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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153456 91177308-0d34-0410-b5e6-96231b3b80d8
888 lines
35 KiB
C++
888 lines
35 KiB
C++
//===- InlineFunction.cpp - Code to perform function inlining -------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements inlining of a function into a call site, resolving
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// parameters and the return value as appropriate.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Utils/Cloning.h"
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#include "llvm/Constants.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/Module.h"
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#include "llvm/Instructions.h"
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#include "llvm/IntrinsicInst.h"
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#include "llvm/Intrinsics.h"
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#include "llvm/Attributes.h"
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#include "llvm/Analysis/CallGraph.h"
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#include "llvm/Analysis/DebugInfo.h"
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#include "llvm/Analysis/InstructionSimplify.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Transforms/Utils/Local.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/Support/CallSite.h"
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#include "llvm/Support/IRBuilder.h"
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using namespace llvm;
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bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI,
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bool InsertLifetime) {
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return InlineFunction(CallSite(CI), IFI, InsertLifetime);
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}
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bool llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
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bool InsertLifetime) {
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return InlineFunction(CallSite(II), IFI, InsertLifetime);
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}
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namespace {
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/// A class for recording information about inlining through an invoke.
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class InvokeInliningInfo {
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BasicBlock *OuterResumeDest; //< Destination of the invoke's unwind.
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BasicBlock *InnerResumeDest; //< Destination for the callee's resume.
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LandingPadInst *CallerLPad; //< LandingPadInst associated with the invoke.
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PHINode *InnerEHValuesPHI; //< PHI for EH values from landingpad insts.
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SmallVector<Value*, 8> UnwindDestPHIValues;
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public:
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InvokeInliningInfo(InvokeInst *II)
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: OuterResumeDest(II->getUnwindDest()), InnerResumeDest(0),
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CallerLPad(0), InnerEHValuesPHI(0) {
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// If there are PHI nodes in the unwind destination block, we need to keep
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// track of which values came into them from the invoke before removing
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// the edge from this block.
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llvm::BasicBlock *InvokeBB = II->getParent();
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BasicBlock::iterator I = OuterResumeDest->begin();
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for (; isa<PHINode>(I); ++I) {
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// Save the value to use for this edge.
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PHINode *PHI = cast<PHINode>(I);
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UnwindDestPHIValues.push_back(PHI->getIncomingValueForBlock(InvokeBB));
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}
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CallerLPad = cast<LandingPadInst>(I);
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}
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/// getOuterResumeDest - The outer unwind destination is the target of
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/// unwind edges introduced for calls within the inlined function.
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BasicBlock *getOuterResumeDest() const {
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return OuterResumeDest;
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}
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BasicBlock *getInnerResumeDest();
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LandingPadInst *getLandingPadInst() const { return CallerLPad; }
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/// forwardResume - Forward the 'resume' instruction to the caller's landing
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/// pad block. When the landing pad block has only one predecessor, this is
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/// a simple branch. When there is more than one predecessor, we need to
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/// split the landing pad block after the landingpad instruction and jump
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/// to there.
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void forwardResume(ResumeInst *RI);
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/// addIncomingPHIValuesFor - Add incoming-PHI values to the unwind
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/// destination block for the given basic block, using the values for the
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/// original invoke's source block.
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void addIncomingPHIValuesFor(BasicBlock *BB) const {
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addIncomingPHIValuesForInto(BB, OuterResumeDest);
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}
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void addIncomingPHIValuesForInto(BasicBlock *src, BasicBlock *dest) const {
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BasicBlock::iterator I = dest->begin();
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for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) {
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PHINode *phi = cast<PHINode>(I);
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phi->addIncoming(UnwindDestPHIValues[i], src);
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}
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}
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};
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}
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/// getInnerResumeDest - Get or create a target for the branch from ResumeInsts.
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BasicBlock *InvokeInliningInfo::getInnerResumeDest() {
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if (InnerResumeDest) return InnerResumeDest;
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// Split the landing pad.
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BasicBlock::iterator SplitPoint = CallerLPad; ++SplitPoint;
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InnerResumeDest =
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OuterResumeDest->splitBasicBlock(SplitPoint,
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OuterResumeDest->getName() + ".body");
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// The number of incoming edges we expect to the inner landing pad.
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const unsigned PHICapacity = 2;
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// Create corresponding new PHIs for all the PHIs in the outer landing pad.
