[hjl@gnu-2 scalar]$ cat f.s .intel_syntax noprefix mov rax,DWORD PTR [rax] [hjl@gnu-2 scalar]$ as -o f.o f.s f.s: Assembler messages: f.s:2: Error: Incorrect register `%rax' used with `l' suffix But there is no %rax register in input.
Fixed by http://sourceware.org/ml/binutils/2007-01/msg00048.html