Hello,
While testing PR 58960 on ia64, I've enabled selective scheduling for
bootstrap and found two small issues. One is the other instance of PR
57662 and another one is a miscompile that happens because we emit an insn
with INSN_DELETED_P flag set; the insn then obviously does not get output
in the assembly file. The reason for this is that we've cached this insn
in the transformation cache and reused it after it was deleted from the
insn stream. The patch resetting the flag qualifies as obvious, but I've
discussed it additionally with Alexander, and will be committing it
shortly. (The bootstrap fail is actually a regression, also I don't see
how to make a (small) test case.)
Steven, we've been adding insns through add_insn_after and since you've
touched the code last, I wanted to ask you two things. First, do you want
an assert there that we do not add INSN_DELETED_P insns (like we have for
the "after" parameter in add_insn_after_nobb?) I have added one and it
didn't fail on the x86-64 bootstrap, which is no wonder since this one is
directly used by reorg and sel-sched only. Second, the comment for
add_insn_after about the BB parameter does not apply -- the code
immediately does
3871 void
3872 add_insn_after (rtx insn, rtx after, basic_block bb)
3873 {
3874 add_insn_after_nobb (insn, after);
3875 if (!BARRIER_P (after)
3876 && !BARRIER_P (insn)
3877 && (bb = BLOCK_FOR_INSN (after)))
so the bb parameter gets overwritten. Should that be fixed in line with
add_insn_before code?
Yours,
Andrey
2013-01-31 Andrey Belevantsev <a...@ispras.ru>
* sel-sched-ir.c (sel_gen_insn_from_expr_after): Reset INSN_DELETED_P on
the insn being emitted.
Index: sel-sched-ir.c
===================================================================
*** sel-sched-ir.c (revision 207299)
--- sel-sched-ir.c (working copy)
*************** sel_gen_insn_from_expr_after (expr_t exp
*** 1398,1403 ****
--- 1398,1408 ----
emit_expr = set_insn_init (expr, vinsn ? vinsn : EXPR_VINSN (expr),
seqno);
insn = EXPR_INSN_RTX (emit_expr);
+
+ /* The insn may come from the transformation cache, which may hold already
+ deleted insns, so mark it as not deleted. */
+ INSN_DELETED_P (insn) = 0;
+
add_insn_after (insn, after, BLOCK_FOR_INSN (insn));
flags = INSN_INIT_TODO_SSID;
