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From: "rth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/31169] Bootstrap comparison error at revision 122821
Date: Thu, 29 Mar 2007 17:13:00 -0000 [thread overview]
Message-ID: <20070329171326.2480.qmail@sourceware.org> (raw)
In-Reply-To: <bug-31169-276@http.gcc.gnu.org/bugzilla/>
------- Comment #34 from rth at gcc dot gnu dot org 2007-03-29 18:13 -------
Actually, on second thought, I don't think the sign_bit_p change is legit:
Value ranges after VRP:
-mask_lo_1: [0, +INF] EQUIVALENCES: { } (0 elements)
+mask_lo_1: [0x0ffffffffffffffff, +INF] EQUIVALENCES: { } (0 elements)
lo_2: [0, +INF] EQUIVALENCES: { } (0 elements)
mask_hi_3: VARYING
hi_4: VARYING
@@ -8971,7 +8971,7 @@ mask_hi_38: VARYING
D.30338_41: [-1, 63] EQUIVALENCES: { } (0 elements)
lo_42: [0, +INF] EQUIVALENCES: { } (0 elements)
D.30339_44: [0, 64] EQUIVALENCES: { } (0 elements)
-mask_lo_45: [0, +INF] EQUIVALENCES: { } (0 elements)
+mask_lo_45: [0x0ffffffffffffffff, +INF] EQUIVALENCES: { } (0 elements)
D.30340_47: [22, 22] EQUIVALENCES: { D.30324_17 D.30324_96 } (2 elements)
D.30341_49: VARYING
D.30342_50: VARYING
@@ -9211,7 +9211,7 @@ sign_bit_p (exp, val)
# hi_4 = PHI <hi_34(13), 0(14)>
# mask_hi_3 = PHI <mask_hi_38(13), 0(14)>
# lo_2 = PHI <0(13), lo_42(14)>
- # mask_lo_1 = PHI <0x0ffffffffffffffff(13), mask_lo_45(14)>
+ # mask_lo_1 = PHI <0x0ffffffffffffffff(13), 0x0ffffffffffffffff(14)>
<L13>:;
D.30340_47 = 22;
D.30341_49 = val_102(D)->int_cst.int_cst.high;
@@ -9221,7 +9221,7 @@ sign_bit_p (exp, val)
<L16>:;
D.30343_52 = 22;
D.30344_54 = val_102(D)->int_cst.int_cst.low;
- D.30345_55 = D.30344_54 & mask_lo_1;
+ D.30345_55 = D.30344_54;
if (D.30345_55 == lo_2) goto <L42>; else goto <L20>;
<L20>:;
The VRP change for mask_lo_1 is correct; the two values that the variable
can obtain are 0xffff...ffff and 0x0fff...ffff. But removing the BIT_AND
is incorrect, afaics.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31169
next prev parent reply other threads:[~2007-03-29 17:13 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-14 2:59 [Bug tree-optimization/31169] New: " danglin at gcc dot gnu dot org
2007-03-14 20:03 ` [Bug tree-optimization/31169] " sje at cup dot hp dot com
2007-03-14 20:53 ` rguenth at gcc dot gnu dot org
2007-03-14 22:34 ` daney at gcc dot gnu dot org
2007-03-15 0:19 ` sje at cup dot hp dot com
2007-03-15 9:46 ` rguenth at gcc dot gnu dot org
2007-03-15 16:45 ` steven at gcc dot gnu dot org
2007-03-15 16:53 ` sje at cup dot hp dot com
2007-03-15 16:56 ` sje at cup dot hp dot com
2007-03-15 16:56 ` sje at cup dot hp dot com
2007-03-15 16:58 ` sje at cup dot hp dot com
2007-03-15 17:20 ` rguenth at gcc dot gnu dot org
2007-03-15 17:28 ` rguenth at gcc dot gnu dot org
2007-03-15 17:57 ` rguenth at gcc dot gnu dot org
2007-03-15 19:27 ` sje at cup dot hp dot com
2007-03-15 20:59 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-15 21:06 ` rguenth at gcc dot gnu dot org
2007-03-15 21:12 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-16 2:07 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-16 9:26 ` rguenth at gcc dot gnu dot org
2007-03-16 14:44 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-17 13:44 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-17 14:12 ` ghazi at gcc dot gnu dot org
2007-03-17 18:03 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-18 1:56 ` daney at gcc dot gnu dot org
2007-03-19 0:08 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-19 9:56 ` rguenth at gcc dot gnu dot org
2007-03-19 11:08 ` rguenth at gcc dot gnu dot org
2007-03-19 16:11 ` sje at cup dot hp dot com
2007-03-19 16:41 ` ghazi at gcc dot gnu dot org
2007-03-19 22:41 ` sje at cup dot hp dot com
2007-03-20 21:14 ` sje at cup dot hp dot com
2007-03-27 23:58 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-28 7:52 ` rguenth at gcc dot gnu dot org
2007-03-29 16:31 ` rth at gcc dot gnu dot org
2007-03-29 17:13 ` rth at gcc dot gnu dot org [this message]
2007-03-29 17:21 ` rth at gcc dot gnu dot org
2007-03-30 8:18 ` rguenth at gcc dot gnu dot org
2007-03-30 9:01 ` rguenth at gcc dot gnu dot org
2007-03-30 9:16 ` rguenth at gcc dot gnu dot org
2007-03-30 9:47 ` rguenth at gcc dot gnu dot org
2007-03-30 15:15 ` rth at gcc dot gnu dot org
2007-03-30 16:31 ` rth at gcc dot gnu dot org
2007-03-31 0:17 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-31 10:28 ` rguenth at gcc dot gnu dot org
2007-03-31 14:11 ` dave at hiauly1 dot hia dot nrc dot ca
2007-03-31 14:13 ` rguenth at gcc dot gnu dot org
2007-03-31 14:38 ` dave at hiauly1 dot hia dot nrc dot ca
2007-04-01 7:30 ` daney at gcc dot gnu dot org
2007-04-01 18:18 ` rth at gcc dot gnu dot org
2007-04-01 18:26 ` rth at gcc dot gnu dot org
2007-04-12 9:21 ` rguenth at gcc dot gnu dot org
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