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-rw-r--r--compiler/GHC/Builtin/Names/TH.hs16
-rw-r--r--compiler/GHC/Core/Opt/CprAnal.hs33
-rw-r--r--compiler/GHC/Core/Opt/DmdAnal.hs26
-rw-r--r--compiler/GHC/Core/Opt/Simplify.hs2
-rw-r--r--compiler/GHC/Core/Opt/SpecConstr.hs9
-rw-r--r--compiler/GHC/Core/Opt/Specialise.hs5
-rw-r--r--compiler/GHC/Core/Opt/WorkWrap.hs32
-rw-r--r--compiler/GHC/HsToCore/Binds.hs2
-rw-r--r--compiler/GHC/HsToCore/Quote.hs1
-rw-r--r--compiler/GHC/Parser.y6
-rw-r--r--compiler/GHC/Parser/Lexer.x2
-rw-r--r--compiler/GHC/Parser/PostProcess.hs15
-rw-r--r--compiler/GHC/ThToHs.hs11
-rw-r--r--compiler/GHC/Types/Basic.hs68
-rw-r--r--compiler/GHC/Types/Demand.hs26
-rw-r--r--docs/users_guide/9.4.1-notes.rst3
-rw-r--r--docs/users_guide/exts/pragmas.rst24
-rw-r--r--libraries/template-haskell/Language/Haskell/TH/Lib/Internal.hs3
-rw-r--r--libraries/template-haskell/Language/Haskell/TH/Ppr.hs2
-rw-r--r--libraries/template-haskell/Language/Haskell/TH/Syntax.hs1
-rw-r--r--testsuite/tests/parser/should_compile/OpaqueParseWarn1.hs6
-rw-r--r--testsuite/tests/parser/should_compile/OpaqueParseWarn1.stderr2
-rw-r--r--testsuite/tests/parser/should_compile/all.T1
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail1.hs4
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail1.stderr2
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail2.hs4
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail2.stderr2
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail3.hs4
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail3.stderr2
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail4.hs6
-rw-r--r--testsuite/tests/parser/should_fail/OpaqueParseFail4.stderr4
-rw-r--r--testsuite/tests/parser/should_fail/all.T4
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.hs5
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.stderr54
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.hs12
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.stderr153
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoRebox.hs24
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoRebox.stderr75
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.hs23
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.stderr66
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.hs43
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.stderr161
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.hs12
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.stderr172
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.hs7
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.stderr74
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.hs5
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.stderr49
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoWW.hs12
-rw-r--r--testsuite/tests/simplCore/should_compile/OpaqueNoWW.stderr78
-rw-r--r--testsuite/tests/simplCore/should_compile/all.T10
m---------utils/haddock0
52 files changed, 1342 insertions, 21 deletions
diff --git a/compiler/GHC/Builtin/Names/TH.hs b/compiler/GHC/Builtin/Names/TH.hs
index 0c1d626581..f5dbc4fdc9 100644
--- a/compiler/GHC/Builtin/Names/TH.hs
+++ b/compiler/GHC/Builtin/Names/TH.hs
@@ -594,10 +594,11 @@ quoteDecName = qqFun (fsLit "quoteDec") quoteDecKey
quoteTypeName = qqFun (fsLit "quoteType") quoteTypeKey
-- data Inline = ...
-noInlineDataConName, inlineDataConName, inlinableDataConName :: Name
+noInlineDataConName, inlineDataConName, inlinableDataConName, opaqueDataConName :: Name
noInlineDataConName = thCon (fsLit "NoInline") noInlineDataConKey
inlineDataConName = thCon (fsLit "Inline") inlineDataConKey
inlinableDataConName = thCon (fsLit "Inlinable") inlinableDataConKey
+opaqueDataConName = thCon (fsLit "Opaque") opaqueDataConKey
-- data RuleMatch = ...
conLikeDataConName, funLikeDataConName :: Name
@@ -700,21 +701,22 @@ modNameTyConKey = mkPreludeTyConUnique 239
-- If you want to change this, make sure you check in GHC.Builtin.Names
-- data Inline = ...
-noInlineDataConKey, inlineDataConKey, inlinableDataConKey :: Unique
+noInlineDataConKey, inlineDataConKey, inlinableDataConKey, opaqueDataConKey :: Unique
noInlineDataConKey = mkPreludeDataConUnique 200
inlineDataConKey = mkPreludeDataConUnique 201
inlinableDataConKey = mkPreludeDataConUnique 202
+opaqueDataConKey = mkPreludeDataConUnique 203
-- data RuleMatch = ...
conLikeDataConKey, funLikeDataConKey :: Unique
-conLikeDataConKey = mkPreludeDataConUnique 203
-funLikeDataConKey = mkPreludeDataConUnique 204
+conLikeDataConKey = mkPreludeDataConUnique 204
+funLikeDataConKey = mkPreludeDataConUnique 205
-- data Phases = ...
allPhasesDataConKey, fromPhaseDataConKey, beforePhaseDataConKey :: Unique
-allPhasesDataConKey = mkPreludeDataConUnique 205
-fromPhaseDataConKey = mkPreludeDataConUnique 206
-beforePhaseDataConKey = mkPreludeDataConUnique 207
+allPhasesDataConKey = mkPreludeDataConUnique 206
+fromPhaseDataConKey = mkPreludeDataConUnique 207
+beforePhaseDataConKey = mkPreludeDataConUnique 208
-- data Overlap = ..
overlappableDataConKey,
diff --git a/compiler/GHC/Core/Opt/CprAnal.hs b/compiler/GHC/Core/Opt/CprAnal.hs
index 51bc507a20..3f6455c9cf 100644
--- a/compiler/GHC/Core/Opt/CprAnal.hs
+++ b/compiler/GHC/Core/Opt/CprAnal.hs
@@ -428,6 +428,31 @@ cprFix orig_env orig_pairs
where
(id', rhs', env') = cprAnalBind env id rhs
+{-
+Note [The OPAQUE pragma and avoiding the reboxing of results]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Consider:
+
+ {-# OPAQUE f #-}
+ f x = (x,y)
+
+ g True = f 2 x
+ g False = (0,0)
+
+Where if we didn't strip the CPR info from 'f' we would end up with the
+following W/W pair for 'g':
+
+ $wg True = case f 2 of (x, y) -> (# x, y #)
+ $wg False = (# 0, 0 #)
+
+ g b = case wg$ b of (# x, y #) -> (x, y)
+
+Where the worker unboxes the result of 'f', only for wrapper to box it again.
+That's because the non-stripped CPR signature of 'f' is saying to W/W-transform
+'f'. However, OPAQUE-annotated binders aren't W/W transformed (see
+Note [OPAQUE pragma]), so we should strip 'f's CPR signature.
+-}
+
-- | Process the RHS of the binding for a sensible arity, add the CPR signature
-- to the Id, and augment the environment with the signature as well.
cprAnalBind
@@ -452,8 +477,12 @@ cprAnalBind env id rhs
| otherwise = rhs_ty
-- See Note [Arity trimming for CPR signatures]
sig = mkCprSigForArity (idArity id) rhs_ty'
- id' = setIdCprSig id sig
- env' = extendSigEnv env id sig
+ -- See Note [OPAQUE pragma]
+ -- See Note [The OPAQUE pragma and avoiding the reboxing of results]
+ sig' | isOpaquePragma (idInlinePragma id) = topCprSig
+ | otherwise = sig
+ id' = setIdCprSig id sig'
+ env' = extendSigEnv env id sig'
-- See Note [CPR for thunks]
stays_thunk = is_thunk && not_strict
diff --git a/compiler/GHC/Core/Opt/DmdAnal.hs b/compiler/GHC/Core/Opt/DmdAnal.hs
index 93c7e38ef9..347cc4228d 100644
--- a/compiler/GHC/Core/Opt/DmdAnal.hs
+++ b/compiler/GHC/Core/Opt/DmdAnal.hs
@@ -1516,6 +1516,24 @@ next layer, using that depleted budget.
To achieve this, we use the classic almost-circular programming technique in
which we we write one pass that takes a lazy list of the Budgets for every
layer.
