LLVM: llc tool

NAME

SYNOPSIS

DESCRIPTION

The choice of architecture for the output assembly code is determined as follows:

• If the user has specified an architecture with the -m option, use that architecture.

• Examine the input LLVM bytecode file:
  • If it specifies little endian and a pointer size of 32 bits, select the x86 architecture.

  • If it specifies big endian and a pointer size of 64 bit pointers, select the SparcV9 architecture.

• If llc was compiled on an architecture for which it can generate code, select the architecture upon which llc was compiled.

• Print a message to the user asking him or her to specify the output architecture explicitly.

If filename is not specified, or if filename is -, llc reads its input from standard input. Otherwise, it will read its input from filename.

If the -o option is left unspecified, 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 as follows:

• If the file ends in .bc, then the .bc suffix is removed, and the .s suffix is appended.

• Otherwise, the .s suffix is appended to the input filename.

OPTIONS

• -f
  Overwrite output files

• -m<arch>
  Specify the architecture for which to generate assembly. Valid architectures are:

  x86

  IA-32 (Pentium and above)

  sparcv9

  SPARC V9

  c

  Emit C code

• -o <filename>
  Specify the output filename.

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

• -help
  Print a summary of command line options.

• -stats
  Print statistics.

• -time-passes
  Record the amount of time needed for each pass and print it to standard error.

X86 Specific Options

• -disable-fp-elim
  Disable frame pointer elimination optimization.

• -disable-pattern-isel
  Use the 'simple' X86 instruction selector (the default).

• -print-machineinstrs
  Print generated machine code.

• -regalloc=<ra>
  Specify the register allocator to use. The default is local. Valid register allocators are:

  simple

  Very simple register allocator

  local

  Local register allocator

  linearscan

  Linear scan global register allocator (experimental)

• -spiller=<sp>
  Specify the spiller to use for register allocators that support it. Currently this option is used by the linear scan register allocator. The default is local. Valid spillers are:

  simple

  Simple spiller

  local

  Local spiller

Sparc Specific Options

• -disable-peephole
  Disable peephole optimization pass.

• -disable-sched
  Disable local scheduling pass.

• -disable-strip
  Do not strip the LLVM bytecode included in executable.

• -enable-maps
  Emit LLVM-to-MachineCode mapping info to assembly.

EXIT STATUS

SEE ALSO