#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/Assembly/AsmAnnotationWriter.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Assembly/Writer.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
char IVUsers::ID = 0;
-static RegisterPass<IVUsers>
-X("iv-users", "Induction Variable Users", false, true);
+INITIALIZE_PASS_BEGIN(IVUsers, "iv-users",
+ "Induction Variable Users", false, true)
+INITIALIZE_PASS_DEPENDENCY(LoopInfo)
+INITIALIZE_PASS_DEPENDENCY(DominatorTree)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
+INITIALIZE_PASS_END(IVUsers, "iv-users",
+ "Induction Variable Users", false, true)
Pass *llvm::createIVUsersPass() {
return new IVUsers();
/// isInteresting - Test whether the given expression is "interesting" when
/// used by the given expression, within the context of analyzing the
/// given loop.
-static bool isInteresting(const SCEV *S, const Instruction *I, const Loop *L) {
- // Anything loop-invariant is interesting.
- if (!isa<SCEVUnknown>(S) && S->isLoopInvariant(L))
- return true;
-
+static bool isInteresting(const SCEV *S, const Instruction *I, const Loop *L,
+ ScalarEvolution *SE, LoopInfo *LI) {
// An addrec is interesting if it's affine or if it has an interesting start.
if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
- // Keep things simple. Don't touch loop-variant strides.
+ // Keep things simple. Don't touch loop-variant strides unless they're
+ // only used outside the loop and we can simplify them.
if (AR->getLoop() == L)
- return AR->isAffine() || !L->contains(I);
- // Otherwise recurse to see if the start value is interesting.
- return isInteresting(AR->getStart(), I, L);
+ return AR->isAffine() ||
+ (!L->contains(I) &&
+ SE->getSCEVAtScope(AR, LI->getLoopFor(I->getParent())) != AR);
+ // Otherwise recurse to see if the start value is interesting, and that
+ // the step value is not interesting, since we don't yet know how to
+ // do effective SCEV expansions for addrecs with interesting steps.
+ return isInteresting(AR->getStart(), I, L, SE, LI) &&
+ !isInteresting(AR->getStepRecurrence(*SE), I, L, SE, LI);
}
- // An add is interesting if any of its operands is.
+ // An add is interesting if exactly one of its operands is interesting.
if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
+ bool AnyInterestingYet = false;
for (SCEVAddExpr::op_iterator OI = Add->op_begin(), OE = Add->op_end();
OI != OE; ++OI)
- if (isInteresting(*OI, I, L))
- return true;
- return false;
+ if (isInteresting(*OI, I, L, SE, LI)) {
+ if (AnyInterestingYet)
+ return false;
+ AnyInterestingYet = true;
+ }
+ return AnyInterestingYet;
}
// Nothing else is interesting here.
return false; // Void and FP expressions cannot be reduced.
// LSR is not APInt clean, do not touch integers bigger than 64-bits.
- if (SE->getTypeSizeInBits(I->getType()) > 64)
+ // Also avoid creating IVs of non-native types. For example, we don't want a
+ // 64-bit IV in 32-bit code just because the loop has one 64-bit cast.
+ uint64_t Width = SE->getTypeSizeInBits(I->getType());
+ if (Width > 64 || (TD && !TD->isLegalInteger(Width)))
return false;
if (!Processed.insert(I))
// If we've come to an uninteresting expression, stop the traversal and
// call this a user.
- if (!isInteresting(ISE, I, L))
+ if (!isInteresting(ISE, I, L, SE, LI))
return false;
SmallPtrSet<Instruction *, 4> UniqueUsers;
<< " OF SCEV: " << *ISE << '\n');
AddUserToIVUsers = true;
}
- } else if (Processed.count(User) ||
- !AddUsersIfInteresting(User)) {
+ } else if (Processed.count(User) || !AddUsersIfInteresting(User)) {
DEBUG(dbgs() << "FOUND USER: " << *User << '\n'
<< " OF SCEV: " << *ISE << '\n');
AddUserToIVUsers = true;
// Okay, we found a user that we cannot reduce.
IVUses.push_back(new IVStrideUse(this, User, I));
IVStrideUse &NewUse = IVUses.back();
- // Transform the expression into a normalized form.
+ // Autodetect the post-inc loop set, populating NewUse.PostIncLoops.
+ // The regular return value here is discarded; instead of recording
+ // it, we just recompute it when we need it.
ISE = TransformForPostIncUse(NormalizeAutodetect,
ISE, User, I,
NewUse.PostIncLoops,
}
IVUsers::IVUsers()
- : LoopPass(&ID) {
+ : LoopPass(ID) {
+ initializeIVUsersPass(*PassRegistry::getPassRegistry());
}
void IVUsers::getAnalysisUsage(AnalysisUsage &AU) const {
LI = &getAnalysis<LoopInfo>();
DT = &getAnalysis<DominatorTree>();
SE = &getAnalysis<ScalarEvolution>();
+ TD = getAnalysisIfAvailable<TargetData>();
// Find all uses of induction variables in this loop, and categorize
// them by stride. Start by finding all of the PHI nodes in the header for
}
OS << ":\n";
- // Use a default AssemblyAnnotationWriter to suppress the default info
- // comments, which aren't relevant here.
- AssemblyAnnotationWriter Annotator;
for (ilist<IVStrideUse>::const_iterator UI = IVUses.begin(),
E = IVUses.end(); UI != E; ++UI) {
OS << " ";
OS << ")";
}
OS << " in ";
- UI->getUser()->print(OS, &Annotator);
+ UI->getUser()->print(OS);
OS << '\n';
}
}
projects / oota-llvm.git / blobdiff