+
+Note [The OPAQUE pragma and avoiding the reboxing of arguments]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In https://gitlab.haskell.org/ghc/ghc/-/issues/13143 it was identified that when
+a function 'f' with a NOINLINE pragma is W/W transformed, then the worker for
+'f' should get the NOINLINE annotation, while the wrapper /should/ be inlined.
+
+That's because if the wrapper for 'f' had stayed NOINLINE, then any worker of a
+W/W-transformed /caller of/ 'f' would immediately rebox any unboxed arguments
+that is applied to the wrapper of 'f'. When the wrapper is inlined, that kind of
+reboxing does not happen.
+
+But now we have functions with OPAQUE pragmas, which by definition (See Note
+[OPAQUE pragma]) do not get W/W-transformed. So in order to avoid reboxing
+workers of any W/W-transformed /callers of/ 'f' we need to strip all boxity
+information from 'f' in the demand analysis. This will inform the
+W/W-transformation code that boxed arguments of 'f' must definitely be passed
+along in boxed form and as such dissuade the creation of reboxing workers.
-}
data Budgets = MkB Arity Budgets -- An infinite list of arity budgets
@@ -1560,10 +1578,14 @@ finaliseArgBoxities env fn arity rhs div
mk_triple :: Id -> (Type,StrictnessMark,Demand)
mk_triple bndr | is_cls_arg ty = (ty, NotMarkedStrict, trimBoxity dmd)
| is_bot_fn = (ty, NotMarkedStrict, unboxDeeplyDmd dmd)
+ -- See Note [OPAQUE pragma]
+ -- See Note [The OPAQUE pragma and avoiding the reboxing of arguments]
+ | is_opaque = (ty, NotMarkedStrict, trimBoxity dmd)
| otherwise = (ty, NotMarkedStrict, dmd)
where
- ty = idType bndr
- dmd = idDemandInfo bndr
+ ty = idType bndr
+ dmd = idDemandInfo bndr
+ is_opaque = isOpaquePragma (idInlinePragma fn)
-- is_cls_arg: see Note [Do not unbox class dictionaries]
is_cls_arg arg_ty = is_inlinable_fn && isClassPred arg_ty
diff --git a/compiler/GHC/Core/Opt/Simplify.hs b/compiler/GHC/Core/Opt/Simplify.hs
index 3c3854bf41..a5b40879b1 100644
--- a/compiler/GHC/Core/Opt/Simplify.hs
+++ b/compiler/GHC/Core/Opt/Simplify.hs
@@ -624,6 +624,8 @@ tryCastWorkerWrapper env top_lvl old_bndr occ_info bndr (Cast rhs co)
, isConcrete (typeKind rhs_ty) -- Don't peel off a cast if doing so would
-- lose the underlying runtime representation.
-- See Note [Preserve RuntimeRep info in cast w/w]
+ , not (isOpaquePragma (idInlinePragma old_bndr)) -- Not for OPAQUE bindings
+ -- See Note [OPAQUE pragma]
= do { (rhs_floats, work_rhs) <- prepareRhs env top_lvl occ_fs rhs
; uniq <- getUniqueM
; let work_name = mkSystemVarName uniq occ_fs
diff --git a/compiler/GHC/Core/Opt/SpecConstr.hs b/compiler/GHC/Core/Opt/SpecConstr.hs
index aec343508e..a5579108e6 100644
--- a/compiler/GHC/Core/Opt/SpecConstr.hs
+++ b/compiler/GHC/Core/Opt/SpecConstr.hs
@@ -1650,7 +1650,14 @@ specialise env bind_calls (RI { ri_fn = fn, ri_lam_bndrs = arg_bndrs
= -- pprTrace "specialise bot" (ppr fn) $
return (nullUsage, spec_info)
- | not (isNeverActive (idInlineActivation fn)) -- See Note [Transfer activation]
+ | not (isNeverActive (idInlineActivation fn))
+ -- See Note [Transfer activation]
+ --
+ --
+ -- Don't specialise OPAQUE things, see Note [OPAQUE pragma].
+ -- Since OPAQUE things are always never-active (see
+ -- GHC.Parser.PostProcess.mkOpaquePragma) this guard never fires for
+ -- OPAQUE things.
, not (null arg_bndrs) -- Only specialise functions
, Just all_calls <- lookupVarEnv bind_calls fn -- Some calls to it
= -- pprTrace "specialise entry {" (ppr fn <+> ppr all_calls) $
diff --git a/compiler/GHC/Core/Opt/Specialise.hs b/compiler/GHC/Core/Opt/Specialise.hs
index d80e78f685..d9cc090d3d 100644
--- a/compiler/GHC/Core/Opt/Specialise.hs
+++ b/compiler/GHC/Core/Opt/Specialise.hs
@@ -1431,6 +1431,11 @@ specCalls spec_imp env existing_rules calls_for_me fn rhs
&& not (isNeverActive (idInlineActivation fn))
-- Don't specialise NOINLINE things
-- See Note [Auto-specialisation and RULES]
+ --
+ -- Don't specialise OPAQUE things, see Note [OPAQUE pragma].
+ -- Since OPAQUE things are always never-active (see
+ -- GHC.Parser.PostProcess.mkOpaquePragma) this guard never fires for
+ -- OPAQUE things.
-- && not (certainlyWillInline (idUnfolding fn)) -- And it's not small
-- See Note [Inline specialisations] for why we do not
diff --git a/compiler/GHC/Core/Opt/WorkWrap.hs b/compiler/GHC/Core/Opt/WorkWrap.hs
index 092fdbb7a7..a6e583a210 100644
--- a/compiler/GHC/Core/Opt/WorkWrap.hs
+++ b/compiler/GHC/Core/Opt/WorkWrap.hs
@@ -534,9 +534,6 @@ tryWW :: WwOpts
-- if two, then a worker and a
-- wrapper.
tryWW ww_opts is_rec fn_id rhs
- -- Do this even if there is a NOINLINE pragma
- -- See Note [Worker/wrapper for NOINLINE functions]
-
-- See Note [Drop absent bindings]
| isAbsDmd (demandInfo fn_info)
, not (isJoinId fn_id)
@@ -551,6 +548,35 @@ tryWW ww_opts is_rec fn_id rhs
| isRecordSelector fn_id
= return [ (new_fn_id, rhs ) ]
+ -- Don't w/w OPAQUE things
+ -- See Note [OPAQUE pragma]
+ --
+ -- Whilst this check might seem superfluous, since we strip boxity
+ -- information in GHC.Core.Opt.DmdAnal.finaliseArgBoxities and
+ -- CPR information in GHC.Core.Opt.CprAnal.cprAnalBind, it actually
+ -- isn't. That is because we would still perform w/w when:
+ --
+ -- * An argument is used strictly, and -fworker-wrapper-cbv is
+ -- enabled, or,
+ -- * When demand analysis marks an argument as absent.
