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Slight PIC optimizations.

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This commit is contained in:
OBattler
2021-04-06 07:32:24 +02:00
parent e04ebd69a2
commit edace2282a
1 changed files with 8 additions and 19 deletions
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27
src/pic.c
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@@ -163,7 +163,7 @@ pic_slave_on(pic_t *dev, int channel)
static __inline int
find_best_interrupt(pic_t *dev)
{
uint8_t b, s;
uint8_t b;
uint8_t intr;
int i, j;
int ret = -1;
@@ -171,18 +171,6 @@ find_best_interrupt(pic_t *dev)
for (i = 0; i < 8; i++) {
j = (i + dev->priority) & 7;
b = 1 << j;
#ifdef OLD_CODE
s = (dev->icw4 & 0x10) && pic_slave_on(dev, j);
if ((dev->isr & b) && !dev->special_mask_mode && !s)
break;
if ((dev->state == 0) && ((dev->irr & ~dev->imr) & b) && (!(dev->isr & b) || s)) {
ret = j;
break;
}
if ((dev->isr & b) && !dev->special_mask_mode && s)
break;
#else
if (dev->isr & b)
break;
@@ -190,7 +178,6 @@ find_best_interrupt(pic_t *dev)
ret = j;
break;
}
#endif
}
intr = dev->interrupt = (ret == -1) ? 0x17 : ret;
@@ -615,7 +602,9 @@ pic_i86_mode(pic_t *dev)
static uint8_t
pic_irq_ack_read(pic_t *dev, int phase)
{
uint8_t intr = dev->interrupt & 7;
uint8_t intr = dev->interrupt & 0x47;
uint8_t slave = intr & 0x40;
intr &= 0x07;
pic_log(" pic_irq_ack_read(%08X, %i)\n", dev, phase);
if (dev != NULL) {
@@ -623,19 +612,19 @@ pic_irq_ack_read(pic_t *dev, int phase)
dev->interrupt |= 0x20; /* Freeze it so it still takes interrupts but they do not
override the one currently being processed. */
pic_acknowledge(dev);
if (pic_slave_on(dev, intr))
if (slave)
dev->data_bus = pic_irq_ack_read(dev->slaves[intr], phase);
else
dev->data_bus = pic_i86_mode(dev) ? 0xff : 0xcd;
} else if (pic_i86_mode(dev)) {
dev->int_pending = 0;
if (pic_slave_on(dev, intr))
if (slave)
dev->data_bus = pic_irq_ack_read(dev->slaves[intr], phase);
else
dev->data_bus = intr + (dev->icw2 & 0xf8);
pic_auto_non_specific_eoi(dev);
} else if (phase == 1) {
if (pic_slave_on(dev, intr))
if (slave)
dev->data_bus = pic_irq_ack_read(dev->slaves[intr], phase);
else if (dev->icw1 & 0x04)
dev->data_bus = (intr << 2) + (dev->icw1 & 0xe0);
@@ -643,7 +632,7 @@ pic_irq_ack_read(pic_t *dev, int phase)
dev->data_bus = (intr << 3) + (dev->icw1 & 0xc0);
} else if (phase == 2) {
dev->int_pending = 0;
if (pic_slave_on(dev, intr))
if (slave)
dev->data_bus = pic_irq_ack_read(dev->slaves[intr], phase);
else
dev->data_bus = dev->icw2;