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Subject[PATCH] staging: s5k3e2fx.c: reduce complexity by factoring
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I was style fixing some code when I ran into this code.
It seems like the code could be reduced, by factoring the expression.
But this results in a very simple expression.

Am I assuming something wrong? Or is this a bug in the original code?
This doesn't look right because the assignment of s_move[i] has no mention
of the loop counter.

Justin

------

the code was looping, seting s_move[i] to the following calculations

if (actual_step >= 0)
s_move[i] = ((((i + 1) * gain + 0x200) - (i * gain + 0x200)) / 0x400);
else
s_move[i] = ((((i + 1) * gain - 0x200) - (i * gain - 0x200)) / 0x400);

but, by factoring the expression, it can be shown that they both reduce
to a very simple expression:

s_move[i] = gain / 0x400;

Signed-off-by: Justin Madru <jdm64@gawab.com>
---
drivers/staging/dream/camera/s5k3e2fx.c | 10 +++-------
1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/dream/camera/s5k3e2fx.c b/drivers/staging/dream/camera/s5k3e2fx.c
index f0e49be..d205a2d 100644
--- a/drivers/staging/dream/camera/s5k3e2fx.c
+++ b/drivers/staging/dream/camera/s5k3e2fx.c
@@ -1092,14 +1092,10 @@ static int32_t s5k3e2fx_move_focus(int direction, int32_t num_steps)

actual_step = step_direction * (int16_t)num_steps;
pos_offset = init_code + s5k3e2fx_ctrl->curr_lens_pos;
- gain = actual_step * 0x400 / 5;
+ gain = actual_step / 5;

- for (i = 0; i <= 4; i++) {
- if (actual_step >= 0)
- s_move[i] = ((((i+1)*gain+0x200) - (i*gain+0x200))/0x400);
- else
- s_move[i] = ((((i+1)*gain-0x200) - (i*gain-0x200))/0x400);
- }
+ for (i = 0; i <= 4; i++)
+ s_move[i] = gain;

/* Ring Damping Code */
for (i = 0; i <= 4; i++) {
--
1.6.5.4


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