[commit: ghc] master: PrelRules: Fix constant folding for WordRemOp (3ddfcc9)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/3ddfcc95cd41dac19c8f4d55e8fc03128b77b738/ghc

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

commit 3ddfcc95cd41dac19c8f4d55e8fc03128b77b738
Author: Ben Gamari <bgamari.foss at gmail.com>
Date:   Mon Mar 14 13:27:00 2016 +0100

    PrelRules: Fix constant folding for WordRemOp
    
    Test Plan: Validate with testcase in D2002
    
    Reviewers: austin, simonpj
    
    Reviewed By: simonpj
    
    Subscribers: simonpj, thomie
    
    Differential Revision: https://phabricator.haskell.org/D2004
    
    GHC Trac Issues: #11702


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

3ddfcc95cd41dac19c8f4d55e8fc03128b77b738
 compiler/prelude/PrelRules.hs            | 7 ++++++-
 testsuite/tests/numeric/should_run/all.T | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/compiler/prelude/PrelRules.hs b/compiler/prelude/PrelRules.hs
index 314dd85..a57609a 100644
--- a/compiler/prelude/PrelRules.hs
+++ b/compiler/prelude/PrelRules.hs
@@ -134,7 +134,12 @@ primOpRules nm WordMulOp   = mkPrimOpRule nm 2 [ binaryLit (wordOp2 (*))
 primOpRules nm WordQuotOp  = mkPrimOpRule nm 2 [ nonZeroLit 1 >> binaryLit (wordOp2 quot)
                                                , rightIdentityDynFlags onew ]
 primOpRules nm WordRemOp   = mkPrimOpRule nm 2 [ nonZeroLit 1 >> binaryLit (wordOp2 rem)
-                                               , rightIdentityDynFlags onew ]
+                                               , leftZero zerow
+                                               , do l <- getLiteral 1
+                                                    dflags <- getDynFlags
+                                                    guard (l == onew dflags)
+                                                    retLit zerow
+                                               , equalArgs >> retLit zerow ]
 primOpRules nm AndOp       = mkPrimOpRule nm 2 [ binaryLit (wordOp2 (.&.))
                                                , idempotent
                                                , zeroElem zerow ]
diff --git a/testsuite/tests/numeric/should_run/all.T b/testsuite/tests/numeric/should_run/all.T
index 515005f..8c80305 100644
--- a/testsuite/tests/numeric/should_run/all.T
+++ b/testsuite/tests/numeric/should_run/all.T
@@ -66,4 +66,4 @@ test('T9407', normal, compile_and_run, [''])
 test('T9810', normal, compile_and_run, [''])
 test('T10011', normal, compile_and_run, [''])
 test('T10962', omit_ways(['ghci']), compile_and_run, [''])
-test('T11702', expect_broken(11702), compile_and_run, [''])
+test('T11702', normal, compile_and_run, [''])