// If they are both volatile then they cannot be reordered.
if (Op0->isVolatile() && Op1->isVolatile()) return true;
+ // If one operation reads from invariant memory, and the other may store, they
+ // cannot alias. These should really be checking the equivalent of mayWrite,
+ // but it only matters for memory nodes other than load /store.
+ if (Op0->isInvariant() && Op1->writeMem())
+ return false;
+
+ if (Op1->isInvariant() && Op0->writeMem())
+ return false;
+
// Gather base node and offset information.
SDValue Base1, Base2;
int64_t Offset1, Offset2;