1.1 --- a/src/cpu/x86/vm/macroAssembler_x86.cpp Mon Dec 02 11:12:32 2013 +0100
1.2 +++ b/src/cpu/x86/vm/macroAssembler_x86.cpp Wed Dec 04 09:31:17 2013 +0100
1.3 @@ -3354,6 +3354,8 @@
1.4
1.5 BarrierSet* bs = Universe::heap()->barrier_set();
1.6 CardTableModRefBS* ct = (CardTableModRefBS*)bs;
1.7 + assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
1.8 +
1.9 Label done;
1.10 Label runtime;
1.11
1.12 @@ -3371,28 +3373,16 @@
1.13
1.14 // storing region crossing non-NULL, is card already dirty?
1.15
1.16 - ExternalAddress cardtable((address) ct->byte_map_base);
1.17 - assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
1.18 -#ifdef _LP64
1.19 const Register card_addr = tmp;
1.20 -
1.21 - movq(card_addr, store_addr);
1.22 - shrq(card_addr, CardTableModRefBS::card_shift);
1.23 -
1.24 - lea(tmp2, cardtable);
1.25 -
1.26 - // get the address of the card
1.27 - addq(card_addr, tmp2);
1.28 -#else
1.29 - const Register card_index = tmp;
1.30 -
1.31 - movl(card_index, store_addr);
1.32 - shrl(card_index, CardTableModRefBS::card_shift);
1.33 -
1.34 - Address index(noreg, card_index, Address::times_1);
1.35 - const Register card_addr = tmp;
1.36 - lea(card_addr, as_Address(ArrayAddress(cardtable, index)));
1.37 -#endif
1.38 + const Register cardtable = tmp2;
1.39 +
1.40 + movptr(card_addr, store_addr);
1.41 + shrptr(card_addr, CardTableModRefBS::card_shift);
1.42 + // Do not use ExternalAddress to load 'byte_map_base', since 'byte_map_base' is NOT
1.43 + // a valid address and therefore is not properly handled by the relocation code.
1.44 + movptr(cardtable, (intptr_t)ct->byte_map_base);
1.45 + addptr(card_addr, cardtable);
1.46 +
1.47 cmpb(Address(card_addr, 0), (int)G1SATBCardTableModRefBS::g1_young_card_val());
1.48 jcc(Assembler::equal, done);
1.49
1.50 @@ -3416,7 +3406,7 @@
1.51 movq(Address(tmp2, 0), card_addr);
1.52 #else
1.53 addl(tmp2, queue_index);
1.54 - movl(Address(tmp2, 0), card_index);
1.55 + movl(Address(tmp2, 0), card_addr);
1.56 #endif
1.57 jmp(done);
1.58
1.59 @@ -3468,25 +3458,19 @@
1.60
1.61 // The calculation for byte_map_base is as follows:
1.62 // byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
1.63 - // So this essentially converts an address to a displacement and
1.64 - // it will never need to be relocated. On 64bit however the value may be too
1.65 - // large for a 32bit displacement
1.66 -
1.67 + // So this essentially converts an address to a displacement and it will
1.68 + // never need to be relocated. On 64bit however the value may be too
1.69 + // large for a 32bit displacement.
1.70 intptr_t disp = (intptr_t) ct->byte_map_base;
1.71 if (is_simm32(disp)) {
1.72 Address cardtable(noreg, obj, Address::times_1, disp);
1.73 movb(cardtable, 0);
1.74 } else {
1.75 - // By doing it as an ExternalAddress disp could be converted to a rip-relative
1.76 - // displacement and done in a single instruction given favorable mapping and
1.77 - // a smarter version of as_Address. Worst case it is two instructions which
1.78 - // is no worse off then loading disp into a register and doing as a simple
1.79 - // Address() as above.
1.80 - // We can't do as ExternalAddress as the only style since if disp == 0 we'll
1.81 - // assert since NULL isn't acceptable in a reloci (see 6644928). In any case
1.82 - // in some cases we'll get a single instruction version.
1.83 -
1.84 - ExternalAddress cardtable((address)disp);
1.85 + // By doing it as an ExternalAddress 'disp' could be converted to a rip-relative
1.86 + // displacement and done in a single instruction given favorable mapping and a
1.87 + // smarter version of as_Address. However, 'ExternalAddress' generates a relocation
1.88 + // entry and that entry is not properly handled by the relocation code.
1.89 + AddressLiteral cardtable((address)ct->byte_map_base, relocInfo::none);
1.90 Address index(noreg, obj, Address::times_1);
1.91 movb(as_Address(ArrayAddress(cardtable, index)), 0);
1.92 }
