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https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25587 91177308-0d34-0410-b5e6-96231b3b80d8
655 lines
26 KiB
C++
655 lines
26 KiB
C++
//===- ScalarReplAggregates.cpp - Scalar Replacement of Aggregates --------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This transformation implements the well known scalar replacement of
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// aggregates transformation. This xform breaks up alloca instructions of
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// aggregate type (structure or array) into individual alloca instructions for
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// each member (if possible). Then, if possible, it transforms the individual
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// alloca instructions into nice clean scalar SSA form.
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//
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// This combines a simple SRoA algorithm with the Mem2Reg algorithm because
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// often interact, especially for C++ programs. As such, iterating between
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// SRoA, then Mem2Reg until we run out of things to promote works well.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/Constants.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/Function.h"
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#include "llvm/Pass.h"
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#include "llvm/Instructions.h"
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#include "llvm/Analysis/Dominators.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Transforms/Utils/PromoteMemToReg.h"
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#include "llvm/Support/GetElementPtrTypeIterator.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/StringExtras.h"
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#include <iostream>
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using namespace llvm;
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namespace {
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Statistic<> NumReplaced("scalarrepl", "Number of allocas broken up");
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Statistic<> NumPromoted("scalarrepl", "Number of allocas promoted");
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Statistic<> NumConverted("scalarrepl",
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"Number of aggregates converted to scalar");
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struct SROA : public FunctionPass {
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bool runOnFunction(Function &F);
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bool performScalarRepl(Function &F);
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bool performPromotion(Function &F);
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// getAnalysisUsage - This pass does not require any passes, but we know it
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// will not alter the CFG, so say so.
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virtual void getAnalysisUsage(AnalysisUsage &AU) const {
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AU.addRequired<DominatorTree>();
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AU.addRequired<DominanceFrontier>();
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AU.addRequired<TargetData>();
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AU.setPreservesCFG();
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}
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private:
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int isSafeElementUse(Value *Ptr);
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int isSafeUseOfAllocation(Instruction *User);
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int isSafeAllocaToScalarRepl(AllocationInst *AI);
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void CanonicalizeAllocaUsers(AllocationInst *AI);
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AllocaInst *AddNewAlloca(Function &F, const Type *Ty, AllocationInst *Base);
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const Type *CanConvertToScalar(Value *V, bool &IsNotTrivial);
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void ConvertToScalar(AllocationInst *AI, const Type *Ty);
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void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset);
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};
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RegisterOpt<SROA> X("scalarrepl", "Scalar Replacement of Aggregates");
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}
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// Public interface to the ScalarReplAggregates pass
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FunctionPass *llvm::createScalarReplAggregatesPass() { return new SROA(); }
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bool SROA::runOnFunction(Function &F) {
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bool Changed = performPromotion(F);
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while (1) {
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bool LocalChange = performScalarRepl(F);
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if (!LocalChange) break; // No need to repromote if no scalarrepl
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Changed = true;
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LocalChange = performPromotion(F);
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if (!LocalChange) break; // No need to re-scalarrepl if no promotion
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}
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return Changed;
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}
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bool SROA::performPromotion(Function &F) {
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std::vector<AllocaInst*> Allocas;
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const TargetData &TD = getAnalysis<TargetData>();
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DominatorTree &DT = getAnalysis<DominatorTree>();
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DominanceFrontier &DF = getAnalysis<DominanceFrontier>();
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BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function
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bool Changed = false;
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while (1) {
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Allocas.clear();
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// Find allocas that are safe to promote, by looking at all instructions in
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// the entry node
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for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I)
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if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca?
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if (isAllocaPromotable(AI, TD))
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Allocas.push_back(AI);
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if (Allocas.empty()) break;
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PromoteMemToReg(Allocas, DT, DF, TD);
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NumPromoted += Allocas.size();
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Changed = true;
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}
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return Changed;
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}
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// performScalarRepl - This algorithm is a simple worklist driven algorithm,
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// which runs on all of the malloc/alloca instructions in the function, removing
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// them if they are only used by getelementptr instructions.
