result back to the LHS type.
1708 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy);
1709
1710 if (atomicPHI) {
1711 llvm::BasicBlock *opBB = Builder.GetInsertBlock();
1712 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
1713 llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI,
1714 Result, llvm::SequentiallyConsistent);
1715 atomicPHI->addIncoming(old, opBB);
1716 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI);
1717 Builder.CreateCondBr(success, contBB, opBB);
1718 Builder.SetInsertPoint(contBB);
1719 return LHSLV;
1720 }
1721
1722 // Store the result value into the LHS lvalue. Bit-fields are handled
1723 // specially because the result is altered by the store, i.e., [C99 6.5.16p1]
1724 // 'An assignment expression has the value of the left operand after the
1725 // assignment...'.
1726 if (LHSLV.isBitField())
1727 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result);
1728 else
1729 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV);
1730
1731 return LHSLV;
1732 }
1733
EmitCompoundAssign(const CompoundAssignOperator * E,Value * (ScalarExprEmitter::* Func)(const BinOpInfo &))1734 Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
1735 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
1736 bool Ignore = TestAndClearIgnoreResultAssign();
1737 Value *RHS;
1738 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS);
1739
1740 // If the result is clearly ignored, return now.
1741 if (Ignore)
1742 return 0;
1743
1744 // The result of an assignment in C is the assigned r-value.
1745 if (!CGF.getContext().getLangOpts().CPlusPlus)
1746 return RHS;
1747
1748 // If the lvalue is non-volatile, return the computed value of the assignment.
1749 if (!LHS.isVolatileQualified())
1750 return RHS;
1751
1752 // Otherwise, reload the value.
1753 return EmitLoadOfLValue(LHS);
1754 }
1755
EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo & Ops,llvm::Value * Zero,bool isDiv)1756 void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck(
1757 const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) {
1758 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType());
1759
1760 if (Ops.Ty->hasSignedIntegerRepresentation()) {
1761 llvm::Value *IntMin =
1762 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth()));
1763 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL);
1764
1765 llvm::Value *Cond1 = Builder.CreateICmpNE(Ops.RHS, Zero);
1766 llvm::Value *LHSCmp = Builder.CreateICmpNE(Ops.LHS, IntMin);
1767 llvm::Value *RHSCmp = Builder.CreateICmpNE(Ops.RHS, NegOne);
1768 llvm::Value *Cond2 = Builder.CreateOr(LHSCmp, RHSCmp, "or");
1769 CGF.EmitCheck(Builder.CreateAnd(Cond1, Cond2, "and"));
1770 } else {
1771 CGF.EmitCheck(Builder.CreateICmpNE(Ops.RHS, Zero));
1772 }
1773 }
1774
EmitDiv(const BinOpInfo & Ops)1775 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
1776 if (isTrapvOverflowBehavior()) {
1777 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
1778
1779 if (Ops.Ty->isIntegerType())
1780 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true);
1781 else if (Ops.Ty->isRealFloatingType())
1782 CGF.EmitCheck(Builder.CreateFCmpUNE(Ops.RHS, Zero));
1783 }
1784 if (Ops.LHS->getType()->isFPOrFPVectorTy()) {
1785 llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div");
1786 if (CGF.getContext().getLangOpts().OpenCL) {
1787 // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp
1788 llvm::Type *ValTy = Val->getType();
1789 if (ValTy->isFloatTy() ||
1790 (isa<llvm::VectorType>(ValTy) &&
1791 cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy()))
1792 CGF.SetFPAccuracy(Val, 2.5);
1793 }
1794 return Val;
1795 }
1796 else if (Ops.Ty->hasUnsignedIntegerRepresentation())
1797 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div");
1798 else
1799 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div");
1800 }
1801
EmitRem(const BinOpInfo & Ops)1802 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
1803 // Rem in C can't be a floating point type: C99 6.5.5p2.
1804 if (isTrapvOverflowBehavior()) {
1805 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
1806
1807 if (Ops.Ty->isIntegerType())
1808 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false);
1809 }
1810
1811 if (Ops.Ty->hasUnsignedIntegerRepresentation())
1812 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem");
1813 else
1814 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem");
1815 }
1816
EmitOverflowCheckedBinOp(const BinOpInfo & Ops)1817 Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
1818 unsigned IID;
1819 unsigned OpID = 0;
1820
1821 switch (Ops.Opcode) {
1822 case BO_Add:
1823 case BO_AddAssign:
1824 OpID = 1;
1825 IID = llvm::Intrinsic::sadd_with_overflow;
1826 break;
1827 case BO_Sub:
1828 case BO_SubAssign:
1829 OpID = 2;
1830 IID = llvm::Intrinsic::ssub_with_overflow;
1831 break;
1832 case BO_Mul:
1833 case BO_MulAssign:
1834 OpID = 3;
1835 IID = llvm::Intrinsic::smul_with_overflow;
1836 break;
1837 default:
1838 llvm_unreachable("Unsupported operation for overflow detection");
1839 }
1840 OpID <<= 1;
1841 OpID |= 1;
1842
1843 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
1844
1845 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy);
1846
1847 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS);
1848 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0);
1849 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1);
1850
1851 // Handle overflow with llvm.trap if no custom handler has been specified.
1852 const std::string *handlerName =
1853 &CGF.getContext().getLangOpts().OverflowHandler;
1854 if (handlerName->empty()) {
1855 CGF.EmitCheck(Builder.CreateNot(overflow));
1856 return result;
1857 }
1858
1859 // Branch in case of overflow.
