[llvm] 86c4242 - [docs] Remove unmaintained target feature matrix

Mon Jul 18 10:38:47 PDT 2022

Author: Alex Bradbury
Date: 2022-07-18T18:38:23+01:00
New Revision: 86c4242976f7d3da52d33558ddc372537fa85b0b

URL: https://github.com/llvm/llvm-project/commit/86c4242976f7d3da52d33558ddc372537fa85b0b
DIFF: https://github.com/llvm/llvm-project/commit/86c4242976f7d3da52d33558ddc372537fa85b0b.diff

LOG: [docs] Remove unmaintained target feature matrix

Back in 2017, a table was added to the codegen documentation listing
which features various backends support. It received a few updates since
then, but not since the end of 2019. Having such a table is a nice idea,
but it hasn't been kept up to date, it isn't easy to ensure that it is
up to date, and the table probably isn't very discoverable for most
users who would be interested in this information anyway (it would be
better suited to some kind of "what can LLVM do for me?" page).

For all of the above reasons, I believe it makes sense to remove it.

Differential Revision: https://reviews.llvm.org/D129996

Added: 
    

Modified: 
    llvm/docs/CodeGenerator.rst

Removed: 
    


################################################################################
diff  --git a/llvm/docs/CodeGenerator.rst b/llvm/docs/CodeGenerator.rst
index d802124aa886..27889b150d0f 100644

--- a/llvm/docs/CodeGenerator.rst
+++ b/llvm/docs/CodeGenerator.rst
@@ -1836,266 +1836,7 @@ Target-specific Implementation Notes
 ====================================
 