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//
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bool SROA::performScalarRepl(Function &F) {
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std::vector<AllocationInst*> WorkList;
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// Scan the entry basic block, adding any alloca's and mallocs to the worklist
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BasicBlock &BB = F.getEntryBlock();
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for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I)
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if (AllocationInst *A = dyn_cast<AllocationInst>(I))
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WorkList.push_back(A);
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// Process the worklist
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bool Changed = false;
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while (!WorkList.empty()) {
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AllocationInst *AI = WorkList.back();
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WorkList.pop_back();
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// If we can turn this aggregate value (potentially with casts) into a
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// simple scalar value that can be mem2reg'd into a register value.
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bool IsNotTrivial = false;
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if (const Type *ActualType = CanConvertToScalar(AI, IsNotTrivial))
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if (IsNotTrivial) {
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ConvertToScalar(AI, ActualType);
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Changed = true;
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continue;
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}
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// We cannot transform the allocation instruction if it is an array
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// allocation (allocations OF arrays are ok though), and an allocation of a
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// scalar value cannot be decomposed at all.
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//
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if (AI->isArrayAllocation() ||
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(!isa<StructType>(AI->getAllocatedType()) &&
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!isa<ArrayType>(AI->getAllocatedType()))) continue;
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// Check that all of the users of the allocation are capable of being
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// transformed.
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switch (isSafeAllocaToScalarRepl(AI)) {
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default: assert(0 && "Unexpected value!");
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case 0: // Not safe to scalar replace.
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continue;
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case 1: // Safe, but requires cleanup/canonicalizations first
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CanonicalizeAllocaUsers(AI);
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case 3: // Safe to scalar replace.
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break;
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}
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DEBUG(std::cerr << "Found inst to xform: " << *AI);
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Changed = true;
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std::vector<AllocaInst*> ElementAllocas;
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if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) {
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ElementAllocas.reserve(ST->getNumContainedTypes());
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for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) {
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AllocaInst *NA = new AllocaInst(ST->getContainedType(i), 0,
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AI->getAlignment(),
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AI->getName() + "." + utostr(i), AI);
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ElementAllocas.push_back(NA);
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WorkList.push_back(NA); // Add to worklist for recursive processing
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}
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} else {
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const ArrayType *AT = cast<ArrayType>(AI->getAllocatedType());
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ElementAllocas.reserve(AT->getNumElements());
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const Type *ElTy = AT->getElementType();
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for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) {
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AllocaInst *NA = new AllocaInst(ElTy, 0, AI->getAlignment(),
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AI->getName() + "." + utostr(i), AI);
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ElementAllocas.push_back(NA);
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WorkList.push_back(NA); // Add to worklist for recursive processing
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}
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}
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// Now that we have created the alloca instructions that we want to use,
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// expand the getelementptr instructions to use them.
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//
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while (!AI->use_empty()) {
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Instruction *User = cast<Instruction>(AI->use_back());
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GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User);
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// We now know that the GEP is of the form: GEP <ptr>, 0, <cst>
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unsigned Idx =
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(unsigned)cast<ConstantInt>(GEPI->getOperand(2))->getRawValue();
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assert(Idx < ElementAllocas.size() && "Index out of range?");
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AllocaInst *AllocaToUse = ElementAllocas[Idx];
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Value *RepValue;
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if (GEPI->getNumOperands() == 3) {
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// Do not insert a new getelementptr instruction with zero indices, only
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// to have it optimized out later.
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RepValue = AllocaToUse;
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} else {
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// We are indexing deeply into the structure, so we still need a
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// getelement ptr instruction to finish the indexing. This may be
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// expanded itself once the worklist is rerun.
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//
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std::string OldName = GEPI->getName(); // Steal the old name.
