Simon Jakobi pushed to branch wip/sjakobi/T4081 at Glasgow Haskell Compiler / GHC Commits: 30413303 by Simon Jakobi at 2026-06-02T11:42:31+02:00 testsuite: Add regression test for #4081 Check that a strict constructor field is unboxed once outside an enclosing loop, not re-inspected each iteration (the float-out case-floating from 9cb20b488). Uses simonpj's `data T a = T !a` example from the ticket; T4081.stderr captures the expected Core. Co-Authored-By: Claude Opus 4.7 - - - - - 3 changed files: - + testsuite/tests/simplCore/should_compile/T4081.hs - + testsuite/tests/simplCore/should_compile/T4081.stderr - testsuite/tests/simplCore/should_compile/all.T Changes: ===================================== testsuite/tests/simplCore/should_compile/T4081.hs ===================================== @@ -0,0 +1,11 @@ +-- #4081: the strict field of T should be unboxed once, outside the blah loop, +-- not re-inspected on every iteration. See the expected Core in T4081.stderr. + +module T4081 (foo) where + +data T a = T !a + +foo :: T Int -> Int -> Int +foo (T x) y = let blah 0 = 0 + blah n = x + blah (n-1) + in blah y ===================================== testsuite/tests/simplCore/should_compile/T4081.stderr ===================================== @@ -0,0 +1,29 @@ + +==================== Tidy Core ==================== +Result size of Tidy Core + = {terms: 40, types: 25, coercions: 0, joins: 0/1} + +$wfoo + = \ ww ww1 -> + letrec { + $wblah + = \ ww2 -> + case ww2 of ds { + __DEFAULT -> + case $wblah (-# ds 1#) of ww3 { __DEFAULT -> +# ww ww3 }; + 0# -> 0# + }; } in + $wblah ww1 + +foo + = \ ds y -> + case ds of { T ww -> + case ww of { I# ww1 -> + case y of { I# ww2 -> + case $wfoo ww1 ww2 of ww3 { __DEFAULT -> I# ww3 } + } + } + } + + + ===================================== testsuite/tests/simplCore/should_compile/all.T ===================================== @@ -601,4 +601,6 @@ test('T25718a', normal, compile, ['-O -ddump-simpl -dsuppress-uniques -dsuppress test('T25718b', normal, compile, ['-O -ddump-simpl -dsuppress-uniques -dsuppress-all -dno-typeable-binds']) test('T25718c', normal, compile, ['-O -ddump-simpl -dsuppress-uniques -dsuppress-all -dno-typeable-binds']) test('T19166', normal, compile, ['-O -ddump-simpl -dsuppress-uniques -dsuppress-all -dno-typeable-binds']) +# #4081: the strict field of T should be unboxed once, outside the loop. +test('T4081', normal, compile, ['-O -ddump-simpl -dsuppress-uniques -dsuppress-all -dno-typeable-binds']) test('T27261', [extra_files(['T27261_aux.hs'])], multimod_compile, ['T27261', '-v0 -O']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/304133030893df192717cfbf5ba04003... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/304133030893df192717cfbf5ba04003... You're receiving this email because of your account on gitlab.haskell.org.