On 11/20/13 13:59, Steven Bosscher wrote:
* jump.c (reset_insn_reg_label_operand_notes): New function,
split out from ...
(init_label_info): ... here. Reset LABEL_NUSES in cfglayout mode.
* cfgcleanup.c (delete_dead_jump_tables_between): New function,
split out from ...
(delete_dead_jumptables): ... here. Handle cfglayout mode.
(cleanup_cfg): Delete dead jump tables in cfglayout mode if an
expensive CFG cleanup is called for.
* cfgrtl.c (fixup_reorder_chain): Remove BARRIERs from fallthru paths.
(cfg_layout_finalize): Delete dead jump tables before re-building
the insns chain.
* ira.c (ira): Rebuild jump labels*after* deleting unreachable
basic blocks, not before.
* loop-init.c (rtl_loop_done): Call for an expensive CFG cleanup.
* modulo-sched.c (sms_schedule): Do not look for BARRIERs in the
insns chain of a scheduling extended basic block, they cannot appear
there in cfglayout mode.
Code is fine from a cursory review -- you're as well versed in this code
as anyone, so I'm going to assume it's a step in the right direction.
My comments are just whitespace and spelling nits.
@@ -186,34 +214,40 @@ init_label_info (rtx f)
{
rtx insn;
- for (insn = f; insn; insn = NEXT_INSN (insn))
- {
- if (LABEL_P (insn))
- LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0);
-
- /* REG_LABEL_TARGET notes (including the JUMP_LABEL field) are
- sticky and not reset here; that way we won't lose association
- with a label when e.g. the source for a target register
- disappears out of reach for targets that may use jump-target
- registers. Jump transformations are supposed to transform
- any REG_LABEL_TARGET notes. The target label reference in a
- branch may disappear from the branch (and from the
- instruction before it) for other reasons, like register
- allocation. */
-
- if (INSN_P (insn))
- {
- rtx note, next;
-
- for (note = REG_NOTES (insn); note; note = next)
- {
- next = XEXP (note, 1);
- if (REG_NOTE_KIND (note) == REG_LABEL_OPERAND
- && ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn)))
- remove_note (insn, note);
- }
- }
- }
+ if (current_ir_type () == IR_RTL_CFGLAYOUT)
+ {
+ basic_block bb;
+
+ FOR_EACH_BB (bb)
+ {
+ /* Labels only appear between BB_HEAD and the basic block note,
+ and in the basic block header and footer. */
+ for (insn = BB_HEAD (bb);
+ insn && LABEL_P (insn);
+ insn = NEXT_INSN (insn))
+ LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0);
+ for (insn = BB_HEADER (bb); insn; insn = NEXT_INSN (insn))
+ if (LABEL_P (insn))
+ LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0);
+ for (insn = BB_FOOTER (bb); insn; insn = NEXT_INSN (insn))
+ if (LABEL_P (insn))
+ LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0);
This seems quite busy to my eyes. Perhaps vertical whitespace between
the loops.
- /* Don't call delete_dead_jumptables in cfglayout mode, because
- that function assumes that jump tables are in the insns stream.
- But we also don't_have_ to delete dead jumptables in cfglayout
^^^ horizontal whitespace.
+ /* Annoying special case - stray barriers left in the code. This happens
+ if a tablejump is transformed to a simpe or confitional jump, or if a
+ basic block ending in a tablejump is removed but the jump table itself
s/simpe/simple/
Nits fixed and it's good to go.
jeff
