ARM: perf: fix compiler warning with gcc 4.6.4 (and tidy code)
authorRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 19 Jun 2014 09:39:41 +0000 (10:39 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 19 Jun 2014 10:29:39 +0000 (11:29 +0100)
commit6a78371acebfe1e9d9eda218a835d712193d35a5
tree1db75548afd45a72fd968949372c01330a608a51
parenta641f3a6abce7e884d15adf073599bb2f2651203
ARM: perf: fix compiler warning with gcc 4.6.4 (and tidy code)

GCC 4.6.4 spits out the following warning when building perf_event_v7.c:

arch/arm/kernel/perf_event_v7.c: In function 'krait_pmu_get_event_idx':
arch/arm/kernel/perf_event_v7.c:1927:6: warning: 'bit' may be used uninitialized in this function

While upgrading the version of gcc may solve this, the code can also be
organised to be more efficient by not carrying more local variables than
is necessary across the armv7pmu_get_event_idx function call.  If we set
'bit' to -1 (which is invalid for clear_bit) we can use that as an
indication whether we need to clear a bit after this function.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/kernel/perf_event_v7.c