1772123 - Ion's RA: reorder methods in BacktrackingAllocator.{cpp,h}

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P3)

Description

[Julian Seward [:jseward]]

BacktrackingAllocator.cpp is a big, complex file. It contains the complete
register allocation pipeline and has dozens of methods and functions.
Unfortunately the organisation is poor, obscures the overall structure, and is
hard to follow:

• often, no clear grouping of methods/functions into logical groups

• inadequate group-heading comments, needed for top level navigation

• inconsistencies in whether methods are defined before or after their use
  points

• inconsistencies in the sequence of methods relative to flow in the allocator
  pipeline

Any attempt to clean up the allocator first needs to address these structuring
issues. This patch:

• makes no functional changes -- it merely reorders methods in
  BacktrackingAllocator.cpp and adds a handful of top-level section marker
  comments. The sequencing of methods is now definition-before-use. The top
  level group sequencing has been changed so as to match the actual flow of
  data through the allocation pipeline.

• The contents of class BacktrackingAllocator in BacktrackingAllocator.h are
  rearranged to follow the .cpp changes. The rest of this file is unchanged.

• minor change: BacktrackingAllocator::SpillWeightFromUsePolicy was a free
  method in the .h file. Has been moved to the .cpp file.

• minor change: typedef LiveRangeVector is unused and has been removed.

Comment 1

[Julian Seward [:jseward]]

Attachment: Bug 1772123 - Ion's RA: reorder methods in BacktrackingAllocator.{cpp,h}. r=jandem.

BacktrackingAllocator.cpp is a big, complex file. It contains the complete
register allocation pipeline and has dozens of methods and functions.
Unfortunately the organisation is poor, which obscures the overall structure
makes it hard to follow:

• often, no clear grouping of methods/functions into logical groups

• inadequate group-heading comments, needed for top level navigation

• inconsistencies in whether methods are defined before or after their use
  points

• inconsistencies in the sequence of methods relative to flow in the allocator
  pipeline

Any attempt to clean up the allocator first needs to address these structuring
issues:

• This patch makes no functional changes -- it merely reorders methods in
  BacktrackingAllocator.cpp and adds a handful of top-level section marker
  comments. The sequencing of methods is now definition-before-use. The top
  level group sequencing has been changed so as to match the actual flow of
  data through the allocation pipeline.

• The contents of class BacktrackingAllocator in BacktrackingAllocator.h are
  rearranged to follow the .cpp changes. The rest of this file is unchanged.

• minor change: BacktrackingAllocator::SpillWeightFromUsePolicy was a free
  method in the .h file. Has been moved to the .cpp file.

• minor change: typedef LiveRangeVector is unused and has been removed.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/mozilla-central/rev/7903ed468b9c
Ion's RA: reorder methods in BacktrackingAllocator.{cpp,h}.  r=jandem.

Comment 3

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/7903ed468b9c