The assert in SB seems to be caused by incorrect alu clause size in the
bytecode.

LLVM with enabled asserts also fails to compile that shader for me with the
following message:

llc: R600ControlFlowFinalizer.cpp:259: ClauseFile <anonymous
namespace>::R600Con
trolFlowFinalizer::MakeALUClause(llvm::MachineBasicBlock &,
MachineBasicBlock::i
terator &) const: Assertion `ClauseContent.size() < 128 && "ALU clause is too
bi
g"' failed.

So this looks like a bug in LLVM backend.