bool ExposesReturnsTwice;
bool HasDynamicAlloca;
bool ContainsNoDuplicateCall;
+ bool HasReturn;
+ bool HasIndirectBr;
/// Number of bytes allocated statically by the callee.
uint64_t AllocatedSize;
bool visitExtractValue(ExtractValueInst &I);
bool visitInsertValue(InsertValueInst &I);
bool visitCallSite(CallSite CS);
+ bool visitReturnInst(ReturnInst &RI);
+ bool visitBranchInst(BranchInst &BI);
+ bool visitSwitchInst(SwitchInst &SI);
+ bool visitIndirectBrInst(IndirectBrInst &IBI);
+ bool visitResumeInst(ResumeInst &RI);
+ bool visitUnreachableInst(UnreachableInst &I);
public:
CallAnalyzer(const DataLayout *TD, const TargetTransformInfo &TTI,
: TD(TD), TTI(TTI), F(Callee), Threshold(Threshold), Cost(0),
IsCallerRecursive(false), IsRecursiveCall(false),
ExposesReturnsTwice(false), HasDynamicAlloca(false),
- ContainsNoDuplicateCall(false), AllocatedSize(0), NumInstructions(0),
- NumVectorInstructions(0), FiftyPercentVectorBonus(0),
- TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0),
- NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0),
- NumConstantPtrDiffs(0), NumInstructionsSimplified(0),
- SROACostSavings(0), SROACostSavingsLost(0) {}
+ ContainsNoDuplicateCall(false), HasReturn(false), HasIndirectBr(false),
+ AllocatedSize(0), NumInstructions(0), NumVectorInstructions(0),
+ FiftyPercentVectorBonus(0), TenPercentVectorBonus(0), VectorBonus(0),
+ NumConstantArgs(0), NumConstantOffsetPtrArgs(0), NumAllocaArgs(0),
+ NumConstantPtrCmps(0), NumConstantPtrDiffs(0),
+ NumInstructionsSimplified(0), SROACostSavings(0),
+ SROACostSavingsLost(0) {}
bool analyzeCall(CallSite CS);
}
bool CallAnalyzer::visitCallSite(CallSite CS) {
- if (CS.isCall() && cast<CallInst>(CS.getInstruction())->canReturnTwice() &&
+ if (CS.hasFnAttr(Attribute::ReturnsTwice) &&
!F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
Attribute::ReturnsTwice)) {
// This aborts the entire analysis.
return Base::visitCallSite(CS);
}
+bool CallAnalyzer::visitReturnInst(ReturnInst &RI) {
+ // At least one return instruction will be free after inlining.
+ bool Free = !HasReturn;
+ HasReturn = true;
+ return Free;
+}
+
+bool CallAnalyzer::visitBranchInst(BranchInst &BI) {
+ // We model unconditional branches as essentially free -- they really
+ // shouldn't exist at all, but handling them makes the behavior of the
+ // inliner more regular and predictable. Interestingly, conditional branches
+ // which will fold away are also free.
+ return BI.isUnconditional() || isa<ConstantInt>(BI.getCondition()) ||
+ dyn_cast_or_null<ConstantInt>(
+ SimplifiedValues.lookup(BI.getCondition()));
+}
+
+bool CallAnalyzer::visitSwitchInst(SwitchInst &SI) {
+ // We model unconditional switches as free, see the comments on handling
+ // branches.
+ return isa<ConstantInt>(SI.getCondition()) ||
+ dyn_cast_or_null<ConstantInt>(
+ SimplifiedValues.lookup(SI.getCondition()));
+}
+
+bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
+ // We never want to inline functions that contain an indirectbr. This is
+ // incorrect because all the blockaddress's (in static global initializers
+ // for example) would be referring to the original function, and this
+ // indirect jump would jump from the inlined copy of the function into the
+ // original function which is extremely undefined behavior.
+ // FIXME: This logic isn't really right; we can safely inline functions with
+ // indirectbr's as long as no other function or global references the
+ // blockaddress of a block within the current function. And as a QOI issue,
+ // if someone is using a blockaddress without an indirectbr, and that
+ // reference somehow ends up in another function or global, we probably don't
+ // want to inline this function.
+ HasIndirectBr = true;
+ return false;
+}
+
+bool CallAnalyzer::visitResumeInst(ResumeInst &RI) {
+ // FIXME: It's not clear that a single instruction is an accurate model for
+ // the inline cost of a resume instruction.
+ return false;
+}
+
+bool CallAnalyzer::visitUnreachableInst(UnreachableInst &I) {
+ // FIXME: It might be reasonably to discount the cost of instructions leading
+ // to unreachable as they have the lowest possible impact on both runtime and
+ // code size.
+ return true; // No actual code is needed for unreachable.
+}
+
bool CallAnalyzer::visitInstruction(Instruction &I) {
// Some instructions are free. All of the free intrinsics can also be
// handled by SROA, etc.
