


LLC(1)                  LLVM Command Guide                 LLC(1)


NAME
       llc - LLVM static compiler

SYNOPSIS
       llc [options] [filename]

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

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

OPTIONS
       If filename is - or omitted, llc reads from standard input.  Otherwise,
       it will from filename.  Inputs can be in either the LLVM assembly
       language format (.ll) or the LLVM bitcode format (.bc).

       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:

   End-user Options
       -help
           Print a summary of command line options.

       -O=uint
           Generate code at different optimization levels. These correspond to
           the -O0, -O1, -O2, -O3, and -O4 optimization levels used by llvm-
           gcc and clang.

       -mtriple=target triple
           Override the target triple specified in the input file with the
           specified string.

       -march=arch
           Specify the architecture for which to generate assembly, overriding
           the target encoded in the input file.  See the output of llc -help
           for a list of valid architectures.  By default this is inferred
           from the target triple or autodetected to the current architecture.

       -mcpu=cpuname
           Specify a specific chip in the current architecture to generate
           code for.  By default this is inferred from the target triple and
           autodetected to the current architecture.  For a list of available



CVS                         2010-05-06                          1





LLC(1)                  LLVM Command Guide                 LLC(1)


           CPUs, use: llvm-as < /dev/null | llc -march=xyz -mcpu=help

       -mattr=a1,+a2,-a3,...
           Override or control specific attributes of the target, such as
           whether SIMD operations are enabled or not.  The default set of
           attributes is set by the current CPU.  For a list of available
           attributes, use: llvm-as < /dev/null | llc -march=xyz -mattr=help

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

       --disable-excess-fp-precision
           Disable optimizations that may produce excess precision for
           floating point.  Note that this option can dramatically slow down
           code on some systems (e.g. X86).

       --enable-unsafe-fp-math
           Enable optimizations that make unsafe assumptions about IEEE math
           (e.g. that addition is associative) or may not work for all input
           ranges.  These optimizations allow the code generator to make use
           of some instructions which would otherwise not be usable (such as
           fsin on X86).

       --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.

       --stats
           Print statistics recorded by code-generation passes.

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

       --load=dso_path
           Dynamically load dso_path (a path to a dynamically shared object)
           that implements an LLVM target. This will permit the target name to
           be used with the -march option so that code can be generated for
           that target.

   Tuning/Configuration Options
       --print-machineinstrs
           Print generated machine code between compilation phases (useful for
           debugging).

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

           simple
               Very simple "always spill" register allocator





CVS                         2010-05-06                          2





LLC(1)                  LLVM Command Guide                 LLC(1)


           local
               Local register allocator

           linearscan
               Linear scan global register allocator

           iterativescan
               Iterative scan global register allocator

       --spiller=spiller
           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
               Simple spiller

           local
               Local spiller

   Intel IA-32-specific Options
       --x86-asm-syntax=att|intel
           Specify whether to emit assembly code in AT&T syntax (the default)
           or intel syntax.

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

SEE ALSO
       lli

AUTHORS
       Maintained by the LLVM Team (<http://llvm.org>).























CVS                         2010-05-06                          3


