https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78879
Bug ID: 78879
Summary: -fprofile-generate causes undefined reference to
`____ilog2_NaN'
Product: gcc
Version: 6.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: coolypf at qq dot com
Target Milestone: ---
Created attachment 40385
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40385&action=edit
test case
When building Linux kernel 3.10 for aarch64 with -fprofile-generate, I
encountered undefined reference to `____ilog2_NaN'. Here are steps to
reproduce:
coolypf@experiment:~$ aarch64-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=aarch64-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/aarch64-linux-gnu/6.2.1/lto-wrapper
Target: aarch64-linux-gnu
Configured with: ../gcc/configure --enable-languages=c --disable-threads
--disable-nls --disable-tls --disable-plugin --disable-bootstrap
--disable-werror --enable-cloog-backend=isl --disable-lto --enable-multiarch
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=aarch64-linux-gnu
Thread model: single
gcc version 6.2.1 20161221 (GCC)
coolypf@experiment:~$ aarch64-linux-gnu-gcc -c -O2 test.i
coolypf@experiment:~$ nm test.o | grep ilog2
coolypf@experiment:~$ aarch64-linux-gnu-gcc -c -O2 -fprofile-generate test.i
coolypf@experiment:~$ nm test.o | grep ilog2
U ____ilog2_NaN
Related source code location is
http://lxr.free-electrons.com/source/drivers/scsi/sd.c?v=3.10#L2197