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std::vector<Value*> NewArgs;
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NewArgs.push_back(Constant::getNullValue(Type::IntTy));
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NewArgs.insert(NewArgs.end(), GEPI->op_begin()+3, GEPI->op_end());
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GEPI->setName("");
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RepValue = new GetElementPtrInst(AllocaToUse, NewArgs, OldName, GEPI);
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}
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// Move all of the users over to the new GEP.
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GEPI->replaceAllUsesWith(RepValue);
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// Delete the old GEP
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GEPI->eraseFromParent();
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}
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// Finally, delete the Alloca instruction
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AI->getParent()->getInstList().erase(AI);
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NumReplaced++;
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}
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return Changed;
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}
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/// isSafeElementUse - Check to see if this use is an allowed use for a
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/// getelementptr instruction of an array aggregate allocation.
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///
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int SROA::isSafeElementUse(Value *Ptr) {
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for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end();
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I != E; ++I) {
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Instruction *User = cast<Instruction>(*I);
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switch (User->getOpcode()) {
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case Instruction::Load: break;
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case Instruction::Store:
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// Store is ok if storing INTO the pointer, not storing the pointer
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if (User->getOperand(0) == Ptr) return 0;
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break;
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case Instruction::GetElementPtr: {
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GetElementPtrInst *GEP = cast<GetElementPtrInst>(User);
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if (GEP->getNumOperands() > 1) {
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if (!isa<Constant>(GEP->getOperand(1)) ||
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!cast<Constant>(GEP->getOperand(1))->isNullValue())
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return 0; // Using pointer arithmetic to navigate the array...
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}
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if (!isSafeElementUse(GEP)) return 0;
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break;
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}
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default:
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DEBUG(std::cerr << " Transformation preventing inst: " << *User);
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return 0;
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}
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}
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return 3; // All users look ok :)
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}
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/// AllUsersAreLoads - Return true if all users of this value are loads.
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static bool AllUsersAreLoads(Value *Ptr) {
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for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end();
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I != E; ++I)
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if (cast<Instruction>(*I)->getOpcode() != Instruction::Load)
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return false;
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return true;
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}
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/// isSafeUseOfAllocation - Check to see if this user is an allowed use for an
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/// aggregate allocation.
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///
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int SROA::isSafeUseOfAllocation(Instruction *User) {
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if (!isa<GetElementPtrInst>(User)) return 0;
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GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User);
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gep_type_iterator I = gep_type_begin(GEPI), E = gep_type_end(GEPI);
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// The GEP is safe to transform if it is of the form GEP <ptr>, 0, <cst>
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if (I == E ||
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I.getOperand() != Constant::getNullValue(I.getOperand()->getType()))
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return 0;
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++I;
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if (I == E) return 0; // ran out of GEP indices??
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// If this is a use of an array allocation, do a bit more checking for sanity.
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if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) {
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uint64_t NumElements = AT->getNumElements();
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if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) {
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// Check to make sure that index falls within the array. If not,
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// something funny is going on, so we won't do the optimization.
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//
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if (cast<ConstantInt>(GEPI->getOperand(2))->getRawValue() >= NumElements)
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return 0;
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} else {
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// If this is an array index and the index is not constant, we cannot
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// promote... that is unless the array has exactly one or two elements in
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// it, in which case we CAN promote it, but we have to canonicalize this
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// out if this is the only problem.
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if (NumElements == 1 || NumElements == 2)
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return AllUsersAreLoads(GEPI) ? 1 : 0; // Canonicalization required!
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return 0;
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}
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}
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// If there are any non-simple uses of this getelementptr, make sure to reject
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// them.
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return isSafeElementUse(GEPI);
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}
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/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of
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/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe,
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/// or 1 if safe after canonicalization has been performed.
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///
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int SROA::isSafeAllocaToScalarRepl(AllocationInst *AI) {
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// Loop over the use list of the alloca. We can only transform it if all of
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// the users are safe to transform.
