[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v2 5/9] Convert ffs() != 0 callers to ctz32()
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PATCH v2 5/9] Convert ffs() != 0 callers to ctz32() |
Date: |
Tue, 17 Mar 2015 15:09:43 +0000 |
There are a number of ffs(3) callers that do roughly:
bit = ffs(val);
if (bit) {
do_something(bit - 1);
}
This pattern can be converted to ctz32() like this:
zeroes = ctz32(val);
if (zeroes != 32) {
do_something(zeroes);
}
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
hw/arm/omap1.c | 6 ++----
hw/char/virtio-serial-bus.c | 8 ++++----
hw/gpio/omap_gpio.c | 13 +++++--------
hw/i2c/omap_i2c.c | 10 +++++++---
hw/intc/allwinner-a10-pic.c | 8 ++++----
kvm-all.c | 8 ++++----
6 files changed, 26 insertions(+), 27 deletions(-)
diff --git a/hw/arm/omap1.c b/hw/arm/omap1.c
index abb183c..fbd4695 100644
--- a/hw/arm/omap1.c
+++ b/hw/arm/omap1.c
@@ -1989,8 +1989,7 @@ static void omap_mpuio_write(void *opaque, hwaddr addr,
case 0x04: /* OUTPUT_REG */
diff = (s->outputs ^ value) & ~s->dir;
s->outputs = value;
- while ((ln = ffs(diff))) {
- ln --;
+ while ((ln = ctz32(diff)) != 32) {
if (s->handler[ln])
qemu_set_irq(s->handler[ln], (value >> ln) & 1);
diff &= ~(1 << ln);
@@ -2002,8 +2001,7 @@ static void omap_mpuio_write(void *opaque, hwaddr addr,
s->dir = value;
value = s->outputs & ~s->dir;
- while ((ln = ffs(diff))) {
- ln --;
+ while ((ln = ctz32(diff)) != 32) {
if (s->handler[ln])
qemu_set_irq(s->handler[ln], (value >> ln) & 1);
diff &= ~(1 << ln);
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index c86814f..17273a8 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -783,12 +783,12 @@ static uint32_t find_free_port_id(VirtIOSerial *vser)
max_nr_ports = vser->serial.max_virtserial_ports;
for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
- uint32_t map, bit;
+ uint32_t map, zeroes;
map = vser->ports_map[i];
- bit = ffs(~map);
- if (bit) {
- return (bit - 1) + i * 32;
+ zeroes = ctz32(~map);
+ if (zeroes != 32) {
+ return zeroes + i * 32;
}
}
return VIRTIO_CONSOLE_BAD_ID;
diff --git a/hw/gpio/omap_gpio.c b/hw/gpio/omap_gpio.c
index 938782a..78c2436 100644
--- a/hw/gpio/omap_gpio.c
+++ b/hw/gpio/omap_gpio.c
@@ -124,8 +124,7 @@ static void omap_gpio_write(void *opaque, hwaddr addr,
case 0x04: /* DATA_OUTPUT */
diff = (s->outputs ^ value) & ~s->dir;
s->outputs = value;
- while ((ln = ffs(diff))) {
- ln --;
+ while ((ln = ctz32(diff)) != 32) {
if (s->handler[ln])
qemu_set_irq(s->handler[ln], (value >> ln) & 1);
diff &= ~(1 << ln);
@@ -137,8 +136,7 @@ static void omap_gpio_write(void *opaque, hwaddr addr,
s->dir = value;
value = s->outputs & ~s->dir;
- while ((ln = ffs(diff))) {
- ln --;
+ while ((ln = ctz32(diff)) != 32) {
if (s->handler[ln])
qemu_set_irq(s->handler[ln], (value >> ln) & 1);
diff &= ~(1 << ln);
@@ -252,8 +250,7 @@ static inline void omap2_gpio_module_out_update(struct
omap2_gpio_s *s,
s->outputs ^= diff;
diff &= ~s->dir;
- while ((ln = ffs(diff))) {
- ln --;
+ while ((ln = ctz32(diff)) != 32) {
qemu_set_irq(s->handler[ln], (s->outputs >> ln) & 1);
diff &= ~(1 << ln);
}
