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Improving lli documentation

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Too many people hope lli would act as an emulator when it's actually
just a tool to help prototype IR code and test the JIT compiler. This
commit makes that fact explicit in the documentation

It also migrates the old style bold/italic doc tags to the preferred
meta tags (.. option::, :program:, etc).

No errors when generating the documents, visual inspection in the HTML
result doesn't show any major difference, apart from the slight style
change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243401 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Renato Golin
2015-07-28 10:24:11 +00:00
parent c335310146
commit d6254520cd
1 changed files with 44 additions and 124 deletions
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docs/CommandGuide/lli.rst
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@@ -1,172 +1,127 @@
lli - directly execute programs from LLVM bitcode lli - directly execute programs from LLVM bitcode
================================================= =================================================
SYNOPSIS SYNOPSIS
-------- --------
:program:`lli` [*options*] [*filename*] [*program args*]
**lli** [*options*] [*filename*] [*program args*]
DESCRIPTION DESCRIPTION
----------- -----------
:program:`lli` directly executes programs in LLVM bitcode format. It takes a program
in LLVM bitcode format and executes it using a just-in-time compiler or an
interpreter.
**lli** directly executes programs in LLVM bitcode format. It takes a program :program:`lli` is *not* an emulator. It will not execute IR of different architectures
in LLVM bitcode format and executes it using a just-in-time compiler, if one is and it can only interpret (or JIT-compile) for the host architecture.
available for the current architecture, or an interpreter. **lli** takes all of
the same code generator options as llc|llc, but they are only effective when
**lli** is using the just-in-time compiler.
If *filename* is not specified, then **lli** reads the LLVM bitcode for the The JIT compiler takes the same arguments as other tools, like :program:`llc`,
but they don't necessarily work for the interpreter.
If `filename` is not specified, then :program:`lli` reads the LLVM bitcode for the
program from standard input. program from standard input.
The optional *args* specified on the command line are passed to the program as The optional *args* specified on the command line are passed to the program as
arguments. arguments.
GENERAL OPTIONS GENERAL OPTIONS
--------------- ---------------
.. option:: -fake-argv0=executable
**-fake-argv0**\ =\ *executable*
Override the ``argv[0]`` value passed into the executing program. Override the ``argv[0]`` value passed into the executing program.
.. option:: -force-interpreter={false,true}
**-force-interpreter**\ =\ *{false,true}*
If set to true, use the interpreter even if a just-in-time compiler is available If set to true, use the interpreter even if a just-in-time compiler is available
for this architecture. Defaults to false. for this architecture. Defaults to false.
.. option:: -help
**-help**
Print a summary of command line options. Print a summary of command line options.
.. option:: -load=pluginfilename
Causes :program:`lli` to load the plugin (shared object) named *pluginfilename* and use
**-load**\ =\ *pluginfilename*
Causes **lli** to load the plugin (shared object) named *pluginfilename* and use
it for optimization. it for optimization.
.. option:: -stats
**-stats**
Print statistics from the code-generation passes. This is only meaningful for Print statistics from the code-generation passes. This is only meaningful for
the just-in-time compiler, at present. the just-in-time compiler, at present.
.. option:: -time-passes
**-time-passes**
Record the amount of time needed for each code-generation pass and print it to Record the amount of time needed for each code-generation pass and print it to
standard error. standard error.
.. option:: -version
Print out the version of :program:`lli` and exit without doing anything else.
**-version**
Print out the version of **lli** and exit without doing anything else.
TARGET OPTIONS TARGET OPTIONS
-------------- --------------
.. option:: -mtriple=target triple
**-mtriple**\ =\ *target triple*
Override the target triple specified in the input bitcode file with the Override the target triple specified in the input bitcode file with the
specified string. This may result in a crash if you pick an specified string. This may result in a crash if you pick an
architecture which is not compatible with the current system. architecture which is not compatible with the current system.
.. option:: -march=arch
**-march**\ =\ *arch*
Specify the architecture for which to generate assembly, overriding the target Specify the architecture for which to generate assembly, overriding the target
encoded in the bitcode file. See the output of **llc -help** for a list of encoded in the bitcode file. See the output of **llc -help** for a list of
valid architectures. By default this is inferred from the target triple or valid architectures. By default this is inferred from the target triple or
autodetected to the current architecture. autodetected to the current architecture.
.. option:: -mcpu=cpuname
**-mcpu**\ =\ *cpuname*
Specify a specific chip in the current architecture to generate code for. Specify a specific chip in the current architecture to generate code for.
By default this is inferred from the target triple and autodetected to By default this is inferred from the target triple and autodetected to
