1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/cpu/x86/vm/c1_MacroAssembler_x86.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,385 @@
1.4 +/*
1.5 + * Copyright 1999-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "incls/_precompiled.incl"
1.29 +#include "incls/_c1_MacroAssembler_x86.cpp.incl"
1.30 +
1.31 +int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) {
1.32 + const int aligned_mask = 3;
1.33 + const int hdr_offset = oopDesc::mark_offset_in_bytes();
1.34 + assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
1.35 + assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
1.36 + assert(BytesPerWord == 4, "adjust aligned_mask and code");
1.37 + Label done;
1.38 + int null_check_offset = -1;
1.39 +
1.40 + verify_oop(obj);
1.41 +
1.42 + // save object being locked into the BasicObjectLock
1.43 + movl(Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()), obj);
1.44 +
1.45 + if (UseBiasedLocking) {
1.46 + assert(scratch != noreg, "should have scratch register at this point");
1.47 + null_check_offset = biased_locking_enter(disp_hdr, obj, hdr, scratch, false, done, &slow_case);
1.48 + } else {
1.49 + null_check_offset = offset();
1.50 + }
1.51 +
1.52 + // Load object header
1.53 + movl(hdr, Address(obj, hdr_offset));
1.54 + // and mark it as unlocked
1.55 + orl(hdr, markOopDesc::unlocked_value);
1.56 + // save unlocked object header into the displaced header location on the stack
1.57 + movl(Address(disp_hdr, 0), hdr);
1.58 + // test if object header is still the same (i.e. unlocked), and if so, store the
1.59 + // displaced header address in the object header - if it is not the same, get the
1.60 + // object header instead
1.61 + if (os::is_MP()) MacroAssembler::lock(); // must be immediately before cmpxchg!
1.62 + cmpxchg(disp_hdr, Address(obj, hdr_offset));
1.63 + // if the object header was the same, we're done
1.64 + if (PrintBiasedLockingStatistics) {
1.65 + cond_inc32(Assembler::equal,
1.66 + ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr()));
1.67 + }
1.68 + jcc(Assembler::equal, done);
1.69 + // if the object header was not the same, it is now in the hdr register
1.70 + // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
1.71 + //
1.72 + // 1) (hdr & aligned_mask) == 0
1.73 + // 2) rsp <= hdr
1.74 + // 3) hdr <= rsp + page_size
1.75 + //
1.76 + // these 3 tests can be done by evaluating the following expression:
1.77 + //
1.78 + // (hdr - rsp) & (aligned_mask - page_size)
1.79 + //
1.80 + // assuming both the stack pointer and page_size have their least
1.81 + // significant 2 bits cleared and page_size is a power of 2
1.82 + subl(hdr, rsp);
1.83 + andl(hdr, aligned_mask - os::vm_page_size());
1.84 + // for recursive locking, the result is zero => save it in the displaced header
1.85 + // location (NULL in the displaced hdr location indicates recursive locking)
1.86 + movl(Address(disp_hdr, 0), hdr);
1.87 + // otherwise we don't care about the result and handle locking via runtime call
1.88 + jcc(Assembler::notZero, slow_case);
1.89 + // done
1.90 + bind(done);
1.91 + return null_check_offset;
1.92 +}
1.93 +
1.94 +
1.95 +void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
1.96 + const int aligned_mask = 3;
1.97 + const int hdr_offset = oopDesc::mark_offset_in_bytes();
1.98 + assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
1.99 + assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
1.100 + assert(BytesPerWord == 4, "adjust aligned_mask and code");
1.101 + Label done;
1.102 +
1.103 + if (UseBiasedLocking) {
1.104 + // load object
1.105 + movl(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
1.106 + biased_locking_exit(obj, hdr, done);
1.107 + }
1.108 +
1.109 + // load displaced header
1.110 + movl(hdr, Address(disp_hdr, 0));
1.111 + // if the loaded hdr is NULL we had recursive locking
1.112 + testl(hdr, hdr);
1.113 + // if we had recursive locking, we are done
1.114 + jcc(Assembler::zero, done);
1.115 + if (!UseBiasedLocking) {
1.116 + // load object
1.117 + movl(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
1.118 + }
1.119 + verify_oop(obj);
1.120 + // test if object header is pointing to the displaced header, and if so, restore
1.121 + // the displaced header in the object - if the object header is not pointing to
1.122 + // the displaced header, get the object header instead
1.123 + if (os::is_MP()) MacroAssembler::lock(); // must be immediately before cmpxchg!
