1.1 --- a/src/share/vm/asm/assembler.cpp Tue Mar 03 18:25:57 2009 -0800
1.2 +++ b/src/share/vm/asm/assembler.cpp Wed Mar 04 09:58:39 2009 -0800
1.3 @@ -239,6 +239,78 @@
1.4 }
1.5 }
1.6
1.7 +struct DelayedConstant {
1.8 + typedef void (*value_fn_t)();
1.9 + BasicType type;
1.10 + intptr_t value;
1.11 + value_fn_t value_fn;
1.12 + // This limit of 20 is generous for initial uses.
1.13 + // The limit needs to be large enough to store the field offsets
1.14 + // into classes which do not have statically fixed layouts.
1.15 + // (Initial use is for method handle object offsets.)
1.16 + // Look for uses of "delayed_value" in the source code
1.17 + // and make sure this number is generous enough to handle all of them.
1.18 + enum { DC_LIMIT = 20 };
1.19 + static DelayedConstant delayed_constants[DC_LIMIT];
1.20 + static DelayedConstant* add(BasicType type, value_fn_t value_fn);
1.21 + bool match(BasicType t, value_fn_t cfn) {
1.22 + return type == t && value_fn == cfn;
1.23 + }
1.24 + static void update_all();
1.25 +};
1.26 +
1.27 +DelayedConstant DelayedConstant::delayed_constants[DC_LIMIT];
1.28 +// Default C structure initialization rules have the following effect here:
1.29 +// = { { (BasicType)0, (intptr_t)NULL }, ... };
1.30 +
1.31 +DelayedConstant* DelayedConstant::add(BasicType type,
1.32 + DelayedConstant::value_fn_t cfn) {
1.33 + for (int i = 0; i < DC_LIMIT; i++) {
1.34 + DelayedConstant* dcon = &delayed_constants[i];
1.35 + if (dcon->match(type, cfn))
1.36 + return dcon;
1.37 + if (dcon->value_fn == NULL) {
1.38 + // (cmpxchg not because this is multi-threaded but because I'm paranoid)
1.39 + if (Atomic::cmpxchg_ptr(CAST_FROM_FN_PTR(void*, cfn), &dcon->value_fn, NULL) == NULL) {
1.40 + dcon->type = type;
1.41 + return dcon;
1.42 + }
1.43 + }
1.44 + }
1.45 + // If this assert is hit (in pre-integration testing!) then re-evaluate
1.46 + // the comment on the definition of DC_LIMIT.
1.47 + guarantee(false, "too many delayed constants");
1.48 + return NULL;
1.49 +}
1.50 +
1.51 +void DelayedConstant::update_all() {
1.52 + for (int i = 0; i < DC_LIMIT; i++) {
1.53 + DelayedConstant* dcon = &delayed_constants[i];
1.54 + if (dcon->value_fn != NULL && dcon->value == 0) {
1.55 + typedef int (*int_fn_t)();
1.56 + typedef address (*address_fn_t)();
1.57 + switch (dcon->type) {
1.58 + case T_INT: dcon->value = (intptr_t) ((int_fn_t) dcon->value_fn)(); break;
1.59 + case T_ADDRESS: dcon->value = (intptr_t) ((address_fn_t)dcon->value_fn)(); break;
1.60 + }
1.61 + }
1.62 + }
1.63 +}
1.64 +
1.65 +intptr_t* AbstractAssembler::delayed_value_addr(int(*value_fn)()) {
1.66 + DelayedConstant* dcon = DelayedConstant::add(T_INT, (DelayedConstant::value_fn_t) value_fn);
1.67 + return &dcon->value;
1.68 +}
1.69 +intptr_t* AbstractAssembler::delayed_value_addr(address(*value_fn)()) {
1.70 + DelayedConstant* dcon = DelayedConstant::add(T_ADDRESS, (DelayedConstant::value_fn_t) value_fn);
1.71 + return &dcon->value;
1.72 +}
1.73 +void AbstractAssembler::update_delayed_values() {
1.74 + DelayedConstant::update_all();
1.75 +}
1.76 +
1.77 +
1.78 +
1.79
1.80 void AbstractAssembler::block_comment(const char* comment) {
1.81 if (sect() == CodeBuffer::SECT_INSTS) {
