From d4d62ea8a80502f85f1ca92b231da56ef3b84baf Mon Sep 17 00:00:00 2001 From: Hsiangkai Wang Date: Fri, 30 Aug 2013 13:35:08 +0800 Subject: [PATCH] target: Correct profiling calculation 1. high_pc should be (maximum sample + 1) (Refer to gprof source code) 2. bucket index should be sample offset --------------- x (number of bucket) sample range For example, if minimum sample is 0 and maximum sample is 5 and the number of bucket is 3. a = sampled_address - 0 b = 3 c = 6 (a, b, c refer to source code variables) sampled_address = 0, => a = 0, => bucket_index = 0 sampled_address = 1, => a = 1, => bucket_index = 0 sampled_address = 2, => a = 2, => bucket_index = 1 sampled_address = 3, => a = 3, => bucket_index = 1 sampled_address = 4, => a = 4, => bucket_index = 2 sampled_address = 5, => a = 5, => bucket_index = 2 Change-Id: Ia9fa0e4d9c7183e3e9d7ceaf73e63729f07aa2ce Signed-off-by: Hsiangkai Wang Reviewed-on: http://openocd.zylin.com/1607 Tested-by: jenkins Reviewed-by: Spencer Oliver --- src/target/target.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/src/target/target.c b/src/target/target.c index 11b12e5e8..1ea1a6166 100644 --- a/src/target/target.c +++ b/src/target/target.c @@ -3387,7 +3387,11 @@ static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filenam max = samples[i]; } - int addressSpace = (max - min + 1); + /* max should be (largest sample + 1) + * Refer to binutils/gprof/hist.c (find_histogram_for_pc) */ + max++; + + int addressSpace = max - min; assert(addressSpace >= 2); static const uint32_t maxBuckets = 16 * 1024; /* maximum buckets. */ @@ -3403,8 +3407,8 @@ static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filenam for (i = 0; i < sampleNum; i++) { uint32_t address = samples[i]; long long a = address - min; - long long b = numBuckets - 1; - long long c = addressSpace - 1; + long long b = numBuckets; + long long c = addressSpace; int index_t = (a * b) / c; /* danger!!!! int32 overflows */ buckets[index_t]++; }