1860 llvm::BasicBlock *initialBB = Builder.GetInsertBlock();
1861 llvm::Function::iterator insertPt = initialBB;
1862 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn,
1863 llvm::next(insertPt));
1864 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn);
1865
1866 Builder.CreateCondBr(overflow, overflowBB, continueBB);
1867
1868 // If an overflow handler is set, then we want to call it and then use its
1869 // result, if it returns.
1870 Builder.SetInsertPoint(overflowBB);
1871
1872 // Get the overflow handler.
1873 llvm::Type *Int8Ty = CGF.Int8Ty;
1874 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty };
1875 llvm::FunctionType *handlerTy =
1876 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true);
1877 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName);
1878
1879 // Sign extend the args to 64-bit, so that we can use the same handler for
1880 // all types of overflow.
1881 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty);
1882 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty);
1883
1884 // Call the handler with the two arguments, the operation, and the size of
1885 // the result.
1886 llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs,
1887 Builder.getInt8(OpID),
1888 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth()));
1889
1890 // Truncate the result back to the desired size.
1891 handlerResult = Builder.CreateTrunc(handlerResult, opTy);
1892 Builder.CreateBr(continueBB);
1893
1894 Builder.SetInsertPoint(continueBB);
1895 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2);
1896 phi->addIncoming(result, initialBB);
1897 phi->addIncoming(handlerResult, overflowBB);
1898
1899 return phi;
1900 }
1901
1902 /// Emit pointer + index arithmetic.
emitPointerArithmetic(CodeGenFunction & CGF,const BinOpInfo & op,bool isSubtraction)1903 static Value *emitPointerArithmetic(CodeGenFunction &CGF,
1904 const BinOpInfo &op,
1905 bool isSubtraction) {
1906 // Must have binary (not unary) expr here. Unary pointer
1907 // increment/decrement doesn't use this path.
1908 const BinaryOperator *expr = cast<BinaryOperator>(op.E);
1909
1910 Value *pointer = op.LHS;
1911 Expr *pointerOperand = expr->getLHS();
1912 Value *index = op.RHS;
1913 Expr *indexOperand = expr->getRHS();
1914
1915 // In a subtraction, the LHS is always the pointer.
1916 if (!isSubtraction && !pointer->getType()->isPointerTy()) {
1917 std::swap(pointer, index);
1918 std::swap(pointerOperand, indexOperand);
1919 }
1920
1921 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth();
1922 if (width != CGF.PointerWidthInBits) {
1923 // Zero-extend or sign-extend the pointer value according to
1924 // whether the index is signed or not.
1925 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
1926 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned,
1927 "idx.ext");
1928 }
1929
1930 // If this is subtraction, negate the index.
1931 if (isSubtraction)
1932 index = CGF.Builder.CreateNeg(index, "idx.neg");
1933
1934 const PointerType *pointerType
1935 = pointerOperand->getType()->getAs<PointerType>();
1936 if (!pointerType) {
1937 QualType objectType = pointerOperand->getType()
1938 ->castAs<ObjCObjectPointerType>()
1939 ->getPointeeType();
1940 llvm::Value *objectSize
1941 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType));
1942
1943 index = CGF.Builder.CreateMul(index, objectSize);
1944
1945 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
1946 result = CGF.Builder.CreateGEP(result, index, "add.ptr");
1947 return CGF.Builder.CreateBitCast(result, pointer->getType());
1948 }
1949
1950 QualType elementType = pointerType->getPointeeType();
1951 if (const VariableArrayType *vla
1952 = CGF.getContext().getAsVariableArrayType(elementType)) {
1953 // The element count here is the total number of non-VLA elements.
1954 llvm::Value *numElements = CGF.getVLASize(vla).first;
1955
1956 // Effectively, the multiply by the VLA size is part of the GEP.
1957 // GEP indexes are signed, and scaling an index isn't permitted to
1958 // signed-overflow, so we use the same semantics for our explicit
1959 // multiply. We suppress this if overflow is not undefined behavior.
1960 if (CGF.getLangOpts().isSignedOverflowDefined()) {
1961 index = CGF.Builder.CreateMul(index, numElements, "vla.index");
1962 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr");
1963 } else {
1964 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index");
1965 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr");
1966 }
1967 return pointer;
1968 }
1969
1970 // Explicitly handle GNU void* and function pointer arithmetic extensions. The
1971 // GNU void* casts amount to no-ops since our void* type is i8*, but this is
1972 // future proof.
1973 if (elementType->isVoidType() || elementType->isFunctionType()) {
1974 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
1975 result = CGF.Builder.CreateGEP(result, index, "add.ptr");
1976 return CGF.Builder.CreateBitCast(result, pointer->getType());
1977 }
1978
1979 if (CGF.getLangOpts().isSignedOverflowDefined())
1980 return CGF.Builder.CreateGEP(pointer, index, "add.ptr");
1981
1982 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr");
1983 }
1984
EmitAdd(const BinOpInfo & op)1985 Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) {
1986 if (op.LHS->getType()->isPointerTy() ||
1987 op.RHS->getType()->isPointerTy())
1988 return emitPointerArithmetic(CGF, op, /*subtraction*/ false);
1989
1990 if (op.Ty->isSignedIntegerOrEnumerationType()) {
1991 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) {
1992 case LangOptions::SOB_Defined:
1993 return Builder.CreateAdd(op.LHS, op.RHS, "add");
1994 case LangOptions::SOB_Undefined:
1995 if (!CGF.CatchUndefined)
1996 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
1997 // Fall through.