+ --
+ -- In a debug build we do assert that boxity and CPR information
+ -- are actually stripped, since we want to prevent callers of OPAQUE
+ -- things to do reboxing. See:
+ -- * Note [The OPAQUE pragma and avoiding the reboxing of arguments]
+ -- * Note [The OPAQUE pragma and avoiding the reboxing of results]
+ | isOpaquePragma (inlinePragInfo fn_info)
+ = assertPpr (onlyBoxedArguments (dmdSigInfo fn_info) &&
+ isTopCprSig (cprSigInfo fn_info))
+ (text "OPAQUE fun with boxity" $$
+ ppr new_fn_id $$
+ ppr (dmdSigInfo fn_info) $$
+ ppr (cprSigInfo fn_info) $$
+ ppr rhs) $
+ return [ (new_fn_id, rhs) ]
+
+ -- Do this even if there is a NOINLINE pragma
+ -- See Note [Worker/wrapper for NOINLINE functions]
| is_fun
= splitFun ww_opts new_fn_id rhs
diff --git a/compiler/GHC/HsToCore/Binds.hs b/compiler/GHC/HsToCore/Binds.hs
index 9220326258..793f8c9ffb 100644
--- a/compiler/GHC/HsToCore/Binds.hs
+++ b/compiler/GHC/HsToCore/Binds.hs
@@ -399,6 +399,7 @@ makeCorePair dflags gbl_id is_default_method dict_arity rhs
= case inlinePragmaSpec inline_prag of
NoUserInlinePrag -> (gbl_id, rhs)
NoInline {} -> (gbl_id, rhs)
+ Opaque {} -> (gbl_id, rhs)
Inlinable {} -> (gbl_id `setIdUnfolding` inlinable_unf, rhs)
Inline {} -> inline_pair
where
@@ -769,6 +770,7 @@ dsSpec mb_poly_rhs (L loc (SpecPrag poly_id spec_co spec_inl))
-- phase specification in the SPECIALISE pragma
no_act_spec = case inlinePragmaSpec spec_inl of
NoInline _ -> isNeverActive spec_prag_act
+ Opaque _ -> isNeverActive spec_prag_act
_ -> isAlwaysActive spec_prag_act
rule_act | no_act_spec = inlinePragmaActivation id_inl -- Inherit
| otherwise = spec_prag_act -- Specified by user
diff --git a/compiler/GHC/HsToCore/Quote.hs b/compiler/GHC/HsToCore/Quote.hs
index 38dc46364e..22fc242e87 100644
--- a/compiler/GHC/HsToCore/Quote.hs
+++ b/compiler/GHC/HsToCore/Quote.hs
@@ -1118,6 +1118,7 @@ rep_specialiseInst ty loc
repInline :: InlineSpec -> MetaM (Core TH.Inline)
repInline (NoInline _ ) = dataCon noInlineDataConName
+repInline (Opaque _ ) = dataCon opaqueDataConName
repInline (Inline _ ) = dataCon inlineDataConName
repInline (Inlinable _ ) = dataCon inlinableDataConName
repInline NoUserInlinePrag = notHandled ThNoUserInline
diff --git a/compiler/GHC/Parser.y b/compiler/GHC/Parser.y
index 418d67dc67..225eabd212 100644
--- a/compiler/GHC/Parser.y
+++ b/compiler/GHC/Parser.y
@@ -622,6 +622,7 @@ are the most common patterns, rewritten as regular expressions for clarity:
'dependency' { L _ ITdependency }
'{-# INLINE' { L _ (ITinline_prag _ _ _) } -- INLINE or INLINABLE
+ '{-# OPAQUE' { L _ (ITopaque_prag _) }
'{-# SPECIALISE' { L _ (ITspec_prag _) }
'{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _ _) }
'{-# SOURCE' { L _ (ITsource_prag _) }
@@ -2575,7 +2576,9 @@ sigdecl :: { LHsDecl GhcPs }
{% acsA (\cs -> (sLL $1 $> $ SigD noExtField (InlineSig (EpAnn (glR $1) ((mo $1:fst $2) ++ [mc $4]) cs) $3
(mkInlinePragma (getINLINE_PRAGs $1) (getINLINE $1)
(snd $2))))) }
-
+ | '{-# OPAQUE' qvar '#-}'
+ {% acsA (\cs -> (sLL $1 $> $ SigD noExtField (InlineSig (EpAnn (glR $1) [mo $1, mc $3] cs) $2
+ (mkOpaquePragma (getOPAQUE_PRAGs $1))))) }
| '{-# SCC' qvar '#-}'
{% acsA (\cs -> sLL $1 $> (SigD noExtField (SCCFunSig (EpAnn (glR $1) [mo $1, mc $3] cs) (getSCC_PRAGs $1) $2 Nothing))) }
@@ -3914,6 +3917,7 @@ getPRIMWORDs (L _ (ITprimword src _)) = src
-- See Note [Pragma source text] in "GHC.Types.Basic" for the following
getINLINE_PRAGs (L _ (ITinline_prag _ inl _)) = inlineSpecSource inl
+getOPAQUE_PRAGs (L _ (ITopaque_prag src)) = src
getSPEC_PRAGs (L _ (ITspec_prag src)) = src
getSPEC_INLINE_PRAGs (L _ (ITspec_inline_prag src _)) = src
getSOURCE_PRAGs (L _ (ITsource_prag src)) = src
diff --git a/compiler/GHC/Parser/Lexer.x b/compiler/GHC/Parser/Lexer.x
index 02717c7dae..b1d8f43350 100644
--- a/compiler/GHC/Parser/Lexer.x
+++ b/compiler/GHC/Parser/Lexer.x
@@ -761,6 +761,7 @@ data Token
-- Pragmas, see Note [Pragma source text] in "GHC.Types.Basic"
| ITinline_prag SourceText InlineSpec RuleMatchInfo
+ | ITopaque_prag SourceText
| ITspec_prag SourceText -- SPECIALISE
| ITspec_inline_prag SourceText Bool -- SPECIALISE INLINE (or NOINLINE)
| ITsource_prag SourceText
@@ -3446,6 +3447,7 @@ oneWordPrags = Map.fromList [
-- Spelling variant
("notinline",
strtoken (\s -> (ITinline_prag (SourceText s) (NoInline (SourceText s)) FunLike))),
+ ("opaque", strtoken (\s -> ITopaque_prag (SourceText s))),
("specialize", strtoken (\s -> ITspec_prag (SourceText s))),
("source", strtoken (\s -> ITsource_prag (SourceText s))),
("warning", strtoken (\s -> ITwarning_prag (SourceText s))),
diff --git a/compiler/GHC/Parser/PostProcess.hs b/compiler/GHC/Parser/PostProcess.hs
index 444471abca..e6daea8fe8 100644
--- a/compiler/GHC/Parser/PostProcess.hs
+++ b/compiler/GHC/Parser/PostProcess.hs
@@ -30,6 +30,7 @@ module GHC.Parser.PostProcess (
mkTyFamInst,
mkFamDecl,
mkInlinePragma,
+ mkOpaquePragma,
mkPatSynMatchGroup,
mkRecConstrOrUpdate,
mkTyClD, mkInstD,
@@ -2559,8 +2560,22 @@ mkInlinePragma src (inl, match_info) mb_act
Nothing -> -- No phase specified
case inl of
NoInline _ -> NeverActive
+ Opaque _ -> NeverActive
_other -> AlwaysActive
+mkOpaquePragma :: SourceText -> InlinePragma
+mkOpaquePragma src
+ = InlinePragma { inl_src = src
+ , inl_inline = Opaque src
+ , inl_sat = Nothing
+ -- By marking the OPAQUE pragma NeverActive we stop
+ -- (constructor) specialisation on OPAQUE things.
+ --
+ -- See Note [OPAQUE pragma]
+ , inl_act = NeverActive
+ , inl_rule = FunLike
+ }
+
-----------------------------------------------------------------------------
-- utilities for foreign declarations
diff --git a/compiler/GHC/ThToHs.hs b/compiler/GHC/ThToHs.hs
index d90ef38341..ebcaad926a 100644
--- a/compiler/GHC/ThToHs.hs
+++ b/compiler/GHC/ThToHs.hs
@@ -780,6 +780,17 @@ cvtPragmaD (InlineP nm inline rm phases)
toSrcTxt a = SourceText $ src a
; returnJustLA $ Hs.SigD noExtField $ InlineSig noAnn nm' ip }
+cvtPragmaD (OpaqueP nm)
+ = do { nm' <- vNameN nm
+ ; let ip = InlinePragma { inl_src = srcTxt
+ , inl_inline = Opaque srcTxt
+ , inl_rule = Hs.FunLike
+ , inl_act = NeverActive
+ , inl_sat = Nothing }
+ where
+ srcTxt = SourceText "{-# OPAQUE"
+ ; returnJustLA $ Hs.SigD noExtField $ InlineSig noAnn nm' ip }
+
cvtPragmaD (SpecialiseP nm ty inline phases)
= do { nm' <- vNameN nm
; ty' <- cvtSigType ty
diff --git a/compiler/GHC/Types/Basic.hs b/compiler/GHC/Types/Basic.hs
index 2e234c383b..3843e2c880 100644
--- a/compiler/GHC/Types/Basic.hs
+++ b/compiler/GHC/Types/Basic.hs
@@ -88,7 +88,7 @@ module GHC.Types.Basic (
InlinePragma(..), defaultInlinePragma, alwaysInlinePragma,
neverInlinePragma, dfunInlinePragma,
isDefaultInlinePragma,
- isInlinePragma, isInlinablePragma, isNoInlinePragma,
+ isInlinePragma, isInlinablePragma, isNoInlinePragma, isOpaquePragma,
isAnyInlinePragma, alwaysInlineConLikePragma,
inlinePragmaSource,
inlinePragmaName, inlineSpecSource,
@@ -1438,6 +1438,7 @@ data InlineSpec -- What the user's INLINE pragma looked like
= Inline SourceText -- User wrote INLINE
| Inlinable SourceText -- User wrote INLINABLE
| NoInline SourceText -- User wrote NOINLINE
+ | Opaque SourceText -- User wrote OPAQUE
-- Each of the above keywords is accompanied with
-- a string of type SourceText written by the user
| NoUserInlinePrag -- User did not write any of INLINE/INLINABLE/NOINLINE
@@ -1465,7 +1466,7 @@ If you want to know where InlinePragmas take effect: Look in GHC.HsToCore.Binds.