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BasicBlock::iterator InsertPoint = InnerResumeDest->begin();
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BasicBlock::iterator I = OuterResumeDest->begin();
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for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) {
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PHINode *OuterPHI = cast<PHINode>(I);
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PHINode *InnerPHI = PHINode::Create(OuterPHI->getType(), PHICapacity,
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OuterPHI->getName() + ".lpad-body",
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InsertPoint);
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OuterPHI->replaceAllUsesWith(InnerPHI);
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InnerPHI->addIncoming(OuterPHI, OuterResumeDest);
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}
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// Create a PHI for the exception values.
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InnerEHValuesPHI = PHINode::Create(CallerLPad->getType(), PHICapacity,
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"eh.lpad-body", InsertPoint);
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CallerLPad->replaceAllUsesWith(InnerEHValuesPHI);
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InnerEHValuesPHI->addIncoming(CallerLPad, OuterResumeDest);
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// All done.
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return InnerResumeDest;
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}
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/// forwardResume - Forward the 'resume' instruction to the caller's landing pad
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/// block. When the landing pad block has only one predecessor, this is a simple
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/// branch. When there is more than one predecessor, we need to split the
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/// landing pad block after the landingpad instruction and jump to there.
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void InvokeInliningInfo::forwardResume(ResumeInst *RI) {
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BasicBlock *Dest = getInnerResumeDest();
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BasicBlock *Src = RI->getParent();
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BranchInst::Create(Dest, Src);
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// Update the PHIs in the destination. They were inserted in an order which
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// makes this work.
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addIncomingPHIValuesForInto(Src, Dest);
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InnerEHValuesPHI->addIncoming(RI->getOperand(0), Src);
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RI->eraseFromParent();
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}
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/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
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/// an invoke, we have to turn all of the calls that can throw into
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/// invokes. This function analyze BB to see if there are any calls, and if so,
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/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
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/// nodes in that block with the values specified in InvokeDestPHIValues.
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///
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/// Returns true to indicate that the next block should be skipped.
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static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
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InvokeInliningInfo &Invoke) {
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LandingPadInst *LPI = Invoke.getLandingPadInst();
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for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
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Instruction *I = BBI++;
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if (LandingPadInst *L = dyn_cast<LandingPadInst>(I)) {
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unsigned NumClauses = LPI->getNumClauses();
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L->reserveClauses(NumClauses);
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for (unsigned i = 0; i != NumClauses; ++i)
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L->addClause(LPI->getClause(i));
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}
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// We only need to check for function calls: inlined invoke
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// instructions require no special handling.
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CallInst *CI = dyn_cast<CallInst>(I);
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// If this call cannot unwind, don't convert it to an invoke.
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if (!CI || CI->doesNotThrow())
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continue;
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// Convert this function call into an invoke instruction. First, split the
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// basic block.
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BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
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// Delete the unconditional branch inserted by splitBasicBlock
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BB->getInstList().pop_back();
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// Create the new invoke instruction.
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ImmutableCallSite CS(CI);
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SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
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InvokeInst *II = InvokeInst::Create(CI->getCalledValue(), Split,
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Invoke.getOuterResumeDest(),
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InvokeArgs, CI->getName(), BB);
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II->setCallingConv(CI->getCallingConv());
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II->setAttributes(CI->getAttributes());
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// Make sure that anything using the call now uses the invoke! This also
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// updates the CallGraph if present, because it uses a WeakVH.
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CI->replaceAllUsesWith(II);
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// Delete the original call
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Split->getInstList().pop_front();
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// Update any PHI nodes in the exceptional block to indicate that there is
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// now a new entry in them.
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Invoke.addIncomingPHIValuesFor(BB);
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return false;
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}
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return false;
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}
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/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
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/// in the body of the inlined function into invokes.
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///
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/// II is the invoke instruction being inlined. FirstNewBlock is the first
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/// block of the inlined code (the last block is the end of the function),
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/// and InlineCodeInfo is information about the code that got inlined.
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static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
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ClonedCodeInfo &InlinedCodeInfo) {
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BasicBlock *InvokeDest = II->getUnwindDest();
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Function *Caller = FirstNewBlock->getParent();
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// The inlined code is currently at the end of the function, scan from the
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// start of the inlined code to its end, checking for stuff we need to
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// rewrite. If the code doesn't have calls or unwinds, we know there is
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// nothing to rewrite.
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if (!InlinedCodeInfo.ContainsCalls) {
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// Now that everything is happy, we have one final detail. The PHI nodes in
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// the exception destination block still have entries due to the original
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// invoke instruction. Eliminate these entries (which might even delete the
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// PHI node) now.
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InvokeDest->removePredecessor(II->getParent());
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return;
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}
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InvokeInliningInfo Invoke(II);
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for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB){
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if (InlinedCodeInfo.ContainsCalls)
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if (HandleCallsInBlockInlinedThroughInvoke(BB, Invoke)) {
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// Honor a request to skip the next block.