1998 case LangOptions::SOB_Trapping:
1999 return EmitOverflowCheckedBinOp(op);
2000 }
2001 }
2002
2003 if (op.LHS->getType()->isFPOrFPVectorTy())
2004 return Builder.CreateFAdd(op.LHS, op.RHS, "add");
2005
2006 return Builder.CreateAdd(op.LHS, op.RHS, "add");
2007 }
2008
EmitSub(const BinOpInfo & op)2009 Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) {
2010 // The LHS is always a pointer if either side is.
2011 if (!op.LHS->getType()->isPointerTy()) {
2012 if (op.Ty->isSignedIntegerOrEnumerationType()) {
2013 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) {
2014 case LangOptions::SOB_Defined:
2015 return Builder.CreateSub(op.LHS, op.RHS, "sub");
2016 case LangOptions::SOB_Undefined:
2017 if (!CGF.CatchUndefined)
2018 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
2019 // Fall through.
2020 case LangOptions::SOB_Trapping:
2021 return EmitOverflowCheckedBinOp(op);
2022 }
2023 }
2024
2025 if (op.LHS->getType()->isFPOrFPVectorTy())
2026 return Builder.CreateFSub(op.LHS, op.RHS, "sub");
2027
2028 return Builder.CreateSub(op.LHS, op.RHS, "sub");
2029 }
2030
2031 // If the RHS is not a pointer, then we have normal pointer
2032 // arithmetic.
2033 if (!op.RHS->getType()->isPointerTy())
2034 return emitPointerArithmetic(CGF, op, /*subtraction*/ true);
2035
2036 // Otherwise, this is a pointer subtraction.
2037
2038 // Do the raw subtraction part.
2039 llvm::Value *LHS
2040 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast");
2041 llvm::Value *RHS
2042 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast");
2043 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub");
2044
2045 // Okay, figure out the element size.
2046 const BinaryOperator *expr = cast<BinaryOperator>(op.E);
2047 QualType elementType = expr->getLHS()->getType()->getPointeeType();
2048
2049 llvm::Value *divisor = 0;
2050
2051 // For a variable-length array, this is going to be non-constant.
2052 if (const VariableArrayType *vla
2053 = CGF.getContext().getAsVariableArrayType(elementType)) {
2054 llvm::Value *numElements;
2055 llvm::tie(numElements, elementType) = CGF.getVLASize(vla);
2056
2057 divisor = numElements;
2058
2059 // Scale the number of non-VLA elements by the non-VLA element size.
2060 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType);
2061 if (!eltSize.isOne())
2062 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor);
2063
2064 // For everything elese, we can just compute it, safe in the
2065 // assumption that Sema won't let anything through that we can't
2066 // safely compute the size of.
2067 } else {
2068 CharUnits elementSize;
2069 // Handle GCC extension for pointer arithmetic on void* and
2070 // function pointer types.
2071 if (elementType->isVoidType() || elementType->isFunctionType())
2072 elementSize = CharUnits::One();
2073 else
2074 elementSize = CGF.getContext().getTypeSizeInChars(elementType);
2075
2076 // Don't even emit the divide for element size of 1.
2077 if (elementSize.isOne())
2078 return diffInChars;
2079
2080 divisor = CGF.CGM.getSize(elementSize);
2081 }
2082
2083 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since
2084 // pointer difference in C is only defined in the case where both operands
2085 // are pointing to elements of an array.
2086 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div");
2087 }
2088
EmitShl(const BinOpInfo & Ops)2089 Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) {
2090 // LLVM requires the LHS and RHS to be the same type: promote or truncate the
2091 // RHS to the same size as the LHS.
2092 Value *RHS = Ops.RHS;
2093 if (Ops.LHS->getType() != RHS->getType())
2094 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
2095
2096 if (CGF.CatchUndefined && isa<llvm::IntegerType>(Ops.LHS->getType())) {
2097 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
2098 llvm::Value *WidthMinusOne =
2099 llvm::ConstantInt::get(RHS->getType(), Width - 1);
2100 CGF.EmitCheck(Builder.CreateICmpULE(RHS, WidthMinusOne));
2101
2102 if (Ops.Ty->hasSignedIntegerRepresentation()) {
2103 // Check whether we are shifting any non-zero bits off the top of the
2104 // integer.
2105 llvm::Value *BitsShiftedOff =
2106 Builder.CreateLShr(Ops.LHS,
2107 Builder.CreateSub(WidthMinusOne, RHS, "shl.zeros",
2108 /*NUW*/true, /*NSW*/true),
2109 "shl.check");
2110 if (CGF.getLangOpts().CPlusPlus) {
2111 // In C99, we are not permitted to shift a 1 bit into the sign bit.
2112 // Under C++11's rules, shifting a 1 bit into the sign bit is
2113 // OK, but shifting a 1 bit out of it is not. (C89 and C++03 don't
2114 // define signed left shifts, so we use the C99 and C++11 rules there).
