| /* |
| * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "asm/macroAssembler.hpp" |
| #include "code/vtableStubs.hpp" |
| #include "interp_masm_x86.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/instanceKlass.hpp" |
| #include "oops/klassVtable.hpp" |
| #include "runtime/sharedRuntime.hpp" |
| #include "vmreg_x86.inline.hpp" |
| #ifdef COMPILER2 |
| #include "opto/runtime.hpp" |
| #endif |
| |
| // machine-dependent part of VtableStubs: create VtableStub of correct size and |
| // initialize its code |
| |
| #define __ masm-> |
| |
| #ifndef PRODUCT |
| extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index); |
| #endif |
| |
| // These stubs are used by the compiler only. |
| // Argument registers, which must be preserved: |
| // rcx - receiver (always first argument) |
| // rdx - second argument (if any) |
| // Other registers that might be usable: |
| // rax - inline cache register (is interface for itable stub) |
| // rbx - method (used when calling out to interpreter) |
| // Available now, but may become callee-save at some point: |
| // rsi, rdi |
| // Note that rax and rdx are also used for return values. |
| // |
| VtableStub* VtableStubs::create_vtable_stub(int vtable_index) { |
| const int i486_code_length = VtableStub::pd_code_size_limit(true); |
| VtableStub* s = new(i486_code_length) VtableStub(true, vtable_index); |
| // Can be NULL if there is no free space in the code cache. |
| if (s == NULL) { |
| return NULL; |
| } |
| |
| ResourceMark rm; |
| CodeBuffer cb(s->entry_point(), i486_code_length); |
| MacroAssembler* masm = new MacroAssembler(&cb); |
| |
| #ifndef PRODUCT |
| |
| if (CountCompiledCalls) { |
| __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr())); |
| } |
| #endif /* PRODUCT */ |
| |
| // get receiver (need to skip return address on top of stack) |
| assert(VtableStub::receiver_location() == rcx->as_VMReg(), "receiver expected in rcx"); |
| |
| // get receiver klass |
| address npe_addr = __ pc(); |
| __ movptr(rax, Address(rcx, oopDesc::klass_offset_in_bytes())); |
| |
| #ifndef PRODUCT |
| if (DebugVtables) { |
| Label L; |
| // check offset vs vtable length |
| __ cmpl(Address(rax, Klass::vtable_length_offset()), vtable_index*vtableEntry::size()); |
| __ jcc(Assembler::greater, L); |
| __ movl(rbx, vtable_index); |
| __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), rcx, rbx); |
| __ bind(L); |
| } |
| #endif // PRODUCT |
| |
| const Register method = rbx; |
| |
| // load Method* and target address |
| __ lookup_virtual_method(rax, vtable_index, method); |
| |
| if (DebugVtables) { |
| Label L; |
| __ cmpptr(method, (int32_t)NULL_WORD); |
| __ jcc(Assembler::equal, L); |
| __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD); |
| __ jcc(Assembler::notZero, L); |
| __ stop("Vtable entry is NULL"); |
| __ bind(L); |
| } |
| |
| // rax,: receiver klass |
| // method (rbx): Method* |
| // rcx: receiver |
| address ame_addr = __ pc(); |
| __ jmp( Address(method, Method::from_compiled_offset())); |
| |
| masm->flush(); |
| |
| if (PrintMiscellaneous && (WizardMode || Verbose)) { |
| tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d", |
| vtable_index, p2i(s->entry_point()), |
| (int)(s->code_end() - s->entry_point()), |
| (int)(s->code_end() - __ pc())); |
| } |
| guarantee(__ pc() <= s->code_end(), "overflowed buffer"); |
| // shut the door on sizing bugs |
| int slop = 3; // 32-bit offset is this much larger than an 8-bit one |
| assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset"); |
| |
| s->set_exception_points(npe_addr, ame_addr); |
| return s; |
| } |
| |
| |
| VtableStub* VtableStubs::create_itable_stub(int itable_index) { |
| // Note well: pd_code_size_limit is the absolute minimum we can get away with. If you |
| // add code here, bump the code stub size returned by pd_code_size_limit! |
| const int i486_code_length = VtableStub::pd_code_size_limit(false); |