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++BB;
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continue;
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}
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if (ResumeInst *RI = dyn_cast<ResumeInst>(BB->getTerminator()))
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Invoke.forwardResume(RI);
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}
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// Now that everything is happy, we have one final detail. The PHI nodes in
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// the exception destination block still have entries due to the original
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// invoke instruction. Eliminate these entries (which might even delete the
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// PHI node) now.
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InvokeDest->removePredecessor(II->getParent());
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}
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/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
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/// into the caller, update the specified callgraph to reflect the changes we
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/// made. Note that it's possible that not all code was copied over, so only
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/// some edges of the callgraph may remain.
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static void UpdateCallGraphAfterInlining(CallSite CS,
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Function::iterator FirstNewBlock,
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ValueToValueMapTy &VMap,
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InlineFunctionInfo &IFI) {
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CallGraph &CG = *IFI.CG;
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const Function *Caller = CS.getInstruction()->getParent()->getParent();
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const Function *Callee = CS.getCalledFunction();
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CallGraphNode *CalleeNode = CG[Callee];
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CallGraphNode *CallerNode = CG[Caller];
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// Since we inlined some uninlined call sites in the callee into the caller,
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// add edges from the caller to all of the callees of the callee.
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CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end();
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// Consider the case where CalleeNode == CallerNode.
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CallGraphNode::CalledFunctionsVector CallCache;
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if (CalleeNode == CallerNode) {
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CallCache.assign(I, E);
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I = CallCache.begin();
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E = CallCache.end();
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}
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for (; I != E; ++I) {
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const Value *OrigCall = I->first;
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ValueToValueMapTy::iterator VMI = VMap.find(OrigCall);
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// Only copy the edge if the call was inlined!
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if (VMI == VMap.end() || VMI->second == 0)
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continue;
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// If the call was inlined, but then constant folded, there is no edge to
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// add. Check for this case.
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Instruction *NewCall = dyn_cast<Instruction>(VMI->second);
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if (NewCall == 0) continue;
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// Remember that this call site got inlined for the client of
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// InlineFunction.
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IFI.InlinedCalls.push_back(NewCall);
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// It's possible that inlining the callsite will cause it to go from an
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// indirect to a direct call by resolving a function pointer. If this
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// happens, set the callee of the new call site to a more precise
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// destination. This can also happen if the call graph node of the caller
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// was just unnecessarily imprecise.
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if (I->second->getFunction() == 0)
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if (Function *F = CallSite(NewCall).getCalledFunction()) {
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// Indirect call site resolved to direct call.
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CallerNode->addCalledFunction(CallSite(NewCall), CG[F]);
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continue;
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}
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CallerNode->addCalledFunction(CallSite(NewCall), I->second);
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}
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// Update the call graph by deleting the edge from Callee to Caller. We must
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// do this after the loop above in case Caller and Callee are the same.
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CallerNode->removeCallEdgeFor(CS);
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}
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/// HandleByValArgument - When inlining a call site that has a byval argument,
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/// we have to make the implicit memcpy explicit by adding it.
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static Value *HandleByValArgument(Value *Arg, Instruction *TheCall,
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const Function *CalledFunc,
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InlineFunctionInfo &IFI,
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unsigned ByValAlignment) {
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Type *AggTy = cast<PointerType>(Arg->getType())->getElementType();
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// If the called function is readonly, then it could not mutate the caller's
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// copy of the byval'd memory. In this case, it is safe to elide the copy and
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// temporary.
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if (CalledFunc->onlyReadsMemory()) {
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// If the byval argument has a specified alignment that is greater than the
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// passed in pointer, then we either have to round up the input pointer or
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// give up on this transformation.
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if (ByValAlignment <= 1) // 0 = unspecified, 1 = no particular alignment.
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return Arg;
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// If the pointer is already known to be sufficiently aligned, or if we can
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// round it up to a larger alignment, then we don't need a temporary.
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if (getOrEnforceKnownAlignment(Arg, ByValAlignment,
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IFI.TD) >= ByValAlignment)
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return Arg;
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// Otherwise, we have to make a memcpy to get a safe alignment. This is bad
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// for code quality, but rarely happens and is required for correctness.
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}
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LLVMContext &Context = Arg->getContext();
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Type *VoidPtrTy = Type::getInt8PtrTy(Context);
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// Create the alloca. If we have TargetData, use nice alignment.
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unsigned Align = 1;
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if (IFI.TD)
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Align = IFI.TD->getPrefTypeAlignment(AggTy);
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// If the byval had an alignment specified, we *must* use at least that
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// alignment, as it is required by the byval argument (and uses of the
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// pointer inside the callee).
