llvm-project/polly/lib/Support/ScopHelper.cpp

127 lines
3.9 KiB
C++

//===- ScopHelper.cpp - Some Helper Functions for Scop. ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Small functions that help with Scop and LLVM-IR.
//
//===----------------------------------------------------------------------===//
#include "polly/Support/ScopHelper.h"
#include "polly/ScopInfo.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/RegionInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Support/CFG.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#define DEBUG_TYPE "polly-scop-helper"
#include "llvm/Support/Debug.h"
using namespace llvm;
// Helper function for Scop
// TODO: Add assertion to not allow parameter to be null
//===----------------------------------------------------------------------===//
// Temporary Hack for extended region tree.
// Cast the region to loop if there is a loop have the same header and exit.
Loop *polly::castToLoop(const Region &R, LoopInfo &LI) {
BasicBlock *entry = R.getEntry();
if (!LI.isLoopHeader(entry))
return 0;
Loop *L = LI.getLoopFor(entry);
BasicBlock *exit = L->getExitBlock();
// Is the loop with multiple exits?
if (!exit)
return 0;
if (exit != R.getExit()) {
// SubRegion/ParentRegion with the same entry.
assert((R.getNode(R.getEntry())->isSubRegion() ||
R.getParent()->getEntry() == entry) &&
"Expect the loop is the smaller or bigger region");
return 0;
}
return L;
}
Value *polly::getPointerOperand(Instruction &Inst) {
if (LoadInst *load = dyn_cast<LoadInst>(&Inst))
return load->getPointerOperand();
else if (StoreInst *store = dyn_cast<StoreInst>(&Inst))
return store->getPointerOperand();
else if (GetElementPtrInst *gep = dyn_cast<GetElementPtrInst>(&Inst))
return gep->getPointerOperand();
return 0;
}
bool polly::hasInvokeEdge(const PHINode *PN) {
for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i)
if (InvokeInst *II = dyn_cast<InvokeInst>(PN->getIncomingValue(i)))
if (II->getParent() == PN->getIncomingBlock(i))
return true;
return false;
}
BasicBlock *polly::createSingleExitEdge(Region *R, Pass *P) {
BasicBlock *BB = R->getExit();
SmallVector<BasicBlock *, 4> Preds;
for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI)
if (R->contains(*PI))
Preds.push_back(*PI);
return SplitBlockPredecessors(BB, Preds, ".region", P);
}
void polly::simplifyRegion(Scop *S, Pass *P) {
Region *R = &S->getRegion();
// Create single entry edge if the region has multiple entry edges.
if (!R->getEnteringBlock()) {
BasicBlock *OldEntry = R->getEntry();
BasicBlock *NewEntry = SplitBlock(OldEntry, OldEntry->begin(), P);
for (Scop::iterator SI = S->begin(), SE = S->end(); SI != SE; ++SI)
if ((*SI)->getBasicBlock() == OldEntry) {
(*SI)->setBasicBlock(NewEntry);
break;
}
R->replaceEntryRecursive(NewEntry);
}
// Create single exit edge if the region has multiple exit edges.
if (!R->getExitingBlock()) {
BasicBlock *NewExit = createSingleExitEdge(R, P);
for (Region::const_iterator RI = R->begin(), RE = R->end(); RI != RE; ++RI)
(*RI)->replaceExitRecursive(NewExit);
}
}
void polly::splitEntryBlockForAlloca(BasicBlock *EntryBlock, Pass *P) {
// Find first non-alloca instruction. Every basic block has a non-alloc
// instruction, as every well formed basic block has a terminator.
BasicBlock::iterator I = EntryBlock->begin();
while (isa<AllocaInst>(I))
++I;
// SplitBlock updates DT, DF and LI.
BasicBlock *NewEntry = SplitBlock(EntryBlock, I, P);
if (RegionInfo *RI = P->getAnalysisIfAvailable<RegionInfo>())
RI->splitBlock(NewEntry, EntryBlock);
}