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//
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int isSafe = 3;
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for (Value::use_iterator I = AI->use_begin(), E = AI->use_end();
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I != E; ++I) {
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isSafe &= isSafeUseOfAllocation(cast<Instruction>(*I));
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if (isSafe == 0) {
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DEBUG(std::cerr << "Cannot transform: " << *AI << " due to user: "
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<< **I);
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return 0;
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}
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}
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// If we require cleanup, isSafe is now 1, otherwise it is 3.
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return isSafe;
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}
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/// CanonicalizeAllocaUsers - If SROA reported that it can promote the specified
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/// allocation, but only if cleaned up, perform the cleanups required.
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void SROA::CanonicalizeAllocaUsers(AllocationInst *AI) {
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// At this point, we know that the end result will be SROA'd and promoted, so
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// we can insert ugly code if required so long as sroa+mem2reg will clean it
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// up.
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for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
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UI != E; ) {
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GetElementPtrInst *GEPI = cast<GetElementPtrInst>(*UI++);
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gep_type_iterator I = gep_type_begin(GEPI);
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++I;
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if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) {
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uint64_t NumElements = AT->getNumElements();
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if (!isa<ConstantInt>(I.getOperand())) {
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if (NumElements == 1) {
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GEPI->setOperand(2, Constant::getNullValue(Type::IntTy));
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} else {
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assert(NumElements == 2 && "Unhandled case!");
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// All users of the GEP must be loads. At each use of the GEP, insert
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// two loads of the appropriate indexed GEP and select between them.
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Value *IsOne = BinaryOperator::createSetNE(I.getOperand(),
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Constant::getNullValue(I.getOperand()->getType()),
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"isone", GEPI);
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// Insert the new GEP instructions, which are properly indexed.
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std::vector<Value*> Indices(GEPI->op_begin()+1, GEPI->op_end());
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Indices[1] = Constant::getNullValue(Type::IntTy);
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Value *ZeroIdx = new GetElementPtrInst(GEPI->getOperand(0), Indices,
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GEPI->getName()+".0", GEPI);
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Indices[1] = ConstantInt::get(Type::IntTy, 1);
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Value *OneIdx = new GetElementPtrInst(GEPI->getOperand(0), Indices,
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GEPI->getName()+".1", GEPI);
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// Replace all loads of the variable index GEP with loads from both
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// indexes and a select.
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while (!GEPI->use_empty()) {
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LoadInst *LI = cast<LoadInst>(GEPI->use_back());
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Value *Zero = new LoadInst(ZeroIdx, LI->getName()+".0", LI);
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Value *One = new LoadInst(OneIdx , LI->getName()+".1", LI);
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Value *R = new SelectInst(IsOne, One, Zero, LI->getName(), LI);
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LI->replaceAllUsesWith(R);
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LI->eraseFromParent();
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}
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GEPI->eraseFromParent();
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}
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}
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}
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}
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}
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/// MergeInType - Add the 'In' type to the accumulated type so far. If the
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/// types are incompatible, return true, otherwise update Accum and return
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/// false.
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static bool MergeInType(const Type *In, const Type *&Accum) {
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if (!In->isIntegral()) return true;
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// If this is our first type, just use it.
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if (Accum == Type::VoidTy) {
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Accum = In;
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} else {
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// Otherwise pick whichever type is larger.
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if (In->getTypeID() > Accum->getTypeID())
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Accum = In;
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}
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return false;
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}
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/// getUIntAtLeastAsBitAs - Return an unsigned integer type that is at least
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/// as big as the specified type. If there is no suitable type, this returns
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/// null.
