#source: call1.s #as: --64 #ld: -melf_x86_64 -z call-nop=prefix-0x90 #objdump: -dw .*: +file format .* Disassembly of section .text: #... [ ]*[a-f0-9]+: 90 nop [ ]*[a-f0-9]+: e8 ([0-9a-f]{2} ){4} * callq +[a-f0-9]+ #pass