1.124 + cmpxchg(hdr, Address(obj, hdr_offset));
1.125 + // if the object header was not pointing to the displaced header,
1.126 + // we do unlocking via runtime call
1.127 + jcc(Assembler::notEqual, slow_case);
1.128 + // done
1.129 + bind(done);
1.130 +}
1.131 +
1.132 +
1.133 +// Defines obj, preserves var_size_in_bytes
1.134 +void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
1.135 + if (UseTLAB) {
1.136 + tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
1.137 + } else {
1.138 + eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
1.139 + }
1.140 +}
1.141 +
1.142 +
1.143 +void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
1.144 + assert_different_registers(obj, klass, len);
1.145 + if (UseBiasedLocking && !len->is_valid()) {
1.146 + assert_different_registers(obj, klass, len, t1, t2);
1.147 + movl(t1, Address(klass, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
1.148 + movl(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
1.149 + } else {
1.150 + movl(Address(obj, oopDesc::mark_offset_in_bytes ()), (int)markOopDesc::prototype());
1.151 + }
1.152 +
1.153 + movl(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
1.154 + if (len->is_valid()) {
1.155 + movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
1.156 + }
1.157 +}
1.158 +
1.159 +
1.160 +// preserves obj, destroys len_in_bytes
1.161 +void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
1.162 + Label done;
1.163 + assert(obj != len_in_bytes && obj != t1 && t1 != len_in_bytes, "registers must be different");
1.164 + assert((hdr_size_in_bytes & (BytesPerWord - 1)) == 0, "header size is not a multiple of BytesPerWord");
1.165 + Register index = len_in_bytes;
1.166 + subl(index, hdr_size_in_bytes);
1.167 + jcc(Assembler::zero, done);
1.168 + // initialize topmost word, divide index by 2, check if odd and test if zero
1.169 + // note: for the remaining code to work, index must be a multiple of BytesPerWord
1.170 +#ifdef ASSERT
1.171 + { Label L;
1.172 + testl(index, BytesPerWord - 1);
1.173 + jcc(Assembler::zero, L);
1.174 + stop("index is not a multiple of BytesPerWord");
1.175 + bind(L);
1.176 + }
1.177 +#endif
1.178 + xorl(t1, t1); // use _zero reg to clear memory (shorter code)
1.179 + if (UseIncDec) {
1.180 + shrl(index, 3); // divide by 8 and set carry flag if bit 2 was set
1.181 + } else {
1.182 + shrl(index, 2); // use 2 instructions to avoid partial flag stall
1.183 + shrl(index, 1);
1.184 + }
1.185 + // index could have been not a multiple of 8 (i.e., bit 2 was set)
1.186 + { Label even;
1.187 + // note: if index was a multiple of 8, than it cannot
1.188 + // be 0 now otherwise it must have been 0 before
1.189 + // => if it is even, we don't need to check for 0 again
1.190 + jcc(Assembler::carryClear, even);
1.191 + // clear topmost word (no jump needed if conditional assignment would work here)
1.192 + movl(Address(obj, index, Address::times_8, hdr_size_in_bytes - 0*BytesPerWord), t1);
1.193 + // index could be 0 now, need to check again
1.194 + jcc(Assembler::zero, done);
1.195 + bind(even);
1.196 + }
1.197 + // initialize remaining object fields: rdx is a multiple of 2 now
1.198 + { Label loop;
1.199 + bind(loop);
1.200 + movl(Address(obj, index, Address::times_8, hdr_size_in_bytes - 1*BytesPerWord), t1);
1.201 + movl(Address(obj, index, Address::times_8, hdr_size_in_bytes - 2*BytesPerWord), t1);
1.202 + decrement(index);
1.203 + jcc(Assembler::notZero, loop);
1.204 + }
1.205 +
1.206 + // done
1.207 + bind(done);
1.208 +}
1.209 +
1.210 +
1.211 +void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
1.212 + assert(obj == rax, "obj must be in rax, for cmpxchg");
1.213 + assert(obj != t1 && obj != t2 && t1 != t2, "registers must be different"); // XXX really?