2115 llvm::Value *One = llvm::ConstantInt::get(BitsShiftedOff->getType(), 1);
2116 BitsShiftedOff = Builder.CreateLShr(BitsShiftedOff, One);
2117 }
2118 llvm::Value *Zero = llvm::ConstantInt::get(BitsShiftedOff->getType(), 0);
2119 CGF.EmitCheck(Builder.CreateICmpEQ(BitsShiftedOff, Zero));
2120 }
2121 }
2122
2123 return Builder.CreateShl(Ops.LHS, RHS, "shl");
2124 }
2125
EmitShr(const BinOpInfo & Ops)2126 Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) {
2127 // LLVM requires the LHS and RHS to be the same type: promote or truncate the
2128 // RHS to the same size as the LHS.
2129 Value *RHS = Ops.RHS;
2130 if (Ops.LHS->getType() != RHS->getType())
2131 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
2132
2133 if (CGF.CatchUndefined && isa<llvm::IntegerType>(Ops.LHS->getType())) {
2134 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
2135 llvm::Value *WidthVal = llvm::ConstantInt::get(RHS->getType(), Width);
2136 CGF.EmitCheck(Builder.CreateICmpULT(RHS, WidthVal));
2137 }
2138
2139 if (Ops.Ty->hasUnsignedIntegerRepresentation())
2140 return Builder.CreateLShr(Ops.LHS, RHS, "shr");
2141 return Builder.CreateAShr(Ops.LHS, RHS, "shr");
2142 }
2143
2144 enum IntrinsicType { VCMPEQ, VCMPGT };
2145 // return corresponding comparison intrinsic for given vector type
GetIntrinsic(IntrinsicType IT,BuiltinType::Kind ElemKind)2146 static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT,
2147 BuiltinType::Kind ElemKind) {
2148 switch (ElemKind) {
2149 default: llvm_unreachable("unexpected element type");
2150 case BuiltinType::Char_U:
2151 case BuiltinType::UChar:
2152 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
2153 llvm::Intrinsic::ppc_altivec_vcmpgtub_p;
2154 case BuiltinType::Char_S:
2155 case BuiltinType::SChar:
2156 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
2157 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p;
2158 case BuiltinType::UShort:
2159 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
2160 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p;
2161 case BuiltinType::Short:
2162 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
2163 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p;
2164 case BuiltinType::UInt:
2165 case BuiltinType::ULong:
2166 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
2167 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p;
2168 case BuiltinType::Int:
2169 case BuiltinType::Long:
2170 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
2171 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p;
2172 case BuiltinType::Float:
2173 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p :
2174 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p;
2175 }
2176 }
2177
EmitCompare(const BinaryOperator * E,unsigned UICmpOpc,unsigned SICmpOpc,unsigned FCmpOpc)2178 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc,
2179 unsigned SICmpOpc, unsigned FCmpOpc) {
2180 TestAndClearIgnoreResultAssign();
2181 Value *Result;
2182 QualType LHSTy = E->getLHS()->getType();
2183 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) {
2184 assert(E->getOpcode() == BO_EQ ||
2185 E->getOpcode() == BO_NE);
2186 Value *LHS = CGF.EmitScalarExpr(E->getLHS());
2187 Value *RHS = CGF.EmitScalarExpr(E->getRHS());
2188 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison(
2189 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE);
2190 } else if (!LHSTy->isAnyComplexType()) {
2191 Value *LHS = Visit(E->getLHS());
2192 Value *RHS = Visit(E->getRHS());
2193
2194 // If AltiVec, the comparison results in a numeric type, so we use
2195 // intrinsics comparing vectors and giving 0 or 1 as a result
2196 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) {
2197 // constants for mapping CR6 register bits to predicate result
2198 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6;
2199
2200 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic;
2201
2202 // in several cases vector arguments order will be reversed
2203 Value *FirstVecArg = LHS,
2204 *SecondVecArg = RHS;
2205
2206 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType();
2207 const BuiltinType *BTy = ElTy->getAs<BuiltinType>();
2208 BuiltinType::Kind ElementKind = BTy->getKind();
2209
2210 switch(E->getOpcode()) {
2211 default: llvm_unreachable("is not a comparison operation");
2212 case BO_EQ:
2213 CR6 = CR6_LT;
2214 ID = GetIntrinsic(VCMPEQ, ElementKind);
2215 break;
2216 case BO_NE:
2217 CR6 = CR6_EQ;
2218 ID = GetIntrinsic(VCMPEQ, ElementKind);
2219 break;
2220 case BO_LT:
2221 CR6 = CR6_LT;
2222 ID = GetIntrinsic(VCMPGT, ElementKind);
2223 std::swap(FirstVecArg, SecondVecArg);
2224 break;
2225 case BO_GT:
2226 CR6 = CR6_LT;
2227 ID = GetIntrinsic(VCMPGT, ElementKind);
2228 break;
2229 case BO_LE:
2230 if (ElementKind == BuiltinType::Float) {
2231 CR6 = CR6_LT;
2232 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
2233 std::swap(FirstVecArg, SecondVecArg);
2234 }
2235 else {
2236 CR6 = CR6_EQ;
2237 ID = GetIntrinsic(VCMPGT, ElementKind);
2238 }
2239 break;
2240 case BO_GE:
2241 if (ElementKind == BuiltinType::Float) {
2242 CR6 = CR6_LT;
2243 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
2244 }
2245 else {
2246 CR6 = CR6_EQ;
2247 ID = GetIntrinsic(VCMPGT, ElementKind);
2248 std::swap(FirstVecArg, SecondVecArg);
2249 }
2250 break;
2251 }
2252
2253 Value *CR6Param = Builder.getInt32(CR6);
2254 llvm::Function *F = CGF.CGM.getIntrinsic(ID);
2255 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, "");
2256 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType());
2257 }
2258
2259 if (LHS->getType()->isFPOrFPVectorTy()) {
2260 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc,
2261 LHS, RHS, "cmp");
2262 } else if (LHSTy->hasSignedIntegerRepresentation()) {
2263 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc,
2264 LHS, RHS, "cmp");
2265 } else {
2266 // Unsigned integers and pointers.
