CS107 Guide to x86-64
See also our x86-64 sheet for a compact one-page reference. Registers. The table below lists the commonly used registers (sixteen general-purpose plus two special). Each register is 64 bits …
x86 Assembly/16, 32, and 64 Bits
The names of the 64-bit registers are the same of those of the 32-bit registers, except beginning with an 'R'. ... R8W, and R8D, respectively. 64-bit versions of x86 also allow the low byte of RSP, RBP, RSI, RDI to be accessed directly. For example, the low byte of RSP can be accessed using SPL. There is no way to directly access bits 8–15 of ...
x64 ABI conventions | Microsoft Learn
Two important differences between x86 and x64 are: 64-bit addressing capability; Sixteen 64-bit registers for general use. Given the expanded register set, x64 uses the __fastcall calling convention and a RISC-based exception-handling model. The __fastcall convention uses registers for the first four arguments, and the stack frame to pass more ...
x86-64-guide
x86-64 overview - x86-64 is a 64-bit version of the x86 ISA - Originally specified in 2000 by AMD as an alternative to IA-64 ("Itanium") - CISC ISA, so we have: ... - 16 64-bit "general purpose" registers - Many have a special purpose (e.g., stack pointer) - Each can be accessed as a 64/32/16/8-bit value (typically LSBs) ...
x86-64 Register Cheatsheet | Jason Turley's Website
x86-64 Register Cheatsheet. 22 Jun, 2024. Notes for x86-64 registers and useful pwning info. References. https://wiki.osdev/CPU_Registers_x86-64; CPU Registers
x86 Registers Cheat Sheet
Contribute to 0pie/x86-Registers-cheat-sheet development by creating an account on GitHub. ... 32/64-bit General-Purpose Registers: Name Meaning Purpose; EAX/RAX: Accumulator: Stores calculation results: EBX/RBX: Base: Points to data in memory: ECX/RCX: Counter: Used for loops: EDX/RDX: Data:
The x86-64 processor (aka amd64, x64): Whirlwind tour
Eight new 64-bit registers were introduced, bring the total to 16. Instead of giving quirky names to the new registers, they are just numbered: r8 through r15. To match the existing classic registers, the new registers also have aliases for referring to partial registers, and partial register aliases were invented for some of the classic ...
X86 64 Register and Instruction Quick Start
Registers General-Purpose Registers. The 64-bit versions of the 'original' x86 registers are named: rax - register a extended; rbx - register b extended
X86-64 Architecture Guide
29 rowsThe caller uses registers to pass the first 6 arguments to the callee. Given the arguments in left-to-right order, the order of registers used is: %rdi, %rsi, %rdx, %rcx, %r8, …
Assembly Language Registers
Systems with x86 architecture have only 32-bit registers, while x64 systems have 64-bit registers. The size of a CPU's registers is a fundamental aspect that determines the amount of data they can handle. Another way of saying this is …
x64 calling convention | Microsoft Learn
The registers used for these arguments depend on the position and type of the argument. Remaining arguments get pushed on the stack in right-to-left order. ... 64-bit result __int64 func1(int a, float b, int c, int d, int e); // Caller passes a in RCX, b in XMM1, c in R8, d in R9, e pushed on stack, // callee returns __int64 result in RAX ...
x64 vs. x86: Key Differences
The processor stores frequently used data in a register for quick access. A 32-bit processor on x86 architecture has 32-bit registers, while 64-bit processors have 64-bit registers. Thus, x64 allows the CPU to store more data and access it faster. The register width also determines the amount of memory a computer can utilize.
CPU Registers x86
NOTE: This register is the only control register that can be written and read via 2 ways unlike the other that can be accessed only via the MOV instruction. Reserved, the CPU will throw a #UD …
Guide to x86-64
x86-64 (also known as just x64 and/or AMD64) is the 64-bit version of the x86/IA32 instruction set. Below is our overview of its features that are relevant to CS107. There is more extensive coverage on these topics in Chapter 3 of the B&O textbook. ... Some registers are designated for a certain purpose, such as %rsp being used as the stack ...
x86-64 Instructions and ABI 1 Introduction
The x86-64 has sixteen 64-bit registers. In the AT&T assembler syntax registers are denoted with a leading "%" character. Some registers have special roles, for example the %rdx and %rax register ... Figure 1: The x86-64 general-purpose registers The ret instruction pops the return address off the stack and jumps to it. The registers %rbp ...
