[commit: ghc] master: Fix performance of flattener patch (#12919) (b47a6c3)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/b47a6c3a6d9c5da341184824549a6a835c79de15/ghc

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commit b47a6c3a6d9c5da341184824549a6a835c79de15
Author: Alexander Vieth <aovieth at gmail.com>
Date:   Mon Mar 26 11:19:27 2018 -0400

    Fix performance of flattener patch (#12919)
    
    This patch, authored by alexvieth and reviewed at D4451,
    makes performance improvements by critically optimizing parts
    of the flattener.
    
    Summary:
    T3064, T5321FD, T5321Fun, T9872a, T9872b, T9872c all pass.
    T9872a and T9872c show improvements beyond the -5% threshold.
    T9872d fails at 10.9% increased allocations.


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b47a6c3a6d9c5da341184824549a6a835c79de15
 compiler/typecheck/TcFlatten.hs         | 499 +++++++++++++++++++++++---------
 compiler/types/CoAxiom.hs               |   2 +-
 compiler/types/Coercion.hs              |   1 -
 compiler/types/FamInstEnv.hs            |  31 +-
 compiler/types/Type.hs                  |  17 +-
 testsuite/tests/perf/compiler/all.T     |   9 +-
 testsuite/tests/polykinds/T14846.stderr |   7 +-
 7 files changed, 405 insertions(+), 161 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 b47a6c3a6d9c5da341184824549a6a835c79de15