Simplify and rename IsLoopInvariant() test.
Simplify IsLoopInvariant() test. Also rename it to IsDefinedOutOfTheLoop()
so there is no ambiguity for example whether a instruction after the loop counts
as a loop invariant. It's up to the caller to make the interpretation.
Change-Id: I999139032b0e4d815dd1e2276f2bd428cf558686
diff --git a/compiler/optimizing/bounds_check_elimination.cc b/compiler/optimizing/bounds_check_elimination.cc
index 7dbfd7c..4c3f66a 100644
--- a/compiler/optimizing/bounds_check_elimination.cc
+++ b/compiler/optimizing/bounds_check_elimination.cc
@@ -1138,8 +1138,8 @@
void VisitArrayGet(HArrayGet* array_get) OVERRIDE {
if (!has_deoptimization_on_constant_subscripts_ && array_get->IsInLoop()) {
HLoopInformation* loop = array_get->GetBlock()->GetLoopInformation();
- if (loop->IsLoopInvariant(array_get->InputAt(0), false) &&
- loop->IsLoopInvariant(array_get->InputAt(1), false)) {
+ if (loop->IsDefinedOutOfTheLoop(array_get->InputAt(0)) &&
+ loop->IsDefinedOutOfTheLoop(array_get->InputAt(1))) {
SideEffects loop_effects = side_effects_.GetLoopEffects(loop->GetHeader());
if (!array_get->GetSideEffects().MayDependOn(loop_effects)) {
HoistToPreheaderOrDeoptBlock(loop, array_get);
@@ -1349,7 +1349,7 @@
* by handling the null check under the hood of the array length operation.
*/
bool CanHandleLength(HLoopInformation* loop, HInstruction* length, bool needs_taken_test) {
- if (loop->IsLoopInvariant(length, false)) {
+ if (loop->IsDefinedOutOfTheLoop(length)) {
return true;
} else if (length->IsArrayLength() && length->GetBlock()->GetLoopInformation() == loop) {
if (CanHandleNullCheck(loop, length->InputAt(0), needs_taken_test)) {
@@ -1365,11 +1365,11 @@
* by generating a deoptimization test.
*/
bool CanHandleNullCheck(HLoopInformation* loop, HInstruction* check, bool needs_taken_test) {
- if (loop->IsLoopInvariant(check, false)) {
+ if (loop->IsDefinedOutOfTheLoop(check)) {
return true;
} else if (check->IsNullCheck() && check->GetBlock()->GetLoopInformation() == loop) {
HInstruction* array = check->InputAt(0);
- if (loop->IsLoopInvariant(array, false)) {
+ if (loop->IsDefinedOutOfTheLoop(array)) {
// Generate: if (array == null) deoptimize;
HBasicBlock* block = TransformLoopForDeoptimizationIfNeeded(loop, needs_taken_test);
HInstruction* cond =
diff --git a/compiler/optimizing/induction_var_analysis.cc b/compiler/optimizing/induction_var_analysis.cc
index fdf8cc9..0b7fdf8 100644
--- a/compiler/optimizing/induction_var_analysis.cc
+++ b/compiler/optimizing/induction_var_analysis.cc
@@ -705,7 +705,8 @@
return loop_it->second;
}
}
- if (loop->IsLoopInvariant(instruction, true)) {
+ if (loop->IsDefinedOutOfTheLoop(instruction)) {
+ DCHECK(instruction->GetBlock()->Dominates(loop->GetPreHeader()));
InductionInfo* info = CreateInvariantFetch(instruction);
AssignInfo(loop, instruction, info);
return info;
diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index 680f89f..389ada7 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -725,7 +725,7 @@
// instruction is a store in the loop so the loop must does write.
DCHECK(side_effects_.GetLoopEffects(loop_info->GetHeader()).DoesAnyWrite());
- if (loop_info->IsLoopInvariant(original_ref, false)) {
+ if (loop_info->IsDefinedOutOfTheLoop(original_ref)) {
DCHECK(original_ref->GetBlock()->Dominates(loop_info->GetPreHeader()));
// Keep the store since its value may be needed at the loop header.
possibly_redundant = false;
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 9b26de4..461be25 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -587,15 +587,8 @@
return other.blocks_.IsBitSet(header_->GetBlockId());
}
-bool HLoopInformation::IsLoopInvariant(HInstruction* instruction, bool must_dominate) const {
- HLoopInformation* other_loop = instruction->GetBlock()->GetLoopInformation();
- if (other_loop != this && (other_loop == nullptr || !other_loop->IsIn(*this))) {
- if (must_dominate) {
- return instruction->GetBlock()->Dominates(GetHeader());
- }
- return true;
- }
- return false;
+bool HLoopInformation::IsDefinedOutOfTheLoop(HInstruction* instruction) const {
+ return !blocks_.IsBitSet(instruction->GetBlock()->GetBlockId());
}
size_t HLoopInformation::GetLifetimeEnd() const {
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 9d3c88c..3e38e9f 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -564,11 +564,8 @@
// Note that `other` *must* be populated before entering this function.
bool IsIn(const HLoopInformation& other) const;
- // Returns true if instruction is not defined within this loop or any loop nested inside
- // this loop. If must_dominate is set, only definitions that actually dominate the loop
- // header can be invariant. Otherwise, any definition outside the loop, including
- // definitions that appear after the loop, is invariant.
- bool IsLoopInvariant(HInstruction* instruction, bool must_dominate) const;
+ // Returns true if instruction is not defined within this loop.
+ bool IsDefinedOutOfTheLoop(HInstruction* instruction) const;
const ArenaBitVector& GetBlocks() const { return blocks_; }