Well, the examples are simplified to present the concept of outlining. In the first example calc_X and OUTLINED_FUNCTION_0 are functions and not basic blocks, t

Well, the examples are simplified to present the concept of outlining. In the first example calc_X and OUTLINED_FUNCTION_0 are functions and not basic blocks, thus they are not guaranteed to placed in that order, but I agree, if they were consecutives blocks the last call should have ben removed. To give more details on the LLVM optimization pipeline there are only two passes which run after the Machine Outliner for ARM before code emission (ConstantIslands and LowOverheadLoops) because they are dependent upon block layout and size.