From c3fb11c2c98a5c28ece6a27093a0f9def350ac64 Mon Sep 17 00:00:00 2001 From: Vas Crabb Date: Sat, 7 Jul 2018 02:40:29 +1000 Subject: devcb3 There are multiple issues with the current device callbacks: * They always dispatch through a pointer-to-member * Chained callbacks are a linked list so the branch unit can't predict the early * There's a runtime decision made on the left/right shift direction * There are runtime NULL checks on various objects * Binding a lambda isn't practical * Arbitrary transformations are not supported * When chaining callbacks it isn't clear what the MCFG_DEVCB_ modifiers apply to * It isn't possible to just append to a callback in derived configuration * The macros need a magic, hidden local called devcb * Moving code that uses the magic locals around is error-prone * Writing the MCFG_ macros to make a device usable is a pain * You can't discover applicable MCFG_ macros with intellisense * Macros are not scoped * Using an inappropriate macro isn't detected at compile time * Lots of other things This changeset overcomes the biggest obstacle to remving MCFG_ macros altogether. Essentially, to allow a devcb to be configured, call .bind() and expose the result (a bind target for the callback). Bind target methods starting with "set" repace the current callbacks; methods starting with "append" append to them. You can't reconfigure a callback after resolving it. There's no need to use a macro matching the handler signatures - use FUNC for everything. Current device is implied if no tag/finder is supplied (no need for explicit this). Lambdas are supported, and the memory space and offset are optional. These kinds of things work: * .read_cb().set([this] () { return something; }); * .read_cb().set([this] (offs_t offset) { return ~offset; }); * .write_cb().set([this] (offs_t offset, u8 data) { m_array[offset] = data; }); * .write_cb().set([this] (int state) { some_var = state; }); Arbitrary transforms are allowed, and they can modify offset/mask for example: * .read_cb().set(FUNC(my_state::handler)).transform([] (u8 data) { return bitswap<4>(data, 1, 3, 0, 2); }); * .read_cb().set(m_dev, FUNC(some_device::member)).transform([] (offs_t &offset, u8 data) { offset ^= 3; return data; }); It's possible to stack arbitrary transforms, at the cost of compile time (the whole transform stack gets inlined at compile time). Shifts count as an arbitrary transform, but mask/exor does not. Order of mask/shift/exor now matters. Modifications are applied in the specified order. These are NOT EQUIVALENT: * .read_cb().set(FUNC(my_state::handler)).mask(0x06).lshift(2); * .read_cb().set(FUNC(my_state::handler)).lshift(2).mask(0x06); The bit helper no longer reverses its behaviour for read callbacks, and I/O ports are no longer aware of the field mask. Binding a read callback to no-op is not supported - specify a constant. The GND and VCC aliases have been removed intentionally - they're TTL-centric, and were already being abused. Other quirks have been preserved, including write logger only logging when the data is non-zero (quite unhelpful in many of the cases where it's used). Legacy syntax is still supported for simple cases, but will be phased out. New devices should not have MCFG_ macros. I don't think I've missed any fundamental issues, but if I've broken something, let me know. --- src/mame/drivers/exterm.cpp | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'src/mame/drivers/exterm.cpp') diff --git a/src/mame/drivers/exterm.cpp b/src/mame/drivers/exterm.cpp index 587a1504c37..8adb0b29721 100644 --- a/src/mame/drivers/exterm.cpp +++ b/src/mame/drivers/exterm.cpp @@ -391,17 +391,11 @@ MACHINE_CONFIG_START(exterm_state::exterm) MCFG_TMS340X0_TO_SHIFTREG_CB(exterm_state, to_shiftreg_slave) MCFG_TMS340X0_FROM_SHIFTREG_CB(exterm_state, from_shiftreg_slave) - MCFG_DEVICE_ADD(m_audiocpu, M6502, 2000000) - MCFG_DEVICE_PROGRAM_MAP(sound_master_map) + M6502(config, m_audiocpu, 2000000).set_addrmap(AS_PROGRAM, &exterm_state::sound_master_map); + M6502(config, m_audioslave, 2000000).set_addrmap(AS_PROGRAM, &exterm_state::sound_slave_map); - MCFG_DEVICE_ADD(m_audioslave, M6502, 2000000) - MCFG_DEVICE_PROGRAM_MAP(sound_slave_map) - - MCFG_GENERIC_LATCH_8_ADD(m_soundlatch[0]) - MCFG_GENERIC_LATCH_DATA_PENDING_CB(INPUTLINE(m_audiocpu, M6502_IRQ_LINE)) - - MCFG_GENERIC_LATCH_8_ADD(m_soundlatch[1]) - MCFG_GENERIC_LATCH_DATA_PENDING_CB(INPUTLINE(m_audioslave, M6502_IRQ_LINE)) + GENERIC_LATCH_8(config, m_soundlatch[0]).data_pending_callback().set_inputline(m_audiocpu, M6502_IRQ_LINE); + GENERIC_LATCH_8(config, m_soundlatch[1]).data_pending_callback().set_inputline(m_audioslave, M6502_IRQ_LINE); MCFG_QUANTUM_TIME(attotime::from_hz(6000)) -- cgit v1.2.3