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[Qemu-block] [PULL 07/76] Convert ffs() != 0 callers to ctz32()
From: |
Kevin Wolf |
Subject: |
[Qemu-block] [PULL 07/76] Convert ffs() != 0 callers to ctz32() |
Date: |
Tue, 28 Apr 2015 16:59:49 +0200 |
From: Stefan Hajnoczi <address@hidden>
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>
Message-id: address@hidden
Signed-off-by: Kevin Wolf <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 91ffb58..de2b289 100644
--- a/hw/arm/omap1.c
+++ b/hw/arm/omap1.c
@@ -2004,8 +2004,7 @@ 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);
@@ -2017,8 +2016,7 @@ 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 e336bdb..6e2ad82 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -814,12 +814,12 @@ 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 9a43486..d92f8cf 100644
--- a/hw/gpio/omap_gpio.c
+++ b/hw/gpio/omap_gpio.c
@@ -125,8 +125,7 @@ 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);
@@ -138,8 +137,7 @@ 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);
@@ -253,8 +251,7 @@ 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);
}
@@ -442,8 +439,8 @@ 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 4ec153d..2a717e5 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1141,18 +1141,18 @@ 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;
--
1.8.3.1
- [Qemu-block] [PULL 00/76] Block patches, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 02/76] MAINTAINERS: Add myself as the maintainer of the Quorum driver, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 01/76] savevm: create snapshot failed when id_str already exists, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 03/76] bt-sdp: fix broken uuids power-of-2 calculation, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 04/76] hw/arm/nseries: convert ffs(3) to ctz32(), Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 05/76] uninorth: convert ffs(3) to ctz32(), Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 07/76] Convert ffs() != 0 callers to ctz32(),
Kevin Wolf <=
- [Qemu-block] [PULL 08/76] sd: convert sd_normal_command() ffs(3) call to ctz32(), Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 09/76] omap_intc: convert ffs(3) to ctz32() in omap_inth_sir_update(), Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 06/76] Convert (ffs(val) - 1) to ctz32(val), Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 10/76] os-win32: drop ffs(3) prototype, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 11/76] checkpatch: complain about ffs(3) calls, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 12/76] block: Switch to host monotonic clock for IO throttling, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 13/76] aio-posix: move pollfds to thread-local storage, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 15/76] iothread: release iothread around aio_poll, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 14/76] AioContext: acquire/release AioContext during aio_poll, Kevin Wolf, 2015/04/28
- [Qemu-block] [PULL 16/76] block-backend: Expose bdrv_write_zeroes(), Kevin Wolf, 2015/04/28