On Wed, 2008-03-19 at 18:59 -0700, Brian Dessent wrote: > The design of the x86_64 instruction set made some compromises for speed > and for keeping the size of the instructions down, namely that there are > very few instructions that take a full 64 bit operand... in fact > 'movabs' is the only one. All the rest all take 32 bit operands and the > address is calculated through either sign extension or as > %rip-relative. This is actually not a big deal because these days most I read that, but then how can I do the 64-bit immediate here: 11 0004 49BAEFCD movq $0x1234567890abcdef, %r10 # 64-bit immediate 11 AB907856 11 3412 12 000e 41BB7856 movl $0x12345678, %r11d # 32-bit immediate 12 3412 13 0014 6641BC34 movw $0x1234, %r12w # 16-bit immediate 13 12 14 0019 41B512 movb $0x12, %r13b # 8-bit immediate Thank you for your quote from x86_64 ELF. It's making sense to me now. I guess I jumped the gun a little when posing my question. I should've read some more. But I was getting stuck in my research trying to figure out what to read. You've helped me a great deal. Bob
