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comparison src/cpu/x86/vm/assembler_x86_64.cpp @ 117:deadee49286e

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6644928: Internal Error (src/share/vm/code/relocInfo.hpp:1089) Summary: Cardtable base can be zero, ExternalAddress can't take a NULL.
author sgoldman
date Fri, 11 Apr 2008 06:18:44 -0700
parents d6fe2e4959d6
children fb75a7673531
comparison
equal deleted inserted replaced
109:9f4457a14b58 117:deadee49286e
4425 void MacroAssembler::store_check_part_2(Register obj) { 4425 void MacroAssembler::store_check_part_2(Register obj) {
4426 BarrierSet* bs = Universe::heap()->barrier_set(); 4426 BarrierSet* bs = Universe::heap()->barrier_set();
4427 assert(bs->kind() == BarrierSet::CardTableModRef, "Wrong barrier set kind"); 4427 assert(bs->kind() == BarrierSet::CardTableModRef, "Wrong barrier set kind");
4428 CardTableModRefBS* ct = (CardTableModRefBS*)bs; 4428 CardTableModRefBS* ct = (CardTableModRefBS*)bs;
4429 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code"); 4429 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
4430 ExternalAddress cardtable((address)ct->byte_map_base); 4430
4431 Address index(noreg, obj, Address::times_1); 4431 // The calculation for byte_map_base is as follows:
4432 movb(as_Address(ArrayAddress(cardtable, index)), 0); 4432 // byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
4433 // So this essentially converts an address to a displacement and
4434 // it will never need to be relocated. On 64bit however the value may be too
4435 // large for a 32bit displacement
4436
4437 intptr_t disp = (intptr_t) ct->byte_map_base;
4438 if (is_simm32(disp)) {
4439 Address cardtable(noreg, obj, Address::times_1, disp);
4440 movb(cardtable, 0);
4441 } else {
4442 // By doing it as an ExternalAddress disp could be converted to a rip-relative
4443 // displacement and done in a single instruction given favorable mapping and
4444 // a smarter version of as_Address. Worst case it is two instructions which
4445 // is no worse off then loading disp into a register and doing as a simple
4446 // Address() as above.
4447 // We can't do as ExternalAddress as the only style since if disp == 0 we'll
4448 // assert since NULL isn't acceptable in a reloci (see 6644928). In any case
4449 // in some cases we'll get a single instruction version.
4450
4451 ExternalAddress cardtable((address)disp);
4452 Address index(noreg, obj, Address::times_1);
4453 movb(as_Address(ArrayAddress(cardtable, index)), 0);
4454 }
4455
4433 } 4456 }
4434 4457
4435 void MacroAssembler::c2bool(Register x) { 4458 void MacroAssembler::c2bool(Register x) {
4436 // implements x == 0 ? 0 : 1 4459 // implements x == 0 ? 0 : 1
4437 // note: must only look at least-significant byte of x 4460 // note: must only look at least-significant byte of x