< prev index next > src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp
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}
}
void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
- assert_different_registers(obj, klass, len);
- movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
+ assert_different_registers(obj, klass, len, t1, t2);
+ if (UseCompactObjectHeaders) {
+ movptr(t1, Address(klass, Klass::prototype_header_offset()));
+ movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
+ } else {
+ movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
#ifdef _LP64
- if (UseCompressedClassPointers) { // Take care not to kill klass
- movptr(t1, klass);
- encode_klass_not_null(t1, rscratch1);
- movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
- } else
+ if (UseCompressedClassPointers) { // Take care not to kill klass
+ movptr(t1, klass);
+ encode_klass_not_null(t1, rscratch1);
+ movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
+ } else
#endif
- {
- movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
+ {
+ 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) {
+ else if (UseCompressedClassPointers && !UseCompactObjectHeaders) {
xorptr(t1, t1);
store_klass_gap(obj, t1);
}
#endif
}
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)
+ int hdr_size_aligned = align_up(hdr_size_in_bytes, BytesPerWord); // klass gap is already cleared by init_header().
if (var_size_in_bytes != noreg) {
mov(index, var_size_in_bytes);
- initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
+ initialize_body(obj, index, hdr_size_aligned, 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)
+ for (int i = hdr_size_aligned; i < con_size_in_bytes; i += BytesPerWord)
movptr(Address(obj, i), t1_zero);
- } else if (con_size_in_bytes > hdr_size_in_bytes) {
+ } else if (con_size_in_bytes > hdr_size_aligned) {
// 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);
+ movptr(index, (con_size_in_bytes - hdr_size_aligned) >> 3);
// initialize last object field if constant size is odd
- if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
+ if (((con_size_in_bytes - hdr_size_aligned) & 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)),
+ movptr(Address(obj, index, Address::times_8, hdr_size_aligned - (1*BytesPerWord)),
t1_zero);
- NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
+ NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_aligned - (2*BytesPerWord)),
t1_zero);)
decrement(index);
jcc(Assembler::notZero, loop);
}
}
}
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) {
+ void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, 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");
cmpptr(len, checked_cast<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, header_size * BytesPerWord + MinObjAlignmentInBytesMask);
+ movptr(arr_size, (int32_t)base_offset_in_bytes + 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);
+ initialize_body(obj, arr_size, base_offset_in_bytes, len_zero);
if (CURRENT_ENV->dtrace_alloc_probes()) {
assert(obj == rax, "must be");
call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
}
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