firewire: ohci: optimize find_branch_descriptor()
When z==2, the condition "key == 2" is superfluous because it cannot occur without "b == 3", as a descriptor with b!=3 and key==2 would be an OUTPUT_MORE_IMMEDIATE descriptor which cannot be used alone. Also remove magic numbers and needless computations on the b field. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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@ -1006,13 +1006,12 @@ static void ar_context_run(struct ar_context *ctx)
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static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
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static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
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{
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{
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int b, key;
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__le16 branch;
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b = (le16_to_cpu(d->control) & DESCRIPTOR_BRANCH_ALWAYS) >> 2;
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branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
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key = (le16_to_cpu(d->control) & DESCRIPTOR_KEY_IMMEDIATE) >> 8;
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/* figure out which descriptor the branch address goes in */
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/* figure out which descriptor the branch address goes in */
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if (z == 2 && (b == 3 || key == 2))
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if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
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return d;
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return d;
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else
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else
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return d + z - 1;
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return d + z - 1;
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