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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2015-01-16 15:39:55 +0100
committerRoland Dreier <roland@purestorage.com>2015-02-18 08:31:05 -0800
commitba64fdca63af5a1bdda8e33d9cc8496089631dde (patch)
tree1accd20f3b25c252a04949b693e321aa3cdcfd56 /drivers/infiniband
parent0ba5dc5cba6d033c47637927e557ad6a7907bec7 (diff)
downloadop-kernel-dev-ba64fdca63af5a1bdda8e33d9cc8496089631dde.zip
op-kernel-dev-ba64fdca63af5a1bdda8e33d9cc8496089631dde.tar.gz
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/infiniband')
-rw-r--r--drivers/infiniband/hw/ocrdma/ocrdma_verbs.c5
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 5f656b9..c1e9f96 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)
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