ART: Fast copy stack mask
StackMap::SetStackMask will currently copy a BitVector into a Memory-
Region bit by bit. This patch adds a new function for copying the data
with memcpy.
This is resubmission of CL I28d45a590b35a4a854cca2f57db864cf8a081487
but with a fix for a broken test which it revealed.
Change-Id: Ib65aa614d3ab7b5c99c6719fdc8e436466a4213d
diff --git a/runtime/base/bit_vector_test.cc b/runtime/base/bit_vector_test.cc
index c51b9b0..19c01f2 100644
--- a/runtime/base/bit_vector_test.cc
+++ b/runtime/base/bit_vector_test.cc
@@ -211,4 +211,62 @@
}
}
+TEST(BitVector, CopyTo) {
+ {
+ // Test copying an empty BitVector. Padding should fill `buf` with zeroes.
+ BitVector bv(0, true, Allocator::GetMallocAllocator());
+ uint32_t buf;
+
+ bv.CopyTo(&buf, sizeof(buf));
+ EXPECT_EQ(0u, bv.GetSizeOf());
+ EXPECT_EQ(0u, buf);
+ }
+
+ {
+ // Test copying when `bv.storage_` and `buf` are of equal lengths.
+ BitVector bv(0, true, Allocator::GetMallocAllocator());
+ uint32_t buf;
+
+ bv.SetBit(0);
+ bv.SetBit(17);
+ bv.SetBit(26);
+ EXPECT_EQ(sizeof(buf), bv.GetSizeOf());
+
+ bv.CopyTo(&buf, sizeof(buf));
+ EXPECT_EQ(0x04020001u, buf);
+ }
+
+ {
+ // Test copying when the `bv.storage_` is longer than `buf`. As long as
+ // `buf` is long enough to hold all set bits, copying should succeed.
+ BitVector bv(0, true, Allocator::GetMallocAllocator());
+ uint8_t buf[5];
+
+ bv.SetBit(18);
+ bv.SetBit(39);
+ EXPECT_LT(sizeof(buf), bv.GetSizeOf());
+
+ bv.CopyTo(buf, sizeof(buf));
+ EXPECT_EQ(0x00u, buf[0]);
+ EXPECT_EQ(0x00u, buf[1]);
+ EXPECT_EQ(0x04u, buf[2]);
+ EXPECT_EQ(0x00u, buf[3]);
+ EXPECT_EQ(0x80u, buf[4]);
+ }
+
+ {
+ // Test zero padding when `bv.storage_` is shorter than `buf`.
+ BitVector bv(0, true, Allocator::GetMallocAllocator());
+ uint32_t buf[2];
+
+ bv.SetBit(18);
+ bv.SetBit(31);
+ EXPECT_GT(sizeof(buf), bv.GetSizeOf());
+
+ bv.CopyTo(buf, sizeof(buf));
+ EXPECT_EQ(0x80040000U, buf[0]);
+ EXPECT_EQ(0x00000000U, buf[1]);
+ }
+}
+
} // namespace art