2267 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
2268 LHS, RHS, "cmp");
2269 }
2270
2271 // If this is a vector comparison, sign extend the result to the appropriate
2272 // vector integer type and return it (don't convert to bool).
2273 if (LHSTy->isVectorType())
2274 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
2275
2276 } else {
2277 // Complex Comparison: can only be an equality comparison.
2278 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS());
2279 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS());
2280
2281 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType();
2282
2283 Value *ResultR, *ResultI;
2284 if (CETy->isRealFloatingType()) {
2285 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
2286 LHS.first, RHS.first, "cmp.r");
2287 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
2288 LHS.second, RHS.second, "cmp.i");
2289 } else {
2290 // Complex comparisons can only be equality comparisons. As such, signed
2291 // and unsigned opcodes are the same.
2292 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
2293 LHS.first, RHS.first, "cmp.r");
2294 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
2295 LHS.second, RHS.second, "cmp.i");
2296 }
2297
2298 if (E->getOpcode() == BO_EQ) {
2299 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
2300 } else {
2301 assert(E->getOpcode() == BO_NE &&
2302 "Complex comparison other than == or != ?");
2303 Result = Builder.CreateOr(ResultR, ResultI, "or.ri");
2304 }
2305 }
2306
2307 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType());
2308 }
2309
VisitBinAssign(const BinaryOperator * E)2310 Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
2311 bool Ignore = TestAndClearIgnoreResultAssign();
2312
2313 Value *RHS;
2314 LValue LHS;
2315
2316 switch (E->getLHS()->getType().getObjCLifetime()) {
2317 case Qualifiers::OCL_Strong:
2318 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore);
2319 break;
2320
2321 case Qualifiers::OCL_Autoreleasing:
2322 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E);
2323 break;
2324
2325 case Qualifiers::OCL_Weak:
2326 RHS = Visit(E->getRHS());
2327 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
2328 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore);
2329 break;
2330
2331 // No reason to do any of these differently.
2332 case Qualifiers::OCL_None:
2333 case Qualifiers::OCL_ExplicitNone:
2334 // __block variables need to have the rhs evaluated first, plus
2335 // this should improve codegen just a little.
2336 RHS = Visit(E->getRHS());
2337 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
2338
2339 // Store the value into the LHS. Bit-fields are handled specially
2340 // because the result is altered by the store, i.e., [C99 6.5.16p1]
2341 // 'An assignment expression has the value of the left operand after
2342 // the assignment...'.
2343 if (LHS.isBitField())
2344 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS);
2345 else
2346 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS);
2347 }
2348
2349 // If the result is clearly ignored, return now.
2350 if (Ignore)
2351 return 0;
2352
2353 // The result of an assignment in C is the assigned r-value.
2354 if (!CGF.getContext().getLangOpts().CPlusPlus)
2355 return RHS;
2356
2357 // If the lvalue is non-volatile, return the computed value of the assignment.
2358 if (!LHS.isVolatileQualified())
2359 return RHS;
2360
2361 // Otherwise, reload the value.
2362 return EmitLoadOfLValue(LHS);
2363 }
2364
VisitBinLAnd(const BinaryOperator * E)2365 Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
2366
2367 // Perform vector logical and on comparisons with zero vectors.
2368 if (E->getType()->isVectorType()) {
2369 Value *LHS = Visit(E->getLHS());
2370 Value *RHS = Visit(E->getRHS());
2371 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType());
2372 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp");
2373 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp");
2374 Value *And = Builder.CreateAnd(LHS, RHS);
2375 return Builder.CreateSExt(And, Zero->getType(), "sext");
2376 }
2377
2378 llvm::Type *ResTy = ConvertType(E->getType());
2379
2380 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
2381 // If we have 1 && X, just emit X without inserting the control flow.
2382 bool LHSCondVal;
2383 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
2384 if (LHSCondVal) { // If we have 1 && X, just emit X.
2385 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
2386 // ZExt result to int or bool.
2387 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
2388 }
2389
2390 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false.
2391 if (!CGF.ContainsLabel(E->getRHS()))
2392 return llvm::Constant::getNullValue(ResTy);
2393 }
2394
2395 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
2396 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs");
2397
2398 CodeGenFunction::ConditionalEvaluation eval(CGF);
2399
2400 // Branch on the LHS first. If it is false, go to the failure (cont) block.
2401 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock);
2402
2403 // Any edges into the ContBlock are now from an (indeterminate number of)
2404 // edges from this first condition. All of these values will be false. Start
2405 // setting up the PHI node in the Cont Block for this.
2406 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2,
2407 "", ContBlock);
2408 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
2409 PI != PE; ++PI)
2410 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI);
2411
2412 eval.begin(CGF);
2413 CGF.EmitBlock(RHSBlock);
2414 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
2415 eval.end(CGF);
2416
2417 // Reaquire the RHS block, as there may be subblocks inserted.
