[commit: ghc] master: Provide Uniquable version of SCC (35d1564)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/35d1564cea2e611a4fecf24f09eff83f8a55af1c/ghc

>---------------------------------------------------------------

commit 35d1564cea2e611a4fecf24f09eff83f8a55af1c
Author: Bartosz Nitka <niteria at gmail.com>
Date:   Tue Jun 14 03:28:30 2016 -0700

    Provide Uniquable version of SCC
    
    We want to remove the `Ord Unique` instance because there's
    no way to implement it in deterministic way and it's too
    easy to use by accident.
    
    We sometimes compute SCC for datatypes whose Ord instance
    is implemented in terms of Unique. The Ord constraint on
    SCC is just an artifact of some internal data structures.
    We can have an alternative implementation with a data
    structure that uses Uniquable instead.
    
    This does exactly that and I'm pleased that I didn't have
    to introduce any duplication to do that.
    
    Test Plan:
    ./validate
    I looked at performance tests and it's a tiny bit better.
    
    Reviewers: bgamari, simonmar, ezyang, austin, goldfire
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D2359
    
    GHC Trac Issues: #4012


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35d1564cea2e611a4fecf24f09eff83f8a55af1c
 compiler/basicTypes/NameEnv.hs                     |   2 +-
 compiler/cmm/CmmBuildInfoTables.hs                 |   2 +-
 compiler/codeGen/StgCmmUtils.hs                    |   2 +-
 compiler/iface/MkIface.hs                          |   2 +-
 compiler/main/GhcMake.hs                           |   5 +-
 compiler/nativeGen/AsmCodeGen.hs                   |   2 +-
 .../nativeGen/RegAlloc/Linear/JoinToTargets.hs     |   4 +-
 compiler/nativeGen/RegAlloc/Liveness.hs            |   6 +-
 compiler/rename/RnSource.hs                        |   5 +-
 compiler/simplCore/OccurAnal.hs                    |  10 +-
 compiler/typecheck/TcBinds.hs                      |   2 +-
 compiler/typecheck/TcEvidence.hs                   |   2 +-
 compiler/typecheck/TcSMonad.hs                     |   2 +-
 compiler/typecheck/TcTyDecls.hs                    |   5 +-
 compiler/types/Type.hs                             |   2 +-
 compiler/utils/Digraph.hs                          | 127 +++++++++++++++++----
 compiler/vectorise/Vectorise/Type/Classify.hs      |   2 +-
 testsuite/tests/determinism/determinism001.hs      |   2 +-
 18 files changed, 136 insertions(+), 48 deletions(-)

Diff suppressed because of size. To see it, use:

    git diff-tree --root --patch-with-stat --no-color --find-copies-harder --ignore-space-at-eol --cc 35d1564cea2e611a4fecf24f09eff83f8a55af1c