diff options
author | Simon Peyton Jones <simonpj@microsoft.com> | 2019-10-02 12:36:44 +0300 |
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committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-02-20 21:17:57 -0500 |
commit | 74ad75e87317196c600dfabc61aee1b87d95c214 (patch) | |
tree | 37f85f608112a1372f097b4c2eea9f4c8c8f00fc /compiler/typecheck/TcRnDriver.hs | |
parent | 19680ee533bb95c0c5c42aca5c81197e4b233979 (diff) | |
download | haskell-74ad75e87317196c600dfabc61aee1b87d95c214.tar.gz |
Re-implement unsafe coercions in terms of unsafe equality proofs
(Commit message written by Omer, most of the code is written by Simon
and Richard)
See Note [Implementing unsafeCoerce] for how unsafe equality proofs and
the new unsafeCoerce# are implemented.
New notes added:
- [Checking for levity polymorphism] in CoreLint.hs
- [Implementing unsafeCoerce] in base/Unsafe/Coerce.hs
- [Patching magic definitions] in Desugar.hs
- [Wiring in unsafeCoerce#] in Desugar.hs
Only breaking change in this patch is unsafeCoerce# is not exported from
GHC.Exts, instead of GHC.Prim.
Fixes #17443
Fixes #16893
NoFib
-----
--------------------------------------------------------------------------------
Program Size Allocs Instrs Reads Writes
--------------------------------------------------------------------------------
CS -0.1% 0.0% -0.0% -0.0% -0.0%
CSD -0.1% 0.0% -0.0% -0.0% -0.0%
FS -0.1% 0.0% -0.0% -0.0% -0.0%
S -0.1% 0.0% -0.0% -0.0% -0.0%
VS -0.1% 0.0% -0.0% -0.0% -0.0%
VSD -0.1% 0.0% -0.0% -0.0% -0.1%
VSM -0.1% 0.0% -0.0% -0.0% -0.0%
anna -0.0% 0.0% -0.0% -0.0% -0.0%
ansi -0.1% 0.0% -0.0% -0.0% -0.0%
atom -0.1% 0.0% -0.0% -0.0% -0.0%
awards -0.1% 0.0% -0.0% -0.0% -0.0%
banner -0.1% 0.0% -0.0% -0.0% -0.0%
bernouilli -0.1% 0.0% -0.0% -0.0% -0.0%
binary-trees -0.1% 0.0% -0.0% -0.0% -0.0%
boyer -0.1% 0.0% -0.0% -0.0% -0.0%
boyer2 -0.1% 0.0% -0.0% -0.0% -0.0%
bspt -0.1% 0.0% -0.0% -0.0% -0.0%
cacheprof -0.1% 0.0% -0.0% -0.0% -0.0%
calendar -0.1% 0.0% -0.0% -0.0% -0.0%
cichelli -0.1% 0.0% -0.0% -0.0% -0.0%
circsim -0.1% 0.0% -0.0% -0.0% -0.0%
clausify -0.1% 0.0% -0.0% -0.0% -0.0%
comp_lab_zift -0.1% 0.0% -0.0% -0.0% -0.0%
compress -0.1% 0.0% -0.0% -0.0% -0.0%
compress2 -0.1% 0.0% -0.0% -0.0% -0.0%
constraints -0.1% 0.0% -0.0% -0.0% -0.0%
cryptarithm1 -0.1% 0.0% -0.0% -0.0% -0.0%
cryptarithm2 -0.1% 0.0% -0.0% -0.0% -0.0%
cse -0.1% 0.0% -0.0% -0.0% -0.0%
digits-of-e1 -0.1% 0.0% -0.0% -0.0% -0.0%
digits-of-e2 -0.1% 0.0% -0.0% -0.0% -0.0%
dom-lt -0.1% 0.0% -0.0% -0.0% -0.0%
eliza -0.1% 0.0% -0.0% -0.0% -0.0%
event -0.1% 0.0% -0.0% -0.0% -0.0%
exact-reals -0.1% 0.0% -0.0% -0.0% -0.0%
exp3_8 -0.1% 0.0% -0.0% -0.0% -0.0%
