[LLVMdev] Strange code generation issue

[Dibyendu Majumdar]

Hi,

I am using the LLVM release_37 branch and have a strange issue.

Please see the two IR outputs I have saved below:

https://github.com/dibyendumajumdar/ravi/tree/master/ravi-tests/comp_issue

The original.ll is the code I am generating.
The aftercompiling.ll is the output from LLVM with opt level 0.

The issue is that LLVM is deciding to remove the blocks with labels
updatei and updatei.64 (lines 433 and 454 in original.ll) for some
reason that I cannot fathom. This is then causing the program to
misbehave.

I will check if the same issue occurs in LLVM 3.6.

I would appreciate any help on understanding what might be causing this issue.

Many thanks

Regards
Dibyendu