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Extends to support read/write permissions in apply.

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This commit is contained in:
Thomas Harte 2021-07-17 21:09:52 -04:00
parent f7de6f790c
commit 0cfc7f732c
1 changed files with 11 additions and 8 deletions
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19
Processors/68000/68000.hpp
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@ -289,29 +289,32 @@ struct Microcycle {
return ((*address) & 0x00fffffe) >> 1;
}
static constexpr int PermitRead = (1 << 11);
static constexpr int PermitWrite = (1 << 12);
/*!
Assuming this to be a cycle with a data select active, applies it to @c target,
where 'applies' means:
Assuming this to be a cycle with a data select active, applies it to @c target
subject to the read_write_mask, where 'applies' means:
* if this is a byte read, reads a single byte from @c target;
* if this is a word read, reads a word (in the host platform's endianness) from @c target; and
* if this is a write, does the converse of a read.
*/
forceinline void apply(uint8_t *target) const {
switch(operation & (SelectWord | SelectByte | Read)) {
forceinline void apply(uint8_t *target, int read_write_mask = PermitRead | PermitWrite) const {
switch((operation | read_write_mask) & (SelectWord | SelectByte | Read | PermitRead | PermitWrite)) {
default:
break;
case SelectWord | Read:
case SelectWord | Read | PermitRead:
value->full = *reinterpret_cast<uint16_t *>(target);
break;
case SelectByte | Read:
case SelectByte | Read | PermitRead:
value->halves.low = *target;
break;
case Microcycle::SelectWord:
case SelectWord | PermitWrite:
*reinterpret_cast<uint16_t *>(target) = value->full;
break;
case Microcycle::SelectByte:
case SelectByte | PermitWrite:
*target = value->halves.low;
break;
}