> Then this must be a very dummy question. How the compiler keep the > instruction order in the RTL IR format in a function? By the information > like "insn 50 56 51" ? e.g., > (insn 50 56 51 4 (clobber (reg/i:SI 0 ax)) -1 (nil) )
It's a linked list. The 56 and 51 link to the previous and next insn in the chain.