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Align = std::max(Align, ByValAlignment);
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Function *Caller = TheCall->getParent()->getParent();
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Value *NewAlloca = new AllocaInst(AggTy, 0, Align, Arg->getName(),
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&*Caller->begin()->begin());
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// Emit a memcpy.
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Type *Tys[3] = {VoidPtrTy, VoidPtrTy, Type::getInt64Ty(Context)};
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Function *MemCpyFn = Intrinsic::getDeclaration(Caller->getParent(),
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Intrinsic::memcpy,
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Tys);
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Value *DestCast = new BitCastInst(NewAlloca, VoidPtrTy, "tmp", TheCall);
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Value *SrcCast = new BitCastInst(Arg, VoidPtrTy, "tmp", TheCall);
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Value *Size;
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if (IFI.TD == 0)
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Size = ConstantExpr::getSizeOf(AggTy);
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else
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Size = ConstantInt::get(Type::getInt64Ty(Context),
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IFI.TD->getTypeStoreSize(AggTy));
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// Always generate a memcpy of alignment 1 here because we don't know
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// the alignment of the src pointer. Other optimizations can infer
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// better alignment.
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Value *CallArgs[] = {
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DestCast, SrcCast, Size,
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ConstantInt::get(Type::getInt32Ty(Context), 1),
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ConstantInt::getFalse(Context) // isVolatile
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};
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IRBuilder<>(TheCall).CreateCall(MemCpyFn, CallArgs);
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// Uses of the argument in the function should use our new alloca
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// instead.
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return NewAlloca;
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}
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// isUsedByLifetimeMarker - Check whether this Value is used by a lifetime
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// intrinsic.
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static bool isUsedByLifetimeMarker(Value *V) {
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for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;
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++UI) {
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if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*UI)) {
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switch (II->getIntrinsicID()) {
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default: break;
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case Intrinsic::lifetime_start:
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case Intrinsic::lifetime_end:
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return true;
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}
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}
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}
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return false;
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}
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// hasLifetimeMarkers - Check whether the given alloca already has
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// lifetime.start or lifetime.end intrinsics.
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static bool hasLifetimeMarkers(AllocaInst *AI) {
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Type *Int8PtrTy = Type::getInt8PtrTy(AI->getType()->getContext());
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if (AI->getType() == Int8PtrTy)
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return isUsedByLifetimeMarker(AI);
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// Do a scan to find all the casts to i8*.
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for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); I != E;
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++I) {
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if (I->getType() != Int8PtrTy) continue;
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if (I->stripPointerCasts() != AI) continue;
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if (isUsedByLifetimeMarker(*I))
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return true;
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}
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return false;
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}
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/// updateInlinedAtInfo - Helper function used by fixupLineNumbers to
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/// recursively update InlinedAtEntry of a DebugLoc.
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static DebugLoc updateInlinedAtInfo(const DebugLoc &DL,
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const DebugLoc &InlinedAtDL,
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LLVMContext &Ctx) {
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if (MDNode *IA = DL.getInlinedAt(Ctx)) {
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DebugLoc NewInlinedAtDL
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= updateInlinedAtInfo(DebugLoc::getFromDILocation(IA), InlinedAtDL, Ctx);
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return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(Ctx),
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NewInlinedAtDL.getAsMDNode(Ctx));
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}
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return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(Ctx),
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InlinedAtDL.getAsMDNode(Ctx));
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}
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/// fixupLineNumbers - Update inlined instructions' line numbers to
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/// to encode location where these instructions are inlined.
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static void fixupLineNumbers(Function *Fn, Function::iterator FI,
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|
Instruction *TheCall) {
|
|
DebugLoc TheCallDL = TheCall->getDebugLoc();
|
|
if (TheCallDL.isUnknown())
|
|
return;
|
|
|
|
for (; FI != Fn->end(); ++FI) {
|
|
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
|
|
BI != BE; ++BI) {
|
|
DebugLoc DL = BI->getDebugLoc();
|
|
if (!DL.isUnknown()) {
|
|
BI->setDebugLoc(updateInlinedAtInfo(DL, TheCallDL, BI->getContext()));
|
|
if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(BI)) {
|
|
LLVMContext &Ctx = BI->getContext();
|
|
MDNode *InlinedAt = BI->getDebugLoc().getInlinedAt(Ctx);
|
|
DVI->setOperand(2, createInlinedVariable(DVI->getVariable(),
|
|
InlinedAt, Ctx));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// InlineFunction - This function inlines the called function into the basic
|
|
/// block of the caller. This returns false if it is not possible to inline
|
|
/// this call. The program is still in a well defined state if this occurs
|
|
/// though.
