llvm/docs/ReleaseNotes.rst
Vedant Kumar 2cac108e97 [Debugify] Add a pass to test debug info preservation
The Debugify pass synthesizes debug info for IR. It's paired with a
CheckDebugify pass which determines how much of the original debug info
is preserved. These passes make it easier to create targeted tests for
debug info preservation.

Here is the Debugify algorithm:

  NextLine = 1
  for (Instruction &I : M)
    attach DebugLoc(NextLine++) to I

  NextVar = 1
  for (Instruction &I : M)
    if (canAttachDebugValue(I))
      attach dbg.value(NextVar++) to I

The CheckDebugify pass expects contiguous ranges of DILocations and
DILocalVariables. If it fails to find all of the expected debug info, it
prints a specific error to stderr which can be FileChecked.

This was discussed on llvm-dev in the thread:
"Passes to add/validate synthetic debug info"

Differential Revision: https://reviews.llvm.org/D40512

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320202 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-08 21:57:28 +00:00

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========================
LLVM 6.0.0 Release Notes
========================
.. contents::
:local:
.. warning::
These are in-progress notes for the upcoming LLVM 6 release.
Release notes for previous releases can be found on
`the Download Page <http://releases.llvm.org/download.html>`_.
Introduction
============
This document contains the release notes for the LLVM Compiler Infrastructure,
release 5.0.0. Here we describe the status of LLVM, including major improvements
from the previous release, improvements in various subprojects of LLVM, and
some of the current users of the code. All LLVM releases may be downloaded
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Non-comprehensive list of changes in this release
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.. NOTE
For small 1-3 sentence descriptions, just add an entry at the end of
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point (e.g. maybe you would like to give an example of the
functionality, or simply have a lot to talk about), see the `NOTE` below
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* The ``Redirects`` argument of ``llvm::sys::ExecuteAndWait`` and
``llvm::sys::ExecuteNoWait`` was changed to an ``ArrayRef`` of optional
``StringRef``'s to make it safer and more convenient to use.
* The backend name was added to the Target Registry to allow run-time
information to be fed back into TableGen. Out-of-tree targets will need to add
the name used in the `def X : Target` definition to the call to
`RegisterTarget`.
* The ``Debugify`` pass was added to ``opt`` to facilitate testing of debug
info preservation. This pass attaches synthetic ``DILocations`` and
``DIVariables`` to the instructions in a ``Module``. The ``CheckDebugify``
pass determines how much of the metadata is lost.
* Note..
.. NOTE
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Special New Feature
-------------------
Makes programs 10x faster by doing Special New Thing.
Changes to the LLVM IR
----------------------
Changes to the ARM Backend
--------------------------
During this release ...
Changes to the MIPS Target
--------------------------
During this release ...
Changes to the PowerPC Target
-----------------------------
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Changes to the X86 Target
-------------------------
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Changes to the AMDGPU Target
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Changes to the AVR Target
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Changes to the OCaml bindings
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Changes to the C API
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External Open Source Projects Using LLVM 6
==========================================
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Additional Information
======================
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<http://llvm.org/>`_, in particular in the `documentation
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