Provided by: llvm-6.0_6.0-1ubuntu2~16.04.1_amd64 
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 described below.
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, and -O3
optimization levels used by 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 CPUs, use:
llvm-as < /dev/null | llc -march=xyz -mcpu=help
-filetype=<output file type>
Specify what kind of output llc should generated. Options are: asm for textual assembly ( '.s'),
obj for native object files ('.o') and null for not emitting anything (for performance testing).
Note that not all targets support all options.
-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-no-infs-fp-math
Enable optimizations that assume no Inf values.
--enable-no-nans-fp-math
Enable optimizations that assume no NAN values.
--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).
--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.
-meabi=[default|gnu|4|5]
Specify which EABI version should conform to. Valid EABI versions are gnu, 4 and 5. Default
value (default) depends on the triple.
-stack-size-section
Emit the .stack_sizes section which contains stack size metadata. The section contains an array of
pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128). The stack size
values only include the space allocated in the function prologue. Functions with dynamic stack
allocations are not included.
Tuning/Configuration Options
--print-machineinstrs
Print generated machine code between compilation phases (useful for debugging).
--regalloc=<allocator>
Specify the register allocator to use. Valid register allocators are:
basic
Basic register allocator.
fast
Fast register allocator. It is the default for unoptimized code.
greedy
Greedy register allocator. It is the default for optimized code.
pbqp
Register allocator based on 'Partitioned Boolean Quadratic Programming'.
--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
AUTHOR
Maintained by The LLVM Team (http://llvm.org/).
COPYRIGHT
2003-2018, LLVM Project