Convert (ffs(val) - 1) to ctz32(val)

This commit was generated mechanically by coccinelle from the following
semantic patch:

@@
expression val;
@@
- (ffs(val) - 1)
+ ctz32(val)

The call sites have been audited to ensure the ffs(0) - 1 == -1 case
never occurs (due to input validation, asserts, etc).  Therefore we
don't need to worry about the fact that ctz32(0) == 32.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1427124571-28598-5-git-send-email-stefanha@redhat.com
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/hw/gpio/max7310.c b/hw/gpio/max7310.c
index 7fbf313ce8..2f59b134ee 100644
--- a/hw/gpio/max7310.c
+++ b/hw/gpio/max7310.c
@@ -96,7 +96,7 @@ static int max7310_tx(I2CSlave *i2c, uint8_t data)
     case 0x01:	/* Output port */
         for (diff = (data ^ s->level) & ~s->direction; diff;
                         diff &= ~(1 << line)) {
-            line = ffs(diff) - 1;
+            line = ctz32(diff);
             if (s->handler[line])
                 qemu_set_irq(s->handler[line], (data >> line) & 1);
         }
diff --git a/hw/gpio/zaurus.c b/hw/gpio/zaurus.c
index 94083424f8..24a77272d7 100644
--- a/hw/gpio/zaurus.c
+++ b/hw/gpio/zaurus.c
@@ -65,7 +65,7 @@ static inline void scoop_gpio_handler_update(ScoopInfo *s) {
     level = s->gpio_level & s->gpio_dir;
 
     for (diff = s->prev_level ^ level; diff; diff ^= 1 << bit) {
-        bit = ffs(diff) - 1;
+        bit = ctz32(diff);
         qemu_set_irq(s->handler[bit], (level >> bit) & 1);
     }