http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48783
Summary: ARM: kernel compiled at -O2 has a unused reference to
__aeabi_uldivmod
Product: gcc
Version: 4.5.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: michael.h...@linaro.org
Created attachment 24107
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24107
Preprocessed source
When compiled, the attached code refers to the 64 bit unsigned divmod helper
function '__aeabi_uldivmod' even though the function is never called. This
causes a link error when cross-compiling an ARM Linux 2.6.38 kernel.
To reproduce:
* Make a arm-linux-gnueabi cross compiler configured with --with-mode=thumb
--with-arch=armv7-a --with-tune=cortex-a9 --with-float=softfp --with-fpu=neon
* Compile the attached code with 'arm-linux-gnueabi-gcc -O2 -S wm8974.i'
* See a '.global __aeabi_uldivmod' in the header of wm8974_set_dai_pll
Marking pll_factors() as noinline or putting asm("" : "+r"(source)); before the
call to do_div() works around the problem.
