https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85180
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> --- Created attachment 43850 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43850&action=edit alternative patch The most simple hash_map variant is the attached. Comparing (-O0 optimized cc1) compile-time for your testcase shows hash-map: > /usr/bin/time ./cc1 -quiet t.c -O -I include 13.80user 0.01system 0:13.83elapsed 99%CPU (0avgtext+0avgdata 43556maxresident)k 0inputs+144outputs (0major+7967minor)pagefaults 0swaps vector-unwind: > /usr/bin/time ./cc1 -quiet t.c -O -I include 12.10user 0.01system 0:12.12elapsed 99%CPU (0avgtext+0avgdata 43656maxresident)k 0inputs+144outputs (0major+7949minor)pagefaults 0swaps just building alias.c with -O2: hash-map: 11.28user 0.01system 0:11.30elapsed 99%CPU (0avgtext+0avgdata 43256maxresident)k 0inputs+144outputs (0major+7855minor)pagefaults 0swaps vector-unwind: 11.03user 0.01system 0:11.04elapsed 100%CPU (0avgtext+0avgdata 43168maxresident)k 0inputs+144outputs (0major+7872minor)pagefaults 0swaps caching directly in an enlarged cselib_val yields in 11.03user 0.02system 0:11.05elapsed 99%CPU (0avgtext+0avgdata 43148maxresident)k 0inputs+144outputs (0major+7852minor)pagefaults 0swaps Index: gcc/alias.c =================================================================== --- gcc/alias.c (revision 259082) +++ gcc/alias.c (working copy) @@ -1939,6 +1939,9 @@ find_base_term (rtx x) if (cselib_sp_based_value_p (val)) return static_reg_base_value[STACK_POINTER_REGNUM]; + if (val->base_term != (rtx)-1) + return val->base_term; + val->base_term = NULL_RTX; f = val->locs; /* Temporarily reset val->locs to avoid infinite recursion. */ val->locs = NULL; @@ -1953,6 +1956,7 @@ find_base_term (rtx x) break; val->locs = f; + val->base_term = ret; return ret; case LO_SUM:
