--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,394 @@
+/*
+ * Copyright (c) 1999, 2015, 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 "c1/c1_MacroAssembler.hpp"
+#include "c1/c1_Runtime1.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "interpreter/interpreter.hpp"
+#include "oops/arrayOop.hpp"
+#include "oops/markOop.hpp"
+#include "runtime/basicLock.hpp"
+#include "runtime/biasedLocking.hpp"
+#include "runtime/os.hpp"
+#include "runtime/sharedRuntime.hpp"
+#include "runtime/stubRoutines.hpp"
+
+int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) {
+ const int aligned_mask = BytesPerWord -1;
+ const int hdr_offset = oopDesc::mark_offset_in_bytes();
+ assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
+ assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
+ Label done;
+ int null_check_offset = -1;
+
+ verify_oop(obj);
+
+ // save object being locked into the BasicObjectLock
+ movptr(Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()), obj);
+
+ if (UseBiasedLocking) {
+ assert(scratch != noreg, "should have scratch register at this point");
+ null_check_offset = biased_locking_enter(disp_hdr, obj, hdr, scratch, false, done, &slow_case);
+ } else {
+ null_check_offset = offset();
+ }
+
+ // Load object header
+ movptr(hdr, Address(obj, hdr_offset));
+ // and mark it as unlocked
+ orptr(hdr, markOopDesc::unlocked_value);
+ // save unlocked object header into the displaced header location on the stack
+ movptr(Address(disp_hdr, 0), hdr);
+ // test if object header is still the same (i.e. unlocked), and if so, store the
+ // displaced header address in the object header - if it is not the same, get the
+ // object header instead
+ if (os::is_MP()) MacroAssembler::lock(); // must be immediately before cmpxchg!
+ cmpxchgptr(disp_hdr, Address(obj, hdr_offset));
+ // if the object header was the same, we're done
+ if (PrintBiasedLockingStatistics) {
+ cond_inc32(Assembler::equal,
+ ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr()));
+ }
+ jcc(Assembler::equal, done);
+ // if the object header was not the same, it is now in the hdr register
+ // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
+ //
+ // 1) (hdr & aligned_mask) == 0
+ // 2) rsp <= hdr
+ // 3) hdr <= rsp + page_size
+ //
+ // these 3 tests can be done by evaluating the following expression:
+ //
+ // (hdr - rsp) & (aligned_mask - page_size)
+ //
+ // assuming both the stack pointer and page_size have their least
+ // significant 2 bits cleared and page_size is a power of 2
+ subptr(hdr, rsp);
+ andptr(hdr, aligned_mask - os::vm_page_size());
+ // for recursive locking, the result is zero => save it in the displaced header
+ // location (NULL in the displaced hdr location indicates recursive locking)
+ movptr(Address(disp_hdr, 0), hdr);
+ // otherwise we don't care about the result and handle locking via runtime call
+ jcc(Assembler::notZero, slow_case);
+ // done
+ bind(done);
+ return null_check_offset;
+}
+
+
+void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
+ const int aligned_mask = BytesPerWord -1;
+ const int hdr_offset = oopDesc::mark_offset_in_bytes();
+ assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
+ assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
+ Label done;
+
+ if (UseBiasedLocking) {
+ // load object
+ movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
+ biased_locking_exit(obj, hdr, done);
+ }
+
+ // load displaced header
+ movptr(hdr, Address(disp_hdr, 0));
+ // if the loaded hdr is NULL we had recursive locking
+ testptr(hdr, hdr);
+ // if we had recursive locking, we are done
+ jcc(Assembler::zero, done);
+ if (!UseBiasedLocking) {
+ // load object
+ movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
+ }
+ verify_oop(obj);
+ // test if object header is pointing to the displaced header, and if so, restore
+ // the displaced header in the object - if the object header is not pointing to
+ // the displaced header, get the object header instead
+ if (os::is_MP()) MacroAssembler::lock(); // must be immediately before cmpxchg!