 This section of the document explains features or design decisions that are
-specific to the code generator for a particular target.  First we start with a
-table that summarizes what features are supported by each target.
-
-.. _target-feature-matrix:
-
-Target Feature Matrix
----------------------
-
-Note that this table does not list features that are not supported fully by any
-target yet.  It considers a feature to be supported if at least one subtarget
-supports it.  A feature being supported means that it is useful and works for
-most cases, it does not indicate that there are zero known bugs in the
-implementation.  Here is the key:
-
-:raw-html:`<table border="1" cellspacing="0">`
-:raw-html:`<tr>`
-:raw-html:`<th>Unknown</th>`
-:raw-html:`<th>Not Applicable</th>`
-:raw-html:`<th>No support</th>`
-:raw-html:`<th>Partial Support</th>`
-:raw-html:`<th>Complete Support</th>`
-:raw-html:`</tr>`
-:raw-html:`<tr>`
-:raw-html:`<td class="unknown"></td>`
-:raw-html:`<td class="na"></td>`
-:raw-html:`<td class="no"></td>`
-:raw-html:`<td class="partial"></td>`
-:raw-html:`<td class="yes"></td>`
-:raw-html:`</tr>`
-:raw-html:`</table>`
-
-Here is the table:
-
-:raw-html:`<table width="689" border="1" cellspacing="0">`
-:raw-html:`<tr><td></td>`
-:raw-html:`<td colspan="13" align="center" style="background-color:#ffc">Target</td>`
-:raw-html:`</tr>`
-:raw-html:`<tr>`
-:raw-html:`<th>Feature</th>`
-:raw-html:`<th>ARM</th>`
-:raw-html:`<th>Hexagon</th>`
-:raw-html:`<th>MSP430</th>`
-:raw-html:`<th>Mips</th>`
-:raw-html:`<th>NVPTX</th>`
-:raw-html:`<th>PowerPC</th>`
-:raw-html:`<th>Sparc</th>`
-:raw-html:`<th>SystemZ</th>`
-:raw-html:`<th>X86</th>`
-:raw-html:`<th>XCore</th>`
-:raw-html:`<th>eBPF</th>`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_reliable">is generally reliable</a></td>`
-:raw-html:`<td class="yes"></td> <!-- ARM -->`
-:raw-html:`<td class="yes"></td> <!-- Hexagon -->`
-:raw-html:`<td class="unknown"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="yes"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="yes"></td> <!-- Sparc -->`
-:raw-html:`<td class="yes"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="yes"></td> <!-- XCore -->`
-:raw-html:`<td class="yes"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_asmparser">assembly parser</a></td>`
-:raw-html:`<td class="no"></td> <!-- ARM -->`
-:raw-html:`<td class="no"></td> <!-- Hexagon -->`
-:raw-html:`<td class="no"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="no"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="no"></td> <!-- Sparc -->`
-:raw-html:`<td class="yes"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="no"></td> <!-- XCore -->`
-:raw-html:`<td class="no"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_disassembler">disassembler</a></td>`
-:raw-html:`<td class="yes"></td> <!-- ARM -->`
-:raw-html:`<td class="no"></td> <!-- Hexagon -->`
-:raw-html:`<td class="no"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="na"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="yes"></td> <!-- Sparc -->`
-:raw-html:`<td class="yes"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="yes"></td> <!-- XCore -->`
-:raw-html:`<td class="yes"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_inlineasm">inline asm</a></td>`
-:raw-html:`<td class="yes"></td> <!-- ARM -->`
-:raw-html:`<td class="yes"></td> <!-- Hexagon -->`
-:raw-html:`<td class="unknown"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="yes"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="unknown"></td> <!-- Sparc -->`
-:raw-html:`<td class="yes"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="yes"></td> <!-- XCore -->`
-:raw-html:`<td class="no"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_jit">jit</a></td>`
-:raw-html:`<td class="partial"><a href="#feat_jit_arm">*</a></td> <!-- ARM -->`
-:raw-html:`<td class="no"></td> <!-- Hexagon -->`
-:raw-html:`<td class="unknown"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="na"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="unknown"></td> <!-- Sparc -->`
-:raw-html:`<td class="yes"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="no"></td> <!-- XCore -->`
-:raw-html:`<td class="yes"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_objectwrite">.o file writing</a></td>`
-:raw-html:`<td class="no"></td> <!-- ARM -->`
-:raw-html:`<td class="no"></td> <!-- Hexagon -->`
-:raw-html:`<td class="no"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="na"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="no"></td> <!-- Sparc -->`
-:raw-html:`<td class="yes"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="no"></td> <!-- XCore -->`
-:raw-html:`<td class="yes"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a hr:raw-html:`ef="#feat_tailcall">tail calls</a></td>`
-:raw-html:`<td class="yes"></td> <!-- ARM -->`
-:raw-html:`<td class="yes"></td> <!-- Hexagon -->`
-:raw-html:`<td class="unknown"></td> <!-- MSP430 -->`
-:raw-html:`<td class="yes"></td> <!-- Mips -->`
-:raw-html:`<td class="no"></td> <!-- NVPTX -->`
-:raw-html:`<td class="yes"></td> <!-- PowerPC -->`
-:raw-html:`<td class="unknown"></td> <!-- Sparc -->`
-:raw-html:`<td class="no"></td> <!-- SystemZ -->`
-:raw-html:`<td class="yes"></td> <!-- X86 -->`
-:raw-html:`<td class="no"></td> <!-- XCore -->`
-:raw-html:`<td class="no"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`<tr>`
-:raw-html:`<td><a href="#feat_segstacks">segmented stacks</a></td>`
-:raw-html:`<td class="no"></td> <!-- ARM -->`
-:raw-html:`<td class="no"></td> <!-- Hexagon -->`
-:raw-html:`<td class="no"></td> <!-- MSP430 -->`
-:raw-html:`<td class="no"></td> <!-- Mips -->`
-:raw-html:`<td class="no"></td> <!-- NVPTX -->`
-:raw-html:`<td class="no"></td> <!-- PowerPC -->`
-:raw-html:`<td class="no"></td> <!-- Sparc -->`
-:raw-html:`<td class="no"></td> <!-- SystemZ -->`
-:raw-html:`<td class="partial"><a href="#feat_segstacks_x86">*</a></td> <!-- X86 -->`
-:raw-html:`<td class="no"></td> <!-- XCore -->`
-:raw-html:`<td class="no"></td> <!-- eBPF -->`
-:raw-html:`</tr>`
-
-:raw-html:`</table>`
-
-.. _feat_reliable:
-
-Is Generally Reliable
-^^^^^^^^^^^^^^^^^^^^^
-
-This box indicates whether the target is considered to be production quality.
-This indicates that the target has been used as a static compiler to compile
-large amounts of code by a variety of 
diff erent people and is in continuous use.
-
-.. _feat_asmparser:
-
-Assembly Parser
-^^^^^^^^^^^^^^^
-
-This box indicates whether the target supports parsing target specific .s files
-by implementing the MCAsmParser interface.  This is required for llvm-mc to be
-able to act as a native assembler and is required for inline assembly support in
-the native .o file writer.
-
-.. _feat_disassembler:
-
-Disassembler
-^^^^^^^^^^^^
-
-This box indicates whether the target supports the MCDisassembler API for
-disassembling machine opcode bytes into MCInst's.
-
-.. _feat_inlineasm:
-
-Inline Asm
-^^^^^^^^^^
-
-This box indicates whether the target supports most popular inline assembly
-constraints and modifiers.
-
-.. _feat_jit:
-
-JIT Support
-^^^^^^^^^^^
-
-This box indicates whether the target supports the JIT compiler through the
-ExecutionEngine interface.
-
-.. _feat_jit_arm:
-
-The ARM backend has basic support for integer code in ARM codegen mode, but
-lacks NEON and full Thumb support.
-
-.. _feat_objectwrite:
-
-.o File Writing
-^^^^^^^^^^^^^^^
-
-This box indicates whether the target supports writing .o files (e.g. MachO,
-ELF, and/or COFF) files directly from the target.  Note that the target also
-must include an assembly parser and general inline assembly support for full
-inline assembly support in the .o writer.
-
-Targets that don't support this feature can obviously still write out .o files,
-they just rely on having an external assembler to translate from a .s file to a
-.o file (as is the case for many C compilers).
-
-.. _feat_tailcall:
-
-Tail Calls
-^^^^^^^^^^
-
-This box indicates whether the target supports guaranteed tail calls.  These are
-calls marked "`tail <LangRef.html#i_call>`_" and use the fastcc calling
-convention.  Please see the `tail call section`_ for more details.
-
-.. _feat_segstacks:
-
-Segmented Stacks
-^^^^^^^^^^^^^^^^
-
-This box indicates whether the target supports segmented stacks. This replaces
-the traditional large C stack with many linked segments. It is compatible with
-the `gcc implementation <http://gcc.gnu.org/wiki/SplitStacks>`_ used by the Go
-front end.
-
-.. _feat_segstacks_x86:
-
-Basic support exists on the X86 backend. Currently vararg doesn't work and the
-object files are not marked the way the gold linker expects, but simple Go
-programs can be built by dragonegg.
+specific to the code generator for a particular target.
 
 .. _tail call section:
 


        
