32bit => 64bit
汎用レジスタ増えた
eax, ebx, ecx, edx, ebp, esp, esi, edi rax, rbx, rcx, rdx, rbp, rsp, rsi, rdi '''r8, r9, r10, r11, r12, r13, r14, r15'''
さっぱり覚えられないレジスタ名
RAX(64) => EAX(32) => AX(16) => AH,AL(8) RSI(64) => ESI(32) => SI(16) => ,SIL(8) R8(64) => R8D(32) => R8W(16) => ,R8B(8)