2418 RHSBlock = Builder.GetInsertBlock();
2419
2420 // Emit an unconditional branch from this block to ContBlock. Insert an entry
2421 // into the phi node for the edge with the value of RHSCond.
2422 if (CGF.getDebugInfo())
2423 // There is no need to emit line number for unconditional branch.
2424 Builder.SetCurrentDebugLocation(llvm::DebugLoc());
2425 CGF.EmitBlock(ContBlock);
2426 PN->addIncoming(RHSCond, RHSBlock);
2427
2428 // ZExt result to int.
2429 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext");
2430 }
2431
VisitBinLOr(const BinaryOperator * E)2432 Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
2433
2434 // Perform vector logical or on comparisons with zero vectors.
2435 if (E->getType()->isVectorType()) {
2436 Value *LHS = Visit(E->getLHS());
2437 Value *RHS = Visit(E->getRHS());
2438 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType());
2439 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp");
2440 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp");
2441 Value *Or = Builder.CreateOr(LHS, RHS);
2442 return Builder.CreateSExt(Or, Zero->getType(), "sext");
2443 }
2444
2445 llvm::Type *ResTy = ConvertType(E->getType());
2446
2447 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
2448 // If we have 0 || X, just emit X without inserting the control flow.
2449 bool LHSCondVal;
2450 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
2451 if (!LHSCondVal) { // If we have 0 || X, just emit X.
2452 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
2453 // ZExt result to int or bool.
2454 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
2455 }
2456
2457 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true.
2458 if (!CGF.ContainsLabel(E->getRHS()))
2459 return llvm::ConstantInt::get(ResTy, 1);
2460 }
2461
2462 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
2463 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
2464
2465 CodeGenFunction::ConditionalEvaluation eval(CGF);
2466
2467 // Branch on the LHS first. If it is true, go to the success (cont) block.
2468 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock);
2469
2470 // Any edges into the ContBlock are now from an (indeterminate number of)
2471 // edges from this first condition. All of these values will be true. Start
2472 // setting up the PHI node in the Cont Block for this.
2473 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2,
2474 "", ContBlock);
2475 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
2476 PI != PE; ++PI)
2477 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI);
2478
2479 eval.begin(CGF);
2480
2481 // Emit the RHS condition as a bool value.
2482 CGF.EmitBlock(RHSBlock);
2483 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
2484
2485 eval.end(CGF);
2486
2487 // Reaquire the RHS block, as there may be subblocks inserted.
2488 RHSBlock = Builder.GetInsertBlock();
2489
2490 // Emit an unconditional branch from this block to ContBlock. Insert an entry
2491 // into the phi node for the edge with the value of RHSCond.
2492 CGF.EmitBlock(ContBlock);
2493 PN->addIncoming(RHSCond, RHSBlock);
2494
2495 // ZExt result to int.
2496 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
2497 }
2498
VisitBinComma(const BinaryOperator * E)2499 Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) {
2500 CGF.EmitIgnoredExpr(E->getLHS());
2501 CGF.EnsureInsertPoint();
2502 return Visit(E->getRHS());
2503 }
2504
2505 //===----------------------------------------------------------------------===//
2506 // Other Operators
2507 //===----------------------------------------------------------------------===//
2508
2509 /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified
2510 /// expression is cheap enough and side-effect-free enough to evaluate
2511 /// unconditionally instead of conditionally. This is used to convert control
2512 /// flow into selects in some cases.
isCheapEnoughToEvaluateUnconditionally(const Expr * E,CodeGenFunction & CGF)2513 static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E,
2514 CodeGenFunction &CGF) {
2515 E = E->IgnoreParens();
2516
2517 // Anything that is an integer or floating point constant is fine.
2518 if (E->isConstantInitializer(CGF.getContext(), false))
2519 return true;
2520
2521 // Non-volatile automatic variables too, to get "cond ? X : Y" where
2522 // X and Y are local variables.
2523 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
2524 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
2525 if (VD->hasLocalStorage() && !(CGF.getContext()
2526 .getCanonicalType(VD->getType())
2527 .isVolatileQualified()))
2528 return true;
2529
2530 return false;
2531 }
2532
2533
2534 Value *ScalarExprEmitter::
VisitAbstractConditionalOperator(const AbstractConditionalOperator * E)2535 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
2536 TestAndClearIgnoreResultAssign();
2537
2538 // Bind the common expression if necessary.
2539 CodeGenFunction::OpaqueValueMapping binding(CGF, E);
2540
2541 Expr *condExpr = E->getCond();
2542 Expr *lhsExpr = E->getTrueExpr();
2543 Expr *rhsExpr = E->getFalseExpr();
2544
2545 // If the condition constant folds and can be elided, try to avoid emitting
2546 // the condition and the dead arm.
2547 bool CondExprBool;
2548 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
2549 Expr *live = lhsExpr, *dead = rhsExpr;
2550 if (!CondExprBool) std::swap(live, dead);
2551
2552 // If the dead side doesn't have labels we need, just emit the Live part.
2553 if (!CGF.ContainsLabel(dead)) {
2554 Value *Result = Visit(live);
2555
2556 // If the live part is a throw expression, it acts like it has a void
2557 // type, so evaluating it returns a null Value*. However, a conditional
2558 // with non-void type must return a non-null Value*.
