--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cpu/x86/vm/c1_MacroAssembler_x86.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,385 @@
+/*
+ * Copyright 1999-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_c1_MacroAssembler_x86.cpp.incl"
+
+int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) {
+  const int aligned_mask = 3;
+  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");
+  assert(BytesPerWord == 4, "adjust aligned_mask and code");
+  Label done;
+  int null_check_offset = -1;
+
+  verify_oop(obj);
+
+  // save object being locked into the BasicObjectLock
+  movl(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
+  movl(hdr, Address(obj, hdr_offset));
+  // and mark it as unlocked
+  orl(hdr, markOopDesc::unlocked_value);
+  // save unlocked object header into the displaced header location on the stack
+  movl(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!
+  cmpxchg(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
+  subl(hdr, rsp);
+  andl(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)
+  movl(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 = 3;
+  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");
+  assert(BytesPerWord == 4, "adjust aligned_mask and code");
+  Label done;
+
+  if (UseBiasedLocking) {
+    // load object
+    movl(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
+    biased_locking_exit(obj, hdr, done);
+  }
+
+  // load displaced header
+  movl(hdr, Address(disp_hdr, 0));
+  // if the loaded hdr is NULL we had recursive locking
+  testl(hdr, hdr);
+  // if we had recursive locking, we are done
+  jcc(Assembler::zero, done);
+  if (!UseBiasedLocking) {
+    // load object
+    movl(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!
+  cmpxchg(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);
+  }
+}
+
+
+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);
+    movl(t1, Address(klass, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
+    movl(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
+  } else {
+    movl(Address(obj, oopDesc::mark_offset_in_bytes ()), (int)markOopDesc::prototype());
+  }
+
+  movl(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
+  if (len->is_valid()) {
+    movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
+  }
+}
+
+
+// preserves obj, destroys len_in_bytes
+void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
+  Label done;
+  assert(obj != len_in_bytes && obj != t1 && t1 != len_in_bytes, "registers must be different");
+  assert((hdr_size_in_bytes & (BytesPerWord - 1)) == 0, "header size is not a multiple of BytesPerWord");
+  Register index = len_in_bytes;
+  subl(index, hdr_size_in_bytes);
+  jcc(Assembler::zero, done);
+  // initialize topmost word, divide index by 2, check if odd and test if zero
+  // note: for the remaining code to work, index must be a multiple of BytesPerWord
+#ifdef ASSERT
+  { Label L;
+    testl(index, BytesPerWord - 1);
+    jcc(Assembler::zero, L);
+    stop("index is not a multiple of BytesPerWord");
+    bind(L);
+  }
+#endif
+  xorl(t1, t1);      // use _zero reg to clear memory (shorter code)
+  if (UseIncDec) {
+    shrl(index, 3);  // divide by 8 and set carry flag if bit 2 was set
+  } else {
+    shrl(index, 2);  // use 2 instructions to avoid partial flag stall
+    shrl(index, 1);
+  }
+  // index could have been not a multiple of 8 (i.e., bit 2 was set)
+  { Label even;
+    // note: if index was a multiple of 8, than it cannot
+    //       be 0 now otherwise it must have been 0 before
+    //       => if it is even, we don't need to check for 0 again
+    jcc(Assembler::carryClear, even);
+    // clear topmost word (no jump needed if conditional assignment would work here)
+    movl(Address(obj, index, Address::times_8, hdr_size_in_bytes - 0*BytesPerWord), t1);
+    // index could be 0 now, need to check again
+    jcc(Assembler::zero, done);
+    bind(even);
+  }
+  // initialize remaining object fields: rdx is a multiple of 2 now
+  { Label loop;
+    bind(loop);
+    movl(Address(obj, index, Address::times_8, hdr_size_in_bytes - 1*BytesPerWord), t1);
+    movl(Address(obj, index, Address::times_8, hdr_size_in_bytes - 2*BytesPerWord), t1);
+    decrement(index);
+    jcc(Assembler::notZero, loop);
+  }
+
+  // done
+  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(obj != t1 && obj != t2 && t1 != t2, "registers must be different"); // 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);
+}
+
+void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2) {
+  assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
+         "con_size_in_bytes is not multiple of alignment");
+  const int hdr_size_in_bytes = oopDesc::header_size_in_bytes();
+
+  initialize_header(obj, klass, noreg, t1, t2);
+
+  // 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) {
+    movl(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)
+    xorl(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)
+      movl(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
+    xorl(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
+    movl(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)
+      movl(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
+    // initialize remaining object fields: rdx is a multiple of 2
+    { Label loop;
+      bind(loop);
+      movl(Address(obj, index, Address::times_8,
+        hdr_size_in_bytes - (1*BytesPerWord)), t1_zero);
+      movl(Address(obj, index, Address::times_8,
+        hdr_size_in_bytes - (2*BytesPerWord)), t1_zero);
+      decrement(index);
+      jcc(Assembler::notZero, loop);
+    }
+  }
+
+  if (DTraceAllocProbes) {
+    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 == 4, "must be a multiple of 2 for masking code to work");
+
+  // check for negative or excessive length
+  cmpl(len, max_array_allocation_length);
+  jcc(Assembler::above, slow_case);
+
+  const Register arr_size = t2; // okay to be the same
+  // align object end
+  movl(arr_size, header_size * BytesPerWord + MinObjAlignmentInBytesMask);
+  leal(arr_size, Address(arr_size, len, f));
+  andl(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 (DTraceAllocProbes) {
+    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();
+  cmpl(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()));
+  assert(offset() - start_offset == 9, "check alignment in emit_method_entry");
+}
+
+
+void C1_MacroAssembler::method_exit(bool restore_frame) {
+  if (restore_frame) {
+    leave();
+  }
+  ret(0);
+}
+
+
+void C1_MacroAssembler::build_frame(int frame_size_in_bytes) {
+  // 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(frame_size_in_bytes);
+
+  enter();
+#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::unverified_entry(Register receiver, Register ic_klass) {
+  if (C1Breakpoint) int3();
+  inline_cache_check(receiver, ic_klass);
+}
+
+
+void C1_MacroAssembler::verified_entry() {
+  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;
+  testl(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) movl(rax, 0xDEAD);
+  if (inv_rbx) movl(rbx, 0xDEAD);
+  if (inv_rcx) movl(rcx, 0xDEAD);
+  if (inv_rdx) movl(rdx, 0xDEAD);
+  if (inv_rsi) movl(rsi, 0xDEAD);
+  if (inv_rdi) movl(rdi, 0xDEAD);
+#endif
+}
+
+#endif // ifndef PRODUCT