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author | kan <kan@FreeBSD.org> | 2002-09-01 20:38:57 +0000 |
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committer | kan <kan@FreeBSD.org> | 2002-09-01 20:38:57 +0000 |
commit | 2e25f3a6c57335cba50111faceb0ce2ab59e9bcb (patch) | |
tree | c6857d31c36dbd89a881b0229bf38b062797d413 /contrib/gcc/sched-deps.c | |
parent | 0895e1acb698e05d503c26bec5471de2e88b7d93 (diff) | |
download | FreeBSD-src-2e25f3a6c57335cba50111faceb0ce2ab59e9bcb.zip FreeBSD-src-2e25f3a6c57335cba50111faceb0ce2ab59e9bcb.tar.gz |
Gcc 3.2.1-prerelease from the FSF anoncvs repo gcc-3_2-branch on 1-Sep-2002 00:00:01 EDT.
Diffstat (limited to 'contrib/gcc/sched-deps.c')
-rw-r--r-- | contrib/gcc/sched-deps.c | 56 |
1 files changed, 53 insertions, 3 deletions
diff --git a/contrib/gcc/sched-deps.c b/contrib/gcc/sched-deps.c index 5fb23b7..5904f91 100644 --- a/contrib/gcc/sched-deps.c +++ b/contrib/gcc/sched-deps.c @@ -1163,6 +1163,16 @@ 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 +1236,8 @@ 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 +1264,6 @@ 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 +1365,46 @@ 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 +1498,7 @@ 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. */ |