|
|
///
|
|
/// Note that this only does one level of inlining. For example, if the
|
|
/// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
|
|
/// exists in the instruction stream. Similarly this will inline a recursive
|
|
/// function by one level.
|
|
bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
|
|
bool InsertLifetime) {
|
|
Instruction *TheCall = CS.getInstruction();
|
|
assert(TheCall->getParent() && TheCall->getParent()->getParent() &&
|
|
"Instruction not in function!");
|
|
|
|
// If IFI has any state in it, zap it before we fill it in.
|
|
IFI.reset();
|
|
|
|
const Function *CalledFunc = CS.getCalledFunction();
|
|
if (CalledFunc == 0 || // Can't inline external function or indirect
|
|
CalledFunc->isDeclaration() || // call, or call to a vararg function!
|
|
CalledFunc->getFunctionType()->isVarArg()) return false;
|
|
|
|
// If the call to the callee is not a tail call, we must clear the 'tail'
|
|
// flags on any calls that we inline.
|
|
bool MustClearTailCallFlags =
|
|
!(isa<CallInst>(TheCall) && cast<CallInst>(TheCall)->isTailCall());
|
|
|
|
// If the call to the callee cannot throw, set the 'nounwind' flag on any
|
|
// calls that we inline.
|
|
bool MarkNoUnwind = CS.doesNotThrow();
|
|
|
|
BasicBlock *OrigBB = TheCall->getParent();
|
|
Function *Caller = OrigBB->getParent();
|
|
|
|
// GC poses two hazards to inlining, which only occur when the callee has GC:
|
|
// 1. If the caller has no GC, then the callee's GC must be propagated to the
|
|
// caller.
|
|
// 2. If the caller has a differing GC, it is invalid to inline.
|
|
if (CalledFunc->hasGC()) {
|
|
if (!Caller->hasGC())
|
|
Caller->setGC(CalledFunc->getGC());
|
|
else if (CalledFunc->getGC() != Caller->getGC())
|
|
return false;
|
|
}
|
|
|
|
// Get the personality function from the callee if it contains a landing pad.
|
|
Value *CalleePersonality = 0;
|
|
for (Function::const_iterator I = CalledFunc->begin(), E = CalledFunc->end();
|
|
I != E; ++I)
|
|
if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
|
|
const BasicBlock *BB = II->getUnwindDest();
|
|
const LandingPadInst *LP = BB->getLandingPadInst();
|
|
CalleePersonality = LP->getPersonalityFn();
|
|
break;
|
|
}
|
|
|
|
// Find the personality function used by the landing pads of the caller. If it
|
|
// exists, then check to see that it matches the personality function used in
|
|
// the callee.
|
|
if (CalleePersonality) {
|
|
for (Function::const_iterator I = Caller->begin(), E = Caller->end();
|
|
I != E; ++I)
|
|
if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
|
|
const BasicBlock *BB = II->getUnwindDest();
|
|
const LandingPadInst *LP = BB->getLandingPadInst();
|
|
|
|
// If the personality functions match, then we can perform the
|
|
// inlining. Otherwise, we can't inline.
|
|
// TODO: This isn't 100% true. Some personality functions are proper
|
|
// supersets of others and can be used in place of the other.
|
|
if (LP->getPersonalityFn() != CalleePersonality)
|
|
return false;
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Get an iterator to the last basic block in the function, which will have
|
|
// the new function inlined after it.
|
|
Function::iterator LastBlock = &Caller->back();
|
|
|
|
// Make sure to capture all of the return instructions from the cloned
|
|
// function.
|
|
SmallVector<ReturnInst*, 8> Returns;
|
|
ClonedCodeInfo InlinedFunctionInfo;
|
|
Function::iterator FirstNewBlock;
|
|
|
|
{ // Scope to destroy VMap after cloning.
|
|
ValueToValueMapTy VMap;
|
|
|
|
assert(CalledFunc->arg_size() == CS.arg_size() &&
|
|
"No varargs calls can be inlined!");
|
|
|
|
// Calculate the vector of arguments to pass into the function cloner, which
|
|
// matches up the formal to the actual argument values.
|
|
CallSite::arg_iterator AI = CS.arg_begin();
|
|
unsigned ArgNo = 0;
|
|
for (Function::const_arg_iterator I = CalledFunc->arg_begin(),
|
|
E = CalledFunc->arg_end(); I != E; ++I, ++AI, ++ArgNo) {
|
|
Value *ActualArg = *AI;
|
|
|
|
// When byval arguments actually inlined, we need to make the copy implied
|
|
// by them explicit. However, we don't do this if the callee is readonly
|
|
// or readnone, because the copy would be unneeded: the callee doesn't
|
|
// modify the struct.
