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    Subject[PATCH 2/2] infiniband: Use unsigned for bit index
    Date
    In the expressions idx/32 and idx%32, both idx and 32 have signed
    type, and unfortunately the C standard prescribes rounding to 0, so
    unless gcc can prove that idx is non-negative, these cannot be
    implemented as simple shift respectively mask operations. Help gcc by
    changing the type of idx to unsigned - this cuts another few
    instructions from the generated code.

    Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
    ---
    drivers/infiniband/hw/ocrdma/ocrdma_verbs.c | 6 +++---
    1 file changed, 3 insertions(+), 3 deletions(-)

    diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
    index eff11e6c6183..61c3047f5170 100644
    --- a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
    +++ b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
    @@ -1479,10 +1479,10 @@ mbx_err:
    return status;
    }

    -static void ocrdma_srq_toggle_bit(struct ocrdma_srq *srq, int idx)
    +static void ocrdma_srq_toggle_bit(struct ocrdma_srq *srq, unsigned int idx)
    {
    - int i = idx / 32;
    - unsigned int mask = (1 << (idx % 32));
    + unsigned int i = idx / 32;
    + u32 mask = (1U << (idx % 32));

    srq->idx_bit_fields[i] ^= mask;
    }
    --
    2.1.3


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