Support VecLoad and VecStore in LSE.
Test: test-art-host
Test: test-art-target
Test: load_store_elimination_test
Change-Id: I95ac13207a0f57225bf0bc62b1e57a629ae24e02
diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index 8678fab..66806d8 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -83,7 +83,8 @@
DCHECK(load != nullptr);
DCHECK(load->IsInstanceFieldGet() ||
load->IsStaticFieldGet() ||
- load->IsArrayGet());
+ load->IsArrayGet() ||
+ load->IsVecLoad());
HInstruction* substitute = substitute_instructions_for_loads_[i];
DCHECK(substitute != nullptr);
// Keep tracing substitute till one that's not removed.
@@ -98,7 +99,10 @@
// At this point, stores in possibly_removed_stores_ can be safely removed.
for (HInstruction* store : possibly_removed_stores_) {
- DCHECK(store->IsInstanceFieldSet() || store->IsStaticFieldSet() || store->IsArraySet());
+ DCHECK(store->IsInstanceFieldSet() ||
+ store->IsStaticFieldSet() ||
+ store->IsArraySet() ||
+ store->IsVecStore());
store->GetBlock()->RemoveInstruction(store);
}
@@ -137,7 +141,9 @@
void KeepIfIsStore(HInstruction* heap_value) {
if (heap_value == kDefaultHeapValue ||
heap_value == kUnknownHeapValue ||
- !(heap_value->IsInstanceFieldSet() || heap_value->IsArraySet())) {
+ !(heap_value->IsInstanceFieldSet() ||
+ heap_value->IsArraySet() ||
+ heap_value->IsVecStore())) {
return;
}
auto idx = std::find(possibly_removed_stores_.begin(),
@@ -320,7 +326,9 @@
return;
}
if (heap_value != kUnknownHeapValue) {
- if (heap_value->IsInstanceFieldSet() || heap_value->IsArraySet()) {
+ if (heap_value->IsInstanceFieldSet() ||
+ heap_value->IsArraySet() ||
+ heap_value->IsVecStore()) {
HInstruction* store = heap_value;
// This load must be from a singleton since it's from the same
// field/element that a "removed" store puts the value. That store
@@ -416,7 +424,9 @@
if (!same_value) {
if (possibly_redundant) {
- DCHECK(instruction->IsInstanceFieldSet() || instruction->IsArraySet());
+ DCHECK(instruction->IsInstanceFieldSet() ||
+ instruction->IsArraySet() ||
+ instruction->IsVecStore());
// Put the store as the heap value. If the value is loaded from heap
// by a load later, this store isn't really redundant.
heap_values[idx] = instruction;
@@ -429,8 +439,24 @@
if (i == idx) {
continue;
}
- if (heap_values[i] == value) {
- // Same value should be kept even if aliasing happens.
+ if (heap_values[i] == value && !instruction->IsVecOperation()) {
+ // For field/array, same value should be kept even if aliasing happens.
+ //
+ // For vector values , this is NOT safe. For example:
+ // packed_data = [0xA, 0xB, 0xC, 0xD]; <-- Different values in each lane.
+ // VecStore array[i ,i+1,i+2,i+3] = packed_data;
+ // VecStore array[i+1,i+2,i+3,i+4] = packed_data; <-- We are here (partial overlap).
+ // VecLoad vx = array[i,i+1,i+2,i+3]; <-- Cannot be eliminated.
+ //
+ // TODO: to allow such 'same value' optimization on vector data,
+ // LSA needs to report more fine-grain MAY alias information:
+ // (1) May alias due to two vector data partial overlap.
+ // e.g. a[i..i+3] and a[i+1,..,i+4].
+ // (2) May alias due to two vector data may complete overlap each other.
+ // e.g. a[i..i+3] and b[i..i+3].
+ // (3) May alias but the exact relationship between two locations is unknown.
+ // e.g. a[i..i+3] and b[j..j+3], where values of a,b,i,j are all unknown.
+ // This 'same value' optimization can apply only on case (2).
continue;
}
if (heap_values[i] == kUnknownHeapValue) {
@@ -520,6 +546,32 @@
value);
}
+ void VisitVecLoad(HVecLoad* instruction) OVERRIDE {
+ HInstruction* array = instruction->InputAt(0);
+ HInstruction* index = instruction->InputAt(1);
+ size_t vector_length = instruction->GetVectorLength();
+ VisitGetLocation(instruction,
+ array,
+ HeapLocation::kInvalidFieldOffset,
+ index,
+ vector_length,
+ HeapLocation::kDeclaringClassDefIndexForArrays);
+ }
+
+ void VisitVecStore(HVecStore* instruction) OVERRIDE {
+ HInstruction* array = instruction->InputAt(0);
+ HInstruction* index = instruction->InputAt(1);
+ HInstruction* value = instruction->InputAt(2);
+ size_t vector_length = instruction->GetVectorLength();
+ VisitSetLocation(instruction,
+ array,
+ HeapLocation::kInvalidFieldOffset,
+ index,
+ vector_length,
+ HeapLocation::kDeclaringClassDefIndexForArrays,
+ value);
+ }
+
void VisitDeoptimize(HDeoptimize* instruction) {
const ScopedArenaVector<HInstruction*>& heap_values =
heap_values_for_[instruction->GetBlock()->GetBlockId()];
@@ -529,7 +581,9 @@
continue;
}
// A store is kept as the heap value for possibly removed stores.
- if (heap_value->IsInstanceFieldSet() || heap_value->IsArraySet()) {
+ if (heap_value->IsInstanceFieldSet() ||
+ heap_value->IsArraySet() ||
+ heap_value->IsVecStore()) {
// Check whether the reference for a store is used by an environment local of
// HDeoptimize.
HInstruction* reference = heap_value->InputAt(0);
@@ -687,11 +741,6 @@
return;
}
- // TODO: analyze VecLoad/VecStore better.
- if (graph_->HasSIMD()) {
- return;
- }
-
LSEVisitor lse_visitor(graph_, heap_location_collector, side_effects_, stats_);
for (HBasicBlock* block : graph_->GetReversePostOrder()) {
lse_visitor.VisitBasicBlock(block);