Use iterators "before" the use node in HUserRecord<>.
Create a new template class IntrusiveForwardList<> that
mimicks std::forward_list<> except that all allocations
are handled externally. This is essentially the same as
boost::intrusive::slist<> but since we're not using Boost
we have to reinvent the wheel.
Use the new container to replace the HUseList and use the
iterators to "before" use nodes in HUserRecord<> to avoid
the extra pointer to the previous node which was used
exclusively for removing nodes from the list. This reduces
the size of the HUseListNode by 25%, 32B to 24B in 64-bit
compiler, 16B to 12B in 32-bit compiler. This translates
directly to overall memory savings for the 64-bit compiler
but due to rounding up of the arena allocations to 8B, we
do not get any improvement in the 32-bit compiler.
Compiling the Nexus 5 boot image with the 64-bit dex2oat
on host this CL reduces the memory used for compiling the
most hungry method, BatteryStats.dumpLocked(), by ~3.3MiB:
Before:
MEM: used: 47829200, allocated: 48769120, lost: 939920
Number of arenas allocated: 345,
Number of allocations: 815492, avg size: 58
...
UseListNode 13744640
...
After:
MEM: used: 44393040, allocated: 45361248, lost: 968208
Number of arenas allocated: 319,
Number of allocations: 815492, avg size: 54
...
UseListNode 10308480
...
Note that while we do not ship the 64-bit dex2oat to the
device, the JIT compilation for 64-bit processes is using
the 64-bit libart-compiler.
Bug: 28173563
Change-Id: I985eabd4816f845372d8aaa825a1489cf9569208
diff --git a/runtime/base/macros.h b/runtime/base/macros.h
index dc692d2..7a293c7 100644
--- a/runtime/base/macros.h
+++ b/runtime/base/macros.h
@@ -138,10 +138,10 @@
#define SIZEOF_MEMBER(t, f) sizeof((reinterpret_cast<t*>(4096))->f)
#define OFFSETOF_MEMBER(t, f) \
- (reinterpret_cast<const char*>(&reinterpret_cast<t*>(16)->f) - reinterpret_cast<const char*>(16)) // NOLINT
+ (reinterpret_cast<uintptr_t>(&reinterpret_cast<t*>(16)->f) - static_cast<uintptr_t>(16u)) // NOLINT
-#define OFFSETOF_VOLATILE_MEMBER(t, f) \
- (reinterpret_cast<volatile char*>(&reinterpret_cast<t*>(16)->f) - reinterpret_cast<volatile char*>(16)) // NOLINT
+#define OFFSETOF_MEMBERPTR(t, f) \
+ (reinterpret_cast<uintptr_t>(&(reinterpret_cast<t*>(16)->*f)) - static_cast<uintptr_t>(16)) // NOLINT
#define PACKED(x) __attribute__ ((__aligned__(x), __packed__))