BCE: Narrow instead of unconditionnaly overwrite the range.
bug:21862741
(cherry picked from commit a09ff9c11f07863ac57e6120a824f0d20dfaa284)
Change-Id: Ia8e903e09a7f9c2b8ef7cf3522f73f154534b81f
diff --git a/compiler/optimizing/bounds_check_elimination.cc b/compiler/optimizing/bounds_check_elimination.cc
index 900dabe..92c7e28 100644
--- a/compiler/optimizing/bounds_check_elimination.cc
+++ b/compiler/optimizing/bounds_check_elimination.cc
@@ -1180,9 +1180,7 @@
}
}
ValueRange* narrowed_range = existing_range->Narrow(range);
- if (narrowed_range != nullptr) {
- GetValueRangeMap(successor)->Overwrite(instruction->GetId(), narrowed_range);
- }
+ GetValueRangeMap(successor)->Overwrite(instruction->GetId(), narrowed_range);
}
// Special case that we may simultaneously narrow two MonotonicValueRange's to
@@ -1730,6 +1728,10 @@
ValueBound upper = ValueBound(new_array, -right_const);
ValueRange* range = new (GetGraph()->GetArena())
ValueRange(GetGraph()->GetArena(), lower, upper);
+ ValueRange* existing_range = LookupValueRange(left, new_array->GetBlock());
+ if (existing_range != nullptr) {
+ range = existing_range->Narrow(range);
+ }
GetValueRangeMap(new_array->GetBlock())->Overwrite(left->GetId(), range);
}
}
diff --git a/test/513-array-deopt/src/Main.java b/test/513-array-deopt/src/Main.java
index a0ae4c3..5ee4d55 100644
--- a/test/513-array-deopt/src/Main.java
+++ b/test/513-array-deopt/src/Main.java
@@ -19,19 +19,36 @@
a[0] = 0;
a[1] = 0;
a[2] = 0;
- // Up to this point, we record that the lower bound is 2.
+ // Up to this point, we record that the lower bound (inclusive) is 3.
// The next instruction will record that the lower bound is 5.
// The deoptimization code used to assume the lower bound has
- // to be check it will add for the deoptimization (here, it
- // would be 2).
+ // to be the one it will add for the deoptimization check (here, it
+ // would be 3).
return new int[a.length - 5];
}
+ public static int[] foo(int[] a) {
+ a[0] = 0;
+ a[1] = 0;
+ a[2] = 0;
+ // Up to this point, we record that the lower bound (inclusive) is 3.
+ // The next instruction will record that the lower bound is 1.
+ // The deoptimization code used to assume the lower bound has
+ // to be the one it will add for the deoptimization check (here, it
+ // would be 3).
+ return new int[a.length - 1];
+ }
+
public static void main(String[] args) {
int[] a = new int[5];
- a = bar(a);
- if (a.length != 0) {
- throw new Error("Expected 0, got " + a.length);
+ int[] result = bar(a);
+ if (result.length != 0) {
+ throw new Error("Expected 0, got " + result.length);
+ }
+
+ result = foo(a);
+ if (result.length != 4) {
+ throw new Error("Expected 5, got " + result.length);
}
}
}