Commit bd2a8884 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Kevin Wolf
Browse files

Convert ffs() != 0 callers to ctz32() 



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: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1427124571-28598-6-git-send-email-stefanha@redhat.com
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 786a4ea8

hw/arm/omap1.c

+2 −4
Original line number Diff line number Diff line
@@ -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);

hw/char/virtio-serial-bus.c

+4 −4
Original line number Diff line number Diff line
@@ -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;

hw/gpio/omap_gpio.c

+5 −8
Original line number Diff line number Diff line
@@ -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);

        }

hw/i2c/omap_i2c.c

+7 −3
Original line number Diff line number Diff line
@@ -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;

hw/intc/allwinner-a10-pic.c

+4 −4
Original line number Diff line number Diff line
@@ -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;

            }

        }

    }