http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58485
Bug ID: 58485
Summary: [4.9 Regression] GMP test on subnormal fails with LTO
and -O3
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: vincent-gcc at vinc17 dot net
When I build GMP with
GNU MP config.status 5.1.2
configured by ./configure, generated by GNU Autoconf 2.69,
with options "'--disable-shared' 'CC=gcc-snapshot' 'CFLAGS=-march=native -O3
-flto=jobserve -fuse-linker-plugin'"
one of the tests fails:
mpn_get_d wrong on denorm
n=1
exp -1020
sign 0
got =[00 00 00 00 00 00 F0 7F] inf
want =[00 00 00 00 00 00 30 00] 8.9002954340288055324e-308
with:
gcc (Debian 20130917-1) 4.9.0 20130917 (experimental) [trunk revision 202647]
This doesn't occur if I replace -O3 by -O2 or if I do not enable LTO.
This doesn't occur either with the same options as above and:
gcc-4.8.real (Debian 4.8.1-10) 4.8.1
gcc-4.7.real (Debian 4.7.3-7) 4.7.3