|
|
if (CS.isByValArgument(ArgNo)) {
|
|
ActualArg = HandleByValArgument(ActualArg, TheCall, CalledFunc, IFI,
|
|
CalledFunc->getParamAlignment(ArgNo+1));
|
|
|
|
// Calls that we inline may use the new alloca, so we need to clear
|
|
// their 'tail' flags if HandleByValArgument introduced a new alloca and
|
|
// the callee has calls.
|
|
MustClearTailCallFlags |= ActualArg != *AI;
|
|
}
|
|
|
|
VMap[I] = ActualArg;
|
|
}
|
|
|
|
// We want the inliner to prune the code as it copies. We would LOVE to
|
|
// have no dead or constant instructions leftover after inlining occurs
|
|
// (which can happen, e.g., because an argument was constant), but we'll be
|
|
// happy with whatever the cloner can do.
|
|
CloneAndPruneFunctionInto(Caller, CalledFunc, VMap,
|
|
/*ModuleLevelChanges=*/false, Returns, ".i",
|
|
&InlinedFunctionInfo, IFI.TD, TheCall);
|
|
|
|
// Remember the first block that is newly cloned over.
|
|
FirstNewBlock = LastBlock; ++FirstNewBlock;
|
|
|
|
// Update the callgraph if requested.
|
|
if (IFI.CG)
|
|
UpdateCallGraphAfterInlining(CS, FirstNewBlock, VMap, IFI);
|
|
|
|
// Update inlined instructions' line number information.
|
|
fixupLineNumbers(Caller, FirstNewBlock, TheCall);
|
|
}
|
|
|
|
// If there are any alloca instructions in the block that used to be the entry
|
|
// block for the callee, move them to the entry block of the caller. First
|
|
// calculate which instruction they should be inserted before. We insert the
|
|
// instructions at the end of the current alloca list.
|
|
{
|
|
BasicBlock::iterator InsertPoint = Caller->begin()->begin();
|
|
for (BasicBlock::iterator I = FirstNewBlock->begin(),
|
|
E = FirstNewBlock->end(); I != E; ) {
|
|
AllocaInst *AI = dyn_cast<AllocaInst>(I++);
|
|
if (AI == 0) continue;
|
|
|
|
// If the alloca is now dead, remove it. This often occurs due to code
|
|
// specialization.
|
|
if (AI->use_empty()) {
|
|
AI->eraseFromParent();
|
|
continue;
|
|
}
|
|
|
|
if (!isa<Constant>(AI->getArraySize()))
|
|
continue;
|
|
|
|
// Keep track of the static allocas that we inline into the caller.
|
|
IFI.StaticAllocas.push_back(AI);
|
|
|
|
// Scan for the block of allocas that we can move over, and move them
|
|
// all at once.
|
|
while (isa<AllocaInst>(I) &&
|
|
isa<Constant>(cast<AllocaInst>(I)->getArraySize())) {
|
|
IFI.StaticAllocas.push_back(cast<AllocaInst>(I));
|
|
++I;
|
|
}
|
|
|
|
// Transfer all of the allocas over in a block. Using splice means
|
|
// that the instructions aren't removed from the symbol table, then
|
|
// reinserted.
|
|
Caller->getEntryBlock().getInstList().splice(InsertPoint,
|
|
FirstNewBlock->getInstList(),
|
|
AI, I);
|
|
}
|
|
}
|
|
|
|
// Leave lifetime markers for the static alloca's, scoping them to the
|
|
// function we just inlined.
|
|
if (InsertLifetime && !IFI.StaticAllocas.empty()) {
|
|
IRBuilder<> builder(FirstNewBlock->begin());
|
|
for (unsigned ai = 0, ae = IFI.StaticAllocas.size(); ai != ae; ++ai) {
|
|
AllocaInst *AI = IFI.StaticAllocas[ai];
|
|
|
|
// If the alloca is already scoped to something smaller than the whole
|
|
// function then there's no need to add redundant, less accurate markers.
|
|
if (hasLifetimeMarkers(AI))
|
|
continue;
|
|
|
|
builder.CreateLifetimeStart(AI);
|
|
for (unsigned ri = 0, re = Returns.size(); ri != re; ++ri) {
|
|
IRBuilder<> builder(Returns[ri]);
|
|
builder.CreateLifetimeEnd(AI);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the inlined code contained dynamic alloca instructions, wrap the inlined
|
|
// code with llvm.stacksave/llvm.stackrestore intrinsics.
