Commit 3ab1b9ce authored Dec 11, 2009 by David Howells Committed by Mauro Carvalho Chehab Dec 16, 2009

V4L/DVB: lgs8gxx: Use shifts rather than multiply/divide when possible



If val is a u64, then following:

	val *= (u64)1 << 32;
	val /= (u64)1 << 32;

should surely be better represented as:

	val <<= 32;
	val >>= 32;

Especially as, for the division, the compiler might want to actually do a
division:

drivers/built-in.o: In function `lgs8gxx_get_afc_phase':
drivers/media/dvb/frontends/lgs8gxx.c:250: undefined reference to `__udivdi3'

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

parent 5bf58347

drivers/media/dvb/frontends/lgs8gxx.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -199,7 +199,7 @@ static int lgs8gxx_set_if_freq(struct lgs8gxx_state priv, u32 freq /in kHz*/)

		val = freq;
		if (freq != 0) {
		val *= (u64)1 << 32;
		val <<= 32;
		if (if_clk != 0)
		do_div(val, if_clk);
		v32 = val & 0xFFFFFFFF;
		@@ -246,7 +246,7 @@ static int lgs8gxx_get_afc_phase(struct lgs8gxx_state *priv)

		val = v32;
		val *= priv->config->if_clk_freq;
		val /= (u64)1 << 32;
		val >>= 32;
		dprintk("AFC = %u kHz\n", (u32)val);
		return 0;
		}

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