/// construct has been detected. It returns false if inlining is no longer
/// viable, and true if inlining remains viable.
bool CallAnalyzer::analyzeBlock(BasicBlock *BB) {
- for (BasicBlock::iterator I = BB->begin(), E = llvm::prior(BB->end());
- I != E; ++I) {
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+ // FIXME: Currently, the number of instructions in a function regardless of
+ // our ability to simplify them during inline to constants or dead code,
+ // are actually used by the vector bonus heuristic. As long as that's true,
+ // we have to special case debug intrinsics here to prevent differences in
+ // inlining due to debug symbols. Eventually, the number of unsimplified
+ // instructions shouldn't factor into the cost computation, but until then,
+ // hack around it here.
+ if (isa<DbgInfoIntrinsic>(I))
+ continue;
+
++NumInstructions;
if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy())
++NumVectorInstructions;
Cost += InlineConstants::InstrCost;
// If the visit this instruction detected an uninlinable pattern, abort.
- if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca)
+ if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
+ HasIndirectBr)
return false;
// If the caller is a recursive function then we don't want to inline
}
}
- // Track whether we've seen a return instruction. The first return
- // instruction is free, as at least one will usually disappear in inlining.
- bool HasReturn = false;
-
// Populate our simplified values by mapping from function arguments to call
// arguments with known important simplifications.
CallSite::arg_iterator CAI = CS.arg_begin();
if (BB->empty())
continue;
- // Handle the terminator cost here where we can track returns and other
- // function-wide constructs.
- TerminatorInst *TI = BB->getTerminator();
-
- // We never want to inline functions that contain an indirectbr. This is
- // incorrect because all the blockaddress's (in static global initializers
- // for example) would be referring to the original function, and this
- // indirect jump would jump from the inlined copy of the function into the
- // original function which is extremely undefined behavior.
- // FIXME: This logic isn't really right; we can safely inline functions
- // with indirectbr's as long as no other function or global references the
- // blockaddress of a block within the current function. And as a QOI issue,
- // if someone is using a blockaddress without an indirectbr, and that
- // reference somehow ends up in another function or global, we probably
- // don't want to inline this function.
- if (isa<IndirectBrInst>(TI))
- return false;
-
- if (!HasReturn && isa<ReturnInst>(TI))
- HasReturn = true;
- else
- Cost += InlineConstants::InstrCost;
-
// Analyze the cost of this block. If we blow through the threshold, this
// returns false, and we can bail on out.
if (!analyzeBlock(BB)) {
- if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca)
+ if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
+ HasIndirectBr)
return false;
// If the caller is a recursive function then we don't want to inline
break;
}
+ TerminatorInst *TI = BB->getTerminator();
+
// Add in the live successors by first checking whether we have terminator
// that may be simplified based on the values simplified by this call.
if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
}
}
- // If this is a noduplicate call, we can still inline as long as
+ // If this is a noduplicate call, we can still inline as long as
// inlining this would cause the removal of the caller (so the instruction
// is not actually duplicated, just moved).
if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall)
DEBUG_PRINT_STAT(SROACostSavings);
DEBUG_PRINT_STAT(SROACostSavingsLost);
DEBUG_PRINT_STAT(ContainsNoDuplicateCall);
+ DEBUG_PRINT_STAT(Cost);
+ DEBUG_PRINT_STAT(Threshold);
+ DEBUG_PRINT_STAT(VectorBonus);
#undef DEBUG_PRINT_STAT
}
#endif
return getInlineCost(CS, CS.getCalledFunction(), Threshold);
}
+/// \brief Test that two functions either have or have not the given attribute
+/// at the same time.
+static bool attributeMatches(Function *F1, Function *F2,
+ Attribute::AttrKind Attr) {
+ return F1->hasFnAttribute(Attr) == F2->hasFnAttribute(Attr);
+}
+
+/// \brief Test that there are no attribute conflicts between Caller and Callee
+/// that prevent inlining.
+static bool functionsHaveCompatibleAttributes(Function *Caller,
+ Function *Callee) {
+ return attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
+ attributeMatches(Caller, Callee, Attribute::SanitizeMemory) &&
+ attributeMatches(Caller, Callee, Attribute::SanitizeThread);
+}
+
InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
int Threshold) {
// Cannot inline indirect calls.
// Calls to functions with always-inline attributes should be inlined
// whenever possible.
- if (Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
- Attribute::AlwaysInline)) {
+ if (Callee->hasFnAttribute(Attribute::AlwaysInline)) {
if (isInlineViable(*Callee))
return llvm::InlineCost::getAlways();
return llvm::InlineCost::getNever();
}
+ // Never inline functions with conflicting attributes (unless callee has
+ // always-inline attribute).
+ if (!functionsHaveCompatibleAttributes(CS.getCaller(), Callee))
+ return llvm::InlineCost::getNever();
+
+ // Don't inline this call if the caller has the optnone attribute.
+ if (CS.getCaller()->hasFnAttribute(Attribute::OptimizeNone))
+ return llvm::InlineCost::getNever();
+
// Don't inline functions which can be redefined at link-time to mean
// something else. Don't inline functions marked noinline or call sites
// marked noinline.
if (Callee->mayBeOverridden() ||
- Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
- Attribute::NoInline) ||
- CS.isNoInline())
+ Callee->hasFnAttribute(Attribute::NoInline) || CS.isNoInline())
return llvm::InlineCost::getNever();
DEBUG(llvm::dbgs() << " Analyzing call of " << Callee->getName()
projects / oota-llvm.git / blobdiff