Messages in this thread | | | Date | Tue, 15 Sep 2015 17:09:03 -0700 | Subject | Re: First kernel patch (optimization) | From | Steve Calfee <> |
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On Tue, Sep 15, 2015 at 12:53 PM, Eric Curtin <ericcurtin17@gmail.com> wrote: > Signed-off-by: Eric Curtin <ericcurtin17@gmail.com> > > diff --git a/tools/usb/usbip/src/usbip_detach.c b/tools/usb/usbip/src/usbip_detach.c > index 05c6d15..9db9d21 100644 > --- a/tools/usb/usbip/src/usbip_detach.c > +++ b/tools/usb/usbip/src/usbip_detach.c > @@ -47,7 +47,9 @@ static int detach_port(char *port) > uint8_t portnum; > char path[PATH_MAX+1]; > > - for (unsigned int i = 0; i < strlen(port); i++) > + unsigned int port_len = strlen(port); > + > + for (unsigned int i = 0; i < port_len; i++) > if (!isdigit(port[i])) { > err("invalid port %s", port); > return -1; > > --
Hi Eric,
This is fine, but what kind of wimpy compiler optimizer will not move the constant initializer out of the loop? I bet if you compare binary sizes/code it will be exactly the same, and you added some characters of code. Reorganizing code for readability is fine, but for compiler (in)efficiency seems like a bad idea.
Regards, Steve
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