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const Type *getUIntAtLeastAsBitAs(unsigned NumBits) {
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if (NumBits > 64) return 0;
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if (NumBits > 32) return Type::ULongTy;
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if (NumBits > 16) return Type::UIntTy;
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if (NumBits > 8) return Type::UShortTy;
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return Type::UByteTy;
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}
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/// CanConvertToScalar - V is a pointer. If we can convert the pointee to a
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/// single scalar integer type, return that type. Further, if the use is not
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/// a completely trivial use that mem2reg could promote, set IsNotTrivial. If
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/// there are no uses of this pointer, return Type::VoidTy to differentiate from
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/// failure.
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///
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const Type *SROA::CanConvertToScalar(Value *V, bool &IsNotTrivial) {
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const Type *UsedType = Type::VoidTy; // No uses, no forced type.
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const TargetData &TD = getAnalysis<TargetData>();
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const PointerType *PTy = cast<PointerType>(V->getType());
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for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) {
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Instruction *User = cast<Instruction>(*UI);
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if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
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if (MergeInType(LI->getType(), UsedType))
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return 0;
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} else if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
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// Storing the pointer, not the into the value?
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if (SI->getOperand(0) == V) return 0;
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// NOTE: We could handle storing of FP imms here!
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if (MergeInType(SI->getOperand(0)->getType(), UsedType))
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return 0;
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} else if (CastInst *CI = dyn_cast<CastInst>(User)) {
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if (!isa<PointerType>(CI->getType())) return 0;
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IsNotTrivial = true;
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const Type *SubTy = CanConvertToScalar(CI, IsNotTrivial);
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if (!SubTy || MergeInType(SubTy, UsedType)) return 0;
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} else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
|
|
// Check to see if this is stepping over an element: GEP Ptr, int C
|
|
if (GEP->getNumOperands() == 2 && isa<ConstantInt>(GEP->getOperand(1))) {
|
|
unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getRawValue();
|
|
unsigned ElSize = TD.getTypeSize(PTy->getElementType());
|
|
unsigned BitOffset = Idx*ElSize*8;
|
|
if (BitOffset > 64 || !isPowerOf2_32(ElSize)) return 0;
|
|
|
|
IsNotTrivial = true;
|
|
const Type *SubElt = CanConvertToScalar(GEP, IsNotTrivial);
|
|
if (SubElt == 0) return 0;
|
|
if (SubElt != Type::VoidTy) {
|
|
const Type *NewTy =
|
|
getUIntAtLeastAsBitAs(SubElt->getPrimitiveSizeInBits()+BitOffset);
|
|
if (NewTy == 0 || MergeInType(NewTy, UsedType)) return 0;
|
|
continue;
|
|
}
|
|
} else if (GEP->getNumOperands() == 3 &&
|
|
isa<ConstantInt>(GEP->getOperand(1)) &&
|
|
isa<ConstantInt>(GEP->getOperand(2)) &&
|
|
cast<Constant>(GEP->getOperand(1))->isNullValue()) {
|
|
// We are stepping into an element, e.g. a structure or an array:
|
|
// GEP Ptr, int 0, uint C
|
|
const Type *AggTy = PTy->getElementType();
|
|
unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getRawValue();
|
|
|
|
if (const ArrayType *ATy = dyn_cast<ArrayType>(AggTy)) {
|
|
if (Idx >= ATy->getNumElements()) return 0; // Out of range.
|
|
} else if (const PackedType *PTy = dyn_cast<PackedType>(AggTy)) {
|
|
if (Idx >= PTy->getNumElements()) return 0; // Out of range.
|
|
} else if (isa<StructType>(AggTy)) {
|
|
// Structs are always ok.
|
|
} else {
|
|
return 0;
|
|
}
|
|
const Type *NTy = getUIntAtLeastAsBitAs(TD.getTypeSize(AggTy)*8);
|
|
if (NTy == 0 || MergeInType(NTy, UsedType)) return 0;
|
|
const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial);
|
|
if (SubTy == 0) return 0;
|
|
if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType))
|
|
return 0;
|
|
continue; // Everything looks ok
|
|
}
|
|
return 0;
|
|
} else {
|
|
// Cannot handle this!