Note [inl_inline and inl_act]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* inl_inline says what the user wrote: did they say INLINE, NOINLINE,
- INLINABLE, or nothing at all
+ INLINABLE, OPAQUE, or nothing at all
* inl_act says in what phases the unfolding is active or inactive
E.g If you write INLINE[1] then inl_act will be set to ActiveAfter 1
@@ -1514,6 +1515,52 @@ The main effects of CONLIKE are:
- The rule matcher consults this field. See
Note [Expanding variables] in GHC.Core.Rules.
+
+Note [OPAQUE pragma]
+~~~~~~~~~~~~~~~~~~~~
+Suppose a function `f` is marked {-# OPAQUE f #-}. Then every call of `f`
+should remain a call of `f` throughout optimisation; it should not be turned
+into a call of a name-mangled variant of `f` (e.g by worker/wrapper).
+
+The motivation for the OPAQUE pragma is discussed in GHC proposal 0415:
+https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0415-opaque-pragma.rst
+Basically it boils down to the desire of GHC API users and GHC RULE writers for
+calls to certain binders to be left completely untouched by GHCs optimisations.
+
+What this entails at the time of writing, is that for every binder annotated
+with the OPAQUE pragma we:
+
+* Do not do worker/wrapper via cast W/W:
+ See the guard in GHC.Core.Opt.Simplify.tryCastWorkerWrapper
+
+* Do not any worker/wrapper after demand/CPR analysis. To that end add a guard
+ in GHC.Core.Opt.WorkWrap.tryWW to disable worker/wrapper
+
+* It is important that the demand signature and CPR signature do not lie, else
+ clients of the function will believe that it has the CPR property etc. But it
+ won't, because we've disabled worker/wrapper. To avoid the signatures lying:
+ * Strip boxity information from the demand signature
+ in GHC.Core.Opt.DmdAnal.finaliseArgBoxities
+ See Note [The OPAQUE pragma and avoiding the reboxing of arguments]
+ * Strip CPR information from the CPR signature
+ in GHC.Core.Opt.CprAnal.cprAnalBind
+ See Note [The OPAQUE pragma and avoiding the reboxing of results]
+
+* Do create specialised versions of the function in
+ * Specialise: see GHC.Core.Opt.Specialise.specCalls
+ * SpecConstr: see GHC.Core.Opt.SpecConstr.specialise
+ Both are accomplished easily: these passes already skip NOINLINE
+ functions with NeverActive activation, and an OPAQUE function is
+ also NeverActive.
+
+At the moment of writing, the major difference between the NOINLINE pragma and
+the OPAQUE pragma is that binders annoted with the NOINLINE pragma _are_ W/W
+transformed (see also Note [Worker/wrapper for NOINLINE functions]) where
+binders annoted with the OPAQUE pragma are _not_ W/W transformed.
+
+Future "name-mangling" optimisations should respect the OPAQUE pragma and
+update the list of moving parts referenced in this note.
+
-}
isConLike :: RuleMatchInfo -> Bool
@@ -1550,6 +1597,7 @@ inlinePragmaSource prag = case inl_inline prag of
Inline x -> x
Inlinable y -> y
NoInline z -> z
+ Opaque q -> q
NoUserInlinePrag -> NoSourceText
inlineSpecSource :: InlineSpec -> SourceText
@@ -1557,6 +1605,7 @@ inlineSpecSource spec = case spec of
Inline x -> x
Inlinable y -> y
NoInline z -> z
+ Opaque q -> q
NoUserInlinePrag -> NoSourceText
-- A DFun has an always-active inline activation so that
@@ -1594,6 +1643,11 @@ isAnyInlinePragma prag = case inl_inline prag of
Inlinable _ -> True
_ -> False
+isOpaquePragma :: InlinePragma -> Bool
+isOpaquePragma prag = case inl_inline prag of
+ Opaque _ -> True
+ _ -> False
+
inlinePragmaSat :: InlinePragma -> Maybe Arity
inlinePragmaSat = inl_sat
@@ -1660,6 +1714,7 @@ instance Outputable InlineSpec where
ppr (Inline src) = text "INLINE" <+> pprWithSourceText src empty
ppr (NoInline src) = text "NOINLINE" <+> pprWithSourceText src empty
ppr (Inlinable src) = text "INLINABLE" <+> pprWithSourceText src empty
+ ppr (Opaque src) = text "OPAQUE" <+> pprWithSourceText src empty
ppr NoUserInlinePrag = empty
instance Binary InlineSpec where
@@ -1670,6 +1725,8 @@ instance Binary InlineSpec where
put_ bh s
put_ bh (NoInline s) = do putByte bh 3
put_ bh s
+ put_ bh (Opaque s) = do putByte bh 4
+ put_ bh s
get bh = do h <- getByte bh
case h of
@@ -1680,9 +1737,12 @@ instance Binary InlineSpec where
2 -> do
s <- get bh
return (Inlinable s)
- _ -> do
+ 3 -> do
s <- get bh
return (NoInline s)
+ _ -> do
+ s <- get bh
+ return (Opaque s)
instance Outputable InlinePragma where
ppr = pprInline
@@ -1710,6 +1770,7 @@ inlinePragmaName :: InlineSpec -> SDoc
inlinePragmaName (Inline _) = text "INLINE"
inlinePragmaName (Inlinable _) = text "INLINABLE"
inlinePragmaName (NoInline _) = text "NOINLINE"
+inlinePragmaName (Opaque _) = text "OPAQUE"
inlinePragmaName NoUserInlinePrag = empty
pprInline :: InlinePragma -> SDoc
@@ -1732,6 +1793,7 @@ pprInline' emptyInline (InlinePragma
pp_act Inline {} AlwaysActive = empty
pp_act NoInline {} NeverActive = empty
+ pp_act Opaque {} NeverActive = empty
pp_act _ act = ppr act
pp_sat | Just ar <- mb_arity = parens (text "sat-args=" <> int ar)
diff --git a/compiler/GHC/Types/Demand.hs b/compiler/GHC/Types/Demand.hs
index 98db1c38b8..4163e9a525 100644
--- a/compiler/GHC/Types/Demand.hs
+++ b/compiler/GHC/Types/Demand.hs
@@ -31,7 +31,7 @@ module GHC.Types.Demand (
-- ** Predicates on @Card@inalities and @Demand@s
isAbs, isUsedOnce, isStrict,
isAbsDmd, isUsedOnceDmd, isStrUsedDmd, isStrictDmd,
- isTopDmd, isWeakDmd,
+ isTopDmd, isWeakDmd, onlyBoxedArguments,
-- ** Special demands
evalDmd,
-- *** Demands used in PrimOp signatures
@@ -66,7 +66,7 @@ module GHC.Types.Demand (
-- * Demand signatures
DmdSig(..), mkDmdSigForArity, mkClosedDmdSig,
splitDmdSig, dmdSigDmdEnv, hasDemandEnvSig,
- nopSig, botSig, isTopSig, isDeadEndSig, appIsDeadEnd,
+ nopSig, botSig, isTopSig, isDeadEndSig, appIsDeadEnd, trimBoxityDmdSig,
-- ** Handling arity adjustments
prependArgsDmdSig, etaConvertDmdSig,
@@ -103,6 +103,7 @@ import GHC.Utils.Outputable
import GHC.Utils.Panic
import GHC.Utils.Panic.Plain
+import Data.Coerce (coerce)
import Data.Function
import GHC.Utils.Trace
@@ -1955,6 +1956,20 @@ isTopSig (DmdSig ty) = isTopDmdType ty
isDeadEndSig :: DmdSig -> Bool
isDeadEndSig (DmdSig (DmdType _ _ res)) = isDeadEndDiv res
+-- | True when the signature indicates all arguments are boxed
+onlyBoxedArguments :: DmdSig -> Bool
+onlyBoxedArguments (DmdSig (DmdType _ dmds _)) = all demandIsBoxed dmds
+ where
+ demandIsBoxed BotDmd = True
+ demandIsBoxed AbsDmd = True
+ demandIsBoxed (_ :* sd) = subDemandIsboxed sd
+
+ subDemandIsboxed (Poly Unboxed _) = False
+ subDemandIsboxed (Poly _ _) = True
+ subDemandIsboxed (Call _ sd) = subDemandIsboxed sd
+ subDemandIsboxed (Prod Unboxed _) = False
+ subDemandIsboxed (Prod _ ds) = all demandIsBoxed ds
+
-- | Returns true if an application to n args would diverge or throw an
-- exception.
