Use of option -fprofile-arcs is not compatible with -fprofile-use

[Edmar Wienskoski-RA8797]

Oops, in my cutting and past I omitted the -O2 that goes with all 
compilations.
Without it no optimization gets done, so no warnings...

Regards
Edmar


Lijuan Hai wrote:
> sorry that I couldn't re-produce the warning as you said.
>
> micro# /import/dr3/s10/gcc-4.2/bin/gcc val-prof-1.c -fprofile-arcs -g
> -o val-prof-1.x1
> micro# /import/dr3/s10/gcc-4.2/bin/gcc -v
> Using built-in specs.
> Target: sparc-sun-solaris2.10
> Configured with: /import/dr2/starlex/1/gcc-4.2-20070228/configure
> --prefix=/import/dr3/s10/gcc-4.2 --enable-languages=c,c++,fortran
> --enable-rpath --with-mpfr=/import/dr3/s10/gcc-4.2
> --with-gmp=/import/dr3/s10/gcc-4.2
> Thread model: posix
> gcc version 4.2.0 20070228 (prerelease)
>
> so is gcc-4.3 on the platform.
>
> 2008/5/7 Edmar Wienskoski-RA8797 <edmar@freescale.com>:
>   
>> I said if you compile val-prof-1.c the same way bprob-1.c is compiled you
>> get an warning.
>>
>>
>>  gcc -g -fprofile-arcs val-prof-1.c -o val-prof-1.x1
>>
>>
>>
>>
>>  Lijuan Hai wrote:
>>
>>     
>>> seen in gcc-4.2, gcc.misc-tests/bprob-1.c is compiled with
>>> -fprofile-arcs and -fbranch-probabilities.
>>> gcc.dg/tree-prof/val-prof-1.c is compiled with -fprofile-generate and
>>> -fprofile-use. so there won't be any warnings.
>>>
>>> 2008/4/25 Edmar Wienskoski-RA8797 <edmar@freescale.com>:
>>>
>>>
>>>       
>>>> The test case gcc.misc/bprob-1.c is compiled with fprofile-arcs /
>>>> fprofile-use.
>>>>
>>>>  The option fprofile-arcs does not enable value profiling.
>>>>
>>>>  At the second stage compilation, the option fprofile-use enables value
>>>> profiling. Within tree_find_values_to_profile, if one of the value
>>>> optimizations algorithms sees an optimization opportunity, it will push
>>>>         
>> an
>>     
>>>> histogram on stack. Later, compute_value_histograms will call
>>>> get_coverage_counts to load this histogram, but none where generated.
>>>>
>>>>  A warning is issued which means a FAIL under dejagnu.
>>>>
>>>>  I found this problem with bprob-1.c while debugging a new value profile
>>>> optimization. But it can be reproduced in any target, with non-modified
>>>>         
>> gcc,
>>     
>>>> at any optimization level, using one of the value profile test cases and
>>>> compiler options fprofile-arcs / fprofile-use (same used with
>>>>         
>> bprob-1.c).
>>     
>>>>  Here is an example using gcc.dg/tree-prof/val-prof-1.c:
>>>>  ./gcc-trunk-reference/install_e600/bin/gcc -g -fprofile-arcs
>>>>         
>> val-prof-1.c
>>     
>>>> -o val-prof-1.x1
>>>>  ./val-prof-1.x1
>>>>  ./gcc-trunk-reference/install_e600/bin/gcc -g -fprofile-use
>>>>         
>> val-prof-1.c -o
>>     
>>>> val-prof-1.x2
>>>>  val-prof-1.c: In function 'main':
>>>>  val-prof-1.c:17: warning: no coverage for function 'main' found
>>>>
>>>>  IMHO there are 3 ways to go with this:
>>>>  1 - Require user behavior change (create new option -fprofile-arcs-use
>>>>         
>> to
>>     
>>>> match -fprofile-arcs, mismatch of options is bad user behavior)
>>>>  2 - Record on the .gcda file how the first stage were done
>>>>         
>> (fprofile-arcs /
>>     
>>>> fprofile-generate, etc) and use it to disable other optimizations under
>>>> fprofile-use (Does this already exists ?, I am not familiar with the
>>>>         
>> .gcda
>>     
>>>> layout)
>>>>  3 - Let get_coverage_counts ignore inconsistencies when loading data.
>>>>
>>>>  Helps / comments are appreciated.
>>>>
>>>>  Edmar
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>         
>>>
>>>
>>>
>>>       
>>     
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