A Basic Look At How The LLVM Compiler Works

Posted by Michael Larabel on November 29, 2012

The LLVM compiler infrastructure is frequently talked about on Phoronix whether it be about its Clang C/C++ compiler or one of the innovative use-cases for LLVM such as with the LLVMpipe Gallium3D driver or as a JIT engine within some free software projects like Mono. However, for those that don't understand much of the internals of LLVM, here's a brief overview.

The LLVM project has posted a new blog entry about the life of an instruction in LLVM.

This blog post basically goes over the process of LLVM's multiple compilation stages in how C source-code is ultimately parsed and then transformed and lowered into binary machine code.

This isn't too technical of a posting but rather just a nice overview of the LLVM process. Covered processes include starting out with Clang and generated LLVM IR, SelectionDAG instruction selection, scheduling and emitting a machine instruction, register allocatio, emitting code, the MC layer, and then the assemblers/disassemblers.

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