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author | Pat Haugen <pthaugen@us.ibm.com> | 2019-11-19 19:49:37 +0000 |
---|---|---|
committer | Pat Haugen <pthaugen@gcc.gnu.org> | 2019-11-19 19:49:37 +0000 |
commit | 9a8819b8828490a83eaf9d069a049e26211cc215 (patch) | |
tree | fc3a5bc2617e243ef9fa7eee8489fd7369433176 /gcc/config | |
parent | dd46a542a8f95ef7abac4da30ee3c03563eb3519 (diff) | |
download | gcc-9a8819b8828490a83eaf9d069a049e26211cc215.zip gcc-9a8819b8828490a83eaf9d069a049e26211cc215.tar.gz gcc-9a8819b8828490a83eaf9d069a049e26211cc215.tar.bz2 |
rs6000.c (move_to_end_of_ready): New, factored out from common code.
* config/rs6000/rs6000.c (move_to_end_of_ready): New, factored out
from common code.
(power6_sched_reorder2): Factored out from rs6000_sched_reorder2,
call new function.
(power9_sched_reorder2): Call new function.
(rs6000_sched_reorder2): Likewise.
From-SVN: r278463
Diffstat (limited to 'gcc/config')
-rw-r--r-- | gcc/config/rs6000/rs6000.c | 424 |
1 files changed, 211 insertions, 213 deletions
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index c7abc60..0282ebd 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -17711,14 +17711,216 @@ get_next_active_insn (rtx_insn *insn, rtx_insn *tail) return insn; } +/* Move instruction at POS to the end of the READY list. */ + +static void +move_to_end_of_ready (rtx_insn **ready, int pos, int lastpos) +{ + rtx_insn *tmp; + int i; + + tmp = ready[pos]; + for (i = pos; i < lastpos; i++) + ready[i] = ready[i + 1]; + ready[lastpos] = tmp; +} + +/* Do Power6 specific sched_reorder2 reordering of ready list. */ + +static int +power6_sched_reorder2 (rtx_insn **ready, int lastpos) +{ + /* For Power6, we need to handle some special cases to try and keep the + store queue from overflowing and triggering expensive flushes. + + This code monitors how load and store instructions are being issued + and skews the ready list one way or the other to increase the likelihood + that a desired instruction is issued at the proper time. + + A couple of things are done. First, we maintain a "load_store_pendulum" + to track the current state of load/store issue. + + - If the pendulum is at zero, then no loads or stores have been + issued in the current cycle so we do nothing. + + - If the pendulum is 1, then a single load has been issued in this + cycle and we attempt to locate another load in the ready list to + issue with it. + + - If the pendulum is -2, then two stores have already been + issued in this cycle, so we increase the priority of the first load + in the ready list to increase it's likelihood of being chosen first + in the next cycle. + + - If the pendulum is -1, then a single store has been issued in this + cycle and we attempt to locate another store in the ready list to + issue with it, preferring a store to an adjacent memory location to + facilitate store pairing in the store queue. + + - If the pendulum is 2, then two loads have already been + issued in this cycle, so we increase the priority of the first store + in the ready list to increase it's likelihood of being chosen first + in the next cycle. + + - If the pendulum < -2 or > 2, then do nothing. + + Note: This code covers the most common scenarios. There exist non + load/store instructions which make use of the LSU and which + would need to be accounted for to strictly model the behavior + of the machine. Those instructions are currently unaccounted + for to help minimize compile time overhead of this code. + */ + int pos; + rtx load_mem, str_mem; + + if (is_store_insn (last_scheduled_insn, &str_mem)) + /* Issuing a store, swing the load_store_pendulum to the left */ + load_store_pendulum--; + else if (is_load_insn (last_scheduled_insn, &load_mem)) + /* Issuing a load, swing the load_store_pendulum to the right */ + load_store_pendulum++; + else + return