On 01/26/2018 06:15 PM, Jakub Jelinek wrote:
Hi! On a testcase which has 100000 consecutive debug insns sched2 spends a lot of time calling prev_nonnote_nondebug_insn on each of the debug insns, even when it is completely useless, because no target wants to fuse a non-debug insn with some debug insn after it, it makes sense only for two non-debug insns. By returning early for those, we'll just walk the long set of them once when we process some non-debug instruction after a long block of debug insns. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
2018-01-26 Jakub Jelinek <ja...@redhat.com> PR middle-end/84040 * sched-deps.c (sched_macro_fuse_insns): Return immediately for debug insns. --- gcc/sched-deps.c.jj 2018-01-03 10:19:56.301534141 +0100 +++ gcc/sched-deps.c 2018-01-26 16:21:01.922414579 +0100 @@ -2834,10 +2834,16 @@ static void sched_macro_fuse_insns (rtx_insn *insn) { rtx_insn *prev; + /* No target hook would return true for debug insn as any of the + hook operand, and with very large sequences of only debug insns + where on each we call sched_macro_fuse_insns it has quadratic + compile time complexity. */ + if (DEBUG_INSN_P (insn)) + return; prev = prev_nonnote_nondebug_insn (insn); if (!prev) return; - + if (any_condjump_p (insn)) { unsigned int condreg1, condreg2;