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, 3 insertions, 3 deletions

diff --git a/hw/arm/pxa2xx_gpio.c b/hw/arm/pxa2xx_gpio.c
index 354ccf1..c89c804 100644
--- a/hw/arm/pxa2xx_gpio.c
+++ b/hw/arm/pxa2xx_gpio.c
@@ -137,7 +137,7 @@ static void pxa2xx_gpio_handler_update(PXA2xxGPIOInfo *s) {
         level = s->olevel[i] & s->dir[i];
 
         for (diff = s->prev_level[i] ^ level; diff; diff ^= 1 << bit) {
-            bit = ffs(diff) - 1;
+            bit = ctz32(diff);
             line = bit + 32 * i;
             qemu_set_irq(s->handler[line], (level >> bit) & 1);
         }
diff --git a/hw/arm/strongarm.c b/hw/arm/strongarm.c
index 1ddea6d..da9fc1d 100644
--- a/hw/arm/strongarm.c
+++ b/hw/arm/strongarm.c
@@ -528,7 +528,7 @@ static void strongarm_gpio_handler_update(StrongARMGPIOInfo *s)
     level = s->olevel & s->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);
     }
 
@@ -745,7 +745,7 @@ static void strongarm_ppc_handler_update(StrongARMPPCInfo *s)
     level = s->olevel & s->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);
     }