Processor atlas
CPU references for people writing code close to metal
Registers, ABI notes, instruction families, operating-system boundaries, object formats, and practical drills for x86-64, ARM64, and RISC-V.
Architecture desks
64-bit long mode, 32-bit compatibility views
x86-64
The dominant desktop and server ISA for operating systems, compilers, debuggers, hypervisors, game engines, binary tools, exploit research, and performance work.
General-purpose registersFlags and control flowAddressing modesStack framesSIMD and vector codeAtomics and memory ordering
64-bit X registers with 32-bit W viewsARM64 / AArch64
A load/store 64-bit architecture used in phones, Apple Silicon, servers, embedded boards, secure firmware, kernels, and modern performance-sensitive software.
X/W registersVector registersLoad/store addressingBranches and conditionsException levelsSystem registers
RV32, RV64, RV128 profilesRISC-V
A modular open ISA used for education, research, embedded systems, Linux-capable cores, open hardware, compiler work, and architecture experimentation.
Base integer ISAM/A/F/D/C/V extensionsRegister ABICSRsTraps and privilegePaging