Move loop invariant utility to more general place.
Change-Id: I15ebfbf9684f0fcce9e63d078ff8dc1381fd1ca3
diff --git a/compiler/optimizing/induction_var_analysis.cc b/compiler/optimizing/induction_var_analysis.cc
index b6220fc..fdf8cc9 100644
--- a/compiler/optimizing/induction_var_analysis.cc
+++ b/compiler/optimizing/induction_var_analysis.cc
@@ -20,19 +20,6 @@
namespace art {
/**
- * Returns true if instruction is invariant within the given loop
- * (instruction is not defined in same or more inner loop).
- */
-static bool IsLoopInvariant(HLoopInformation* loop, HInstruction* instruction) {
- HLoopInformation* other_loop = instruction->GetBlock()->GetLoopInformation();
- if (other_loop != loop && (other_loop == nullptr || !other_loop->IsIn(*loop))) {
- DCHECK(instruction->GetBlock()->Dominates(loop->GetHeader()));
- return true;
- }
- return false;
-}
-
-/**
* Since graph traversal may enter a SCC at any position, an initial representation may be rotated,
* along dependences, viz. any of (a, b, c, d), (d, a, b, c) (c, d, a, b), (b, c, d, a) assuming
* a chain of dependences (mutual independent items may occur in arbitrary order). For proper
@@ -718,7 +705,7 @@
return loop_it->second;
}
}
- if (IsLoopInvariant(loop, instruction)) {
+ if (loop->IsLoopInvariant(instruction, true)) {
InductionInfo* info = CreateInvariantFetch(instruction);
AssignInfo(loop, instruction, info);
return info;
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 3480265..8b28ff9 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -574,6 +574,17 @@
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;
+}
+
size_t HLoopInformation::GetLifetimeEnd() const {
size_t last_position = 0;
for (HBasicBlock* back_edge : GetBackEdges()) {
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 7ac39d1..0565c9a 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -551,6 +551,12 @@
// 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;
+
const ArenaBitVector& GetBlocks() const { return blocks_; }
void Add(HBasicBlock* block);