1.214 + assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
1.215 +
1.216 + try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
1.217 +
1.218 + initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2);
1.219 +}
1.220 +
1.221 +void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2) {
1.222 + assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
1.223 + "con_size_in_bytes is not multiple of alignment");
1.224 + const int hdr_size_in_bytes = oopDesc::header_size_in_bytes();
1.225 +
1.226 + initialize_header(obj, klass, noreg, t1, t2);
1.227 +
1.228 + // clear rest of allocated space
1.229 + const Register t1_zero = t1;
1.230 + const Register index = t2;
1.231 + const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
1.232 + if (var_size_in_bytes != noreg) {
1.233 + movl(index, var_size_in_bytes);
1.234 + initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
1.235 + } else if (con_size_in_bytes <= threshold) {
1.236 + // use explicit null stores
1.237 + // code size = 2 + 3*n bytes (n = number of fields to clear)
1.238 + xorl(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
1.239 + for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
1.240 + movl(Address(obj, i), t1_zero);
1.241 + } else if (con_size_in_bytes > hdr_size_in_bytes) {
1.242 + // use loop to null out the fields
1.243 + // code size = 16 bytes for even n (n = number of fields to clear)
1.244 + // initialize last object field first if odd number of fields
1.245 + xorl(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
1.246 + movl(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
1.247 + // initialize last object field if constant size is odd
1.248 + if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
1.249 + movl(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
1.250 + // initialize remaining object fields: rdx is a multiple of 2
1.251 + { Label loop;
1.252 + bind(loop);
1.253 + movl(Address(obj, index, Address::times_8,
1.254 + hdr_size_in_bytes - (1*BytesPerWord)), t1_zero);
1.255 + movl(Address(obj, index, Address::times_8,
1.256 + hdr_size_in_bytes - (2*BytesPerWord)), t1_zero);
1.257 + decrement(index);
1.258 + jcc(Assembler::notZero, loop);
1.259 + }
1.260 + }
1.261 +
1.262 + if (DTraceAllocProbes) {
1.263 + assert(obj == rax, "must be");
1.264 + call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
1.265 + }
1.266 +
1.267 + verify_oop(obj);
1.268 +}
1.269 +
1.270 +void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) {
1.271 + assert(obj == rax, "obj must be in rax, for cmpxchg");
1.272 + assert_different_registers(obj, len, t1, t2, klass);
1.273 +
1.274 + // determine alignment mask
1.275 + assert(BytesPerWord == 4, "must be a multiple of 2 for masking code to work");
1.276 +
1.277 + // check for negative or excessive length
1.278 + cmpl(len, max_array_allocation_length);
1.279 + jcc(Assembler::above, slow_case);
1.280 +
1.281 + const Register arr_size = t2; // okay to be the same
1.282 + // align object end
1.283 + movl(arr_size, header_size * BytesPerWord + MinObjAlignmentInBytesMask);
1.284 + leal(arr_size, Address(arr_size, len, f));
1.285 + andl(arr_size, ~MinObjAlignmentInBytesMask);
1.286 +
1.287 + try_allocate(obj, arr_size, 0, t1, t2, slow_case);
1.288 +
1.289 + initialize_header(obj, klass, len, t1, t2);
1.290 +
1.291 + // clear rest of allocated space
1.292 + const Register len_zero = len;
1.293 + initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero);
1.294 +
1.295 + if (DTraceAllocProbes) {
1.296 + assert(obj == rax, "must be");
1.297 + call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
1.298 + }
1.299 +
1.300 + verify_oop(obj);
1.301 +}
1.302 +
1.303 +
1.304 +
1.305 +void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
1.306 + verify_oop(receiver);
1.307 + // explicit NULL check not needed since load from [klass_offset] causes a trap
1.308 + // check against inline cache
1.309 + assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
1.310 + int start_offset = offset();
1.311 + cmpl(iCache, Address(receiver, oopDesc::klass_offset_in_bytes()));
1.312 + // if icache check fails, then jump to runtime routine
1.313 + // Note: RECEIVER must still contain the receiver!
