Example Programs

• Hello world: hello.ic, hello.s
• Fibonacci computation: fib.ic, fib.s
• Objects example: objects.ic, objects.s


Calling conventions

• Function arguments pushed on stack in reverse order
• Return value stored in %rax register (not on stack)
• Caller-saved registers: %rax, %rcx, %rdx, %rdi, %rsi, %r8-%r11
• Callee-saved registers: %rbx, %rbp, %rsp %r12-%r15
  

x86_64 Instruction Set Architecture

• Duane Bailey's summary of the x86_64 architecture
• Intel Architecture Software Developer's Manual
1. Basic Architecture
2. Instruction Set Reference
3. System Programming Guide
• Intel Architecture Optimization Manual
• Gentle Introduction to x86-64 Assembly
• x86-64 Machine-Level Programming

Other Tools

• GDB, the GNU debugger
• Documentation for the as assembler: Postscript, HTML (uses the AT&T syntax)
  

AT&T versus Intel Syntax

	AT&T	Intel
Order of operands	op a,b  means  b = a op b  (second operand is destination)	op a, b   means  a = a op b (first operand is destination)
Memory addressing	disp(base, offset, scale)	[base + offset*scale + disp]
Size of memory operands	instruction suffixes (b,w,l,q) (e.g., movb, movw, movl,movq)	operand prefixes (e.g., byte ptr, word ptr, dword ptr, qword ptr)
Registers	%rax, %rbx, etc.	rax, rbx, etc.
Constants	$4, $foo, etc	4, foo, etc

Assembling and linking commands

To assemble and link the file "file.s" on our Linux lab computers, use:

gcc -m64 -g -o file.exe file.s libic64.a


The -m64 flag turns on 64-bit mode. The -g flag causes debugging info to be placed in the executable.

The library file libic64.a is a collection of .o files bundled together, containing the code for all of the library functions defined in the language specification, along with run-time support for garbage collection.

The IC library is also available for Intel Macs running FreeBSD: libic64.osx.a.