--
@@ -1966,6 +1981,13 @@ appIsDeadEnd :: DmdSig -> Int -> Bool
appIsDeadEnd (DmdSig (DmdType _ ds res)) n
= isDeadEndDiv res && not (lengthExceeds ds n)
+trimBoxityDmdType :: DmdType -> DmdType
+trimBoxityDmdType (DmdType fvs ds res) =
+ DmdType (mapVarEnv trimBoxity fvs) (map trimBoxity ds) res
+
+trimBoxityDmdSig :: DmdSig -> DmdSig
+trimBoxityDmdSig = coerce trimBoxityDmdType
+
prependArgsDmdSig :: Int -> DmdSig -> DmdSig
-- ^ Add extra ('topDmd') arguments to a strictness signature.
-- In contrast to 'etaConvertDmdSig', this /prepends/ additional argument
diff --git a/docs/users_guide/9.4.1-notes.rst b/docs/users_guide/9.4.1-notes.rst
index caac4e9362..39ab943356 100644
--- a/docs/users_guide/9.4.1-notes.rst
+++ b/docs/users_guide/9.4.1-notes.rst
@@ -67,6 +67,9 @@ Compiler
- The way GHC checks for representation polymorphism has been overhauled:
all the checks are now done during typechecking. The error messages
now contain more detailed information about the specific check that was performed.
+- A new pragma, :pragma:`OPAQUE`, that ensures that every call of a named function
+ annotated with an :pragma:`OPAQUE` pragma remains a call of that named function,
+ not some name-mangled variant.
- The parsing of implicit parameters is slightly more permissive, as GHC now allows ::
diff --git a/docs/users_guide/exts/pragmas.rst b/docs/users_guide/exts/pragmas.rst
index f533dd834e..5aa4e9a783 100644
--- a/docs/users_guide/exts/pragmas.rst
+++ b/docs/users_guide/exts/pragmas.rst
@@ -454,6 +454,30 @@ arguments etc). Another way to understand the semantics is this:
The same phase-numbering control is available for :pragma:`RULE <RULES>`\s
(:ref:`rewrite-rules`).
+.. _opaque-pragma:
+
+``OPAQUE`` pragma
+-----------------
+
+.. pragma:: OPAQUE ⟨name⟩
+
+ :where: top-level
+
+ Instructs the compiler to ensure that every call of ``name`` remains a
+ call of ``name``, and not some name-mangled variant.
+
+The :pragma:`OPAQUE` pragma is an even stronger variant of the :pragma:`NOINLINE`
+pragma. Like the :pragma:`NOINLINE`, named functions annotated with a
+:pragma:`OPAQUE` pragma are not inlined, nor will they be be specialized.
+Unlike the :pragma:`NOINLINE`, named functions annotated with a
+:pragma:`OPAQUE` pragma are left untouched by the Worker/Wrapper transformation.
+Unlike :pragma:`NOINLINE`, :pragma:`OPAQUE` has no phase control.
+
+In effect, every call of a named function annotated with an :pragma:`OPAQUE`
+pragma remains a call of that named function, not some name-mangled variant.
+You shouldn't ever need to use the :pragma:`OPAQUE` pragma, unless you have a
+reason to care about name-mangling.
+
.. _line-pragma:
``LINE`` pragma
diff --git a/libraries/template-haskell/Language/Haskell/TH/Lib/Internal.hs b/libraries/template-haskell/Language/Haskell/TH/Lib/Internal.hs
index 95ccf39447..e960f35bb3 100644
--- a/libraries/template-haskell/Language/Haskell/TH/Lib/Internal.hs
+++ b/libraries/template-haskell/Language/Haskell/TH/Lib/Internal.hs
@@ -484,6 +484,9 @@ pragInlD :: Quote m => Name -> Inline -> RuleMatch -> Phases -> m Dec
pragInlD name inline rm phases
= pure $ PragmaD $ InlineP name inline rm phases
+pragOpaqueD :: Quote m => Name -> m Dec
+pragOpaqueD name = pure $ PragmaD $ OpaqueP name
+
pragSpecD :: Quote m => Name -> m Type -> Phases -> m Dec
pragSpecD n ty phases
= do
diff --git a/libraries/template-haskell/Language/Haskell/TH/Ppr.hs b/libraries/template-haskell/Language/Haskell/TH/Ppr.hs
index 449a6e5087..51e89fda2a 100644
--- a/libraries/template-haskell/Language/Haskell/TH/Ppr.hs
+++ b/libraries/template-haskell/Language/Haskell/TH/Ppr.hs
@@ -593,6 +593,8 @@ instance Ppr Pragma where
<+> ppr phases
<+> pprName' Applied n
<+> text "#-}"
+ ppr (OpaqueP n)
+ = text "{-# OPAQUE" <+> pprName' Applied n <+> text "#-}"
ppr (SpecialiseP n ty inline phases)
= text "{-# SPECIALISE"
<+> maybe empty ppr inline
diff --git a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs
index 3d3f46d2c4..5acf96e011 100644
--- a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs
+++ b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs
@@ -2499,6 +2499,7 @@ data Safety = Unsafe | Safe | Interruptible
deriving( Show, Eq, Ord, Data, Generic )
data Pragma = InlineP Name Inline RuleMatch Phases
+ | OpaqueP Name
| SpecialiseP Name Type (Maybe Inline) Phases
| SpecialiseInstP Type
| RuleP String (Maybe [TyVarBndr ()]) [RuleBndr] Exp Exp Phases
diff --git a/testsuite/tests/parser/should_compile/OpaqueParseWarn1.hs b/testsuite/tests/parser/should_compile/OpaqueParseWarn1.hs
new file mode 100644
index 0000000000..d4307a463c
--- /dev/null
+++ b/testsuite/tests/parser/should_compile/OpaqueParseWarn1.hs
@@ -0,0 +1,6 @@
+module OpaqueParseWarn1 where
+
+f :: Num a => a -> a
+f = (+1)
+{-# OPAQUE f #-}
+{-# SPECIALISE f :: Int -> Int #-}
diff --git a/testsuite/tests/parser/should_compile/OpaqueParseWarn1.stderr b/testsuite/tests/parser/should_compile/OpaqueParseWarn1.stderr
new file mode 100644
index 0000000000..49682aae19
--- /dev/null
+++ b/testsuite/tests/parser/should_compile/OpaqueParseWarn1.stderr
@@ -0,0 +1,2 @@
+OpaqueParseWarn1.hs:6:1: warning:
+ Ignoring useless SPECIALISE pragma for NOINLINE function: ‘f’
diff --git a/testsuite/tests/parser/should_compile/all.T b/testsuite/tests/parser/should_compile/all.T
index 21787b3794..5412557d10 100644
--- a/testsuite/tests/parser/should_compile/all.T
+++ b/testsuite/tests/parser/should_compile/all.T
@@ -184,3 +184,4 @@ test('DumpSemis', normal, compile, ['-dsuppress-uniques -ddump-parsed-ast'])
test('T20846', normal, compile, ['-dsuppress-uniques -ddump-parsed-ast'])
test('T20551', normal, compile, [''])
+test('OpaqueParseWarn1', normal, compile, [''])
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail1.hs b/testsuite/tests/parser/should_fail/OpaqueParseFail1.hs
new file mode 100644
index 0000000000..368b73f2d7
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail1.hs
@@ -0,0 +1,4 @@
+module OpaqueParseFail1 where
+
+f = id
+{-# OPAQUE[1] f #-}
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail1.stderr b/testsuite/tests/parser/should_fail/OpaqueParseFail1.stderr
new file mode 100644
index 0000000000..057b3a8f92
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail1.stderr
@@ -0,0 +1,2 @@
+OpaqueParseFail1.hs:4:11: error:
+ parse error on input ‘[’
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail2.hs b/testsuite/tests/parser/should_fail/OpaqueParseFail2.hs
new file mode 100644
