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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2015-03-23 15:29:28 +0000 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2015-04-28 15:36:08 +0200 |
| commit | c9d933185181cb1cf81bc4c9e5c3a10a5934b017 (patch) | |
| tree | 0f0965841808c3ec2cae78e9bc8eaf3bb32d4f8f /hw | |
| parent | bd2a88840e2496e29442f333c8fdd6491e831a35 (diff) | |
| download | qemu-c9d933185181cb1cf81bc4c9e5c3a10a5934b017.tar.gz qemu-c9d933185181cb1cf81bc4c9e5c3a10a5934b017.tar.bz2 qemu-c9d933185181cb1cf81bc4c9e5c3a10a5934b017.zip | |
sd: convert sd_normal_command() ffs(3) call to ctz32()
ffs() cannot be replaced with ctz32() when the argument might be zero,
because ffs(0) returns 0 while ctz32(0) returns 32.
The ffs(3) call in sd_normal_command() is a special case though. It can
be converted to ctz32() + 1 because the argument is never zero:
if (!(req.arg >> 8) || (req.arg >> (ctz32(req.arg & ~0xff) + 1))) {
~~~~~~~~~~~~~~~
^--------------- req.arg cannot be zero
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1427124571-28598-7-git-send-email-stefanha@redhat.com
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/sd/sd.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/hw/sd/sd.c b/hw/sd/sd.c index f955265f74..8abf0c9e31 100644 --- a/hw/sd/sd.c +++ b/hw/sd/sd.c @@ -796,8 +796,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, sd->vhs = 0; /* No response if not exactly one VHS bit is set. */ - if (!(req.arg >> 8) || (req.arg >> ffs(req.arg & ~0xff))) + if (!(req.arg >> 8) || (req.arg >> (ctz32(req.arg & ~0xff) + 1))) { return sd->spi ? sd_r7 : sd_r0; + } /* Accept. */ sd->vhs = req.arg; |