| VtableStub* s = new(i486_code_length) VtableStub(false, itable_index); |
| // Can be NULL if there is no free space in the code cache. |
| if (s == NULL) { |
| return NULL; |
| } |
| |
| ResourceMark rm; |
| CodeBuffer cb(s->entry_point(), i486_code_length); |
| MacroAssembler* masm = new MacroAssembler(&cb); |
| |
| // Entry arguments: |
| // rax,: Interface |
| // rcx: Receiver |
| |
| #ifndef PRODUCT |
| if (CountCompiledCalls) { |
| __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr())); |
| } |
| #endif /* PRODUCT */ |
| // get receiver (need to skip return address on top of stack) |
| |
| assert(VtableStub::receiver_location() == rcx->as_VMReg(), "receiver expected in rcx"); |
| |
| // get receiver klass (also an implicit null-check) |
| address npe_addr = __ pc(); |
| __ movptr(rsi, Address(rcx, oopDesc::klass_offset_in_bytes())); |
| |
| // Most registers are in use; we'll use rax, rbx, rsi, rdi |
| // (If we need to make rsi, rdi callee-save, do a push/pop here.) |
| const Register method = rbx; |
| Label throw_icce; |
| |
| // Get Method* and entrypoint for compiler |
| __ lookup_interface_method(// inputs: rec. class, interface, itable index |
| rsi, rax, itable_index, |
| // outputs: method, scan temp. reg |
| method, rdi, |
| throw_icce); |
| |
| // method (rbx): Method* |
| // rcx: receiver |
| |
| #ifdef ASSERT |
| if (DebugVtables) { |
| Label L1; |
| __ cmpptr(method, (int32_t)NULL_WORD); |
| __ jcc(Assembler::equal, L1); |
| __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD); |
| __ jcc(Assembler::notZero, L1); |
| __ stop("Method* is null"); |
| __ bind(L1); |
| } |
| #endif // ASSERT |
| |
| address ame_addr = __ pc(); |
| __ jmp(Address(method, Method::from_compiled_offset())); |
| |
| __ bind(throw_icce); |
| __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry())); |
| masm->flush(); |
| |
| if (PrintMiscellaneous && (WizardMode || Verbose)) { |
| tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d", |
| itable_index, p2i(s->entry_point()), |
| (int)(s->code_end() - s->entry_point()), |
| (int)(s->code_end() - __ pc())); |
| } |
| guarantee(__ pc() <= s->code_end(), "overflowed buffer"); |
| // shut the door on sizing bugs |
| int slop = 3; // 32-bit offset is this much larger than an 8-bit one |
| assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset"); |
| |
| s->set_exception_points(npe_addr, ame_addr); |
| return s; |
| } |
| |
| |
| |
| int VtableStub::pd_code_size_limit(bool is_vtable_stub) { |
| if (is_vtable_stub) { |
| // Vtable stub size |
| return (DebugVtables ? 210 : 16) + (CountCompiledCalls ? 6 : 0); |
| } else { |
| // Itable stub size |
| return (DebugVtables ? 256 : 66) + (CountCompiledCalls ? 6 : 0); |
| } |
| // In order to tune these parameters, run the JVM with VM options |
| // +PrintMiscellaneous and +WizardMode to see information about |
| // actual itable stubs. Look for lines like this: |
| // itable #1 at 0x5551212[65] left over: 3 |
| // Reduce the constants so that the "left over" number is >=3 |
| // for the common cases. |
| // Do not aim at a left-over number of zero, because a |
| // large vtable or itable index (> 16) will require a 32-bit |
| // immediate displacement instead of an 8-bit one. |
| // |
| // The JVM98 app. _202_jess has a megamorphic interface call. |
| // The itable code looks like this: |
| // Decoding VtableStub itbl[1]@1 |
| // mov 0x4(%ecx),%esi |
| // mov 0xe8(%esi),%edi |
| // lea 0x130(%esi,%edi,4),%edi |
| // add $0x7,%edi |
| // and $0xfffffff8,%edi |
| // lea 0x4(%esi),%esi |
| // mov (%edi),%ebx |
| // cmp %ebx,%eax |
| // je success |
| // loop: |
| // test %ebx,%ebx |
| // je throw_icce |
| // add $0x8,%edi |
| // mov (%edi),%ebx |
| // cmp %ebx,%eax |
| // jne loop |
| // success: |
| // mov 0x4(%edi),%edi |
| // mov (%esi,%edi,1),%ebx |
| // jmp *0x44(%ebx) |
| // throw_icce: |
| // jmp throw_ICCE_entry |
| } |
| |
| int VtableStub::pd_code_alignment() { |
| return wordSize; |
| } |