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return UsedType;
|
|
}
|
|
|
|
/// ConvertToScalar - The specified alloca passes the CanConvertToScalar
|
|
/// predicate and is non-trivial. Convert it to something that can be trivially
|
|
/// promoted into a register by mem2reg.
|
|
void SROA::ConvertToScalar(AllocationInst *AI, const Type *ActualTy) {
|
|
DEBUG(std::cerr << "CONVERT TO SCALAR: " << *AI << " TYPE = "
|
|
<< *ActualTy << "\n");
|
|
++NumConverted;
|
|
|
|
BasicBlock *EntryBlock = AI->getParent();
|
|
assert(EntryBlock == &EntryBlock->getParent()->front() &&
|
|
"Not in the entry block!");
|
|
EntryBlock->getInstList().remove(AI); // Take the alloca out of the program.
|
|
|
|
// Create and insert the alloca.
|
|
AllocaInst *NewAI = new AllocaInst(ActualTy->getUnsignedVersion(), 0,
|
|
AI->getName(), EntryBlock->begin());
|
|
ConvertUsesToScalar(AI, NewAI, 0);
|
|
delete AI;
|
|
}
|
|
|
|
|
|
/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca
|
|
/// directly. Offset is an offset from the original alloca, in bits that need
|
|
/// to be shifted to the right. By the end of this, there should be no uses of
|
|
/// Ptr.
|
|
void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) {
|
|
while (!Ptr->use_empty()) {
|
|
Instruction *User = cast<Instruction>(Ptr->use_back());
|
|
|
|
if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
|
|
// The load is a bit extract from NewAI shifted right by Offset bits.
|
|
Value *NV = new LoadInst(NewAI, LI->getName(), LI);
|
|
if (Offset && Offset < NV->getType()->getPrimitiveSizeInBits())
|
|
NV = new ShiftInst(Instruction::Shr, NV,
|
|
ConstantUInt::get(Type::UByteTy, Offset),
|
|
LI->getName(), LI);
|
|
if (NV->getType() != LI->getType())
|
|
NV = new CastInst(NV, LI->getType(), LI->getName(), LI);
|
|
LI->replaceAllUsesWith(NV);
|
|
LI->eraseFromParent();
|
|
} else if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
|
|
assert(SI->getOperand(0) != Ptr && "Consistency error!");
|
|
|
|
// Convert the stored type to the actual type, shift it left to insert
|
|
// then 'or' into place.
|
|
Value *SV = SI->getOperand(0);
|
|
if (SV->getType() != NewAI->getType()->getElementType() || Offset != 0) {
|
|
Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI);
|
|
// If SV is signed, convert it to unsigned, so that the next cast zero
|
|
// extends the value.
|
|
if (SV->getType()->isSigned())
|
|
SV = new CastInst(SV, SV->getType()->getUnsignedVersion(),
|
|
SV->getName(), SI);
|
|
SV = new CastInst(SV, Old->getType(), SV->getName(), SI);
|
|
if (Offset && Offset < SV->getType()->getPrimitiveSizeInBits())
|
|
SV = new ShiftInst(Instruction::Shl, SV,
|
|
ConstantUInt::get(Type::UByteTy, Offset),
|
|
SV->getName()+".adj", SI);
|
|
// Mask out the bits we are about to insert from the old value.
