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Optimize port_6x

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Try to avoid branching as this is a hot path in some machines
About 250% speedup
This commit is contained in:
Adrien Moulin
2022-07-10 15:14:55 +02:00
parent 04cabaa43e
commit 55cbbe79f7
1 changed files with 73 additions and 59 deletions
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46
src/port_6x.c
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@@ -71,20 +71,23 @@ port_6x_write(uint16_t port, uint8_t val, void *priv)
}
}
static uint8_t
port_61_read_simple(uint16_t port, void *priv)
{
uint8_t ret = ppi.pb & 0x1f;
if (ppispeakon)
ret |= 0x20;
return(ret);
}
static uint8_t
port_6x_read(uint16_t port, void *priv)
port_61_read(uint16_t port, void *priv)
{
port_6x_t *dev = (port_6x_t *) priv;
uint8_t ret = 0xff;
port &= 3;
if ((port == 3) && (dev->flags & PORT_6X_MIRROR))
port = 1;
switch (port) {
case 1:
if (dev->flags & PORT_6X_EXT_REF) {
ret = ppi.pb & 0x0f;
@@ -98,9 +101,15 @@ port_6x_read(uint16_t port, void *priv)
if (dev->flags & PORT_6X_TURBO)
ret = (ret & 0xfb) | (xi8088_turbo_get() ? 0x04 : 0x00);
break;
case 2:
if (dev->flags & PORT_6X_SWA) {
return(ret);
}
static uint8_t
port_62_read(uint16_t port, void *priv)
{
uint8_t ret = 0xff;
/* SWA on Olivetti M240 mainboard (off=1) */
ret = 0x00;
if (ppi.pb & 0x8) {
@@ -128,14 +137,10 @@ port_6x_read(uint16_t port, void *priv)
if (hasfpu)
ret |= 0x02;
}
}
break;
}
return(ret);
}
static void
port_6x_refresh(void *priv)
{
@@ -165,7 +170,16 @@ port_6x_init(const device_t *info)
dev->flags = info->local & 0xff;
io_sethandler(0x0061, 3, port_6x_read, NULL, NULL, port_6x_write, NULL, NULL, dev);
if (!(dev->flags & PORT_6X_TURBO) || (dev->flags & PORT_6X_EXT_REF))
io_sethandler(0x0061, 1, port_61_read_simple, NULL, NULL, port_6x_write, NULL, NULL, dev);
else
io_sethandler(0x0061, 1, port_61_read, NULL, NULL, port_6x_write, NULL, NULL, dev);
if (dev->flags & PORT_6X_SWA)
io_sethandler(0x0062, 1, port_62_read, NULL, NULL, NULL, NULL, NULL, dev);
if (dev->flags & PORT_6X_MIRROR)
io_sethandler(0x0063, 1, port_61_read, NULL, NULL, port_6x_write, NULL, NULL, dev);
if (dev->flags & PORT_6X_EXT_REF)
timer_add(&dev->refresh_timer, port_6x_refresh, dev, 1);