This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug rtl-optimization/19097] Lots of else ifs take forever to compile
- From: "steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 23 Dec 2004 01:43:37 -0000
- Subject: [Bug rtl-optimization/19097] Lots of else ifs take forever to compile
- References: <20041221015654.19097.phython@gcc.gnu.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From steven at gcc dot gnu dot org 2004-12-23 01:43 -------
This looks like a problem with the hash function for a REG when we
have many implicit sets:
Found 6001 implicit sets
SET hash table (6001 buckets, 6001 entries)
Index 0 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 1 [0x1]))
Index 1 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10000 [0x2710]))
Index 2 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10001 [0x2711]))
Index 3 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10002 [0x2712]))
Index 4 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10003 [0x2713]))
Index 5 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10004 [0x2714]))
Index 6 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10005 [0x2715]))
Index 7 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10006 [0x2716]))
Index 8 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10007 [0x2717]))
Index 9 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10008 [0x2718]))
Index 10 (hash value 58)
(set (reg/v:SI 58 [ b ])
(const_int 10009 [0x2719]))
(etc.)
Needless to say, this results in truely dramatically bad compile
time behavior of the hash table.
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |roger at eyesopen dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19097