|
|
unsigned TotalBits = SV->getType()->getPrimitiveSizeInBits();
|
|
unsigned InsertBits =
|
|
SI->getOperand(0)->getType()->getPrimitiveSizeInBits();
|
|
if (TotalBits != InsertBits) {
|
|
assert(TotalBits > InsertBits);
|
|
uint64_t Mask = ~(((1ULL << InsertBits)-1) << Offset);
|
|
if (TotalBits != 64)
|
|
Mask = Mask & ((1ULL << TotalBits)-1);
|
|
Old = BinaryOperator::createAnd(Old,
|
|
ConstantUInt::get(Old->getType(), Mask),
|
|
Old->getName()+".mask", SI);
|
|
SV = BinaryOperator::createOr(Old, SV, SV->getName()+".ins", SI);
|
|
}
|
|
}
|
|
new StoreInst(SV, NewAI, SI);
|
|
SI->eraseFromParent();
|
|
|
|
} else if (CastInst *CI = dyn_cast<CastInst>(User)) {
|
|
unsigned NewOff = Offset;
|
|
const TargetData &TD = getAnalysis<TargetData>();
|
|
if (TD.isBigEndian()) {
|
|
// Adjust the pointer. For example, storing 16-bits into a 32-bit
|
|
// alloca with just a cast makes it modify the top 16-bits.
|
|
const Type *SrcTy = cast<PointerType>(Ptr->getType())->getElementType();
|
|
const Type *DstTy = cast<PointerType>(CI->getType())->getElementType();
|
|
int PtrDiffBits = TD.getTypeSize(SrcTy)*8-TD.getTypeSize(DstTy)*8;
|
|
NewOff += PtrDiffBits;
|
|
}
|
|
ConvertUsesToScalar(CI, NewAI, NewOff);
|
|
CI->eraseFromParent();
|
|
} else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
|
|
const PointerType *AggPtrTy =
|
|
cast<PointerType>(GEP->getOperand(0)->getType());
|
|
const TargetData &TD = getAnalysis<TargetData>();
|
|
unsigned AggSizeInBits = TD.getTypeSize(AggPtrTy->getElementType())*8;
|
|
|
|
// Check to see if this is stepping over an element: GEP Ptr, int C
|
|
unsigned NewOffset = Offset;
|
|
if (GEP->getNumOperands() == 2) {
|
|
unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getRawValue();
|
|
unsigned BitOffset = Idx*AggSizeInBits;
|
|
|
|
if (TD.isLittleEndian())
|
|
NewOffset += BitOffset;
|
|
else
|
|
NewOffset -= BitOffset;
|
|
|
|
} else if (GEP->getNumOperands() == 3) {
|
|
// We know that operand #2 is zero.
|
|
unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getRawValue();
|
|
const Type *AggTy = AggPtrTy->getElementType();
|
|
if (const SequentialType *SeqTy = dyn_cast<SequentialType>(AggTy)) {
|
|
unsigned ElSizeBits = TD.getTypeSize(SeqTy->getElementType())*8;
|
|
|
|
if (TD.isLittleEndian())
|
|
NewOffset += ElSizeBits*Idx;
|
|
else
|
|
NewOffset += AggSizeInBits-ElSizeBits*(Idx+1);
|
|
} else if (const StructType *STy = dyn_cast<StructType>(AggTy)) {
|
|
unsigned EltBitOffset = TD.getStructLayout(STy)->MemberOffsets[Idx]*8;
|
|
|
|
if (TD.isLittleEndian())
|
|
NewOffset += EltBitOffset;
|
|
else {
|
|
const PointerType *ElPtrTy = cast<PointerType>(GEP->getType());
|
|
unsigned ElSizeBits = TD.getTypeSize(ElPtrTy->getElementType())*8;
|
|
NewOffset += AggSizeInBits-(EltBitOffset+ElSizeBits);
|
|
}
|
|
|
|
} else {
|
|
assert(0 && "Unsupported operation!");
|
|
abort();
|
|
}
|
|
} else {
|
|
assert(0 && "Unsupported operation!");
|
|
abort();
|
|
}
|
|
ConvertUsesToScalar(GEP, NewAI, NewOffset);
|
|
GEP->eraseFromParent();
|
|
} else {
|
|
assert(0 && "Unsupported operation!");
|
|
abort();
|
|
}
|
|
}
|
|
}
|