Add read barrier support to the entrypoints.
Also remove "THIS_LOAD_REQUIRES_READ_BARRIER" since reading
an ArtMethod* no longer needs read barrier.
stub_test should also work with read barriers now.
Change-Id: I3fba18042de2f867a18dbdc38519986212bd9769
diff --git a/runtime/arch/x86/quick_entrypoints_x86.S b/runtime/arch/x86/quick_entrypoints_x86.S
index ebfb3fa..1da5a2f 100644
--- a/runtime/arch/x86/quick_entrypoints_x86.S
+++ b/runtime/arch/x86/quick_entrypoints_x86.S
@@ -33,7 +33,6 @@
movl SYMBOL(_ZN3art7Runtime9instance_E)@GOT(REG_VAR(got_reg)), REG_VAR(temp_reg)
movl (REG_VAR(temp_reg)), REG_VAR(temp_reg)
// Push save all callee-save method.
- THIS_LOAD_REQUIRES_READ_BARRIER
pushl RUNTIME_SAVE_ALL_CALLEE_SAVE_FRAME_OFFSET(REG_VAR(temp_reg))
CFI_ADJUST_CFA_OFFSET(4)
// Store esp as the top quick frame.
@@ -60,7 +59,6 @@
movl SYMBOL(_ZN3art7Runtime9instance_E)@GOT(REG_VAR(got_reg)), REG_VAR(temp_reg)
movl (REG_VAR(temp_reg)), REG_VAR(temp_reg)
// Push save all callee-save method.
- THIS_LOAD_REQUIRES_READ_BARRIER
pushl RUNTIME_REFS_ONLY_CALLEE_SAVE_FRAME_OFFSET(REG_VAR(temp_reg))
CFI_ADJUST_CFA_OFFSET(4)
// Store esp as the top quick frame.
@@ -106,7 +104,6 @@
movl SYMBOL(_ZN3art7Runtime9instance_E)@GOT(REG_VAR(got_reg)), REG_VAR(temp_reg)
movl (REG_VAR(temp_reg)), REG_VAR(temp_reg)
// Push save all callee-save method.
- THIS_LOAD_REQUIRES_READ_BARRIER
pushl RUNTIME_REFS_AND_ARGS_CALLEE_SAVE_FRAME_OFFSET(REG_VAR(temp_reg))
CFI_ADJUST_CFA_OFFSET(4)
// Store esp as the stop quick frame.
@@ -1126,6 +1123,53 @@
UNREACHABLE
END_FUNCTION art_quick_check_cast
+// Restore reg's value if reg is not the same as exclude_reg, otherwise just adjust stack.
+MACRO2(POP_REG_NE, reg, exclude_reg)
+ .ifc RAW_VAR(reg), RAW_VAR(exclude_reg)
+ addl MACRO_LITERAL(4), %esp
+ CFI_ADJUST_CFA_OFFSET(-4)
+ .else
+ POP RAW_VAR(reg)
+ .endif
+END_MACRO
+
+ /*
+ * Macro to insert read barrier, only used in art_quick_aput_obj.
+ * obj_reg and dest_reg are registers, offset is a defined literal such as
+ * MIRROR_OBJECT_CLASS_OFFSET.
+ * pop_eax is a boolean flag, indicating if eax is popped after the call.
+ * TODO: When read barrier has a fast path, add heap unpoisoning support for the fast path.
+ */
+MACRO4(READ_BARRIER, obj_reg, offset, dest_reg, pop_eax)
+#ifdef USE_READ_BARRIER
+ PUSH eax // save registers used in art_quick_aput_obj
+ PUSH ebx
+ PUSH edx
+ PUSH ecx
+ // Outgoing argument set up
+ pushl MACRO_LITERAL((RAW_VAR(offset))) // pass offset, double parentheses are necessary
+ CFI_ADJUST_CFA_OFFSET(4)
+ PUSH RAW_VAR(obj_reg) // pass obj_reg
+ PUSH eax // pass ref, just pass eax for now since parameter ref is unused
+ call SYMBOL(artReadBarrierSlow) // artReadBarrierSlow(ref, obj_reg, offset)
+ // No need to unpoison return value in eax, artReadBarrierSlow() would do the unpoisoning.