index 0000000000..e9685581e8
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail2.hs
@@ -0,0 +1,4 @@
+module OpaqueParseFail2 where
+
+f = id
+{-# OPAQUE SPECIALISE f :: Int -> Int #-}
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail2.stderr b/testsuite/tests/parser/should_fail/OpaqueParseFail2.stderr
new file mode 100644
index 0000000000..5c4063bd23
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail2.stderr
@@ -0,0 +1,2 @@
+OpaqueParseFail2.hs:4:12: error:
+ parse error on input ‘SPECIALISE’
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail3.hs b/testsuite/tests/parser/should_fail/OpaqueParseFail3.hs
new file mode 100644
index 0000000000..a3a13aeba0
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail3.hs
@@ -0,0 +1,4 @@
+module OpaqueParseFail2 where
+
+f = id
+{-# OPAQUE CONLIKE f #-}
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail3.stderr b/testsuite/tests/parser/should_fail/OpaqueParseFail3.stderr
new file mode 100644
index 0000000000..7680f18ead
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail3.stderr
@@ -0,0 +1,2 @@
+OpaqueParseFail3.hs:4:12: error:
+ parse error on input ‘CONLIKE’
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail4.hs b/testsuite/tests/parser/should_fail/OpaqueParseFail4.hs
new file mode 100644
index 0000000000..aecd866fb9
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail4.hs
@@ -0,0 +1,6 @@
+module OpaqueParseWarn2 where
+
+f :: Num a => a -> a
+f = (+1)
+{-# OPAQUE f #-}
+{-# INLINE f #-}
diff --git a/testsuite/tests/parser/should_fail/OpaqueParseFail4.stderr b/testsuite/tests/parser/should_fail/OpaqueParseFail4.stderr
new file mode 100644
index 0000000000..413b4fcc0c
--- /dev/null
+++ b/testsuite/tests/parser/should_fail/OpaqueParseFail4.stderr
@@ -0,0 +1,4 @@
+OpaqueParseFail4.hs:6:12: error:
+ Duplicate INLINE pragmas for ‘f’
+ at OpaqueParseFail4.hs:5:12
+ OpaqueParseFail4.hs:6:12
diff --git a/testsuite/tests/parser/should_fail/all.T b/testsuite/tests/parser/should_fail/all.T
index b3a79e38c4..1d90ab407e 100644
--- a/testsuite/tests/parser/should_fail/all.T
+++ b/testsuite/tests/parser/should_fail/all.T
@@ -201,3 +201,7 @@ test('ParserNoTH2', normal, compile_fail, [''])
test('T17865', normal, compile_fail, [''])
test('T20654a', normal, compile_fail, [''])
test('T20654b', normal, compile_fail, [''])
+test('OpaqueParseFail1', normal, compile_fail, [''])
+test('OpaqueParseFail2', normal, compile_fail, [''])
+test('OpaqueParseFail3', normal, compile_fail, [''])
+test('OpaqueParseFail4', normal, compile_fail, [''])
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.hs
new file mode 100644
index 0000000000..6dfb874e3c
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.hs
@@ -0,0 +1,5 @@
+module OpaqueNoAbsentArgWW where
+
+f :: Int -> Int -> Bool
+f _ i = i == 0
+{-# OPAQUE f #-}
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.stderr
new file mode 100644
index 0000000000..023dd7d502
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoAbsentArgWW.stderr
@@ -0,0 +1,54 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 26, types: 13, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoAbsentArgWW.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoAbsentArgWW.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoAbsentArgWW.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoAbsentArgWW.$trModule3
+ = GHC.Types.TrNameS OpaqueNoAbsentArgWW.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoAbsentArgWW.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 60 0}]
+OpaqueNoAbsentArgWW.$trModule2 = "OpaqueNoAbsentArgWW"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoAbsentArgWW.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoAbsentArgWW.$trModule1
+ = GHC.Types.TrNameS OpaqueNoAbsentArgWW.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoAbsentArgWW.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoAbsentArgWW.$trModule
+ = GHC.Types.Module
+ OpaqueNoAbsentArgWW.$trModule3 OpaqueNoAbsentArgWW.$trModule1
+
+-- RHS size: {terms: 11, types: 5, coercions: 0, joins: 0/0}
+f [InlPrag=OPAQUE] :: Int -> Int -> Bool
+[GblId, Arity=2, Str=<A><1P(1L)>, Unf=OtherCon []]
+f = / _ [Occ=Dead] (i :: Int) ->
+ case i of { GHC.Types.I# x ->
+ case x of {
+ __DEFAULT -> GHC.Types.False;
+ 0# -> GHC.Types.True
+ }
+ } \ No newline at end of file
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.hs
new file mode 100644
index 0000000000..068ac4d4af
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE DataKinds #-}
+{-# OPTIONS_GHC -O0 #-}
+module OpaqueNoCastWW where
+
+import GHC.TypeNats
+
+newtype Signed (n :: Nat) = S { unsafeToInteger :: Integer}
+
+-- Normally introduces a worker of type: Signed m -> Signed n -> Integer
+times :: Signed m -> Signed n -> Signed (m + n)
+times (S a) (S b) = S (a * b)
+{-# OPAQUE times #-}
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.stderr
new file mode 100644
index 0000000000..00a0421915
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.stderr
@@ -0,0 +1,153 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 82, types: 52, coercions: 29, joins: 0/0}
+
+-- RHS size: {terms: 3, types: 3, coercions: 0, joins: 0/0}
+unsafeToInteger1 :: forall {n :: Nat}. Signed n -> Signed n
+[GblId, Arity=1, Unf=OtherCon []]
+unsafeToInteger1 = \ (@(n :: Nat)) (ds :: Signed n) -> ds
+
+-- RHS size: {terms: 1, types: 0, coercions: 8, joins: 0/0}
+unsafeToInteger :: forall (n :: Nat). Signed n -> Integer
+[GblId[[RecSel]], Arity=1, Unf=OtherCon []]
+unsafeToInteger
+ = unsafeToInteger1
+ `cast` (forall (n :: <Nat>_N).
+ <Signed n>_R %<'Many>_N ->_R OpaqueNoCastWW.N:Signed[0] <n>_P
+ :: (forall {n :: Nat}. Signed n -> Signed n)
+ ~R# (forall {n :: Nat}. Signed n -> Integer))
+
+-- RHS size: {terms: 8, types: 7, coercions: 21, joins: 0/0}
+times [InlPrag=OPAQUE]
+ :: forall (m :: Nat) (n :: Nat).
+ Signed m -> Signed n -> Signed (m + n)
+[GblId, Arity=2, Unf=OtherCon []]
+times
+ = (\ (@(m :: Nat))
+ (@(n :: Nat))
+ (ds :: Signed m)
+ (ds1 :: Signed n) ->
+ * @Integer
+ GHC.Num.$fNumInteger
+ (ds
+ `cast` (OpaqueNoCastWW.N:Signed[0] <m>_P :: Signed m ~R# Integer))
+ (ds1
+ `cast` (OpaqueNoCastWW.N:Signed[0] <n>_P :: Signed n ~R# Integer)))
+ `cast` (forall (m :: <Nat>_N) (n :: <Nat>_N).
+ <Signed m>_R
+ %<'Many>_N ->_R <Signed n>_R
+ %<'Many>_N ->_R Sym (OpaqueNoCastWW.N:Signed[0] <m + n>_P)
+ :: (forall {m :: Nat} {n :: Nat}. Signed m -> Signed n -> Integer)
+ ~R# (forall {m :: Nat} {n :: Nat}.
