On Fri, Oct 21, 2011 at 11:16 AM, Mans Rullgard mans.rullgard@linaro.org wrote:
On 20 October 2011 23:07, Michael Hope michael.hope@linaro.org wrote:
On Fri, Oct 21, 2011 at 7:48 AM, James Tunnicliffe james.tunnicliffe@linaro.org wrote:
This isn't exactly overflowing with up to date numbers, but...
http://elinux.org/images/8/8a/Experiment_with_Linux_and_ARM_Thumb-2_ISA.pdf
Slides 14 and 15 say that across EEMBC Thumb-2 gives 98% of the performance of ARM 32 bit instructions (assume performance optimised) and binaries are 26% smaller (didn't catch what binary/binaries that was). These are numbers from 2007 and benchmarked on an ARM 11. I assume using ARMCC.
I just ran EEMBC with gcc-linaro-4.6-2011.10 with -mfpu=neon -O3 -mtune=cortex-a9 and got similar numbers. Five of the 32 tests ran faster with Thumb-2 which is nice. I'll send the results privately as I'm not sure we can share.
How much faster? What about the ones that didn't run faster?
More than 10 %. I can't share raw numbers in public as our EEMBC license doesn't allow it. I've sent the raw numbers to the linaro-toolchain-benchmarks list.
I also don't think EEMBC is representative of real-world apps.
Agreed. It's an embedded benchmark. SPEC would be interesting.
EEMBC embeds the test data in the executable so it it's hard to tell the change in text size.
The 'size' command?
It turns the images and such into C arrays so they appear in the text segment. Hmm, I wonder if they get split into .rodata?
-- Michael