//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "inline-cost"
#include "llvm/Analysis/InlineCost.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/CallSite.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
+#include "llvm/IR/InstVisitor.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Operator.h"
-#include "llvm/InstVisitor.h"
-#include "llvm/Support/CallSite.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+#define DEBUG_TYPE "inline-cost"
+
STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
namespace {
void disableSROA(Value *V);
void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
int InstructionCost);
- bool handleSROACandidate(bool IsSROAValid,
- DenseMap<Value *, int>::iterator CostIt,
- int InstructionCost);
bool isGEPOffsetConstant(GetElementPtrInst &GEP);
bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
bool simplifyCallSite(Function *F, CallSite CS);
SROACostSavings += InstructionCost;
}
-/// \brief Helper for the common pattern of handling a SROA candidate.
-/// Either accumulates the cost savings if the SROA remains valid, or disables
-/// SROA for the candidate.
-bool CallAnalyzer::handleSROACandidate(bool IsSROAValid,
- DenseMap<Value *, int>::iterator CostIt,
- int InstructionCost) {
- if (IsSROAValid) {
- accumulateSROACost(CostIt, InstructionCost);
- return true;
- }
-
- disableSROA(CostIt);
- return false;
-}
-
/// \brief Check whether a GEP's indices are all constant.
///
/// Respects any simplified values known during the analysis of this callsite.
}
bool CallAnalyzer::visitAlloca(AllocaInst &I) {
- // FIXME: Check whether inlining will turn a dynamic alloca into a static
+ // Check whether inlining will turn a dynamic alloca into a static
// alloca, and handle that case.
+ if (I.isArrayAllocation()) {
+ if (Constant *Size = SimplifiedValues.lookup(I.getArraySize())) {
+ ConstantInt *AllocSize = dyn_cast<ConstantInt>(Size);
+ assert(AllocSize && "Allocation size not a constant int?");
+ Type *Ty = I.getAllocatedType();
+ AllocatedSize += Ty->getPrimitiveSizeInBits() * AllocSize->getZExtValue();
+ return Base::visitAlloca(I);
+ }
+ }
// Accumulate the allocated size.
if (I.isStaticAlloca()) {
// a common base.
Value *LHSBase, *RHSBase;
APInt LHSOffset, RHSOffset;
- llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+ std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
if (LHSBase) {
- llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+ std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
if (RHSBase && LHSBase == RHSBase) {
// We have common bases, fold the icmp to a constant based on the
// offsets.
Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
Value *LHSBase, *RHSBase;
APInt LHSOffset, RHSOffset;
- llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+ std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
if (LHSBase) {
- llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+ std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
if (RHSBase && LHSBase == RHSBase) {
// We have common bases, fold the subtract to a constant based on the
// offsets.
return false;
}
if (CS.isCall() &&
- cast<CallInst>(CS.getInstruction())->hasFnAttr(Attribute::NoDuplicate))
+ cast<CallInst>(CS.getInstruction())->cannotDuplicate())
ContainsNoDuplicateCall = true;
if (Function *F = CS.getCalledFunction()) {
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()));
+ if (isa<ConstantInt>(SI.getCondition()))
+ return true;
+ if (Value *V = SimplifiedValues.lookup(SI.getCondition()))
+ if (isa<ConstantInt>(V))
+ return true;
+
+ // Otherwise, we need to accumulate a cost proportional to the number of
+ // distinct successor blocks. This fan-out in the CFG cannot be represented
+ // for free even if we can represent the core switch as a jumptable that
+ // takes a single instruction.
+ //
+ // NB: We convert large switches which are just used to initialize large phi
+ // nodes to lookup tables instead in simplify-cfg, so this shouldn't prevent
+ // inlining those. It will prevent inlining in cases where the optimization
+ // does not (yet) fire.
+ SmallPtrSet<BasicBlock *, 8> SuccessorBlocks;
+ SuccessorBlocks.insert(SI.getDefaultDest());
+ for (auto I = SI.case_begin(), E = SI.case_end(); I != E; ++I)
+ SuccessorBlocks.insert(I.getCaseSuccessor());
+ // Add cost corresponding to the number of distinct destinations. The first
+ // we model as free because of fallthrough.
+ Cost += (SuccessorBlocks.size() - 1) * InlineConstants::InstrCost;
+ return false;
}
bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
// 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.
+ // blockaddress of a block within the current function.
HasIndirectBr = true;
return false;
}
/// no constant offsets applied.
ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
if (!DL || !V->getType()->isPointerTy())
- return 0;
+ return nullptr;
unsigned IntPtrWidth = DL->getPointerSizeInBits();
APInt Offset = APInt::getNullValue(IntPtrWidth);
do {
if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
- return 0;
+ return nullptr;
V = GEP->getPointerOperand();
} else if (Operator::getOpcode(V) == Instruction::BitCast) {
V = cast<Operator>(V)->getOperand(0);
Function *Caller = CS.getInstruction()->getParent()->getParent();
// Check if the caller function is recursive itself.
- for (Value::use_iterator U = Caller->use_begin(), E = Caller->use_end();
- U != E; ++U) {
- CallSite Site(cast<Value>(*U));
+ for (User *U : Caller->users()) {
+ CallSite Site(U);
if (!Site)
continue;
Instruction *I = Site.getInstruction();
if (BB->empty())
continue;
+ // Disallow inlining a blockaddress. A blockaddress only has defined
+ // behavior for an indirect branch in the same function, and we do not
+ // currently support inlining indirect branches. But, the inliner may not
+ // see an indirect branch that ends up being dead code at a particular call
+ // site. If the blockaddress escapes the function, e.g., via a global
+ // variable, inlining may lead to an invalid cross-function reference.
+ if (BB->hasAddressTaken())
+ return false;
+
// Analyze the cost of this block. If we blow through the threshold, this
// returns false, and we can bail on out.
if (!analyzeBlock(BB)) {
// Calls to functions with always-inline attributes should be inlined
// whenever possible.
- if (Callee->hasFnAttribute(Attribute::AlwaysInline)) {
+ if (CS.hasFnAttr(Attribute::AlwaysInline)) {
if (isInlineViable(*Callee))
return llvm::InlineCost::getAlways();
return llvm::InlineCost::getNever();
F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
Attribute::ReturnsTwice);
for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
- // Disallow inlining of functions which contain an indirect branch.
- if (isa<IndirectBrInst>(BI->getTerminator()))
+ // Disallow inlining of functions which contain indirect branches or
+ // blockaddresses.
+ if (isa<IndirectBrInst>(BI->getTerminator()) || BI->hasAddressTaken())
return false;
for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
projects / oota-llvm.git / blobdiff