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[Bug middle-end/57370] New: [4.9 Regression] compile time hog in reassoc
- From: "Joost.VandeVondele at mat dot ethz.ch" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 22 May 2013 14:18:11 +0000
- Subject: [Bug middle-end/57370] New: [4.9 Regression] compile time hog in reassoc
- Auto-submitted: auto-generated
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370
Bug ID: 57370
Summary: [4.9 Regression] compile time hog in reassoc
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: Joost.VandeVondele at mat dot ethz.ch
Between rev 199047 and 199075 the attached testcase started using an excessive
amount of time (up from about 4s with 4.7.2). The important option seems to be
-ffast-math (16s without this option).
Reproduce with:
time gfortran -c -g -O2 -ffast-math bug.f90
The stack looks like:
#0 0x0000000000af4b79 in reassociate_bb(basic_block_def*) ()
#1 0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#2 0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#3 0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#4 0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#5 0x0000000000af6701 in execute_reassoc() ()
#6 0x0000000000906550 in execute_one_pass(opt_pass*) ()