From d6254520cd9e72822ed34001eb73b6fdeaa017fb Mon Sep 17 00:00:00 2001 From: Renato Golin Date: Tue, 28 Jul 2015 10:24:11 +0000 Subject: [PATCH] Improving lli documentation 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 --- docs/CommandGuide/lli.rst | 168 ++++++++++---------------------------- 1 file changed, 44 insertions(+), 124 deletions(-) diff --git a/docs/CommandGuide/lli.rst b/docs/CommandGuide/lli.rst index 502fbd60935..9da13ee47e0 100644 --- a/docs/CommandGuide/lli.rst +++ b/docs/CommandGuide/lli.rst @@ -1,172 +1,127 @@ lli - directly execute programs from LLVM bitcode ================================================= - SYNOPSIS -------- - -**lli** [*options*] [*filename*] [*program args*] - +:program:`lli` [*options*] [*filename*] [*program args*] 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 -in LLVM bitcode format and executes it using a just-in-time compiler, if one is -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. +:program:`lli` is *not* an emulator. It will not execute IR of different architectures +and it can only interpret (or JIT-compile) for the host architecture. -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. The optional *args* specified on the command line are passed to the program as arguments. - GENERAL OPTIONS --------------- - - -**-fake-argv0**\ =\ *executable* +.. option:: -fake-argv0=executable Override the ``argv[0]`` value passed into the executing program. - - -**-force-interpreter**\ =\ *{false,true}* +.. option:: -force-interpreter={false,true} If set to true, use the interpreter even if a just-in-time compiler is available for this architecture. Defaults to false. - - -**-help** +.. option:: -help Print a summary of command line options. +.. option:: -load=pluginfilename - -**-load**\ =\ *pluginfilename* - - Causes **lli** to load the plugin (shared object) named *pluginfilename* and use + Causes :program:`lli` to load the plugin (shared object) named *pluginfilename* and use it for optimization. - - -**-stats** +.. option:: -stats Print statistics from the code-generation passes. This is only meaningful for the just-in-time compiler, at present. - - -**-time-passes** +.. option:: -time-passes Record the amount of time needed for each code-generation pass and print it to standard error. +.. option:: -version - -**-version** - - Print out the version of **lli** and exit without doing anything else. - - - + Print out the version of :program:`lli` and exit without doing anything else. TARGET OPTIONS -------------- - - -**-mtriple**\ =\ *target triple* +.. option:: -mtriple=target triple Override the target triple specified in the input bitcode file with the specified string. This may result in a crash if you pick an architecture which is not compatible with the current system. - - -**-march**\ =\ *arch* +.. option:: -march=arch 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 valid architectures. By default this is inferred from the target triple or autodetected to the current architecture. - - -**-mcpu**\ =\ *cpuname* +.. 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: **llvm-as < /dev/null | llc -march=xyz -mcpu=help** - - -**-mattr**\ =\ *a1,+a2,-a3,...* +.. 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: **llvm-as < /dev/null | llc -march=xyz -mattr=help** - - - FLOATING POINT OPTIONS ---------------------- - - -**-disable-excess-fp-precision** +.. option:: -disable-excess-fp-precision Disable optimizations that may increase floating point precision. - - -**-enable-no-infs-fp-math** +.. option:: -enable-no-infs-fp-math Enable optimizations that assume no Inf values. - - -**-enable-no-nans-fp-math** +.. option:: -enable-no-nans-fp-math Enable optimizations that assume no NAN values. +.. option:: -enable-unsafe-fp-math - -**-enable-unsafe-fp-math** - - Causes **lli** to enable optimizations that may decrease floating point + Causes :program:`lli` to enable optimizations that may decrease floating point precision. +.. option:: -soft-float - -**-soft-float** - - Causes **lli** to generate software floating point library calls instead of + Causes :program:`lli` to generate software floating point library calls instead of equivalent hardware instructions. - - - CODE GENERATION OPTIONS ----------------------- - - -**-code-model**\ =\ *model* +.. option:: -code-model=model Choose the code model from: - .. code-block:: perl default: Target default code model @@ -175,42 +130,30 @@ CODE GENERATION OPTIONS medium: Medium code model large: Large code model - - - -**-disable-post-RA-scheduler** +.. option:: -disable-post-RA-scheduler Disable scheduling after register allocation. - - -**-disable-spill-fusing** +.. option:: -disable-spill-fusing Disable fusing of spill code into instructions. - - -**-jit-enable-eh** +.. option:: -jit-enable-eh Exception handling should be enabled in the just-in-time compiler. - - -**-join-liveintervals** +.. option:: -join-liveintervals 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. - - - -**-pre-RA-sched**\ =\ *scheduler* +.. option:: -pre-RA-sched=scheduler Instruction schedulers available (before register allocation): - .. code-block:: perl =default: Best scheduler for the target @@ -221,74 +164,51 @@ CODE GENERATION OPTIONS =list-tdrr: Top-down register reduction list scheduling =list-td: Top-down list scheduler -print-machineinstrs - Print generated machine code - - - -**-regalloc**\ =\ *allocator* +.. option:: -regalloc=allocator Register allocator to use (default=linearscan) - .. code-block:: perl =bigblock: Big-block register allocator =linearscan: linear scan register allocator =local - local register allocator =simple: simple register allocator - - - -**-relocation-model**\ =\ *model* +.. option:: -relocation-model=model Choose relocation model from: - .. code-block:: perl =default: Target default relocation model =static: Non-relocatable code =pic - Fully relocatable, position independent code =dynamic-no-pic: Relocatable external references, non-relocatable code - - - -**-spiller** +.. option:: -spiller Spiller to use (default=local) - .. code-block:: perl =simple: simple spiller =local: local spiller - - - -**-x86-asm-syntax**\ =\ *syntax* +.. option:: -x86-asm-syntax=syntax Choose style of code to emit from X86 backend: - .. code-block:: perl =att: Emit AT&T-style assembly =intel: Emit Intel-style assembly - - - - EXIT STATUS ----------- - -If **lli** fails to load the program, it will exit with an exit code of 1. +If :program:`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. - SEE ALSO -------- - -llc|llc +:program:`llc` -- 2.34.1