lkml.org 
[lkml]   [2015]   [Jan]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
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


\
 
 \ /
  Last update: 2015-01-16 16:01    [W:0.145 / U:0.940 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site