< prev index next > src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
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#include "gc/shenandoah/mode/shenandoahMode.hpp"
#include "gc/shenandoah/shenandoahBarrierSet.hpp"
#include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
#include "gc/shenandoah/shenandoahHeap.inline.hpp"
#include "gc/shenandoah/shenandoahHeapRegion.hpp"
+ #include "gc/shenandoah/shenandoahNMethod.inline.hpp"
#include "gc/shenandoah/shenandoahRuntime.hpp"
#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
#include "interpreter/interp_masm.hpp"
#include "interpreter/interpreter.hpp"
+ #include "nativeInst_aarch64.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/sharedRuntime.hpp"
#ifdef COMPILER1
#include "c1/c1_LIRAssembler.hpp"
#include "c1/c1_MacroAssembler.hpp"
}
void ShenandoahBarrierStubC2::enter_if_gc_state(MacroAssembler& masm, const char test_state, Register tmp) {
Assembler::InlineSkippedInstructionsCounter skip_counter(&masm);
PhaseOutput* const output = Compile::current()->output();
- Address gc_state_fast(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_fast_array_offset(test_state)));
! // We piggyback on scratch_emit_size mode to compute the slowpath stub size.
! // We'll use that information to decide whether we need a far jump to the
! // stub entry point or not. In scratch_emit_size mode we don't bind entry()
! // because otherwise it will be rebound when we later emit the instructions
! // for real.
! if (_needs_far_jump) {
! __ ldrb(tmp, gc_state_fast);
! __ cbz(tmp, *continuation());
! __ b(output->in_scratch_emit_size() ? *continuation() : *entry());
} else {
! __ ldrb(tmp, gc_state_fast);
! __ cbnz(tmp, output->in_scratch_emit_size() ? *continuation() : *entry());
}
// This is were the slowpath stub will return to or the code above will
// jump to if the checks are false
__ bind(*continuation());
}
void ShenandoahBarrierStubC2::emit_code(MacroAssembler& masm) {
Assembler::InlineSkippedInstructionsCounter skip_counter(&masm);
assert(_needs_keep_alive_barrier || _needs_load_ref_barrier, "Why are you here?");
PhaseOutput* const output = Compile::current()->output();
}
void ShenandoahBarrierStubC2::enter_if_gc_state(MacroAssembler& masm, const char test_state, Register tmp) {
Assembler::InlineSkippedInstructionsCounter skip_counter(&masm);
PhaseOutput* const output = Compile::current()->output();
! // Emit the unconditional branch in the first version of the method.
! // Let the rest of runtime figure out how to manage it.
! if (output->in_scratch_emit_size()) {
! // We piggyback on scratch_emit_size mode to compute the slowpath stub size.
! // We'll use that information to decide whether we need a far jump to the
! // stub entry point or not. In scratch_emit_size mode we don't bind entry()
! // because otherwise it will be rebound when we later emit the instructions
! // for real.
! __ nop();
} else {
! __ relocate(barrier_Relocation::spec(), ShenandoahNMethod::gc_state_to_reloc(test_state));
! __ b(*entry());
}
// This is were the slowpath stub will return to or the code above will
// jump to if the checks are false
__ bind(*continuation());
}
+ 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();
+ }
+
+ static bool is_nop(address pc) {
+ if (*(pc + 0) != 0x1F) return false;
+ if (*(pc + 1) != 0x20) return false;
+ if (*(pc + 2) != 0x03) return false;
+ if (*(pc + 3) != 0xD5) return false;
+ return true;
+ }
+
+ static void insert_nop(address pc) {
+ *reinterpret_cast<int32_t*>(pc) = 0xD503201F;
+ assert(is_nop(pc), "Should be");
+ ICache::invalidate_range(pc, 4);
+ }
+
+ static void check_at(bool cond, address pc, const char* msg) {
+ assert(cond, "%s: at PC " PTR_FORMAT ": %02x%02x%02x%02x",
+ msg, p2i(pc), *(pc + 0), *(pc + 1), *(pc + 2), *(pc + 3));
+ }
+
+ bool ShenandoahBarrierSetAssembler::is_active(address pc) {
+ NativeInstruction* ni = nativeInstruction_at(pc);
+ return ni->is_jump();
+ }
+
+ void ShenandoahBarrierSetAssembler::patch_branch_to_nop(address pc) {
+ NativeInstruction* ni = nativeInstruction_at(pc);
+ if (ni->is_jump()) {
+ insert_nop(pc);
+ } else {
+ check_at(is_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_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");
+ }
+ }
+
void ShenandoahBarrierStubC2::emit_code(MacroAssembler& masm) {
Assembler::InlineSkippedInstructionsCounter skip_counter(&masm);
assert(_needs_keep_alive_barrier || _needs_load_ref_barrier, "Why are you here?");
PhaseOutput* const output = Compile::current()->output();
__ cbz(reg, *continuation());
}
}
void ShenandoahBarrierStubC2::keepalive(MacroAssembler& masm, Label* L_done) {
- Address gcstate(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_fast_array_offset(ShenandoahHeap::MARKING)));
Address index(rthread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
Address buffer(rthread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
Label L_through, L_slowpath;
! // If another barrier is enabled as well, do a runtime check for a specific barrier.
