Re: gf_unit 16 A -1 -m SPLIT 16 4 -r ALTMAP - failure

[Loic Dachary <loic@dachary.org>]

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I should add that this failure only happens on ARMv7 Ubuntu with gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu7)

On 10/01/2015 18:54, Loic Dachary wrote:
> Hi Kevin & Janne,
> 
> The test gf_unit 16 A -1 -m SPLIT 16 4 -r ALTMAP - fails on the current gf-complete master. The first commit where it fails is
> 
> commit 474010a91d35fef5ca7dea77205b6a5c7e68c3e9
> Author: Janne Grunau <j@jannau.net>
> Date:   Wed Sep 17 16:10:25 2014 +0200
> 
>     arm: NEON optimisations for gf_w16
> 
>     Optimisations for the 4,16 split table region multiplications.
> 
>     Selected time_tool.sh 16 -A -B results for a 1.7 GHz cortex-a9:
>     Region Best (MB/s):   532.14   W-Method: 16 -m SPLIT 16 4 -r SIMD -
>     Region Best (MB/s):   212.34   W-Method: 16 -m SPLIT 16 4 -r NOSIMD -
>     Region Best (MB/s):   801.36   W-Method: 16 -m SPLIT 16 4 -r SIMD -r ALTMAP -
>     Region Best (MB/s):    93.20   W-Method: 16 -m SPLIT 16 4 -r NOSIMD -r ALTMAP -
>     Region Best (MB/s):   273.99   W-Method: 16 -m SPLIT 16 8 -
>     Region Best (MB/s):   270.81   W-Method: 16 -m SPLIT 8 8 -
>     Region Best (MB/s):    70.42   W-Method: 16 -m COMPOSITE 2 - -
>     Region Best (MB/s):   393.54   W-Method: 16 -m COMPOSITE 2 - -r ALTMAP -
> 
> but the test did exit(0) on error instead of exit(1) and we failed to notice.
> 
> gf_unit 16 A -1 -m SPLIT 16 4 -r ALTMAP -
> Args: 16 A -1 -m SPLIT 16 4 -r ALTMAP - / size (bytes): 524428
> Problem with region multiply (all values in hex):
>    Target address base: 0x8fd08e.  Word 0x1 of 0x1fee.  Xor: 0
>    Value: 2
>    Original source word: d00a
>    Product word: a000
>    It should be: b01f
> 
> Do you have an idea why this happens ? For the record here is the bisect command I used:
> 
> git bisect start 6fdd8bc3d32cb2f7fa55d2de9dc7cc5bb2f885aa 36e75c3efec08b1e9bdb9c1f69a5b0018abd8ac7
> git bisect run try.sh
> 
> #!/bin/bash
> log=$(git rev-parse HEAD)
> echo $log.log
> make distclean > $log.log 2>&1
> ./autogen.sh >> $log.log 2>&1
> ./configure >> $log.log 2>&1
> make -j4 >> $log.log 2>&1
> ! test/gf_unit 16 A -1 -m SPLIT 16 4 -r ALTMAP - 2>&1 | grep 'It should be'
> 
> Note that b87c41f282dccc1b3649e3ea3fb80d19f820310 fails the test for different reasons:
> 
> Args: 16 A -1 -m SPLIT 16 4 -r ALTMAP - / size (bytes): 524428
> *** Error in `/home/ubuntu/f/gf-complete/test/.libs/lt-gf_unit': free(): invalid pointer: 0x00ce7070 ***
> try.sh: line 8: 12193 Aborted                 test/gf_unit 16 A -1 -m SPLIT 16 4 -r ALTMAP -
> 
> Cheers
> 

-- 
Loïc Dachary, Artisan Logiciel Libre


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