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[Bug tree-optimization/31081] [4.3 Regression] Inliner messes up SSA for abnormals
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 3 Dec 2007 02:44:07 -0000
- Subject: [Bug tree-optimization/31081] [4.3 Regression] Inliner messes up SSA for abnormals
- References: <bug-31081-6528@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #9 from pinskia at gcc dot gnu dot org 2007-12-03 02:44 -------
>From PR 30604:
OK, new investigation show that using the smaller testcase firebird2-nav.cc
shows the inliner is misbehaving.
before inlining (*041t.profile):
# BLOCK 2 freq:10000
# PRED: ENTRY [100.0%] (fallthru,exec)
D.2709_4 = request_3(D)->req_pool;
D.2710_5 = (struct blk *) D.2709_4;
D.2711_6 = request_3(D)->req_transaction;
D.2712_10 = VIO_get (tdbb_7(D), rpb_8(D), rsb_9(D), D.2711_6, D.2710_5);
# SUCC: 4 (ab,eh,exec) 3 [100.0%] (fallthru,exec)
# BLOCK 3 freq:10000
# PRED: 2 [100.0%] (fallthru,exec)
result_12(ab) = (BOOLEAN) D.2712_10;
<...>
BTR_key (tdbb_7(D), D.2719_20, D.2718_19, D.2717_18, &value, 0B);
goto <bb 5>;
# SUCC: 4 (ab,eh,exec) 5 [100.0%] (fallthru,exec)
# BLOCK 4
# PRED: 2 (ab,eh,exec) 3 (ab,eh,exec)
# result_1(ab) = PHI <result_11(ab)(2), result_12(ab)(3)>
<L0>:;
<...>
# BLOCK 5 freq:10000
# PRED: 3 [100.0%] (fallthru,exec) 4 [100.0%] (fallthru,exec)
# result_2 = PHI <result_12(ab)(3), result_1(ab)(4)>
return result_2;
# SUCC: EXIT [100.0%]
and after inlining (*046i.inline) we see:
<bb 2>:
<bb 7>:
D.2882_11 = request_9(D)->req_pool;
D.2883_12 = (struct blk *) D.2882_11;
D.2884_13 = request_9(D)->req_transaction;
D.2885_14 = VIO_get (tdbb_8(D), rpb_3(D), rsb_1(D), D.2884_13, D.2883_12);
<bb 3>:
result_15(ab) = (BOOLEAN) D.2885_14;
<...>
BTR_key (tdbb_8(D), D.2892_22, D.2891_21, D.2890_20, &value, 0B);
goto <bb 5>;
# result_24(ab) = PHI <result_10(ab)(7), result_15(ab)(3)>
<L4>:;
<...>
<bb 5>:
# result_23 = PHI <result_15(ab)(3), result_24(ab)(4)>
if (result_23 != 0)
goto <bb 6>;
else
goto <bb 7>;
<bb 6>:
return 1;
Basic block 7 is missing a PHI node which should merge result_23 and result_10.
The result of this missing PHI should then be used in block 5 instead of
result_10.
The way it currently sits, result 10 is live through basic block 3, which makes
it conflict with result_15, and makes the abnormal edges uncoalescable.
Someone familiar with the inliner can probably fix this quickly. I took a quick
look but its a different world in there :-)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31081