On Tue, Apr 15, 2014 at 02:09:34PM +0000, De Lara Guarch, Pablo wrote: > Hi, > > I have checked that on gcc-4.5, I get a compilation error due to the > following patch: > > > > Neil Horman reported that on x86-64 the upper half of %rbx would get > > > clobbered when the code was compiled PIC or PIE, because the > > > i386-specific code to preserve %ebx was incorrectly compiled. > > > > > > However, the code is really way more complex than it needs to be. > > > For one thing, the CPUID instruction only needs %eax (leaf) and %ecx > > > (subleaf) as parameters, and since we are testing for bits, we might > > > as well list the bits explicitly. Furthermore, we can use an array > > > rather than doing a switch statement inside a structure. > > > > > > Reported-by: Neil Horman <nhorman at tuxdriver.com> > > > Signed-off-by: H. Peter Anvin <hpa at linux.intel.com> > > > Signed-off-by: Neil Horman <nhorman at tuxdriver.com> > > The compilation error is: > > /root/dpdk/lib/librte_eal/common/eal_common_cpuflags.c: In function > 'rte_cpu_check_supported': > /root/dpdk/lib/librte_eal/common/eal_common_cpuflags.c:271:48: error: array > subscript is above array bounds > make[7]: *** [eal_common_cpuflags.o] Error 1 > > This error is not present in newer gcc versions (4.6 and above). > > Thanks, > > Pablo de Lara > DPDK SW Engineer >
What was the value of RTE_COMPILE_TIME_CPUFLAGS when you built your library? If you added defines for flag support that are not tested for yet in the cpu_feature_table, that would be the error you would see I think Regards Neil > -------------------------------------------------------------- > Intel Shannon Limited > Registered in Ireland > Registered Office: Collinstown Industrial Park, Leixlip, County Kildare > Registered Number: 308263 Business address: Dromore House, East Park, > Shannon, Co. Clare > > >