CS107 Guide to x86-64
See also our x86-64 sheet for a compact one-page reference. Registers. The table below lists the commonly used registers (sixteen general-purpose plus two special). Each register is 64 bits wide; the lower 32-, 16- and 8-bit portions are selectable by a pseudo-register name.
Registers in x86 Assembly
Here's the full list of x86 registers. The 64 bit registers are shown in red. "Scratch" registers any function is allowed to overwrite, and use for anything you want without asking anybody. "Preserved" registers have to be put back ("save" the register) if you use them. Name: Notes: Type: 64-bit long: 32-bit int: 16-bit short: 8-bit ...
x64 Cheat Sheet
There are sixteen 64-bit registers in x86-64: %rax, %rbx, %rcx, %rdx, %rdi, %rsi, %rbp, %rsp, and %r8-r15. Of these, %rax, %rcx, %rdx, %rdi, %rsi, %rsp, and %r8-r11 are considered caller …
CS107 x86-64 Reference Sheet
CS107 x86-64 Reference Sheet Registers %rip Instruction pointer %rsp Stack pointer %rax Return value %rdi 1st argument %rsi 2nd argument %rdx 3rd argument %rcx 4th argument ...
CS107 Guide to x86-64
There is more extensive coverage on these topics in Chapter 3 of the B&O textbook. See also our x86-64 sheet for a compact reference. Registers. The table below lists the commonly used registers (sixteen general-purpose plus two special). Each register is 64 bits wide; the lower 32-, 16- and 8-bit portions are selectable by a pseudo-register name.
Intel x86 Assembly Language & Microarchitecture Tutorial => 64-bit...
Intel ended up following AMD's design in their versions of the 64-bit architecture. The 64-bit design made a number of changes to the register set, while still being backward compatible: The existing general-purpose registers were extended to 64 bits, and named with an R prefix: RAX, RBX, RCX, RDX, RSI, RDI, RBP, and RSP.
x86-64 Register Cheatsheet | Jason Turley's Website
Registers Notes; 64-bit 32-bit 16-bit 8-bit high 8-bit low; RAX: EAX: AX: AH: AL: Accumulator. Stores return value: RBX: EBX: BX: BH: BL: Base: RCX: ECX: CX: CH: CL ...
x86 Assembly, 64 bit
1.2 Registers Modern 64-bit x86 processors have sixteen 64-bit general purpose registers, as depicted in Figure 1.1. The register names for the first eight registers are mostly historical in nature; the last eight registers were given sequential numbers. For example, RAX used to be EAX (in the 32-bit machine), which used to be called
How many registers does an x86-64 CPU have?
General-purpose registers. The general-purpose registers (or GPRs) are the primary registers in the x86-64 register model. As their name implies, they are the only registers that are general purpose: each has a set of …
x64 Architecture
x64 extends x86's 8 general-purpose registers to be 64-bit, and adds 8 new 64-bit registers. The 64-bit registers have names beginning with "r". For example, the 64-bit …
X86-64 Architecture Guide
This section presents a guide to the X86-64 instruction set and architecture. Includes example code, a link to a more complete reference, and information on registers, instruction set, stack organization, and calling convention.
x86_64 NASM Assembly Quick Reference ("Cheat Sheet")
The 64 bit registers are shown in red. "Scratch" registers any function is allowed to overwrite, and use for anything you want without asking anybody. ... Instructions (basically identical to 32-bit x86) For gory instruction set details, read this per-instruction reference, or the full Intel PDFs: part 1 (A-M) and part 2 (N-Z). Mnemonic:
CPU Registers x86-64
Note: you cannot access AH, BH, CH and DHwhen using the REX.W instruction prefix.This prefix is added (automatically by assemblers) when an operand contains a 64-bit register.
x86_64 NASM Assembly Quick Reference ("Cheat Sheet")
Here's the full list of ordinary integer x86 registers. The 64 bit registers are shown in red. "Scratch" registers any function is allowed to overwrite, and use for anything you want without asking …
How many registers does an x86_64 CPU actually have?
There are extensions that certain AMD64 based CPUs support/implement that extend the set of XMM registers available. The XMM (and later YMM and ZMM) are currently extended to up to 32 registers of 512 bit each in AVX-512. Similar to general registers, XMM registers allow access to the lower parts of their YMM and ZMM counterparts.