Inifinite loop with -O3.

[nomaddo]

The following command make an infinite loop.

$ VC4C -O3 -DLOCAL_SIZE_LIMIT=12 testing/NVIDIA/BitonicSort.cl

...
[D] Sat Dec  8 21:31:41 2018: Replaced access to memory buffer with access to VPM
[D] Sat Dec  8 21:31:41 2018: Replaced access to memory buffer with access to VPM
[D] Sat Dec  8 21:31:41 2018: Trying to lower access to shared local memory into VPM: copy i8 1 entries from (l) i32* %arrayidx50.1.1 into (l) i32* %arrayidx46.1.1
[D] Sat Dec  8 21:31:41 2018: Replaced access to memory buffer with access to VPM
[D] Sat Dec  8 21:31:41 2018: Trying to lower access to shared local memory into VPM: copy i8 1 entries from (l) i32* %arrayidx50 into (l) i32* %arrayidx46
[D] Sat Dec  8 21:31:41 2018: Trying to lower access to shared local memory into VPM: copy i8 1 entries from (l) i32* %arrayidx68 into (l) i32* %arrayidx64
....

[nomaddo]

The problem is inifinite loop in the following code:

VC4C/src/normalization/MemoryAccess.cpp

Line 1368 in 87417e4

while(it != memoryInstructions.end())

In case of case MemoryOperation::COPY: in line 1385, and break in line 1394, it is not incremented at all. Then it loops forever.

I am not sure what should do here. Can you fix it? @doe300

[doe300]

True, there is a TODO where probably either something should be done or at least an exception thrown. This should probably be fixed with #120.
@nomaddo, on what kernel/test do you get the loop?

[nomaddo]

I'm sorry, I missed the file name. bitonicMergeLocal in NVIDIA/BItnicSort.cl .