expert -0.1% 0.0% -0.0% -0.0% -0.0%
fannkuch-redux -0.1% 0.0% -0.0% -0.0% -0.0%
fasta -0.1% 0.0% -0.5% -0.3% -0.4%
fem -0.1% 0.0% -0.0% -0.0% -0.0%
fft -0.1% 0.0% -0.0% -0.0% -0.0%
fft2 -0.1% 0.0% -0.0% -0.0% -0.0%
fibheaps -0.1% 0.0% -0.0% -0.0% -0.0%
fish -0.1% 0.0% -0.0% -0.0% -0.0%
fluid -0.1% 0.0% -0.0% -0.0% -0.0%
fulsom -0.1% 0.0% +0.0% +0.0% +0.0%
gamteb -0.1% 0.0% -0.0% -0.0% -0.0%
gcd -0.1% 0.0% -0.0% -0.0% -0.0%
gen_regexps -0.1% 0.0% -0.0% -0.0% -0.0%
genfft -0.1% 0.0% -0.0% -0.0% -0.0%
gg -0.1% 0.0% -0.0% -0.0% -0.0%
grep -0.1% 0.0% -0.0% -0.0% -0.0%
hidden -0.1% 0.0% -0.0% -0.0% -0.0%
hpg -0.1% 0.0% -0.0% -0.0% -0.0%
ida -0.1% 0.0% -0.0% -0.0% -0.0%
infer -0.1% 0.0% -0.0% -0.0% -0.0%
integer -0.1% 0.0% -0.0% -0.0% -0.0%
integrate -0.1% 0.0% -0.0% -0.0% -0.0%
k-nucleotide -0.1% 0.0% -0.0% -0.0% -0.0%
kahan -0.1% 0.0% -0.0% -0.0% -0.0%
knights -0.1% 0.0% -0.0% -0.0% -0.0%
lambda -0.1% 0.0% -0.0% -0.0% -0.0%
last-piece -0.1% 0.0% -0.0% -0.0% -0.0%
lcss -0.1% 0.0% -0.0% -0.0% -0.0%
life -0.1% 0.0% -0.0% -0.0% -0.0%
lift -0.1% 0.0% -0.0% -0.0% -0.0%
linear -0.1% 0.0% -0.0% -0.0% -0.0%
listcompr -0.1% 0.0% -0.0% -0.0% -0.0%
listcopy -0.1% 0.0% -0.0% -0.0% -0.0%
maillist -0.1% 0.0% -0.0% -0.0% -0.0%
mandel -0.1% 0.0% -0.0% -0.0% -0.0%
mandel2 -0.1% 0.0% -0.0% -0.0% -0.0%
mate -0.1% 0.0% -0.0% -0.0% -0.0%
minimax -0.1% 0.0% -0.0% -0.0% -0.0%
mkhprog -0.1% 0.0% -0.0% -0.0% -0.0%
multiplier -0.1% 0.0% -0.0% -0.0% -0.0%
n-body -0.1% 0.0% -0.0% -0.0% -0.0%
nucleic2 -0.1% 0.0% -0.0% -0.0% -0.0%
para -0.1% 0.0% -0.0% -0.0% -0.0%
paraffins -0.1% 0.0% -0.0% -0.0% -0.0%
parser -0.1% 0.0% -0.0% -0.0% -0.0%
parstof -0.1% 0.0% -0.0% -0.0% -0.0%
pic -0.1% 0.0% -0.0% -0.0% -0.0%
pidigits -0.1% 0.0% -0.0% -0.0% -0.0%
power -0.1% 0.0% -0.0% -0.0% -0.0%
pretty -0.1% 0.0% -0.1% -0.1% -0.1%
primes -0.1% 0.0% -0.0% -0.0% -0.0%
primetest -0.1% 0.0% -0.0% -0.0% -0.0%
prolog -0.1% 0.0% -0.0% -0.0% -0.0%
puzzle -0.1% 0.0% -0.0% -0.0% -0.0%
queens -0.1% 0.0% -0.0% -0.0% -0.0%
reptile -0.1% 0.0% -0.0% -0.0% -0.0%
reverse-complem -0.1% 0.0% -0.0% -0.0% -0.0%
rewrite -0.1% 0.0% -0.0% -0.0% -0.0%
rfib -0.1% 0.0% -0.0% -0.0% -0.0%
rsa -0.1% 0.0% -0.0% -0.0% -0.0%
scc -0.1% 0.0% -0.1% -0.1% -0.1%
sched -0.1% 0.0% -0.0% -0.0% -0.0%
scs -0.1% 0.0% -0.0% -0.0% -0.0%
simple -0.1% 0.0% -0.0% -0.0% -0.0%
solid -0.1% 0.0% -0.0% -0.0% -0.0%
sorting -0.1% 0.0% -0.0% -0.0% -0.0%
spectral-norm -0.1% 0.0% -0.0% -0.0% -0.0%
sphere -0.1% 0.0% -0.0% -0.0% -0.0%
symalg -0.1% 0.0% -0.0% -0.0% -0.0%
tak -0.1% 0.0% -0.0% -0.0% -0.0%
transform -0.1% 0.0% -0.0% -0.0% -0.0%
treejoin -0.1% 0.0% -0.0% -0.0% -0.0%
typecheck -0.1% 0.0% -0.0% -0.0% -0.0%