cached_can_issue_more; + + /* If the pendulum is balanced, or there is only one instruction on + the ready list, then all is well, so return. */ + if ((load_store_pendulum == 0) || (lastpos <= 0)) + return cached_can_issue_more; + + if (load_store_pendulum == 1) + { + /* A load has been issued in this cycle. Scan the ready list + for another load to issue with it */ + pos = lastpos; + + while (pos >= 0) + { + if (is_load_insn (ready[pos], &load_mem)) + { + /* Found a load. Move it to the head of the ready list, + and adjust it's priority so that it is more likely to + stay there */ + move_to_end_of_ready (ready, pos, lastpos); + + if (!sel_sched_p () + && INSN_PRIORITY_KNOWN (ready[lastpos])) + INSN_PRIORITY (ready[lastpos])++; + break; + } + pos--; + } + } + else if (load_store_pendulum == -2) + { + /* Two stores have been issued in this cycle. Increase the + priority of the first load in the ready list to favor it for + issuing in the next cycle. */ + pos = lastpos; + + while (pos >= 0) + { + if (is_load_insn (ready[pos], &load_mem) + && !sel_sched_p () + && INSN_PRIORITY_KNOWN (ready[pos])) + { + INSN_PRIORITY (ready[pos])++; + + /* Adjust the pendulum to account for the fact that a load + was found and increased in priority. This is to prevent + increasing the priority of multiple loads */ + load_store_pendulum--; + + break; + } + pos--; + } + } + else if (load_store_pendulum == -1) + { + /* A store has been issued in this cycle. Scan the ready list for + another store to issue with it, preferring a store to an adjacent + memory location */ + int first_store_pos = -1; + + pos = lastpos; + + while (pos >= 0) + { + if (is_store_insn (ready[pos], &str_mem)) + { + rtx str_mem2; + /* Maintain the index of the first store found on the + list */ + if (first_store_pos == -1) + first_store_pos = pos; + + if (is_store_insn (last_scheduled_insn, &str_mem2) + && adjacent_mem_locations (str_mem, str_mem2)) + { + /* Found an adjacent store. Move it to the head of the + ready list, and adjust it's priority so that it is + more likely to stay there */ + move_to_end_of_ready (ready, pos, lastpos); + + if (!sel_sched_p () + && INSN_PRIORITY_KNOWN (ready[lastpos])) + INSN_PRIORITY (ready[lastpos])++; + + first_store_pos = -1; + + break; + }; + } + pos--; + } + + if (first_store_pos >= 0) + { + /* An adjacent store wasn't found, but a non-adjacent store was, + so move the non-adjacent store to the front of the ready + list, and adjust its priority so that it is more likely to + stay there. */ + move_to_end_of_ready (ready, first_store_pos, lastpos); + if (!sel_sched_p () + && INSN_PRIORITY_KNOWN (ready[lastpos])) + INSN_PRIORITY (ready[lastpos])++; + } + } + else if (load_store_pendulum == 2) + { + /* Two loads have been issued in this cycle. Increase the priority + of the first store in the ready list to favor it for issuing in + the next cycle. */ + pos = lastpos; + + while (pos >= 0) + { + if (is_store_insn (ready[pos], &str_mem) + && !sel_sched_p () + && INSN_PRIORITY_KNOWN (ready[pos])) + { + INSN_PRIORITY (ready[pos])++; + + /* Adjust the pendulum to account for the fact that a store + was found and increased in priority. This is to prevent + increasing the priority of multiple stores */ + load_store_pendulum++; + + break; + } + pos--; + } + } + + return cached_can_issue_more; +} + /* Do Power9 specific sched_reorder2 reordering of ready list. */ static int power9_sched_reorder2 (rtx_insn **ready, int lastpos) { int pos; - int i; - rtx_insn *tmp; enum attr_type type, type2; type = get_attr_type (last_scheduled_insn); @@ -17738,10 +17940,7 @@ power9_sched_reorder2 (rtx_insn **ready, int lastpos) if (recog_memoized (ready[pos]) >= 0 && get_attr_type (ready[pos]) == TYPE_DIV) { - tmp = ready[pos]; - for (i = pos; i < lastpos; i++) - ready[i] = ready[i + 1]; - ready[lastpos] = tmp; + move_to_end_of_ready (ready, pos, lastpos); break; } pos--; @@ -17784,10 +17983,7 @@ power9_sched_reorder2 (rtx_insn **ready, int lastpos) { /* Found a vector insn to pair with, move it to the end of the ready list so it is scheduled next. */ - tmp = ready[pos]; - for (i = pos; i < lastpos; i++) - ready[i] = ready[i + 1]; - ready[lastpos] = tmp; + move_to_end_of_ready (ready, pos, lastpos); vec_pairing = 1; return cached_can_issue_more; } @@ -17801,10 +17997,7 @@ power9_sched_reorder2 (rtx_insn **ready, int lastpos) { /* Didn't find a vector to pair with but did find a vecload, move it to the end of the ready list. */ - tmp = ready[vecload_pos]; - for (i = vecload_pos; i < lastpos; i++) - ready[i] = ready[i + 1]; - ready[lastpos] = tmp; + move_to_end_of_ready (ready, vecload_pos, lastpos); vec_pairing = 1; return cached_can_issue_more; } @@ -17828,10 +18021,7 @@ power9_sched_reorder2 (rtx_insn **ready, int lastpos) { /* Found a vecload insn to pair with, move it to the end of the ready list so it is scheduled next. */ - tmp = ready[pos]; - for (i = pos; i < lastpos; i++) - ready[i] = ready[i + 1]; - ready[lastpos] = tmp; + move_to_end_of_ready (ready, pos, lastpos); vec_pairing = 1; return cached_can_issue_more; } @@ -17846,10 +18036,7 @@ power9_sched_reorder2 (rtx_insn **ready, int lastpos) { /* Didn't find a vecload to pair with but did find a vector insn, move it to the end of the ready list. */ - tmp = ready[vec_pos]; - for (i = vec_pos; i < lastpos; i++) - ready[i] = ready[i + 1]; - ready[lastpos] = tmp; + move_to_end_of_ready (ready, vec_pos, lastpos); vec_pairing = 1; return cached_can_issue_more; } @@ -17903,198 +18090,9 @@ rs6000_sched_reorder2 (FILE *dump, int sched_verbose, rtx_insn **ready, if (sched_verbose) fprintf (dump, "// rs6000_sched_reorder2 :\n"); - /* For Power6, we need to handle some special cases to try and keep the - store queue from overflowing and triggering expensive flushes. - - This code monitors how load and store instructions are being issued - and skews the ready list one way or the other to increase the likelihood - that a desired instruction is issued at the proper time. - - A couple of things are done. First, we maintain a "load_store_pendulum" - to track the current state of load/store issue. - - - If the pendulum is at zero, then no loads or stores have been - issued in the current cycle so we do nothing. - - - If the pendulum is 1, then a single load has been issued in this - cycle and we attempt to locate another load in the ready list to - issue with it. - - - If the pendulum is -2, then two stores have already been - issued in this cycle, so we increase the priority of the first load - in the ready list to increase it's likelihood of being chosen first - in the next cycle. - - - If the pendulum is -1, then a single store has been issued in this - cycle and we attempt to locate another store in the ready list to - issue with it, preferring a store to an adjacent memory location to - facilitate store pairing in the store queue. - - - If the pendulum is 2, then two loads have already been - issued in this cycle, so we increase the priority of the first store - in the ready list to increase it's likelihood of being chosen first - in the next cycle. - - - If the pendulum < -2 or > 2, then do nothing. - - Note: This code covers the most common scenarios. There exist non - load/store instructions which make use of the LSU and which - would need to be accounted for to strictly model the behavior - of the machine. Those instructions are currently unaccounted - for to help minimize compile time overhead of this code. - */ + /* Do Power6 dependent reordering if necessary. */ if (rs6000_tune == PROCESSOR_POWER6 && last_scheduled_insn) - { - int pos; - int i; - rtx_insn *tmp; - rtx load_mem, str_mem; - - if (is_store_insn (last_scheduled_insn, &str_mem)) - /* Issuing a