+ .ifnc RAW_VAR(dest_reg), eax
+ movl %eax, REG_VAR(dest_reg) // save loaded ref in dest_reg
+ .endif
+ addl MACRO_LITERAL(12), %esp // pop arguments
+ CFI_ADJUST_CFA_OFFSET(-12)
+ POP_REG_NE ecx, RAW_VAR(dest_reg) // Restore args except dest_reg
+ POP_REG_NE edx, RAW_VAR(dest_reg)
+ POP_REG_NE ebx, RAW_VAR(dest_reg)
+ .ifc RAW_VAR(pop_eax), true
+ POP_REG_NE eax, RAW_VAR(dest_reg)
+ .endif
+#else
+ movl RAW_VAR(offset)(REG_VAR(obj_reg)), REG_VAR(dest_reg)
+ UNPOISON_HEAP_REF RAW_VAR(dest_reg)
+#endif // USE_READ_BARRIER
+END_MACRO
+
/*
* Entry from managed code for array put operations of objects where the value being stored
* needs to be checked for compatibility.
@@ -1149,17 +1193,20 @@
DEFINE_FUNCTION art_quick_aput_obj
test %edx, %edx // store of null
jz .Ldo_aput_null
- movl MIRROR_OBJECT_CLASS_OFFSET(%eax), %ebx
- UNPOISON_HEAP_REF ebx
- movl MIRROR_CLASS_COMPONENT_TYPE_OFFSET(%ebx), %ebx
- UNPOISON_HEAP_REF ebx
+ READ_BARRIER eax, MIRROR_OBJECT_CLASS_OFFSET, ebx, true
+ READ_BARRIER ebx, MIRROR_CLASS_COMPONENT_TYPE_OFFSET, ebx, true
// value's type == array's component type - trivial assignability
-#ifdef USE_HEAP_POISONING
- PUSH eax // save eax
+#if defined(USE_READ_BARRIER)
+ READ_BARRIER edx, MIRROR_OBJECT_CLASS_OFFSET, eax, false
+ cmpl %eax, %ebx
+ POP eax // restore eax from the push in the beginning of READ_BARRIER macro
+#elif defined(USE_HEAP_POISONING)
+ PUSH eax // save eax
+ // Cannot call READ_BARRIER macro here, because the above push messes up stack alignment.
movl MIRROR_OBJECT_CLASS_OFFSET(%edx), %eax
UNPOISON_HEAP_REF eax
cmpl %eax, %ebx
- POP eax // restore eax
+ POP eax // restore eax
#else
cmpl MIRROR_OBJECT_CLASS_OFFSET(%edx), %ebx
#endif
@@ -1181,6 +1228,8 @@
subl LITERAL(8), %esp // alignment padding
CFI_ADJUST_CFA_OFFSET(8)
#ifdef USE_HEAP_POISONING
+ // This load does not need read barrier, since edx is unchanged and there's no GC safe point
+ // from last read of MIRROR_OBJECT_CLASS_OFFSET(%edx).
movl MIRROR_OBJECT_CLASS_OFFSET(%edx), %eax // pass arg2 - type of the value to be stored
UNPOISON_HEAP_REF eax
PUSH eax
@@ -1696,5 +1745,15 @@
UNREACHABLE
END_FUNCTION art_nested_signal_return
+DEFINE_FUNCTION art_quick_read_barrier_slow
+ PUSH edx // pass arg3 - offset
+ PUSH ecx // pass arg2 - obj
+ PUSH eax // pass arg1 - ref
+ call SYMBOL(artReadBarrierSlow) // artReadBarrierSlow(ref, obj, offset)
+ addl LITERAL(12), %esp // pop arguments
+ CFI_ADJUST_CFA_OFFSET(-12)
+ ret
+END_FUNCTION art_quick_read_barrier_slow
+
// TODO: implement these!
UNIMPLEMENTED art_quick_memcmp16