| Message ID | 4F574775.4040500@ispras.ru |
|---|---|
| State | New |
| Headers | show |
On Wed, 7 Mar 2012, Andrey Belevantsev wrote: > Hello, > > This PR is again about insns that are recog'ed as >=0 but do not change the > processor state. As explained in > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52203#c8, I've tried experimenting > with an attribute marking those "empty" insns in MD files and asserting that > all other insns do have reservations. As this doesn't seem to be interesting, > I give up with the idea, and the below patch makes sel-sched do exactly what > the Haifa scheduler does, i.e. do not count such insns against issue_rate when > modelling clock cycles. > > Tested on ia64 and x86-64, OK for trunk? No testcase again because of the > amount of flags needed. > > Andrey > > 2012-03-07 Andrey Belevantsev <abel@ispras.ru> > > PR rtl-optimization/52203 > * sel-sched.c (estimate_insn_cost): New parameter pempty. Adjust > all callers to pass NULL except ... > (reset_sched_cycles_in_current_ebb): ... here, save the value > in new variable 'empty'. Increase issue_rate only for > non-empty insns. This is OK. Thanks.
diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c index 2af01ae..2829f60 100644 --- a/gcc/sel-sched.c +++ b/gcc/sel-sched.c @@ -4265,9 +4265,10 @@ invoke_aftermath_hooks (fence_t fence, rtx best_insn, int issue_more) return issue_more; } -/* Estimate the cost of issuing INSN on DFA state STATE. */ +/* Estimate the cost of issuing INSN on DFA state STATE. Write to PEMPTY + true when INSN does not change the processor state. */ static int -estimate_insn_cost (rtx insn, state_t state) +estimate_insn_cost (rtx insn, state_t state, bool *pempty) { static state_t temp = NULL;
Hello, This PR is again about insns that are recog'ed as >=0 but do not change the processor state. As explained in http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52203#c8, I've tried experimenting with an attribute marking those "empty" insns in MD files and asserting that all other insns do have reservations. As this doesn't seem to be interesting, I give up with the idea, and the below patch makes sel-sched do exactly what the Haifa scheduler does, i.e. do not count such insns against issue_rate when modelling clock cycles. Tested on ia64 and x86-64, OK for trunk? No testcase again because of the amount of flags needed. Andrey 2012-03-07 Andrey Belevantsev <abel@ispras.ru> PR rtl-optimization/52203 * sel-sched.c (estimate_insn_cost): New parameter pempty. Adjust all callers to pass NULL except ... (reset_sched_cycles_in_current_ebb): ... here, save the value in new variable 'empty'. Increase issue_rate only for non-empty insns. int cost; @@ -4277,6 +4278,8 @@ estimate_insn_cost (rtx insn, state_t state) memcpy (temp, state, dfa_state_size); cost = state_transition (temp, insn); + if (pempty) + *pempty = (memcmp (temp, state, dfa_state_size) == 0); if (cost < 0) return 0; @@ -4307,7 +4310,7 @@ get_expr_cost (expr_t expr, fence_t fence) return 0; } else - return estimate_insn_cost (insn, FENCE_STATE (fence)); + return estimate_insn_cost (insn, FENCE_STATE (fence), NULL); } /* Find the best insn for scheduling, either via max_issue or just take @@ -7020,7 +7023,7 @@ reset_sched_cycles_in_current_ebb (void) { int cost, haifa_cost; int sort_p; - bool asm_p, real_insn, after_stall, all_issued; + bool asm_p, real_insn, after_stall, all_issued, empty; int clock; if (!INSN_P (insn)) @@ -7047,7 +7050,7 @@ reset_sched_cycles_in_current_ebb (void) haifa_cost = 0; } else - haifa_cost = estimate_insn_cost (insn, curr_state); + haifa_cost = estimate_insn_cost (insn, curr_state, &empty); /* Stall for whatever cycles we've stalled before. */ after_stall = 0; @@ -7081,7 +7084,7 @@ reset_sched_cycles_in_current_ebb (void) if (!after_stall && real_insn && haifa_cost > 0 - && estimate_insn_cost (insn, curr_state) == 0) + && estimate_insn_cost (insn, curr_state, NULL) == 0) break; /* When the data dependency stall is longer than the DFA stall, @@ -7093,7 +7096,7 @@ reset_sched_cycles_in_current_ebb (void) if ((after_stall || all_issued) && real_insn && haifa_cost == 0) - haifa_cost = estimate_insn_cost (insn, curr_state); + haifa_cost = estimate_insn_cost (insn, curr_state, NULL); } haifa_clock += i; @@ -7125,7 +7128,8 @@ reset_sched_cycles_in_current_ebb (void) if (real_insn) { cost = state_transition (curr_state, insn); - issued_insns++; + if (!empty) + issued_insns++; if (sched_verbose >= 2) {