[commit: ghc] master: Make callToPats deterministic in SpecConstr (5b2b7e3)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/5b2b7e338c822c34f86e8bd3ff442a979711d1fe/ghc

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

commit 5b2b7e338c822c34f86e8bd3ff442a979711d1fe
Author: Bartosz Nitka <bnitka at fb.com>
Date:   Wed Dec 2 06:20:55 2015 -0800

    Make callToPats deterministic in SpecConstr
    
    This fixes a non-determinism bug where where depending on the
    order of uniques allocated, the specialized workers would have different
    order of arguments.
    
    Compare:
    
    ```
      $s$wgo_s1CN :: Int# -> Int -> Int#
      [LclId, Arity=2, Str=DmdType <L,U><L,U>]
      $s$wgo_s1CN =
        \ (sc_s1CI :: Int#) (sc_s1CJ :: Int) ->
          case tagToEnum# @ Bool (<=# sc_s1CI 0#) of _ [Occ=Dead] {
            False ->
              $wgo_s1BU (Just @ Int (I# (-# sc_s1CI 1#))) (Just @ Int sc_s1CJ);
            True -> 0#
          }
    ```
    
    vs
    
    ```
      $s$wgo_s18mTj :: Int -> Int# -> Int#
      [LclId, Arity=2, Str=DmdType <L,U><L,U>]
      $s$wgo_s18mTj =
        \ (sc_s18mTn :: Int) (sc_s18mTo :: Int#) ->
          case tagToEnum# @ Bool (<=# sc_s18mTo 0#) of _ [Occ=Dead] {
            False ->
              $wgo_s18mUc
                (Just @ Int (I# (-# sc_s18mTo 1#))) (Just @ Int sc_s18mTn);
            True -> 0#
          }
    ```
    
    Test Plan:
    I've added a new testcase
    ./validate
    
    Reviewers: simonmar, simonpj, austin, goldfire, bgamari
    
    Reviewed By: bgamari
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D1508
    
    GHC Trac Issues: #4012


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

5b2b7e338c822c34f86e8bd3ff442a979711d1fe
 compiler/specialise/SpecConstr.hs                  | 10 ++++--
 .../determinism/simplCore/should_compile/Makefile  | 13 +++++++
 .../determinism/simplCore/should_compile/all.T     |  4 +++
 .../simplCore/should_compile/determ006.stdout      |  2 ++
 .../simplCore/should_compile/spec-inline-determ.hs | 40 ++++++++++++++++++++++
 .../tests/simplCore/should_compile/T4908.stderr    | 18 +++++-----
 .../tests/simplCore/should_compile/T7865.stdout    |  2 +-
 .../simplCore/should_compile/spec-inline.stderr    | 26 +++++++-------
 8 files changed, 90 insertions(+), 25 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 5b2b7e338c822c34f86e8bd3ff442a979711d1fe