More ExecutionEngine XPASS on ARM

I’m seeing more XPASSes on ExecutionEngine on ARM, but only on Release mode, not Release+Assert:

$ grep XPASS final/logs/llvm.check-Phase3-Release.log
XPASS: LLVM :: ExecutionEngine/2003-05-06-LivenessClobber.ll (10862 of 14500)
XPASS: LLVM :: ExecutionEngine/2003-08-15-AllocaAssertion.ll (10868 of 14500)
XPASS: LLVM :: ExecutionEngine/2003-08-23-RegisterAllocatePhysReg.ll (10870 of 14500)

Any ideas why this is the case?

cheers,
–renato