1.314 + jump_cc(Assembler::notEqual,
1.315 + RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
1.316 + assert(offset() - start_offset == 9, "check alignment in emit_method_entry");
1.317 +}
1.318 +
1.319 +
1.320 +void C1_MacroAssembler::method_exit(bool restore_frame) {
1.321 + if (restore_frame) {
1.322 + leave();
1.323 + }
1.324 + ret(0);
1.325 +}
1.326 +
1.327 +
1.328 +void C1_MacroAssembler::build_frame(int frame_size_in_bytes) {
1.329 + // Make sure there is enough stack space for this method's activation.
1.330 + // Note that we do this before doing an enter(). This matches the
1.331 + // ordering of C2's stack overflow check / rsp decrement and allows
1.332 + // the SharedRuntime stack overflow handling to be consistent
1.333 + // between the two compilers.
1.334 + generate_stack_overflow_check(frame_size_in_bytes);
1.335 +
1.336 + enter();
1.337 +#ifdef TIERED
1.338 + // c2 leaves fpu stack dirty. Clean it on entry
1.339 + if (UseSSE < 2 ) {
1.340 + empty_FPU_stack();
1.341 + }
1.342 +#endif // TIERED
1.343 + decrement(rsp, frame_size_in_bytes); // does not emit code for frame_size == 0
1.344 +}
1.345 +
1.346 +
1.347 +void C1_MacroAssembler::unverified_entry(Register receiver, Register ic_klass) {
1.348 + if (C1Breakpoint) int3();
1.349 + inline_cache_check(receiver, ic_klass);
1.350 +}
1.351 +
1.352 +
1.353 +void C1_MacroAssembler::verified_entry() {
1.354 + if (C1Breakpoint)int3();
1.355 + // build frame
1.356 + verify_FPU(0, "method_entry");
1.357 +}
1.358 +
1.359 +
1.360 +#ifndef PRODUCT
1.361 +
1.362 +void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
1.363 + if (!VerifyOops) return;
1.364 + verify_oop_addr(Address(rsp, stack_offset));
1.365 +}
1.366 +
1.367 +void C1_MacroAssembler::verify_not_null_oop(Register r) {
1.368 + if (!VerifyOops) return;
1.369 + Label not_null;
1.370 + testl(r, r);
1.371 + jcc(Assembler::notZero, not_null);
1.372 + stop("non-null oop required");
1.373 + bind(not_null);
1.374 + verify_oop(r);
1.375 +}
1.376 +
1.377 +void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
1.378 +#ifdef ASSERT
1.379 + if (inv_rax) movl(rax, 0xDEAD);
1.380 + if (inv_rbx) movl(rbx, 0xDEAD);
1.381 + if (inv_rcx) movl(rcx, 0xDEAD);
1.382 + if (inv_rdx) movl(rdx, 0xDEAD);
1.383 + if (inv_rsi) movl(rsi, 0xDEAD);
1.384 + if (inv_rdi) movl(rdi, 0xDEAD);
1.385 +#endif
1.386 +}
1.387 +
1.388 +#endif // ifndef PRODUCT
