From 0d5a281c671444bfa75d63caf1427a8c0e6e1177 Mon Sep 17 00:00:00 2001 From: Roland Levillain Date: Fri, 13 Nov 2015 10:07:31 +0000 Subject: x86/x86-64 read barrier support for concurrent GC in Optimizing. This first implementation uses slow paths to instrument heap reference loads and GC root loads for the concurrent copying collector, respectively calling the artReadBarrierSlow and artReadBarrierForRootSlow (new) runtime entry points. Notes: - This implementation does not instrument HInvokeVirtual nor HInvokeInterface instructions (for class reference loads), as the corresponding read barriers are not stricly required with the current concurrent copying collector. - Intrinsics which may eventually call (on slow path) are disabled when read barriers are enabled, as the current slow path infrastructure does not support this case. - When read barriers are enabled, the code generated for a HArraySet instruction always go into the array set slow path for object arrays (delegating the operation to the runtime), as we are lacking a mechanism to keep a temporary register live accross a runtime call (needed for the instrumentation of type checking code, which requires two successive read barriers). Bug: 12687968 Change-Id: I14cd6107233c326389120336f93955b28ffbb329 --- compiler/optimizing/nodes.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'compiler/optimizing/nodes.h') diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h index 2878ac9899..1da2a1dfd0 100644 --- a/compiler/optimizing/nodes.h +++ b/compiler/optimizing/nodes.h @@ -1436,7 +1436,7 @@ class SideEffects : public ValueObject { return flags_ == (kAllChangeBits | kAllDependOnBits); } - // Returns true if this may read something written by other. + // Returns true if `this` may read something written by `other`. bool MayDependOn(SideEffects other) const { const uint64_t depends_on_flags = (flags_ & kAllDependOnBits) >> kChangeBits; return (other.flags_ & depends_on_flags); -- cgit v1.2.3-59-g8ed1b