diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2015-01-16 15:39:55 +0100 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2015-02-18 08:31:05 -0800 |
| commit | ba64fdca63af5a1bdda8e33d9cc8496089631dde (patch) | |
| tree | 1accd20f3b25c252a04949b693e321aa3cdcfd56 /drivers | |
| parent | 0ba5dc5cba6d033c47637927e557ad6a7907bec7 (diff) | |
| download | linux-ba64fdca63af5a1bdda8e33d9cc8496089631dde.tar.bz2 | |
RDMA/ocrdma: Help gcc generate better code for ocrdma_srq_toggle_bit
gcc emits a surprising amount of code in order to flip a bit. One
would think that a single instruction is enough.
$ scripts/bloat-o-meter /tmp/ocrdma_verbs.o drivers/infiniband/hw/ocrdma/ocrdma_verbs.o
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-142 (-142)
function old new delta
ocrdma_post_srq_recv 498 460 -38
ocrdma_poll_cq 2010 1962 -48
ocrdma_discard_cqes 495 439 -56
All three calls of ocrdma_srq_toggle_bit happen within spinlocks, so
saving a few useless instructions might be worthwhile.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/infiniband/hw/ocrdma/ocrdma_verbs.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c index 5f656b936de4..c1e9f9617ab9 100644 --- a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c +++ b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c @@ -1591,10 +1591,7 @@ static void ocrdma_srq_toggle_bit(struct ocrdma_srq *srq, int idx) int i = idx / 32; unsigned int mask = (1 << (idx % 32)); - if (srq->idx_bit_fields[i] & mask) - srq->idx_bit_fields[i] &= ~mask; - else - srq->idx_bit_fields[i] |= mask; + srq->idx_bit_fields[i] ^= mask; } static int ocrdma_hwq_free_cnt(struct ocrdma_qp_hwq_info *q) |