Alternative instructions in the Linux kernel may modify control flow in a function. As such, it is unsafe to optimize functions with alternative instructions until we properly support CFG alternatives. Previously, we marked functions with alt instructions before the emission, but that could be too late if we remove or replace instructions with alternatives. We could have marked functions as non-simple immediately after reading .altinstructions, but it's nice to be able to view functions after CFG is built. Thus assign the non-simple status after building CFG.
70 KiB
70 KiB