store, swing the load_store_pendulum to the left */ - load_store_pendulum--; - else if (is_load_insn (last_scheduled_insn, &load_mem)) - /* Issuing a load, swing the load_store_pendulum to the right */ - load_store_pendulum++; - else - return cached_can_issue_more; - - /* If the pendulum is balanced, or there is only one instruction on - the ready list, then all is well, so return. */ - if ((load_store_pendulum == 0) || (*pn_ready <= 1)) - return cached_can_issue_more; - - if (load_store_pendulum == 1) - { - /* A load has been issued in this cycle. Scan the ready list - for another load to issue with it */ - pos = *pn_ready-1; - - while (pos >= 0) - { - if (is_load_insn (ready[pos], &load_mem)) - { - /* Found a load. Move it to the head of the ready list, - and adjust it's priority so that it is more likely to - stay there */ - tmp = ready[pos]; - for (i=pos; i<*pn_ready-1; i++) - ready[i] = ready[i + 1]; - ready[*pn_ready-1] = tmp; - - if (!sel_sched_p () && INSN_PRIORITY_KNOWN (tmp)) - INSN_PRIORITY (tmp)++; - break; - } - pos--; - } - } - else if (load_store_pendulum == -2) - { - /* Two stores have been issued in this cycle. Increase the - priority of the first load in the ready list to favor it for - issuing in the next cycle. */ - pos = *pn_ready-1; - - while (pos >= 0) - { - if (is_load_insn (ready[pos], &load_mem) - && !sel_sched_p () - && INSN_PRIORITY_KNOWN (ready[pos])) - { - INSN_PRIORITY (ready[pos])++; - - /* Adjust the pendulum to account for the fact that a load - was found and increased in priority. This is to prevent - increasing the priority of multiple loads */ - load_store_pendulum--; - - break; - } - pos--; - } - } - else if (load_store_pendulum == -1) - { - /* A store has been issued in this cycle. Scan the ready list for - another store to issue with it, preferring a store to an adjacent - memory location */ - int first_store_pos = -1; - - pos = *pn_ready-1; - - while (pos >= 0) - { - if (is_store_insn (ready[pos], &str_mem)) - { - rtx str_mem2; - /* Maintain the index of the first store found on the - list */ - if (first_store_pos == -1) - first_store_pos = pos; - - if (is_store_insn (last_scheduled_insn, &str_mem2) - && adjacent_mem_locations (str_mem, str_mem2)) - { - /* Found an adjacent store. Move it to the head of the - ready list, and adjust it's priority so that it is - more likely to stay there */ - tmp = ready[pos]; - for (i=pos; i<*pn_ready-1; i++) - ready[i] = ready[i + 1]; - ready[*pn_ready-1] = tmp; - - if (!sel_sched_p () && INSN_PRIORITY_KNOWN (tmp)) - INSN_PRIORITY (tmp)++; - - first_store_pos = -1; - - break; - }; - } - pos--; - } - - if (first_store_pos >= 0) - { - /* An adjacent store wasn't found, but a non-adjacent store was, - so move the non-adjacent store to the front of the ready - list, and adjust its priority so that it is more likely to - stay there. */ - tmp = ready[first_store_pos]; - for (i=first_store_pos; i<*pn_ready-1; i++) - ready[i] = ready[i + 1]; - ready[*pn_ready-1] = tmp; - if (!sel_sched_p () && INSN_PRIORITY_KNOWN (tmp)) - INSN_PRIORITY (tmp)++; - } - } - else if (load_store_pendulum == 2) - { - /* Two loads have been issued in this cycle. Increase the priority - of the first store in the ready list to favor it for issuing in - the next cycle. */ - pos = *pn_ready-1; - - while (pos >= 0) - { - if (is_store_insn (ready[pos], &str_mem) - && !sel_sched_p () - && INSN_PRIORITY_KNOWN (ready[pos])) - { - INSN_PRIORITY (ready[pos])++; - - /* Adjust the pendulum to account for the fact that a store - was found and increased in priority. This is to prevent - increasing the priority of multiple stores */ - load_store_pendulum++; - - break; - } - pos--; - } - } - } + return power6_sched_reorder2 (ready, *pn_ready - 1); /* Do Power9 dependent reordering if necessary. */ if (rs6000_tune == PROCESSOR_POWER9 && last_scheduled_insn |