llc - LLVM static compiler


llc [options] [filename]


The llc command compiles LLVM bytecode into assembly language for a specified architecture. The assembly language output can then be passed through a native assembler and linker to generate native code.

The choice of architecture for the output assembly code is automatically determined from the input bytecode file, unless a -m option is used to override the default.


If filename is - or omitted, llc reads LLVM bytecode from standard input. Otherwise, it will read LLVM bytecode from filename.

If the -o option is omitted, then llc will send its output to standard output if the input is from standard input. If the -o option specifies -, then the output will also be sent to standard output.

If no -o option is specified and an input file other than - is specified, then llc creates the output filename by taking the input filename, removing any existing .bc extension, and adding a .s suffix.

Other llc options are as follows:

Overwrite output files. By default, llc will refuse to overwrite an output file which already exists.

Specify the architecture for which to generate assembly. Valid architectures are:
Intel IA-32 (Pentium and above)

32-bit PowerPC (MacOS X, 32-bit ABI)

64-bit SPARC V9

Emit C code, not assembly

Disable frame pointer elimination optimization.

Instruct the lowerinvoke pass to insert code for correct exception handling support. This is expensive and is by default omitted for efficiency.

Print a summary of command line options.

Print statistics recorded by code-generation passes.

Record the amount of time needed for each pass and print a report to standard error.

Print generated machine code between compilation phases (useful for debugging).

Specify the register allocator to use. The default allocator is local. Valid register allocators are:
Very simple ``always spill'' register allocator

Local register allocator

Linear scan global register allocator

Iterative scan global register allocator

Specify the spiller to use for register allocators that support it. Currently this option is used only by the linear scan register allocator. The default spiller is local. Valid spillers are:
Simple spiller

Local spiller

Intel IA-32-specific Options

Specify whether to emit assembly code in AT&T syntax (the default) or intel syntax.

SPARCV9-specific Options

Disable peephole optimization pass.

Disable local scheduling pass.


If llc succeeds, it will exit with 0. Otherwise, if an error occurs, it will exit with a non-zero value.




Maintained by the LLVM Team (