diff options
-rw-r--r-- | compiler/optimizing/bounds_check_elimination.cc | 15 | ||||
-rw-r--r-- | test/449-checker-bce/src/Main.java | 23 |
2 files changed, 38 insertions, 0 deletions
diff --git a/compiler/optimizing/bounds_check_elimination.cc b/compiler/optimizing/bounds_check_elimination.cc index 811a3bd..deaeb8e 100644 --- a/compiler/optimizing/bounds_check_elimination.cc +++ b/compiler/optimizing/bounds_check_elimination.cc @@ -823,6 +823,21 @@ class BCEVisitor : public HGraphVisitor { FindAndHandlePartialArrayLength(ushr); } + void VisitAnd(HAnd* instruction) { + if (instruction->GetRight()->IsIntConstant()) { + int32_t constant = instruction->GetRight()->AsIntConstant()->GetValue(); + if (constant > 0) { + // constant serves as a mask so any number masked with it + // gets a [0, constant] value range. + ValueRange* range = new (GetGraph()->GetArena()) ValueRange( + GetGraph()->GetArena(), + ValueBound(nullptr, 0), + ValueBound(nullptr, constant)); + GetValueRangeMap(instruction->GetBlock())->Overwrite(instruction->GetId(), range); + } + } + } + void VisitNewArray(HNewArray* new_array) { HInstruction* len = new_array->InputAt(0); if (!len->IsIntConstant()) { diff --git a/test/449-checker-bce/src/Main.java b/test/449-checker-bce/src/Main.java index ad4092b..ebd5b0e 100644 --- a/test/449-checker-bce/src/Main.java +++ b/test/449-checker-bce/src/Main.java @@ -314,6 +314,29 @@ public class Main { array[10] = 1; // Bounds check can't be eliminated. } + + static byte readData() { + return 1; + } + + // CHECK-START: void Main.circularBufferProducer() BCE (before) + // CHECK: BoundsCheck + // CHECK: ArraySet + + // CHECK-START: void Main.circularBufferProducer() BCE (after) + // CHECK-NOT: BoundsCheck + // CHECK: ArraySet + + static void circularBufferProducer() { + byte[] array = new byte[4096]; + int i = 0; + while (true) { + array[i & (array.length - 1)] = readData(); + i++; + } + } + + // CHECK-START: void Main.pyramid1(int[]) BCE (before) // CHECK: BoundsCheck // CHECK: ArraySet |