@@ -441,8 +438,8 @@ static void omap2_gpio_module_write(void *opaque, hwaddr
addr,
s->dir = value;
value = s->outputs & ~s->dir;
- while ((ln = ffs(diff))) {
- diff &= ~(1 <<-- ln);
+ while ((ln = ctz32(diff)) != 32) {
+ diff &= ~(1 << ln);
qemu_set_irq(s->handler[ln], (value >> ln) & 1);
}
diff --git a/hw/i2c/omap_i2c.c b/hw/i2c/omap_i2c.c
index d63278d..b6f544a 100644
--- a/hw/i2c/omap_i2c.c
+++ b/hw/i2c/omap_i2c.c
@@ -171,9 +171,13 @@ static uint32_t omap_i2c_read(void *opaque, hwaddr addr)
case 0x0c: /* I2C_IV */
if (s->revision >= OMAP2_INTR_REV)
break;
- ret = ffs(s->stat & s->mask);
- if (ret)
- s->stat ^= 1 << (ret - 1);
+ ret = ctz32(s->stat & s->mask);
+ if (ret != 32) {
+ s->stat ^= 1 << ret;
+ ret++;
+ } else {
+ ret = 0;
+ }
omap_i2c_interrupts_update(s);
return ret;
diff --git a/hw/intc/allwinner-a10-pic.c b/hw/intc/allwinner-a10-pic.c
index de820b9..eed7621 100644
--- a/hw/intc/allwinner-a10-pic.c
+++ b/hw/intc/allwinner-a10-pic.c
@@ -23,7 +23,7 @@
static void aw_a10_pic_update(AwA10PICState *s)
{
uint8_t i;
- int irq = 0, fiq = 0, pending;
+ int irq = 0, fiq = 0, zeroes;
s->vector = 0;
@@ -32,9 +32,9 @@ static void aw_a10_pic_update(AwA10PICState *s)
fiq |= s->select[i] & s->irq_pending[i] & ~s->mask[i];
if (!s->vector) {
- pending = ffs(s->irq_pending[i] & ~s->mask[i]);
- if (pending) {
- s->vector = (i * 32 + pending - 1) * 4;
+ zeroes = ctz32(s->irq_pending[i] & ~s->mask[i]);
+ if (zeroes != 32) {
+ s->vector = (i * 32 + zeroes) * 4;
}
}
}
diff --git a/kvm-all.c b/kvm-all.c
index 55025cc..003312f 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1121,18 +1121,18 @@ static int kvm_irqchip_get_virq(KVMState *s)
{
uint32_t *word = s->used_gsi_bitmap;
int max_words = ALIGN(s->gsi_count, 32) / 32;
- int i, bit;
+ int i, zeroes;
bool retry = true;
again:
/* Return the lowest unused GSI in the bitmap */
for (i = 0; i < max_words; i++) {
- bit = ffs(~word[i]);
- if (!bit) {
+ zeroes = ctz32(~word[i]);
+ if (zeroes == 32) {
continue;
}
- return bit - 1 + i * 32;
+ return zeroes + i * 32;
}
if (!s->direct_msi && retry) {
retry = false;
--
2.1.0
- [Qemu-devel] [PATCH v2 0/9] Convert ffs(3) to ctz32(), Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 1/9] bt-sdp: fix broken uuids power-of-2 calculation, Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 4/9] Convert (ffs(val) - 1) to ctz32(val), Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 3/9] uninorth: convert ffs(3) to ctz32(), Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 6/9] sd: convert sd_normal_command() ffs(3) call to ctz32(), Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 2/9] hw/arm/nseries: convert ffs(3) to ctz32(), Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 7/9] omap_intc: convert ffs(3) to ctz32() in omap_inth_sir_update(), Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 5/9] Convert ffs() != 0 callers to ctz32(),
Stefan Hajnoczi <=
- [Qemu-devel] [PATCH v2 8/9] os-win32: drop ffs(3) prototype, Stefan Hajnoczi, 2015/03/17
- [Qemu-devel] [PATCH v2 9/9] checkpatch: complain about ffs(3) calls, Stefan Hajnoczi, 2015/03/17