Hi, On i386, "66 e8 26 00" should be disassemble as "CALLW 0x2a", but currently llvm-mc fails, as demonstrated below. Thanks. Jun $ echo "0x66,0xe8,0x26,0x00" | ./Release+Asserts/bin/llvm-mc -triple=i386-unknown-unknown -disassemble -show-encoding .text <stdin>:1:1: warning: invalid instruction encoding 0x66,0xe8,0x26,0x00 ^ <stdin>:1:11: warning: invalid instruction encoding 0x66,0xe8,0x26,0x00 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140113/8ee07ff0/attachment.html>