2559 if (!Result && !E->getType()->isVoidType())
2560 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType()));
2561
2562 return Result;
2563 }
2564 }
2565
2566 // OpenCL: If the condition is a vector, we can treat this condition like
2567 // the select function.
2568 if (CGF.getContext().getLangOpts().OpenCL
2569 && condExpr->getType()->isVectorType()) {
2570 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr);
2571 llvm::Value *LHS = Visit(lhsExpr);
2572 llvm::Value *RHS = Visit(rhsExpr);
2573
2574 llvm::Type *condType = ConvertType(condExpr->getType());
2575 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType);
2576
2577 unsigned numElem = vecTy->getNumElements();
2578 llvm::Type *elemType = vecTy->getElementType();
2579
2580 llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy);
2581 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec);
2582 llvm::Value *tmp = Builder.CreateSExt(TestMSB,
2583 llvm::VectorType::get(elemType,
2584 numElem),
2585 "sext");
2586 llvm::Value *tmp2 = Builder.CreateNot(tmp);
2587
2588 // Cast float to int to perform ANDs if necessary.
2589 llvm::Value *RHSTmp = RHS;
2590 llvm::Value *LHSTmp = LHS;
2591 bool wasCast = false;
2592 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType());
2593 if (rhsVTy->getElementType()->isFloatingPointTy()) {
2594 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType());
2595 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType());
2596 wasCast = true;
2597 }
2598
2599 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2);
2600 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp);
2601 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond");
2602 if (wasCast)
2603 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType());
2604
2605 return tmp5;
2606 }
2607
2608 // If this is a really simple expression (like x ? 4 : 5), emit this as a
2609 // select instead of as control flow. We can only do this if it is cheap and
2610 // safe to evaluate the LHS and RHS unconditionally.
2611 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) &&
2612 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) {
2613 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr);
2614 llvm::Value *LHS = Visit(lhsExpr);
2615 llvm::Value *RHS = Visit(rhsExpr);
2616 if (!LHS) {
2617 // If the conditional has void type, make sure we return a null Value*.
2618 assert(!RHS && "LHS and RHS types must match");
2619 return 0;
2620 }
2621 return Builder.CreateSelect(CondV, LHS, RHS, "cond");
2622 }
2623
2624 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
2625 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
2626 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
2627
2628 CodeGenFunction::ConditionalEvaluation eval(CGF);
2629 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock);
2630
2631 CGF.EmitBlock(LHSBlock);
2632 eval.begin(CGF);
2633 Value *LHS = Visit(lhsExpr);
2634 eval.end(CGF);
2635
2636 LHSBlock = Builder.GetInsertBlock();
2637 Builder.CreateBr(ContBlock);
2638
2639 CGF.EmitBlock(RHSBlock);
2640 eval.begin(CGF);
2641 Value *RHS = Visit(rhsExpr);
2642 eval.end(CGF);
2643
2644 RHSBlock = Builder.GetInsertBlock();
2645 CGF.EmitBlock(ContBlock);
2646
2647 // If the LHS or RHS is a throw expression, it will be legitimately null.
2648 if (!LHS)
2649 return RHS;
2650 if (!RHS)
2651 return LHS;
2652
2653 // Create a PHI node for the real part.
2654 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond");
2655 PN->addIncoming(LHS, LHSBlock);
2656 PN->addIncoming(RHS, RHSBlock);
2657 return PN;
2658 }
2659
VisitChooseExpr(ChooseExpr * E)2660 Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) {
2661 return Visit(E->getChosenSubExpr(CGF.getContext()));
2662 }
2663
VisitVAArgExpr(VAArgExpr * VE)2664 Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
2665 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
2666 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
2667
2668 // If EmitVAArg fails, we fall back to the LLVM instruction.
2669 if (!ArgPtr)
2670 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType()));
2671
2672 // FIXME Volatility.
2673 return Builder.CreateLoad(ArgPtr);
2674 }
2675
VisitBlockExpr(const BlockExpr * block)2676 Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) {
2677 return CGF.EmitBlockLiteral(block);
2678 }
2679
VisitAsTypeExpr(AsTypeExpr * E)2680 Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) {
2681 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr());
2682 llvm::Type *DstTy = ConvertType(E->getType());
2683
2684 // Going from vec4->vec3 or vec3->vec4 is a special case and requires
2685 // a shuffle vector instead of a bitcast.
2686 llvm::Type *SrcTy = Src->getType();
2687 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) {
2688 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements();
2689 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements();
2690 if ((numElementsDst == 3 && numElementsSrc == 4)
2691 || (numElementsDst == 4 && numElementsSrc == 3)) {
2692
2693
2694 // In the case of going from int4->float3, a bitcast is needed before
2695 // doing a shuffle.
2696 llvm::Type *srcElemTy =
2697 cast<llvm::VectorType>(SrcTy)->getElementType();
2698 llvm::Type *dstElemTy =
2699 cast<llvm::VectorType>(DstTy)->getElementType();
2700
2701 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy())
2702 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) {
2703 // Create a float type of the same size as the source or destination.