+ cmpxchgptr(hdr, Address(obj, hdr_offset));
+ // if the object header was not pointing to the displaced header,
+ // we do unlocking via runtime call
+ jcc(Assembler::notEqual, slow_case);
+ // done
+ bind(done);
+}
+
+
+// Defines obj, preserves var_size_in_bytes
+void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
+ if (UseTLAB) {
+ tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
+ } else {
+ eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
+ incr_allocated_bytes(noreg, var_size_in_bytes, con_size_in_bytes, t1);
+ }
+}
+
+
+void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
+ assert_different_registers(obj, klass, len);
+ if (UseBiasedLocking && !len->is_valid()) {
+ assert_different_registers(obj, klass, len, t1, t2);
+ movptr(t1, Address(klass, Klass::prototype_header_offset()));
+ movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
+ } else {
+ // This assumes that all prototype bits fit in an int32_t
+ movptr(Address(obj, oopDesc::mark_offset_in_bytes ()), (int32_t)(intptr_t)markOopDesc::prototype());
+ }
+#ifdef _LP64
+ if (UseCompressedClassPointers) { // Take care not to kill klass
+ movptr(t1, klass);
+ encode_klass_not_null(t1);
+ movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
+ } else
+#endif
+ {
+ movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
+ }
+
+ if (len->is_valid()) {
+ movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
+ }
+#ifdef _LP64
+ else if (UseCompressedClassPointers) {
+ xorptr(t1, t1);
+ store_klass_gap(obj, t1);
+ }
+#endif
+}
+
+
+// preserves obj, destroys len_in_bytes
+void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
+ assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
+ Label done;
+
+ // len_in_bytes is positive and ptr sized
+ subptr(len_in_bytes, hdr_size_in_bytes);
+ jcc(Assembler::zero, done);
+ zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1);
+ bind(done);
+}
+
+
+void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
+ assert(obj == rax, "obj must be in rax, for cmpxchg");
+ assert_different_registers(obj, t1, t2); // XXX really?
+ assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
+
+ try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
+
+ initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
+}
+
+void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, bool is_tlab_allocated) {
+ assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
+ "con_size_in_bytes is not multiple of alignment");
+ const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
+
+ initialize_header(obj, klass, noreg, t1, t2);
+
+ if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
+ // clear rest of allocated space
+ const Register t1_zero = t1;
+ const Register index = t2;
+ const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
+ if (var_size_in_bytes != noreg) {
+ mov(index, var_size_in_bytes);
+ initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
+ } else if (con_size_in_bytes <= threshold) {
+ // use explicit null stores
+ // code size = 2 + 3*n bytes (n = number of fields to clear)
+ xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
+ for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
+ movptr(Address(obj, i), t1_zero);
+ } else if (con_size_in_bytes > hdr_size_in_bytes) {
+ // use loop to null out the fields
+ // code size = 16 bytes for even n (n = number of fields to clear)
+ // initialize last object field first if odd number of fields
+ xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
+ movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
+ // initialize last object field if constant size is odd
+ if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
+ movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
+ // initialize remaining object fields: rdx is a multiple of 2
+ { Label loop;
+ bind(loop);
+ movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
+ t1_zero);
+ NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
+ t1_zero);)
+ decrement(index);
+ jcc(Assembler::notZero, loop);
+ }
+ }
+ }
+
+ if (CURRENT_ENV->dtrace_alloc_probes()) {
+ assert(obj == rax, "must be");
+ call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
+ }
+
+ verify_oop(obj);
+}
+
+void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) {
+ assert(obj == rax, "obj must be in rax, for cmpxchg");
+ assert_different_registers(obj, len, t1, t2, klass);
+
+ // determine alignment mask
+ assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
+
+ // check for negative or excessive length
+ cmpptr(len, (int32_t)max_array_allocation_length);
+ jcc(Assembler::above, slow_case);
+
+ const Register arr_size = t2; // okay to be the same
+ // align object end
+ movptr(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask);
+ lea(arr_size, Address(arr_size, len, f));
+ andptr(arr_size, ~MinObjAlignmentInBytesMask);
+
+ try_allocate(obj, arr_size, 0, t1, t2, slow_case);
+
+ initialize_header(obj, klass, len, t1, t2);
+
+ // clear rest of allocated space
+ const Register len_zero = len;
+ initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero);
+
+ if (CURRENT_ENV->dtrace_alloc_probes()) {
+ assert(obj == rax, "must be");
+ call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
+ }
+
+ verify_oop(obj);
+}
+
+
+
+void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
+ verify_oop(receiver);
+ // explicit NULL check not needed since load from [klass_offset] causes a trap
+ // check against inline cache
+ assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
+ int start_offset = offset();
+
+ if (UseCompressedClassPointers) {
+ load_klass(rscratch1, receiver);
+ cmpptr(rscratch1, iCache);
+ } else {
+ cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes()));
+ }
+ // if icache check fails, then jump to runtime routine
+ // Note: RECEIVER must still contain the receiver!