the current architecture. For a list of available CPUs, use: the current architecture. For a list of available CPUs, use:
**llvm-as < /dev/null | llc -march=xyz -mcpu=help** **llvm-as < /dev/null | llc -march=xyz -mcpu=help**
.. option:: -mattr=a1,+a2,-a3,...
**-mattr**\ =\ *a1,+a2,-a3,...*
Override or control specific attributes of the target, such as whether SIMD 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 operations are enabled or not. The default set of attributes is set by the
current CPU. For a list of available attributes, use: current CPU. For a list of available attributes, use:
**llvm-as < /dev/null | llc -march=xyz -mattr=help** **llvm-as < /dev/null | llc -march=xyz -mattr=help**
FLOATING POINT OPTIONS FLOATING POINT OPTIONS
---------------------- ----------------------
.. option:: -disable-excess-fp-precision
**-disable-excess-fp-precision**
Disable optimizations that may increase floating point precision. Disable optimizations that may increase floating point precision.
.. option:: -enable-no-infs-fp-math
**-enable-no-infs-fp-math**
Enable optimizations that assume no Inf values. Enable optimizations that assume no Inf values.
.. option:: -enable-no-nans-fp-math
**-enable-no-nans-fp-math**
Enable optimizations that assume no NAN values. Enable optimizations that assume no NAN values.
.. option:: -enable-unsafe-fp-math
Causes :program:`lli` to enable optimizations that may decrease floating point
**-enable-unsafe-fp-math**
Causes **lli** to enable optimizations that may decrease floating point
precision. precision.
.. option:: -soft-float
Causes :program:`lli` to generate software floating point library calls instead of
**-soft-float**
Causes **lli** to generate software floating point library calls instead of
equivalent hardware instructions. equivalent hardware instructions.
CODE GENERATION OPTIONS CODE GENERATION OPTIONS
----------------------- -----------------------
.. option:: -code-model=model
**-code-model**\ =\ *model*
Choose the code model from: Choose the code model from:
.. code-block:: perl .. code-block:: perl
default: Target default code model default: Target default code model
@@ -175,42 +130,30 @@ CODE GENERATION OPTIONS
medium: Medium code model medium: Medium code model
large: Large code model large: Large code model
.. option:: -disable-post-RA-scheduler
**-disable-post-RA-scheduler**
Disable scheduling after register allocation. Disable scheduling after register allocation.
.. option:: -disable-spill-fusing
**-disable-spill-fusing**
Disable fusing of spill code into instructions. Disable fusing of spill code into instructions.
.. option:: -jit-enable-eh
**-jit-enable-eh**
Exception handling should be enabled in the just-in-time compiler. Exception handling should be enabled in the just-in-time compiler.
.. option:: -join-liveintervals
**-join-liveintervals**
Coalesce copies (default=true). Coalesce copies (default=true).
.. option:: -nozero-initialized-in-bss
Don't place zero-initialized symbols into the BSS section.
**-nozero-initialized-in-bss** Don't place zero-initialized symbols into the BSS section. .. option:: -pre-RA-sched=scheduler
**-pre-RA-sched**\ =\ *scheduler*
Instruction schedulers available (before register allocation): Instruction schedulers available (before register allocation):
.. code-block:: perl .. code-block:: perl
=default: Best scheduler for the target =default: Best scheduler for the target
@@ -221,74 +164,51 @@ CODE GENERATION OPTIONS
=list-tdrr: Top-down register reduction list scheduling =list-tdrr: Top-down register reduction list scheduling
=list-td: Top-down list scheduler -print-machineinstrs - Print generated machine code =list-td: Top-down list scheduler -print-machineinstrs - Print generated machine code
.. option:: -regalloc=allocator
**-regalloc**\ =\ *allocator*
Register allocator to use (default=linearscan) Register allocator to use (default=linearscan)
.. code-block:: perl .. code-block:: perl
=bigblock: Big-block register allocator =bigblock: Big-block register allocator
=linearscan: linear scan register allocator =local - local register allocator =linearscan: linear scan register allocator =local - local register allocator
=simple: simple register allocator =simple: simple register allocator
.. option:: -relocation-model=model
**-relocation-model**\ =\ *model*
Choose relocation model from: Choose relocation model from:
.. code-block:: perl .. code-block:: perl
=default: Target default relocation model =default: Target default relocation model
=static: Non-relocatable code =pic - Fully relocatable, position independent code =static: Non-relocatable code =pic - Fully relocatable, position independent code
=dynamic-no-pic: Relocatable external references, non-relocatable code =dynamic-no-pic: Relocatable external references, non-relocatable code
.. option:: -spiller
**-spiller**
Spiller to use (default=local) Spiller to use (default=local)
.. code-block:: perl .. code-block:: perl
=simple: simple spiller =simple: simple spiller
=local: local spiller =local: local spiller
.. option:: -x86-asm-syntax=syntax
**-x86-asm-syntax**\ =\ *syntax*
Choose style of code to emit from X86 backend: Choose style of code to emit from X86 backend:
.. code-block:: perl .. code-block:: perl
=att: Emit AT&T-style assembly =att: Emit AT&T-style assembly
=intel: Emit Intel-style assembly =intel: Emit Intel-style assembly
EXIT STATUS EXIT STATUS
----------- -----------
If :program:`lli` fails to load the program, it will exit with an exit code of 1.
If **lli** fails to load the program, it will exit with an exit code of 1.
Otherwise, it will return the exit code of the program it executes. Otherwise, it will return the exit code of the program it executes.
SEE ALSO SEE ALSO
-------- --------
:program:`llc`
llc|llc