2704 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy,
2705 numElementsSrc);
2706
2707 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast");
2708 }
2709
2710 llvm::Value *UnV = llvm::UndefValue::get(Src->getType());
2711
2712 SmallVector<llvm::Constant*, 3> Args;
2713 Args.push_back(Builder.getInt32(0));
2714 Args.push_back(Builder.getInt32(1));
2715 Args.push_back(Builder.getInt32(2));
2716
2717 if (numElementsDst == 4)
2718 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
2719
2720 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
2721
2722 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype");
2723 }
2724 }
2725
2726 return Builder.CreateBitCast(Src, DstTy, "astype");
2727 }
2728
VisitAtomicExpr(AtomicExpr * E)2729 Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) {
2730 return CGF.EmitAtomicExpr(E).getScalarVal();
2731 }
2732
2733 //===----------------------------------------------------------------------===//
2734 // Entry Point into this File
2735 //===----------------------------------------------------------------------===//
2736
2737 /// EmitScalarExpr - Emit the computation of the specified expression of scalar
2738 /// type, ignoring the result.
EmitScalarExpr(const Expr * E,bool IgnoreResultAssign)2739 Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) {
2740 assert(E && !hasAggregateLLVMType(E->getType()) &&
2741 "Invalid scalar expression to emit");
2742
2743 if (isa<CXXDefaultArgExpr>(E))
2744 disableDebugInfo();
2745 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign)
2746 .Visit(const_cast<Expr*>(E));
2747 if (isa<CXXDefaultArgExpr>(E))
2748 enableDebugInfo();
2749 return V;
2750 }
2751
2752 /// EmitScalarConversion - Emit a conversion from the specified type to the
2753 /// specified destination type, both of which are LLVM scalar types.
EmitScalarConversion(Value * Src,QualType SrcTy,QualType DstTy)2754 Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy,
2755 QualType DstTy) {
2756 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) &&
2757 "Invalid scalar expression to emit");
2758 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy);
2759 }
2760
2761 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex
2762 /// type to the specified destination type, where the destination type is an
2763 /// LLVM scalar type.
EmitComplexToScalarConversion(ComplexPairTy Src,QualType SrcTy,QualType DstTy)2764 Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src,
2765 QualType SrcTy,
2766 QualType DstTy) {
2767 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) &&
2768 "Invalid complex -> scalar conversion");
2769 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy,
2770 DstTy);
2771 }
2772
2773
2774 llvm::Value *CodeGenFunction::
EmitScalarPrePostIncDec(const UnaryOperator * E,LValue LV,bool isInc,bool isPre)2775 EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
2776 bool isInc, bool isPre) {
2777 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre);
2778 }
2779
EmitObjCIsaExpr(const ObjCIsaExpr * E)2780 LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
2781 llvm::Value *V;
2782 // object->isa or (*object).isa
2783 // Generate code as for: *(Class*)object
2784 // build Class* type
2785 llvm::Type *ClassPtrTy = ConvertType(E->getType());
2786
2787 Expr *BaseExpr = E->getBase();
2788 if (BaseExpr->isRValue()) {
2789 V = CreateMemTemp(E->getType(), "resval");
2790 llvm::Value *Src = EmitScalarExpr(BaseExpr);
2791 Builder.CreateStore(Src, V);
2792 V = ScalarExprEmitter(*this).EmitLoadOfLValue(
2793 MakeNaturalAlignAddrLValue(V, E->getType()));
2794 } else {
2795 if (E->isArrow())
2796 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr);
2797 else
2798 V = EmitLValue(BaseExpr).getAddress();
2799 }
2800
2801 // build Class* type
2802 ClassPtrTy = ClassPtrTy->getPointerTo();
2803 V = Builder.CreateBitCast(V, ClassPtrTy);
2804 return MakeNaturalAlignAddrLValue(V, E->getType());
2805 }
2806
2807
EmitCompoundAssignmentLValue(const CompoundAssignOperator * E)2808 LValue CodeGenFunction::EmitCompoundAssignmentLValue(
2809 const CompoundAssignOperator *E) {
2810 ScalarExprEmitter Scalar(*this);
2811 Value *Result = 0;
2812 switch (E->getOpcode()) {
2813 #define COMPOUND_OP(Op) \
2814 case BO_##Op##Assign: \
2815 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \
2816 Result)
2817 COMPOUND_OP(Mul);
2818 COMPOUND_OP(Div);
2819 COMPOUND_OP(Rem);
2820 COMPOUND_OP(Add);
2821 COMPOUND_OP(Sub);
2822 COMPOUND_OP(Shl);
2823 COMPOUND_OP(Shr);
2824 COMPOUND_OP(And);
2825 COMPOUND_OP(Xor);
2826 COMPOUND_OP(Or);
2827 #undef COMPOUND_OP
2828
2829 case BO_PtrMemD:
2830 case BO_PtrMemI:
2831 case BO_Mul:
2832 case BO_Div:
2833 case BO_Rem:
2834 case BO_Add:
2835 case BO_Sub:
2836 case BO_Shl:
2837 case BO_Shr:
2838 case BO_LT:
2839 case BO_GT:
2840 case BO_LE:
2841 case BO_GE:
2842 case BO_EQ:
2843 case BO_NE:
2844 case BO_And:
2845 case BO_Xor:
2846 case BO_Or:
2847 case BO_LAnd:
2848 case BO_LOr:
2849 case BO_Assign:
2850 case BO_Comma:
2851 llvm_unreachable("Not valid compound assignment operators");
2852 }
2853
2854 llvm_unreachable("Unhandled compound assignment operator");
2855 }
2856