+ Signed m -> Signed n -> Signed (m + n)))
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+$trModule1 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+$trModule1 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+$trModule2 :: GHC.Types.TrName
+[GblId, Unf=OtherCon []]
+$trModule2 = GHC.Types.TrNameS $trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+$trModule3 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+$trModule3 = "OpaqueNoCastWW"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+$trModule4 :: GHC.Types.TrName
+[GblId, Unf=OtherCon []]
+$trModule4 = GHC.Types.TrNameS $trModule3
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoCastWW.$trModule :: GHC.Types.Module
+[GblId, Unf=OtherCon []]
+OpaqueNoCastWW.$trModule = GHC.Types.Module $trModule2 $trModule4
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+$krep :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+$krep = GHC.Types.KindRepVar 0#
+
+-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0}
+$krep1 :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+$krep1
+ = GHC.Types.KindRepTyConApp
+ GHC.Num.Integer.$tcInteger (GHC.Types.[] @GHC.Types.KindRep)
+
+-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0}
+$krep2 :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+$krep2
+ = GHC.Types.KindRepTyConApp
+ GHC.Num.Natural.$tcNatural (GHC.Types.[] @GHC.Types.KindRep)
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+$krep3 :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+$krep3 = GHC.Types.KindRepFun $krep2 GHC.Types.krep$*
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+$tcSigned1 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+$tcSigned1 = "Signed"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+$tcSigned2 :: GHC.Types.TrName
+[GblId, Unf=OtherCon []]
+$tcSigned2 = GHC.Types.TrNameS $tcSigned1
+
+-- RHS size: {terms: 7, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoCastWW.$tcSigned :: GHC.Types.TyCon
+[GblId, Unf=OtherCon []]
+OpaqueNoCastWW.$tcSigned
+ = GHC.Types.TyCon
+ 12374680438872388605##
+ 16570143229152367467##
+ OpaqueNoCastWW.$trModule
+ $tcSigned2
+ 0#
+ $krep3
+
+-- RHS size: {terms: 3, types: 2, coercions: 0, joins: 0/0}
+$krep4 :: [GHC.Types.KindRep]
+[GblId, Unf=OtherCon []]
+$krep4
+ = GHC.Types.:
+ @GHC.Types.KindRep $krep (GHC.Types.[] @GHC.Types.KindRep)
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+$krep5 :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+$krep5 = GHC.Types.KindRepTyConApp OpaqueNoCastWW.$tcSigned $krep4
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+$krep6 :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+$krep6 = GHC.Types.KindRepFun $krep1 $krep5
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+$tc'S1 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+$tc'S1 = "'S"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+$tc'S2 :: GHC.Types.TrName
+[GblId, Unf=OtherCon []]
+$tc'S2 = GHC.Types.TrNameS $tc'S1
+
+-- RHS size: {terms: 7, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoCastWW.$tc'S :: GHC.Types.TyCon
+[GblId, Unf=OtherCon []]
+OpaqueNoCastWW.$tc'S
+ = GHC.Types.TyCon
+ 9801584576887380300##
+ 5757617350287545124##
+ OpaqueNoCastWW.$trModule
+ $tc'S2
+ 1#
+ $krep6
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoRebox.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox.hs
new file mode 100644
index 0000000000..4728c03046
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox.hs
@@ -0,0 +1,24 @@
+module OpaqueNoRebox where
+
+f :: (Int,Int) -> Int
+f (x,y) = x + y
+{-# OPAQUE f #-}
+
+-- No W/W happens for f because it is OPAQUE, and by design its Boxity
+-- information is stripped, which is good!
+--
+-- If we hadn't stripped the boxity information, we would make a worker
+-- for g that would just rebox its arguments:
+--
+-- $wg :: Int# -> Int# -> Int
+-- $wg ww ww1 =
+-- let x = I# ww in
+-- let y = I# ww1 in
+-- let p = (x,y) in
+-- case f (f p, f p) of { I# z -> ww +# z}
+--
+-- as $wg was expecting that a worker for f that would be inlined.
+--
+-- See Note [The OPAQUE pragma and avoiding the reboxing of arguments]
+g :: (Int, Int) -> Int
+g p = fst p + f (f p, f p)
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoRebox.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox.stderr
new file mode 100644
index 0000000000..ad82c9e16c
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox.stderr
@@ -0,0 +1,75 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 42, types: 35, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoRebox.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox.$trModule3
+ = GHC.Types.TrNameS OpaqueNoRebox.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 50 0}]
+OpaqueNoRebox.$trModule2 = "OpaqueNoRebox"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox.$trModule1
+ = GHC.Types.TrNameS OpaqueNoRebox.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox.$trModule
+ = GHC.Types.Module
+ OpaqueNoRebox.$trModule3 OpaqueNoRebox.$trModule1
+
+-- RHS size: {terms: 7, types: 8, coercions: 0, joins: 0/0}
+f [InlPrag=OPAQUE] :: (Int, Int) -> Int
+[GblId, Arity=1, Str=<1P(1L,1L)>, Unf=OtherCon []]
+f = / (ds :: (Int, Int)) ->
+ case ds of { (x, y) -> GHC.Num.$fNumInt_$c+ x y }
+
+-- RHS size: {terms: 19, types: 14, coercions: 0, joins: 0/0}
+g [InlPrag=[2]] :: (Int, Int) -> Int
+[GblId,
+ Arity=1,
+ Str=<1P(SL,SL)>,
+ Cpr=1,
+ Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True,
+ Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=False)
+ Tmpl= / (p [Occ=Once1!] :: (Int, Int)) ->
+ case p of wild { (x [Occ=Once1!], _ [Occ=Dead]) ->
+ case x of { GHC.Types.I# x1 [Occ=Once1] ->
+ case f (f wild, f wild) of { GHC.Types.I# y [Occ=Once1] ->
+ GHC.Types.I# (GHC.Prim.+# x1 y)
+ }
+ }
+ }}]
+g = / (p :: (Int, Int)) ->
+ case p of wild { (x, ds1) ->
+ case x of { GHC.Types.I# x1 ->
+ case f (f wild, f wild) of { GHC.Types.I# y ->
+ GHC.Types.I# (GHC.Prim.+# x1 y)
+ }
+ }
+ }
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.hs
new file mode 100644
index 0000000000..1384eea1d6
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.hs
@@ -0,0 +1,23 @@
+module OpaqueNoRebox2 where
+
+{-# OPAQUE f #-}
+f :: Int -> Int -> (Int, Int)
+f x y = (x,y)
+
+-- No W/W happens for f because it is OPAQUE, and by design its CPR
+-- information is stripped, which is good!
+--
+-- If we hadn't stripped the CPR information, we would make a worker/wrapper
+-- for g that would rebox the result of 'g':
+--
+-- $wg :: Bool -> Int -> (# Int, Int #)
+-- $wg True a = case f 2 a of (x, y) -> (# x, y #)
+-- $wg False a = $wg True (a + 1)
+--
+-- g ds a = case $wg ds a of (# x, y#) -> (x, y)
+--
+-- as $wg was expecting that a worker for f that would be inlined.
