| Value | Meaning | 
|---|---|
| x86 | Intel and AMD 32-bit processors | 
| x86_64 | Intel and AMD 64-bit processors | 
| arm | The ARM architecture (32-bit) (AArch32 et al) | 
| aarch64 | The Advanced RISC Machine architecture (64-bit) | 
| asmJS | The asm.js intermediate programming language | 
| avr | 8-bit Atmel AVR Microcontrollers | 
| epiphany | The Epiphany architecture | 
| ppc | The PowerPC architecture, 32-bit | 
| ppc64 | The PowerPC architecture, 64-bit | 
| ia64 | The Itanium architecture (64-bit) | 
| mips32 | The MIPS architecture, 32-bit | 
| mips64 | The MIPS architecture, 64-bit | 
| msp430 | The MSP430 architecture | 
| nvptx | The Nvidia Parallel Thread Execution (PTX) architecture, 32-bit | 
| nvptx64 | The Nvidia Parallel Thread Execution (PTX) architecture, 64-bit | 
| riscv32 | The RISC-V architecture, 32-bit | 
| riscv64 | The RISC-V architecture, 64-bit | 
| sparc | The SPARC architecture, 32-bit | 
| sparc64 | The SPARC architecture, 64-bit | 
| s390 | The System/390 architecture, 32-bit | 
| systemZ | The System Z architecture, 64-bit | 
| hppa | The HP PA-RISC architecture, 32-bit | 
| hppa64 | The HP PA-RISC architecture, 64-bit | 
| sh | The SuperH architecture, 32-bit | 
| webAssembly | The WebAssembly virtual ISA (instruction set architecture), 32-bit | 
| alpha | The Alpha architecture | 
| unknown | Unknown | 
Instruction Set Architecture.
Note: This is intended for cases where you need a value representing the instruction set architecture at runtime. If you're doing something which should compile differently depending on instruction set architecture, then please use version (X86_64), version (ARM), etc.