if (_needs_load_ref_barrier) {
! assert(L_done == nullptr, "L_done is always null when _needs_load_ref_barrier is true");
! __ ldrb(_tmp1, gcstate);
! __ cbz(_tmp1, L_through);
}
// Fast-path: put object into buffer.
// If buffer is already full, go slow.
__ ldr(_tmp1, index);
__ cbz(reg, *continuation());
}
}
void ShenandoahBarrierStubC2::keepalive(MacroAssembler& masm, Label* L_done) {
Address index(rthread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
Address buffer(rthread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
Label L_through, L_slowpath;
! // If another barrier is enabled as well, do a check for a specific barrier.
if (_needs_load_ref_barrier) {
! assert(L_done == nullptr, "Should be");
! // Emit the unconditional branch in the first version of the method.
! // Let the rest of runtime figure out how to manage it.
+ // TODO: We could have spared the over-jump if patching knew we need the inverse branch.
+ char state_to_check = ShenandoahHeap::MARKING;
+ Label L_over;
+ __ relocate(barrier_Relocation::spec(), ShenandoahNMethod::gc_state_to_reloc(state_to_check));
+ __ b(L_over);
+ __ b(L_through);
+ __ bind(L_over);
}
// Fast-path: put object into buffer.
// If buffer is already full, go slow.
__ ldr(_tmp1, index);
}
void ShenandoahBarrierStubC2::lrb(MacroAssembler& masm) {
Label L_slow;
- // If another barrier is enabled as well, do a runtime check for a specific barrier.
- if (_needs_keep_alive_barrier) {
- char state_to_check = ShenandoahHeap::HAS_FORWARDED | (_needs_load_ref_weak_barrier ? ShenandoahHeap::WEAK_ROOTS : 0);
- Address gc_state_fast(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_fast_array_offset(state_to_check)));
- __ ldrb(_tmp1, gc_state_fast);
- maybe_far_jump_if_zero(masm, _tmp1);
- }
-
// If weak references are being processed, weak/phantom loads need to go slow,
// regardless of their cset status.
if (_needs_load_ref_weak_barrier) {
! Address gc_state_fast(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_fast_array_offset(ShenandoahHeap::WEAK_ROOTS)));
! __ ldrb(_tmp1, gc_state_fast);
! __ cbnz(_tmp1, L_slow);
}
// Cset-check. Fall-through to slow if in collection set.
bool is_aot = AOTCodeCache::is_on_for_dump();
if (!is_aot) {
}
void ShenandoahBarrierStubC2::lrb(MacroAssembler& masm) {
Label L_slow;
// If weak references are being processed, weak/phantom loads need to go slow,
// regardless of their cset status.
if (_needs_load_ref_weak_barrier) {
! char state_to_check = ShenandoahHeap::WEAK_ROOTS;
! __ relocate(barrier_Relocation::spec(), ShenandoahNMethod::gc_state_to_reloc(state_to_check));
! __ b(L_slow);
+ }
+
+ if (_needs_keep_alive_barrier) {
+ // Emit the unconditional branch in the first version of the method.
+ // Let the rest of runtime figure out how to manage it.
+ // TODO: We could have spared the over-jump if patching knew we need the inverse branch.
+ char state_to_check = ShenandoahHeap::HAS_FORWARDED | (_needs_load_ref_weak_barrier ? ShenandoahHeap::WEAK_ROOTS : 0);
+ Label L_over;
+ __ relocate(barrier_Relocation::spec(), ShenandoahNMethod::gc_state_to_reloc(state_to_check));
+ __ b(L_over);
+ __ b(*continuation());
+ __ bind(L_over);
}
// Cset-check. Fall-through to slow if in collection set.
bool is_aot = AOTCodeCache::is_on_for_dump();
if (!is_aot) {
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