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#include "gc/shenandoah/shenandoahHeap.inline.hpp"
#include "gc/shenandoah/shenandoahHeapRegion.hpp"
#include "gc/shenandoah/shenandoahRuntime.hpp"
#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
#include "interpreter/interpreter.hpp"
+ #include "nativeInst_x86.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/sharedRuntime.hpp"
#include "utilities/macros.hpp"
#ifdef COMPILER1
#include "c1/c1_LIRAssembler.hpp"
#endif // COMPILER1
#ifdef COMPILER2
+ address ShenandoahBarrierSetAssembler::parse_stub_address(address pc) {
+ NativeInstruction* ni = nativeInstruction_at(pc);
+ assert(ni->is_jump(), "Initial code version: GC barrier fastpath must be a jump");
+ NativeJump* jmp = nativeJump_at(pc);
+ return jmp->jump_destination();
+ }
+
+ void insert_5_byte_nop(address pc) {
+ *(pc + 0) = 0x0F;
+ *(pc + 1) = 0x1F;
+ *(pc + 2) = 0x44;
+ *(pc + 3) = 0x00;
+ *(pc + 4) = 0x00;
+ ICache::invalidate_range(pc, 5);
+ }
+
+ bool is_5_byte_nop(address pc) {
+ if (*(pc + 0) != 0x0F) return false;
+ if (*(pc + 1) != 0x1F) return false;
+ if (*(pc + 2) != 0x44) return false;
+ if (*(pc + 3) != 0x00) return false;
+ if (*(pc + 4) != 0x00) return false;
+ return true;
+ }
+
+ void check_at(bool cond, address pc, const char* msg) {
+ assert(cond, "%s: at PC " PTR_FORMAT ": %02x%02x%02x%02x%02x",
+ msg, p2i(pc), *(pc + 0), *(pc + 1), *(pc + 2), *(pc + 3), *(pc + 4));
+ }
+
+ void ShenandoahBarrierSetAssembler::patch_branch_to_nop(address pc) {
+ NativeInstruction* ni = nativeInstruction_at(pc);
+ if (ni->is_jump()) {
+ insert_5_byte_nop(pc);
+ } else {
+ check_at(is_5_byte_nop(pc), pc, "Should already be nop");
+ }
+ }
+
+ void ShenandoahBarrierSetAssembler::patch_nop_to_branch(address pc, address stub_addr) {
+ NativeInstruction* ni = nativeInstruction_at(pc);
+ if (is_5_byte_nop(pc)) {
+ NativeJump::insert(pc, stub_addr);
+ } else {
+ check_at(ni->is_jump(), pc, "Should already be jump");
+ check_at(nativeJump_at(pc)->jump_destination() == stub_addr, pc, "Jump should be to the same address");
+ }
+ }
+
#undef __
#define __ masm->
void ShenandoahBarrierSetAssembler::load_c2(const MachNode* node, MacroAssembler* masm, Register dst, Address src, bool narrow) {
// Do the actual load. This load is the candidate for implicit null check, and MUST come first.
#define __ masm.
void ShenandoahBarrierStubC2::enter_if_gc_state(MacroAssembler& masm, const char test_state) {
Assembler::InlineSkippedInstructionsCounter skip_counter(&masm);
! Address gc_state_fast(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_fast_offset()));
! __ testb(gc_state_fast, ShenandoahThreadLocalData::gc_state_to_fast(test_state));
! __ jcc(Assembler::notZero, *entry());
! __ bind(*continuation());
}
void ShenandoahBarrierStubC2::emit_code(MacroAssembler& masm) {
assert(_needs_keep_alive_barrier || _needs_load_ref_barrier, "Why are you here?");
#define __ masm.
void ShenandoahBarrierStubC2::enter_if_gc_state(MacroAssembler& masm, const char test_state) {
Assembler::InlineSkippedInstructionsCounter skip_counter(&masm);
! if (ShenandoahGCStateCheckRemove) {
! // Unrealistic: remove all barrier fastpath checks.
! } else if (ShenandoahGCStateCheckHotpatch) {
! // Emit the unconditional branch in the first version of the method.
+ // Let the rest of runtime figure out how to manage it.
+ __ relocate(barrier_Relocation::spec());
+ __ jmp(*entry(), /* maybe_short = */ false);
+
+ Label L_done;
+ #ifdef ASSERT
+ Address gc_state(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
+ __ testb(gc_state, 0xFF);
+ __ jccb(Assembler::zero, L_done);
+ __ hlt(); // Correctness bug: barrier is NOP-ed, but heap is NOT IDLE
+ #endif
+ __ bind(*continuation());
+ // This is futile to assert, because barriers are turned off asynchronously.
+ // #ifdef ASSERT
+ // __ testb(gc_state, 0xFF);
+ // __ jccb(Assembler::notZero, L_done);
+ // __ hlt(); // Performance bug: barrier is JMP-ed, but heap is IDLE
+ // #endif
+ __ bind(L_done);
+ } else {
+ Address gc_state_fast(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_fast_offset()));
+ __ testb(gc_state_fast, ShenandoahThreadLocalData::gc_state_to_fast(test_state));
+ __ jcc(Assembler::notZero, *entry());
+ __ bind(*continuation());
+ }
}
void ShenandoahBarrierStubC2::emit_code(MacroAssembler& masm) {
assert(_needs_keep_alive_barrier || _needs_load_ref_barrier, "Why are you here?");
Address buffer(r15_thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
Label L_fast, L_done;
// If another barrier is enabled as well, do a runtime check for a specific barrier.
! if (_needs_load_ref_barrier) {
Address gc_state(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ testb(gc_state, ShenandoahHeap::MARKING);
__ jccb(Assembler::zero, L_done);
}
Address buffer(r15_thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
Label L_fast, L_done;
// If another barrier is enabled as well, do a runtime check for a specific barrier.
! // Hotpatched GC checks only care about idle/non-idle state, so needs a check anyhow.
+ if (_needs_load_ref_barrier || ShenandoahGCStateCheckHotpatch) {
Address gc_state(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ testb(gc_state, ShenandoahHeap::MARKING);
__ jccb(Assembler::zero, L_done);
}
void ShenandoahBarrierStubC2::lrb(MacroAssembler& masm, Register obj, Address addr, Register tmp) {
Label L_done;
// If another barrier is enabled as well, do a runtime check for a specific barrier.
! if (_needs_keep_alive_barrier) {
Address gc_state(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ testb(gc_state, ShenandoahHeap::HAS_FORWARDED | (_needs_load_ref_weak_barrier ? ShenandoahHeap::WEAK_ROOTS : 0));
__ jccb(Assembler::zero, L_done);
}
void ShenandoahBarrierStubC2::lrb(MacroAssembler& masm, Register obj, Address addr, Register tmp) {
Label L_done;
// If another barrier is enabled as well, do a runtime check for a specific barrier.
! // Hotpatched GC checks only care about idle/non-idle state, so needs a check anyhow.
+ if (_needs_keep_alive_barrier || ShenandoahGCStateCheckHotpatch) {
Address gc_state(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ testb(gc_state, ShenandoahHeap::HAS_FORWARDED | (_needs_load_ref_weak_barrier ? ShenandoahHeap::WEAK_ROOTS : 0));
__ jccb(Assembler::zero, L_done);
}
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