llc - LLVM static compiler
llc [options] [filename]
LLC(1) LLVM 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 exe-
cutable.
The choice of architecture for the output assembly code is automati-
cally 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. Other-
wise, 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 speci-
fied, then llc creates the output filename by taking the input file-
name, 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 <filename>
Use <filename> as the output filename. See the summary above for
more details.
-O=uint
Generate code at different optimization levels. These corre-
spond 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, over-
riding 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 test-
ing).
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
--frame-pointer
Specify effect of frame pointer elimination optimization
(all,non-leaf,none).
--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-no-signed-zeros-fp-math
Enable FP math optimizations that assume the sign of 0 is
insignificant.
--enable-no-trapping-fp-math
Enable setting the FP exceptions build attribute not to use
exceptions.
--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 ver-
sions are gnu, 4 and 5. Default value (default) depends on the
triple.
-stack-size-section
Emit the .stack_sizes section which contains stack size meta-
data. The section contains an array of pairs of function symbol
values (pointer size) and stack sizes (unsigned LEB128). The
stack size values only include the space allocated in the func-
tion prologue. Functions with dynamic stack allocations are not
included.
-remarks-section
Emit the __remarks (MachO) section which contains metadata about
remark diagnostics.
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 alloca-
tors 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 reg-
ister 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.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+---------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+---------------------+
|Availability | developer/llvm/llvm |
+---------------+---------------------+
|Stability | Uncommitted |
+---------------+---------------------+
SEE ALSO
lli(1)
AUTHOR
Maintained by the LLVM Team (https://llvm.org/).
COPYRIGHT
2003-2022, LLVM Project
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from https://github.com/llvm/llvm-
project/releases/download/llvmorg-11.0.0/llvm-11.0.0.src.tar.xz.
Further information about this software can be found on the open source
community website at https://llvm.org/.
11 2022-06-28 LLC(1)