diff options
Diffstat (limited to 'gcc/sched-deps.c')
| -rw-r--r-- | gcc/sched-deps.c | 69 |
1 files changed, 63 insertions, 6 deletions
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c index 5fb23b76d9b..4e14ee26eaa 100644 --- a/gcc/sched-deps.c +++ b/gcc/sched-deps.c @@ -923,7 +923,15 @@ sched_analyze_insn (deps, x, insn, loop_notes) code = GET_CODE (x); } if (code == SET || code == CLOBBER) - sched_analyze_1 (deps, x, insn); + { + sched_analyze_1 (deps, x, insn); + + /* Bare clobber insns are used for letting life analysis, reg-stack + and others know that a value is dead. Depend on the last call + instruction so that reg-stack won't get confused. */ + if (code == CLOBBER) + add_dependence_list (insn, deps->last_function_call, REG_DEP_OUTPUT); + } else if (code == PARALLEL) { int i; @@ -1118,8 +1126,6 @@ sched_analyze_insn (deps, x, insn, loop_notes) EXECUTE_IF_SET_IN_REG_SET (reg_pending_clobbers, 0, i, { struct deps_reg *reg_last = &deps->reg_last[i]; - add_dependence_list (insn, reg_last->sets, REG_DEP_OUTPUT); - add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI); if (reg_last->uses_length > MAX_PENDING_LIST_LENGTH || reg_last->clobbers_length > MAX_PENDING_LIST_LENGTH) { @@ -1129,6 +1135,7 @@ sched_analyze_insn (deps, x, insn, loop_notes) REG_DEP_ANTI); add_dependence_list_and_free (insn, ®_last->clobbers, REG_DEP_OUTPUT); + reg_last->sets = alloc_INSN_LIST (insn, reg_last->sets); reg_last->clobbers_length = 0; reg_last->uses_length = 0; } @@ -1163,6 +1170,16 @@ sched_analyze_insn (deps, x, insn, loop_notes) CLEAR_REG_SET (reg_pending_clobbers); CLEAR_REG_SET (reg_pending_sets); + /* If we are currently in a libcall scheduling group, then mark the + current insn as being in a scheduling group and that it can not + be moved into a different basic block. */ + + if (deps->libcall_block_tail_insn) + { + set_sched_group_p (insn); + CANT_MOVE (insn) = 1; + } + /* If a post-call group is still open, see if it should remain so. This insn must be a simple move of a hard reg to a pseudo or vice-versa. @@ -1226,6 +1243,8 @@ sched_analyze (deps, head, tail) for (insn = head;; insn = NEXT_INSN (insn)) { + rtx link, end_seq, r0, set, note; + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN) { /* Clear out the stale LOG_LINKS from flow. */ @@ -1252,9 +1271,6 @@ sched_analyze (deps, head, tail) { int i; - /* Clear out stale SCHED_GROUP_P. */ - SCHED_GROUP_P (insn) = 0; - CANT_MOVE (insn) = 1; /* Clear out the stale LOG_LINKS from flow. */ @@ -1356,6 +1372,46 @@ sched_analyze (deps, head, tail) if (current_sched_info->use_cselib) cselib_process_insn (insn); + + /* Now that we have completed handling INSN, check and see if it is + a CLOBBER beginning a libcall block. If it is, record the + end of the libcall sequence. + + We want to schedule libcall blocks as a unit before reload. While + this restricts scheduling, it preserves the meaning of a libcall + block. + + As a side effect, we may get better code due to decreased register + pressure as well as less chance of a foreign insn appearing in + a libcall block. */ + if (!reload_completed + /* Note we may have nested libcall sequences. We only care about + the outermost libcall sequence. */ + && deps->libcall_block_tail_insn == 0 + /* The sequence must start with a clobber of a register. */ + && GET_CODE (insn) == INSN + && GET_CODE (PATTERN (insn)) == CLOBBER + && (r0 = XEXP (PATTERN (insn), 0), GET_CODE (r0) == REG) + && GET_CODE (XEXP (PATTERN (insn), 0)) == REG + /* The CLOBBER must also have a REG_LIBCALL note attached. */ + && (link = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0 + && (end_seq = XEXP (link, 0)) != 0 + /* The insn referenced by the REG_LIBCALL note must be a + simple nop copy with the same destination as the register + mentioned in the clobber. */ + && (set = single_set (end_seq)) != 0 + && SET_DEST (set) == r0 && SET_SRC (set) == r0 + /* And finally the insn referenced by the REG_LIBCALL must + also contain a REG_EQUAL note and a REG_RETVAL note. */ + && find_reg_note (end_seq, REG_EQUAL, NULL_RTX) != 0 + && find_reg_note (end_seq, REG_RETVAL, NULL_RTX) != 0) + deps->libcall_block_tail_insn = XEXP (link, 0); + + /* If we have reached the end of a libcall block, then close the + block. */ + if (deps->libcall_block_tail_insn == insn) + deps->libcall_block_tail_insn = 0; + if (insn == tail) { if (current_sched_info->use_cselib) @@ -1449,6 +1505,7 @@ init_deps (deps) deps->last_function_call = 0; deps->sched_before_next_call = 0; deps->in_post_call_group_p = false; + deps->libcall_block_tail_insn = 0; } /* Free insn lists found in DEPS. */ |