On 08/07/2012 02:22 AM, Steven Bosscher wrote:
Hello,In the test case for PR54146, build_insn_chain spends almost all its time in this loop: FOR_EACH_BB_REVERSE (bb) { bitmap_iterator bi; rtx insn; CLEAR_REG_SET (live_relevant_regs); --> memset (live_subregs_used, 0, max_regno * sizeof (int)); The test case has >400,000 basic blocks and >1,000,000 regs... Fortunately this can be done much more efficiently if one realizes that an sbitmap knows its own size (using SBITMAP_SIZE that I introduced recently). With that, live_subregs_used can be a sparse bitmap. Bootstrapped&tested on x86_64-unknown-linux-gnu. OK for trunk?
Ok. Thanks for the patch, Steven.
