mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-30 17:33:24 +00:00
dff966c9d8
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168912 91177308-0d34-0410-b5e6-96231b3b80d8
188 lines
5.2 KiB
ReStructuredText
188 lines
5.2 KiB
ReStructuredText
llc - LLVM static compiler
|
|
==========================
|
|
|
|
SYNOPSIS
|
|
--------
|
|
|
|
:program:`llc` [*options*] [*filename*]
|
|
|
|
DESCRIPTION
|
|
-----------
|
|
|
|
The :program:`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 :option:`-march` option is used to
|
|
override the default.
|
|
|
|
OPTIONS
|
|
-------
|
|
|
|
If ``filename`` is "``-``" or omitted, :program:`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 :option:`-o` option is omitted, then :program:`llc` will send its output
|
|
to standard output if the input is from standard input. If the :option:`-o`
|
|
option specifies "``-``", then the output will also be sent to standard output.
|
|
|
|
If no :option:`-o` option is specified and an input file other than "``-``" is
|
|
specified, then :program:`llc` creates the output filename by taking the input
|
|
filename, removing any existing ``.bc`` extension, and adding a ``.s`` suffix.
|
|
|
|
Other :program:`llc` options are described below.
|
|
|
|
End-user Options
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
.. option:: -help
|
|
|
|
Print a summary of command line options.
|
|
|
|
.. option:: -O=uint
|
|
|
|
Generate code at different optimization levels. These correspond to the
|
|
``-O0``, ``-O1``, ``-O2``, and ``-O3`` optimization levels used by
|
|
:program:`llvm-gcc` and :program:`clang`.
|
|
|
|
.. option:: -mtriple=<target triple>
|
|
|
|
Override the target triple specified in the input file with the specified
|
|
string.
|
|
|
|
.. option:: -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.
|
|
|
|
.. option:: -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:
|
|
|
|
.. code-block:: none
|
|
|
|
llvm-as < /dev/null | llc -march=xyz -mcpu=help
|
|
|
|
.. option:: -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:
|
|
|
|
.. code-block:: none
|
|
|
|
llvm-as < /dev/null | llc -march=xyz -mattr=help
|
|
|
|
.. option:: --disable-fp-elim
|
|
|
|
Disable frame pointer elimination optimization.
|
|
|
|
.. option:: --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).
|
|
|
|
.. option:: --enable-no-infs-fp-math
|
|
|
|
Enable optimizations that assume no Inf values.
|
|
|
|
.. option:: --enable-no-nans-fp-math
|
|
|
|
Enable optimizations that assume no NAN values.
|
|
|
|
.. option:: --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).
|
|
|
|
.. option:: --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.
|
|
|
|
.. option:: --stats
|
|
|
|
Print statistics recorded by code-generation passes.
|
|
|
|
.. option:: --time-passes
|
|
|
|
Record the amount of time needed for each pass and print a report to standard
|
|
error.
|
|
|
|
.. option:: --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 :option:`-march` option so that code can be generated for that target.
|
|
|
|
Tuning/Configuration Options
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. option:: --print-machineinstrs
|
|
|
|
Print generated machine code between compilation phases (useful for debugging).
|
|
|
|
.. option:: --regalloc=<allocator>
|
|
|
|
Specify the register allocator to use. The default ``allocator`` is *local*.
|
|
Valid register allocators are:
|
|
|
|
*simple*
|
|
|
|
Very simple "always spill" register allocator
|
|
|
|
*local*
|
|
|
|
Local register allocator
|
|
|
|
*linearscan*
|
|
|
|
Linear scan global register allocator
|
|
|
|
*iterativescan*
|
|
|
|
Iterative scan global register allocator
|
|
|
|
.. option:: --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
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. option:: --x86-asm-syntax=[att|intel]
|
|
|
|
Specify whether to emit assembly code in AT&T syntax (the default) or Intel
|
|
syntax.
|
|
|
|
EXIT STATUS
|
|
-----------
|
|
|
|
If :program:`llc` succeeds, it will exit with 0. Otherwise, if an error
|
|
occurs, it will exit with a non-zero value.
|
|
|
|
SEE ALSO
|
|
--------
|
|
|
|
lli
|
|
|