+ jump_cc(Assembler::notEqual,
+ RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
+ const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9);
+ assert(UseCompressedClassPointers || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry");
+}
+
+
+void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
+ assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
+ // Make sure there is enough stack space for this method's activation.
+ // Note that we do this before doing an enter(). This matches the
+ // ordering of C2's stack overflow check / rsp decrement and allows
+ // the SharedRuntime stack overflow handling to be consistent
+ // between the two compilers.
+ generate_stack_overflow_check(bang_size_in_bytes);
+
+ push(rbp);
+ if (PreserveFramePointer) {
+ mov(rbp, rsp);
+ }
+#ifdef TIERED
+ // c2 leaves fpu stack dirty. Clean it on entry
+ if (UseSSE < 2 ) {
+ empty_FPU_stack();
+ }
+#endif // TIERED
+ decrement(rsp, frame_size_in_bytes); // does not emit code for frame_size == 0
+}
+
+
+void C1_MacroAssembler::remove_frame(int frame_size_in_bytes) {
+ increment(rsp, frame_size_in_bytes); // Does not emit code for frame_size == 0
+ pop(rbp);
+}
+
+
+void C1_MacroAssembler::unverified_entry(Register receiver, Register ic_klass) {
+ if (C1Breakpoint) int3();
+ inline_cache_check(receiver, ic_klass);
+}
+
+
+void C1_MacroAssembler::verified_entry() {
+ if (C1Breakpoint || VerifyFPU || !UseStackBanging) {
+ // Verified Entry first instruction should be 5 bytes long for correct
+ // patching by patch_verified_entry().
+ //
+ // C1Breakpoint and VerifyFPU have one byte first instruction.
+ // Also first instruction will be one byte "push(rbp)" if stack banging
+ // code is not generated (see build_frame() above).
+ // For all these cases generate long instruction first.
+ fat_nop();
+ }
+ if (C1Breakpoint)int3();
+ // build frame
+ verify_FPU(0, "method_entry");
+}
+
+
+#ifndef PRODUCT
+
+void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
+ if (!VerifyOops) return;
+ verify_oop_addr(Address(rsp, stack_offset));
+}
+
+void C1_MacroAssembler::verify_not_null_oop(Register r) {
+ if (!VerifyOops) return;
+ Label not_null;
+ testptr(r, r);
+ jcc(Assembler::notZero, not_null);
+ stop("non-null oop required");
+ bind(not_null);
+ verify_oop(r);
+}
+
+void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
+#ifdef ASSERT
+ if (inv_rax) movptr(rax, 0xDEAD);
+ if (inv_rbx) movptr(rbx, 0xDEAD);
+ if (inv_rcx) movptr(rcx, 0xDEAD);
+ if (inv_rdx) movptr(rdx, 0xDEAD);
+ if (inv_rsi) movptr(rsi, 0xDEAD);
+ if (inv_rdi) movptr(rdi, 0xDEAD);
+#endif
+}
+
+#endif // ifndef PRODUCT