|
|
if (InlinedFunctionInfo.ContainsDynamicAllocas) {
|
|
Module *M = Caller->getParent();
|
|
// Get the two intrinsics we care about.
|
|
Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave);
|
|
Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore);
|
|
|
|
// Insert the llvm.stacksave.
|
|
CallInst *SavedPtr = IRBuilder<>(FirstNewBlock, FirstNewBlock->begin())
|
|
.CreateCall(StackSave, "savedstack");
|
|
|
|
// Insert a call to llvm.stackrestore before any return instructions in the
|
|
// inlined function.
|
|
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
|
|
IRBuilder<>(Returns[i]).CreateCall(StackRestore, SavedPtr);
|
|
}
|
|
}
|
|
|
|
// If we are inlining tail call instruction through a call site that isn't
|
|
// marked 'tail', we must remove the tail marker for any calls in the inlined
|
|
// code. Also, calls inlined through a 'nounwind' call site should be marked
|
|
// 'nounwind'.
|
|
if (InlinedFunctionInfo.ContainsCalls &&
|
|
(MustClearTailCallFlags || MarkNoUnwind)) {
|
|
for (Function::iterator BB = FirstNewBlock, E = Caller->end();
|
|
BB != E; ++BB)
|
|
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
|
|
if (CallInst *CI = dyn_cast<CallInst>(I)) {
|
|
if (MustClearTailCallFlags)
|
|
CI->setTailCall(false);
|
|
if (MarkNoUnwind)
|
|
CI->setDoesNotThrow();
|
|
}
|
|
}
|
|
|
|
// If we are inlining for an invoke instruction, we must make sure to rewrite
|
|
// any call instructions into invoke instructions.
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall))
|
|
HandleInlinedInvoke(II, FirstNewBlock, InlinedFunctionInfo);
|
|
|
|
// If we cloned in _exactly one_ basic block, and if that block ends in a
|
|
// return instruction, we splice the body of the inlined callee directly into
|
|
// the calling basic block.
|
|
if (Returns.size() == 1 && std::distance(FirstNewBlock, Caller->end()) == 1) {
|
|
// Move all of the instructions right before the call.
|
|
OrigBB->getInstList().splice(TheCall, FirstNewBlock->getInstList(),
|
|
FirstNewBlock->begin(), FirstNewBlock->end());
|
|
// Remove the cloned basic block.
|
|
Caller->getBasicBlockList().pop_back();
|
|
|
|
// If the call site was an invoke instruction, add a branch to the normal
|
|
// destination.
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall))
|
|
BranchInst::Create(II->getNormalDest(), TheCall);
|
|
|
|
// If the return instruction returned a value, replace uses of the call with
|
|
// uses of the returned value.
|
|
if (!TheCall->use_empty()) {
|
|
ReturnInst *R = Returns[0];
|
|
if (TheCall == R->getReturnValue())
|
|
TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
|
|
else
|
|
TheCall->replaceAllUsesWith(R->getReturnValue());
|
|
}
|
|
// Since we are now done with the Call/Invoke, we can delete it.
|
|
TheCall->eraseFromParent();
|
|
|
|
// Since we are now done with the return instruction, delete it also.
|
|
Returns[0]->eraseFromParent();
|
|
|
|
// We are now done with the inlining.
|
|
return true;
|
|
}
|
|
|
|
// Otherwise, we have the normal case, of more than one block to inline or
|
|
// multiple return sites.
|
|
|
|
// We want to clone the entire callee function into the hole between the
|
|
// "starter" and "ender" blocks. How we accomplish this depends on whether
|
|
// this is an invoke instruction or a call instruction.
|
|
BasicBlock *AfterCallBB;
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
|
|
|
|
// Add an unconditional branch to make this look like the CallInst case...
|
|
BranchInst *NewBr = BranchInst::Create(II->getNormalDest(), TheCall);
|
|
|
|
// Split the basic block. This guarantees that no PHI nodes will have to be
|
|
// updated due to new incoming edges, and make the invoke case more
|
|
// symmetric to the call case.
|
|
AfterCallBB = OrigBB->splitBasicBlock(NewBr,
|
|
CalledFunc->getName()+".exit");
|
|
|
|
} else { // It's a call
|
|
// If this is a call instruction, we need to split the basic block that
|
|
// the call lives in.
|
|
//
|
|
AfterCallBB = OrigBB->splitBasicBlock(TheCall,
|
|
CalledFunc->getName()+".exit");
|
|
}
|
|
|
|
// Change the branch that used to go to AfterCallBB to branch to the first
|
|
// basic block of the inlined function.
