bool UseDeferred = SetIteration > 0;
PtrAccessSet &S = UseDeferred ? DeferredAccesses : Accesses;
- for (auto A : AS) {
- Value *Ptr = A.getValue();
- bool IsWrite = S.count(MemAccessInfo(Ptr, true));
+ for (auto AV : AS) {
+ Value *Ptr = AV.getValue();
- // If we're using the deferred access set, then it contains only reads.
- bool IsReadOnlyPtr = ReadOnlyPtr.count(Ptr) && !IsWrite;
- if (UseDeferred && !IsReadOnlyPtr)
- continue;
- // Otherwise, the pointer must be in the PtrAccessSet, either as a read
- // or a write.
- assert(((IsReadOnlyPtr && UseDeferred) || IsWrite ||
- S.count(MemAccessInfo(Ptr, false))) &&
- "Alias-set pointer not in the access set?");
-
- MemAccessInfo Access(Ptr, IsWrite);
- DepCands.insert(Access);
-
- // Memorize read-only pointers for later processing and skip them in the
- // first round (they need to be checked after we have seen all write
- // pointers). Note: we also mark pointer that are not consecutive as
- // "read-only" pointers (so that we check "a[b[i]] +="). Hence, we need
- // the second check for "!IsWrite".
- if (!UseDeferred && IsReadOnlyPtr) {
- DeferredAccesses.insert(Access);
- continue;
- }
+ // For a single memory access in AliasSetTracker, Accesses may contain
+ // both read and write, and they both need to be handled for CheckDeps.
+ for (auto AC : S) {
+ if (AC.getPointer() != Ptr)
+ continue;
- // If this is a write - check other reads and writes for conflicts. If
- // this is a read only check other writes for conflicts (but only if
- // there is no other write to the ptr - this is an optimization to
- // catch "a[i] = a[i] + " without having to do a dependence check).
- if ((IsWrite || IsReadOnlyPtr) && SetHasWrite) {
- CheckDeps.insert(Access);
- IsRTCheckNeeded = true;
- }
+ bool IsWrite = AC.getInt();
+
+ // If we're using the deferred access set, then it contains only
+ // reads.
+ bool IsReadOnlyPtr = ReadOnlyPtr.count(Ptr) && !IsWrite;
+ if (UseDeferred && !IsReadOnlyPtr)
+ continue;
+ // Otherwise, the pointer must be in the PtrAccessSet, either as a
+ // read or a write.
+ assert(((IsReadOnlyPtr && UseDeferred) || IsWrite ||
+ S.count(MemAccessInfo(Ptr, false))) &&
+ "Alias-set pointer not in the access set?");
+
+ MemAccessInfo Access(Ptr, IsWrite);
+ DepCands.insert(Access);
+
+ // Memorize read-only pointers for later processing and skip them in
+ // the first round (they need to be checked after we have seen all
+ // write pointers). Note: we also mark pointer that are not
+ // consecutive as "read-only" pointers (so that we check
+ // "a[b[i]] +="). Hence, we need the second check for "!IsWrite".
+ if (!UseDeferred && IsReadOnlyPtr) {
+ DeferredAccesses.insert(Access);
+ continue;
+ }
- if (IsWrite)
- SetHasWrite = true;
-
- // Create sets of pointers connected by a shared alias set and
- // underlying object.
- typedef SmallVector<Value *, 16> ValueVector;
- ValueVector TempObjects;
- GetUnderlyingObjects(Ptr, TempObjects, DL);
- for (Value *UnderlyingObj : TempObjects) {
- UnderlyingObjToAccessMap::iterator Prev =
- ObjToLastAccess.find(UnderlyingObj);
- if (Prev != ObjToLastAccess.end())
- DepCands.unionSets(Access, Prev->second);
-
- ObjToLastAccess[UnderlyingObj] = Access;
+ // If this is a write - check other reads and writes for conflicts. If
+ // this is a read only check other writes for conflicts (but only if
+ // there is no other write to the ptr - this is an optimization to
+ // catch "a[i] = a[i] + " without having to do a dependence check).
+ if ((IsWrite || IsReadOnlyPtr) && SetHasWrite) {
+ CheckDeps.insert(Access);
+ IsRTCheckNeeded = true;
+ }
+
+ if (IsWrite)
+ SetHasWrite = true;
+
+ // Create sets of pointers connected by a shared alias set and
+ // underlying object.
+ typedef SmallVector<Value *, 16> ValueVector;
+ ValueVector TempObjects;
+ GetUnderlyingObjects(Ptr, TempObjects, DL);
+ for (Value *UnderlyingObj : TempObjects) {
+ UnderlyingObjToAccessMap::iterator Prev =
+ ObjToLastAccess.find(UnderlyingObj);
+ if (Prev != ObjToLastAccess.end())
+ DepCands.unionSets(Access, Prev->second);
+
+ ObjToLastAccess[UnderlyingObj] = Access;
+ }
}
}
}
--- /dev/null
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; RUN: opt < %s -S -loop-vectorize -debug-only=loop-vectorize 2>&1 | FileCheck %s
+
+; CHECK: LV: Can't vectorize due to memory conflicts
+
+define void @test_loop_novect(double** %arr, i64 %n) {
+for.body.lr.ph:
+ %t = load double** %arr, align 8
+ br label %for.body
+
+for.body: ; preds = %for.body, %for.body.lr.ph
+ %i = phi i64 [ 0, %for.body.lr.ph ], [ %i.next, %for.body ]
+ %a = getelementptr inbounds double* %t, i64 %i
+ %i.next = add nuw nsw i64 %i, 1
+ %a.next = getelementptr inbounds double* %t, i64 %i.next
+ %t1 = load double* %a, align 8
+ %t2 = load double* %a.next, align 8
+ store double %t1, double* %a.next, align 8
+ store double %t2, double* %a, align 8
+ %c = icmp eq i64 %i, %n
+ br i1 %c, label %final, label %for.body
+
+final: ; preds = %for.body
+ ret void
+}