veritas -0.0% 0.0% -0.0% -0.0% -0.0%
wang -0.1% 0.0% -0.0% -0.0% -0.0%
wave4main -0.1% 0.0% -0.0% -0.0% -0.0%
wheel-sieve1 -0.1% 0.0% -0.0% -0.0% -0.0%
wheel-sieve2 -0.1% 0.0% -0.0% -0.0% -0.0%
x2n1 -0.1% 0.0% -0.0% -0.0% -0.0%
--------------------------------------------------------------------------------
Min -0.1% 0.0% -0.5% -0.3% -0.4%
Max -0.0% 0.0% +0.0% +0.0% +0.0%
Geometric Mean -0.1% -0.0% -0.0% -0.0% -0.0%
Test changes
------------
- break006 is marked as broken, see #17833
- The compiler allocates less when building T14683 (an unsafeCoerce#-
heavy happy-generated code) on 64-platforms. Allocates more on 32-bit
platforms.
- Rest of the increases are tiny amounts (still enough to pass the
threshold) in micro-benchmarks. I briefly looked at each one in a
profiling build: most of the increased allocations seem to be because
of random changes in the generated code.
Metric Decrease:
T14683
Metric Increase:
T12150
T12234
T12425
T13035
T14683
T5837
T6048
Co-Authored-By: Richard Eisenberg <rae@cs.brynmawr.edu>
Co-Authored-By: Ömer Sinan Ağacan <omeragacan@gmail.com>
Diffstat (limited to 'compiler/typecheck/TcRnDriver.hs')
-rw-r--r-- | compiler/typecheck/TcRnDriver.hs | 75 |
1 files changed, 40 insertions, 35 deletions
diff --git a/compiler/typecheck/TcRnDriver.hs b/compiler/typecheck/TcRnDriver.hs index 99cbcf1578..2caee7df9f 100644 --- a/compiler/typecheck/TcRnDriver.hs +++ b/compiler/typecheck/TcRnDriver.hs @@ -62,7 +62,6 @@ import GHC.Rename.Types import GHC.Rename.Expr import GHC.Rename.Utils ( HsDocContext(..) ) import GHC.Rename.Fixity ( lookupFixityRn ) -import MkId import TysWiredIn ( unitTy, mkListTy ) import Plugins import DynFlags @@ -2270,51 +2269,57 @@ leaking memory as it is repeatedly queried. -- statement in the form 'IO [()]'. tcGhciStmts :: [GhciLStmt GhcRn] -> TcM PlanResult tcGhciStmts stmts - = do { ioTyCon <- tcLookupTyCon ioTyConName ; - ret_id <- tcLookupId returnIOName ; -- return @ IO - let { - ret_ty = mkListTy unitTy ; - io_ret_ty = mkTyConApp ioTyCon [ret_ty] ; + = do { ioTyCon <- tcLookupTyCon ioTyConName + ; ret_id <- tcLookupId returnIOName -- return @ IO + ; let ret_ty = mkListTy unitTy + io_ret_ty = mkTyConApp ioTyCon [ret_ty] tc_io_stmts = tcStmtsAndThen GhciStmtCtxt tcDoStmt stmts - (mkCheckExpType io_ret_ty) ; - names = collectLStmtsBinders stmts ; - } ; + (mkCheckExpType io_ret_ty) + names = collectLStmtsBinders stmts -- OK, we're ready to typecheck the stmts - traceTc "TcRnDriver.tcGhciStmts: tc stmts" empty ; - ((tc_stmts, ids), lie) <- captureTopConstraints $ + ; traceTc "TcRnDriver.tcGhciStmts: tc stmts" empty + ; ((tc_stmts, ids), lie) <- captureTopConstraints $ tc_io_stmts $ \ _ -> - mapM tcLookupId names ; + mapM tcLookupId names -- Look up the names right in the middle, -- where they will all be in scope -- Simplify the context - traceTc "TcRnDriver.tcGhciStmts: simplify ctxt" empty ; - const_binds <- checkNoErrs (simplifyInteractive lie) ; + ; traceTc "TcRnDriver.tcGhciStmts: simplify ctxt" empty + ; const_binds <- checkNoErrs (simplifyInteractive lie) -- checkNoErrs ensures that the plan fails if context redn fails - traceTc "TcRnDriver.tcGhciStmts: done" empty ; - let { -- mk_return builds the expression - -- returnIO @ [()] [coerce () x, .., coerce () z] - -- - -- Despite the inconvenience of building the type applications etc, - -- this *has* to be done in type-annotated post-typecheck form - -- because we are going to return a list of *polymorphic* values - -- coerced to type (). If we built a *source* stmt - -- return [coerce x, ..., coerce z] - -- then the type checker would instantiate x..z, and we wouldn't - -- get their *polymorphic* values. (And we'd get ambiguity errs - -- if they were overloaded, since they aren't applied to anything.) - ret_expr = nlHsApp (nlHsTyApp ret_id [ret_ty]) - (noLoc $ ExplicitList unitTy Nothing - (map mk_item ids)) ; - mk_item id = let ty_args = [idType id, unitTy] in - nlHsApp (nlHsTyApp unsafeCoerceId - (map getRuntimeRep ty_args ++ ty_args)) - (nlHsVar id) ; + + ; traceTc "TcRnDriver.tcGhciStmts: done" empty + + -- rec_expr is the expression + -- returnIO @ [()] [unsafeCoerce# () x, .., unsafeCorece# () z] + -- + -- Despite the inconvenience of building the type applications etc, + -- this *has* to be done in type-annotated post-typecheck form + -- because we are going to return a list of *polymorphic* values + -- coerced to type (). If we built a *source* stmt + -- return [coerce x, ..., coerce z] + -- then the type checker would instantiate x..z, and we wouldn't + -- get their *polymorphic* values. (And we'd get ambiguity errs + -- if they were overloaded, since they aren't applied to anything.) + + ; AnId unsafe_coerce_id <- tcLookupGlobal unsafeCoercePrimName + -- We use unsafeCoerce# here because of (U11) in + -- Note [Implementing unsafeCoerce] in base:Unsafe.Coerce + + ; let ret_expr = nlHsApp (nlHsTyApp ret_id [ret_ty]) $ + noLoc $ ExplicitList unitTy Nothing $ + map mk_item ids + + mk_item id = unsafe_coerce_id `nlHsTyApp` [ getRuntimeRep (idType id) + , getRuntimeRep unitTy + , idType id, unitTy] + `nlHsApp` nlHsVar id stmts = tc_stmts ++ [noLoc (mkLastStmt ret_expr)] - } ; - return (ids, mkHsDictLet (EvBinds const_binds) $ + + ; return (ids, mkHsDictLet (EvBinds const_binds) $ noLoc (HsDo io_ret_ty GhciStmtCtxt (noLoc stmts))) } |