#define DEBUG_TYPE "iv-users"
#include "llvm/Analysis/IVUsers.h"
-#include "llvm/Constants.h"
-#include "llvm/Instructions.h"
-#include "llvm/Type.h"
-#include "llvm/DerivedTypes.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/Target/TargetData.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Assembly/Writer.h"
-#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Type.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
return true;
}
-/// AddUsersIfInteresting - Inspect the specified instruction. If it is a
+/// AddUsersImpl - Inspect the specified instruction. If it is a
/// reducible SCEV, recursively add its users to the IVUsesByStride set and
/// return true. Otherwise, return false.
-bool IVUsers::AddUsersIfInteresting(Instruction *I,
- SmallPtrSet<Loop*,16> &SimpleLoopNests) {
+bool IVUsers::AddUsersImpl(Instruction *I,
+ SmallPtrSet<Loop*,16> &SimpleLoopNests) {
// Add this IV user to the Processed set before returning false to ensure that
// all IV users are members of the set. See IVUsers::isIVUserOrOperand.
if (!Processed.insert(I))
if (!SE->isSCEVable(I->getType()))
return false; // Void and FP expressions cannot be reduced.
+ // IVUsers is used by LSR which assumes that all SCEV expressions are safe to
+ // pass to SCEVExpander. Expressions are not safe to expand if they represent
+ // operations that are not safe to speculate, namely integer division.
+ if (!isa<PHINode>(I) && !isSafeToSpeculativelyExecute(I, TD))
+ return false;
+
// LSR is not APInt clean, do not touch integers bigger than 64-bits.
// 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.
bool AddUserToIVUsers = false;
if (LI->getLoopFor(User->getParent()) != L) {
if (isa<PHINode>(User) || Processed.count(User) ||
- !AddUsersIfInteresting(User, SimpleLoopNests)) {
+ !AddUsersImpl(User, SimpleLoopNests)) {
DEBUG(dbgs() << "FOUND USER in other loop: " << *User << '\n'
<< " OF SCEV: " << *ISE << '\n');
AddUserToIVUsers = true;
}
- } else if (Processed.count(User)
- || !AddUsersIfInteresting(User, SimpleLoopNests)) {
+ } else if (Processed.count(User) || !AddUsersImpl(User, SimpleLoopNests)) {
DEBUG(dbgs() << "FOUND USER: " << *User << '\n'
<< " OF SCEV: " << *ISE << '\n');
AddUserToIVUsers = true;
return true;
}
+bool IVUsers::AddUsersIfInteresting(Instruction *I) {
+ // SCEVExpander can only handle users that are dominated by simplified loop
+ // entries. Keep track of all loops that are only dominated by other simple
+ // loops so we don't traverse the domtree for each user.
+ SmallPtrSet<Loop*,16> SimpleLoopNests;
+
+ return AddUsersImpl(I, SimpleLoopNests);
+}
+
IVStrideUse &IVUsers::AddUser(Instruction *User, Value *Operand) {
IVUses.push_back(new IVStrideUse(this, User, Operand));
return IVUses.back();
LI = &getAnalysis<LoopInfo>();
DT = &getAnalysis<DominatorTree>();
SE = &getAnalysis<ScalarEvolution>();
- TD = getAnalysisIfAvailable<TargetData>();
-
- // SCEVExpander can only handle users that are dominated by simplified loop
- // entries. Keep track of all loops that are only dominated by other simple
- // loops so we don't traverse the domtree for each user.
- SmallPtrSet<Loop*,16> SimpleLoopNests;
+ TD = getAnalysisIfAvailable<DataLayout>();
// 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
// this loop. If they are induction variables, inspect their uses.
for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ++I)
- (void)AddUsersIfInteresting(I, SimpleLoopNests);
+ (void)AddUsersIfInteresting(I);
return false;
}
}
}
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void IVUsers::dump() const {
print(dbgs());
}
+#endif
void IVUsers::releaseMemory() {
Processed.clear();