[polly] r265260 - [FIX] Do not create a SCoP in the presence of infinite loops

[Tobias Grosser via llvm-commits]

On 04/03/2016 03:02 PM, Tobias Grosser via llvm-commits wrote:
> On 04/03/2016 01:12 PM, Johannes Doerfert via llvm-commits wrote:
>> Author: jdoerfert
>> Date: Sun Apr  3 06:12:39 2016
>> New Revision: 265260
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=265260&view=rev
>> Log:
>> [FIX] Do not create a SCoP in the presence of infinite loops
>>
>>    If a loop has no exiting blocks the region covering we use during
>>    schedule genertion might not cover that loop properly. For now we bail
>>    out as we would not optimize these loops anyway.
>
> Hi Johannes,
>
> this commit unfortunately broke 'make check-polly':
>
>      http://lab.llvm.org:8011/builders/polly-amd64-linux/builds/40663

I reverted this in r265272. Some (but not all?) of the failures show the 
following backtrace:

--
/home/grosser/Projects/polly/git/tools/polly/lib/External/isl/isl_aff.c:199: 
position out of bounds
#0 0x00007f8b73a1a658 llvm::sys::PrintStackTrace(llvm::raw_ostream&) 
(/home/grosser/Projects/polly/cmake_opt/lib/libLLVMSupport.so+0xce658)
#1 0x00007f8b73a18e86 llvm::sys::RunSignalHandlers() 
(/home/grosser/Projects/polly/cmake_opt/lib/libLLVMSupport.so+0xcce86)
#2 0x00007f8b73a1ad46 SignalHandler(int) 
(/home/grosser/Projects/polly/cmake_opt/lib/libLLVMSupport.so+0xced46)
#3 0x00007f8b729902f0 (/lib/x86_64-linux-gnu/libc.so.6+0x352f0)
#4 0x00007f8b72990267 gsignal 
/build/glibc-ryFjv0/glibc-2.21/signal/../sysdeps/unix/sysv/linux/raise.c:55:0
#5 0x00007f8b72991eca abort 
/build/glibc-ryFjv0/glibc-2.21/stdlib/abort.c:91:0
#6 0x00007f8b74636467 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0x12b467)
#7 0x00007f8b745e420f isl_aff_var_on_domain 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0xd920f)
#8 0x00007f8b745f4207 isl_multi_aff_project_out_map 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0xe9207)
#9 0x00007f8b745f4276 isl_pw_multi_aff_project_out_map 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0xe9276)
#10 0x00007f8b74583be1 mapToDimension_AddSet(isl_set*, void*) 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0x78be1)
#11 0x00007f8b7463cd6e isl_hash_table_foreach 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0x131d6e)
#12 0x00007f8b746edb9b isl_union_set_foreach_set 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0x1e2b9b)
#13 0x00007f8b7457b75b polly::Scop::buildSchedule(llvm::RegionNode*, 
llvm::SmallVector<polly::Scop::LoopStackElement, 4u>&, 
polly::ScopDetection&, llvm::LoopInfo&) 
(/home/grosser/Projects/polly/cmake_opt/lib/libPolly.so+0x7075b)

I see failures on both my laptop as well as on our buildbots.

Best,
Tobias