On 4 July 2013 18:33, Richard Henderson <r...@twiddle.net> wrote: > On 07/04/2013 04:02 AM, Peter Maydell wrote: >>> + unsigned long hwcap = getauxval(AT_HWCAP); >>> + use_idiv_instructions = hwcap & (HWCAP_ARM_IDIVA | >>> HWCAP_ARM_IDIVT); >> >> Doesn't this mean we'll try to use the ARM division >> insns even if the CPU only supports the Thumb encodings? >> I think you should only be testing for whether HWCAP_ARM_IDIVA >> is set. > > I suppose. Though later kernels have actually merged these bits: > > uapi/asm/hwcap.h:27:#define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT)
Yes, but the two bits are still separate values: #define HWCAP_IDIVA (1 << 17) #define HWCAP_IDIVT (1 << 18) Presumably the HWCAP_IDIV is if you want to check that you have full division support via (hwcap & HWCAP_IDIV) == HWCAP_IDIV We could do that if you prefer; it would be effectively the same as just testing the IDIVA bit though. -- PMM