|
|
//
|
|
TerminatorInst *Br = OrigBB->getTerminator();
|
|
assert(Br && Br->getOpcode() == Instruction::Br &&
|
|
"splitBasicBlock broken!");
|
|
Br->setOperand(0, FirstNewBlock);
|
|
|
|
|
|
// Now that the function is correct, make it a little bit nicer. In
|
|
// particular, move the basic blocks inserted from the end of the function
|
|
// into the space made by splitting the source basic block.
|
|
Caller->getBasicBlockList().splice(AfterCallBB, Caller->getBasicBlockList(),
|
|
FirstNewBlock, Caller->end());
|
|
|
|
// Handle all of the return instructions that we just cloned in, and eliminate
|
|
// any users of the original call/invoke instruction.
|
|
Type *RTy = CalledFunc->getReturnType();
|
|
|
|
PHINode *PHI = 0;
|
|
if (Returns.size() > 1) {
|
|
// The PHI node should go at the front of the new basic block to merge all
|
|
// possible incoming values.
|
|
if (!TheCall->use_empty()) {
|
|
PHI = PHINode::Create(RTy, Returns.size(), TheCall->getName(),
|
|
AfterCallBB->begin());
|
|
// Anything that used the result of the function call should now use the
|
|
// PHI node as their operand.
|
|
TheCall->replaceAllUsesWith(PHI);
|
|
}
|
|
|
|
// Loop over all of the return instructions adding entries to the PHI node
|
|
// as appropriate.
|
|
if (PHI) {
|
|
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
|
|
ReturnInst *RI = Returns[i];
|
|
assert(RI->getReturnValue()->getType() == PHI->getType() &&
|
|
"Ret value not consistent in function!");
|
|
PHI->addIncoming(RI->getReturnValue(), RI->getParent());
|
|
}
|
|
}
|
|
|
|
|
|
// Add a branch to the merge points and remove return instructions.
|
|
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
|
|
ReturnInst *RI = Returns[i];
|
|
BranchInst::Create(AfterCallBB, RI);
|
|
RI->eraseFromParent();
|
|
}
|
|
} else if (!Returns.empty()) {
|
|
// Otherwise, if there is exactly one return value, just replace anything
|
|
// using the return value of the call with the computed value.
|
|
if (!TheCall->use_empty()) {
|
|
if (TheCall == Returns[0]->getReturnValue())
|
|
TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
|
|
else
|
|
TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
|
|
}
|
|
|
|
// Update PHI nodes that use the ReturnBB to use the AfterCallBB.
|
|
BasicBlock *ReturnBB = Returns[0]->getParent();
|
|
ReturnBB->replaceAllUsesWith(AfterCallBB);
|
|
|
|
// Splice the code from the return block into the block that it will return
|
|
// to, which contains the code that was after the call.
|
|
AfterCallBB->getInstList().splice(AfterCallBB->begin(),
|
|
ReturnBB->getInstList());
|
|
|
|
// Delete the return instruction now and empty ReturnBB now.
|
|
Returns[0]->eraseFromParent();
|
|
ReturnBB->eraseFromParent();
|
|
} else if (!TheCall->use_empty()) {
|
|
// No returns, but something is using the return value of the call. Just
|
|
// nuke the result.
|
|
TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
|
|
}
|
|
|
|
// Since we are now done with the Call/Invoke, we can delete it.
|
|
TheCall->eraseFromParent();
|
|
|
|
// We should always be able to fold the entry block of the function into the
|
|
// single predecessor of the block...
|
|
assert(cast<BranchInst>(Br)->isUnconditional() && "splitBasicBlock broken!");
|
|
BasicBlock *CalleeEntry = cast<BranchInst>(Br)->getSuccessor(0);
|
|
|
|
// Splice the code entry block into calling block, right before the
|
|
// unconditional branch.
|
|
CalleeEntry->replaceAllUsesWith(OrigBB); // Update PHI nodes
|
|
OrigBB->getInstList().splice(Br, CalleeEntry->getInstList());
|
|
|
|
// Remove the unconditional branch.
|
|
OrigBB->getInstList().erase(Br);
|
|
|
|
// Now we can remove the CalleeEntry block, which is now empty.
|
|
Caller->getBasicBlockList().erase(CalleeEntry);
|
|
|
|
// If we inserted a phi node, check to see if it has a single value (e.g. all
|
|
// the entries are the same or undef). If so, remove the PHI so it doesn't
|
|
// block other optimizations.
|
|
if (PHI) {
|
|
if (Value *V = SimplifyInstruction(PHI, IFI.TD)) {
|
|
PHI->replaceAllUsesWith(V);
|
|
PHI->eraseFromParent();
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|