https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64317
--- Comment #19 from Jeffrey A. Law <law at redhat dot com> --- Making reload_cse_regs less pessimistic at CODE_LABELs really isn't feasible. cselib isn't easily turned into a scoped hash table and the multiple assignment nature of RTL means that a simple scoped hash table isn't sufficient anyway. I'm currently poking at postreload-gcse. The basic idea being to detect when an occurrence is transparent through a block and an occurrence exists in the block's one and only predecessor. In that case pretend the occurrence also exists at the end of the current block. I don't expect this to occur often, thus I'm not computing transparency for each expression in all blocks and doing a traditional dataflow propagation. With that special case in place, I get just 5 reloads of the PIC register, which appears minimal given the other register allocation decisions. I need to ponder a couple implementation details, but this may be the final resolution to this BZ :-)
