After upgrade to glibc-2.25-9.fc26.i686 specialized SSE/AVX versions of memcpy() and other string functions are not available. Only 32-bit build of glibc is affected. $ objdump -t /lib/libc-2.25.so | grep memcpy | grep sse $ objdump -t /lib64/libc-2.25.so | grep memcpy | grep sse 00000000000979c0 l F .text 0000000000000009 __memcpy_chk_sse2_unaligned_erms 00000000000979d0 l F .text 00000000000002f9 __memcpy_sse2_unaligned_erms 0000000000163e70 l F .text 0000000000002ab6 __memcpy_ssse3_back 0000000000097920 l F .text 0000000000000009 __memcpy_chk_sse2_unaligned 0000000000163e60 l F .text 0000000000000009 __memcpy_chk_ssse3_back 000000000015e900 l F .text 00000000000029b6 __memcpy_ssse3 000000000015e8f0 l F .text 0000000000000009 __memcpy_chk_ssse3 0000000000097930 l F .text 0000000000000028 __memcpy_sse2_unaligned
This change is deliberate, see bug 1471427.