+--
+-- See Note [The OPAQUE pragma and avoiding the reboxing of results]
+g True a = f 2 a
+g False a = g True (a+1)
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.stderr
new file mode 100644
index 0000000000..a790f1047f
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox2.stderr
@@ -0,0 +1,66 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 42, types: 25, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 5, types: 4, coercions: 0, joins: 0/0}
+f [InlPrag=OPAQUE] :: Int -> Int -> (Int, Int)
+[GblId, Arity=2, Str=<L><L>, Unf=OtherCon []]
+f = / (x :: Int) (y :: Int) -> (x, y)
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl :: Int
+[GblId, Unf=OtherCon []]
+lvl = GHC.Types.I# 2#
+
+Rec {
+-- RHS size: {terms: 18, types: 5, coercions: 0, joins: 0/0}
+g [Occ=LoopBreaker] :: Bool -> Int -> (Int, Int)
+[GblId, Arity=2, Str=<1L><L>, Unf=OtherCon []]
+g = / (ds :: Bool) (a :: Int) ->
+ case ds of {
+ False ->
+ g GHC.Types.True
+ (case a of { GHC.Types.I# x -> GHC.Types.I# (GHC.Prim.+# x 1#) });
+ True -> f lvl a
+ }
+end Rec }
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox2.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoRebox2.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox2.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox2.$trModule3
+ = GHC.Types.TrNameS OpaqueNoRebox2.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox2.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 50 0}]
+OpaqueNoRebox2.$trModule2 = "OpaqueNoRebox2"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox2.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox2.$trModule1
+ = GHC.Types.TrNameS OpaqueNoRebox2.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox2.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox2.$trModule
+ = GHC.Types.Module
+ OpaqueNoRebox2.$trModule3 OpaqueNoRebox2.$trModule1 \ No newline at end of file
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.hs
new file mode 100644
index 0000000000..887e40a432
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.hs
@@ -0,0 +1,43 @@
+module OpaqueNoRebox3 where
+
+f :: Int -> Int
+f x = x `seq` (x + 1)
+{-# OPAQUE f #-}
+
+-- Historical note:
+--
+-- Since no W/W happens for f because it is OPAQUE, currently, the worker for g
+-- does the dreaded reboxing of p similar to what is mentioned in
+-- https://gitlab.haskell.org/ghc/ghc/-/issues/13143
+--
+-- 16-Nov-2021, Sebastian Graf says:
+-- "Right, this is again not related to correct handling of OPAQUE but rather a
+-- weakness in boxity analysis at the moment. this is because when boxity
+-- analysis sees a `Case`, it will look at its `Alt`s. If one of the `Alt`
+-- says `Unboxed`, we let the `Unboxed` win. We'd only say Boxed if all the Alts
+-- had Boxed occs or if the scrutinee (or any of the occurrences that happen as
+-- part of the same trace, guaranteed) had a Boxed occ. It's kind of a necessary
+-- work-around until we have boxity analysis integrate with CPR analysis."
+--
+-- See Note [The OPAQUE pragma and avoiding the reboxing of arguments]
+--
+-- 16-Mar-2022:
+-- With https://gitlab.haskell.org/ghc/ghc/-/merge_requests/7609 merged, we no
+-- longer get a reboxing worker for g
+g :: Bool -> Bool -> Bool -> Int -> Int
+g = \w w1 w2 p ->
+ let fail_ = case w1 of
+ False -> case w2 of
+ False -> g w True w2 p
+ True -> f (f p)
+ True -> error "patError"
+ in case w of
+ False -> case w1 of
+ False -> fail_
+ True -> case w2 of
+ False -> p + 1
+ True -> fail_
+ True -> case w1 of
+ False -> fail_
+ True -> case w2 of
+ _ -> f p
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.stderr
new file mode 100644
index 0000000000..a74980ed99
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoRebox3.stderr
@@ -0,0 +1,161 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 120, types: 47, coercions: 4, joins: 1/1}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox3.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoRebox3.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox3.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox3.$trModule3
+ = GHC.Types.TrNameS OpaqueNoRebox3.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox3.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 50 0}]
+OpaqueNoRebox3.$trModule2 = "OpaqueNoRebox3"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox3.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox3.$trModule1
+ = GHC.Types.TrNameS OpaqueNoRebox3.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoRebox3.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoRebox3.$trModule
+ = GHC.Types.Module
+ OpaqueNoRebox3.$trModule3 OpaqueNoRebox3.$trModule1
+
+-- RHS size: {terms: 8, types: 3, coercions: 0, joins: 0/0}
+f [InlPrag=OPAQUE] :: Int -> Int
+[GblId, Arity=1, Str=<1L>, Unf=OtherCon []]
+f = / (x :: Int) ->
+ case x of { GHC.Types.I# ipv -> GHC.Types.I# (GHC.Prim.+# ipv 1#) }
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+lvl :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+lvl = "error"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl1 :: [Char]
+[GblId]
+lvl1 = GHC.CString.unpackCString# lvl
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl2 :: [Char]
+[GblId]
+lvl2 = GHC.CString.unpackCString# OpaqueNoRebox3.$trModule4
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl3 :: [Char]
+[GblId]
+lvl3 = GHC.CString.unpackCString# OpaqueNoRebox3.$trModule2
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+lvl4 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+lvl4 = "OpaqueNoRebox3.hs"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl5 :: [Char]
+[GblId]
+lvl5 = GHC.CString.unpackCString# lvl4
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl6 :: Int
+[GblId, Unf=OtherCon []]
+lvl6 = GHC.Types.I# 33#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl7 :: Int
+[GblId, Unf=OtherCon []]
+lvl7 = GHC.Types.I# 23#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl8 :: Int
+[GblId, Unf=OtherCon []]
+lvl8 = GHC.Types.I# 28#
+
+-- RHS size: {terms: 8, types: 0, coercions: 0, joins: 0/0}
+lvl9 :: GHC.Stack.Types.SrcLoc
+[GblId, Unf=OtherCon []]
+lvl9 = GHC.Stack.Types.SrcLoc lvl2 lvl3 lvl5 lvl6 lvl7 lvl6 lvl8
+
+-- RHS size: {terms: 4, types: 0, coercions: 0, joins: 0/0}
+lvl10 :: GHC.Stack.Types.CallStack
+[GblId, Unf=OtherCon []]
+lvl10
+ = GHC.Stack.Types.PushCallStack
+ lvl1 lvl9 GHC.Stack.Types.EmptyCallStack
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+lvl11 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+lvl11 = "patError"#
+
+-- RHS size: {terms: 4, types: 2, coercions: 4, joins: 0/0}
+lvl12 :: Int
+[GblId, Str=b, Cpr=b]
+lvl12
+ = error
+ @GHC.Types.LiftedRep
+ @Int
+ (lvl10
+ `cast` (Sym (GHC.Classes.N:IP[0]
+ <"callStack">_N <GHC.Stack.Types.CallStack>_N)
+ :: GHC.Stack.Types.CallStack
+ ~R# (?callStack::GHC.Stack.Types.CallStack)))
+ (GHC.CString.unpackCString# lvl11)
+
+Rec {
+-- RHS size: {terms: 50, types: 13, coercions: 0, joins: 1/1}
+g [Occ=LoopBreaker] :: Bool -> Bool -> Bool -> Int -> Int
+[GblId, Arity=4, Str=<SL><SL><L><1L>, Unf=OtherCon []]
+g = / (w :: Bool) (w1 :: Bool) (w2 :: Bool) (p :: Int) ->
+ join {
+ fail_ [Dmd=M!P(L)] :: Int
+ [LclId[JoinId(0)(Nothing)]]
+ fail_
+ = case w1 of {
+ False ->
+ case w2 of {
+ False -> g w GHC.Types.True GHC.Types.False p;
+ True -> f (f p)
+ };
+ True -> lvl12
+ } } in
+ case w of {
+ False ->
+ case w1 of {
+ False -> jump fail_;
+ True ->
+ case w2 of {
+ False ->
+ case p of { GHC.Types.I# x -> GHC.Types.I# (GHC.Prim.+# x 1#) };
+ True -> jump fail_
+ }
+ };
+ True ->
+ case w1 of {
+ False -> jump fail_;
+ True -> f p
+ }
+ }
+end Rec } \ No newline at end of file
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.hs
new file mode 100644
index 0000000000..e0c1617923
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.hs
@@ -0,0 +1,12 @@
+module OpaqueNoSpecConstr where
+
+import GHC.Exts ( SpecConstrAnnotation(..) )
+
+data SPEC = SPEC | SPEC2
+{-# ANN type SPEC ForceSpecConstr #-}
+
+-- Would normally induce a SpecConstr on the constructors of SPEC
+loop :: SPEC -> [Int] -> [Int] -> [Int]
+loop SPEC z [] = z
+loop SPEC z (x:xs) = loop SPEC (x:z) xs
+{-# OPAQUE loop #-}
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.stderr
new file mode 100644
index 0000000000..e2a51a21b3
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecConstr.stderr
@@ -0,0 +1,172 @@
+
+==================== Simplified expression ====================
+GHC.Desugar.toAnnotationWrapper
+ @GHC.Exts.SpecConstrAnnotation
+ GHC.Exts.$fDataSpecConstrAnnotation
+ GHC.Exts.ForceSpecConstr
+
+
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 83, types: 40, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+lvl :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+lvl = "OpaqueNoSpecConstr.hs:(10,1)-(11,39)|function loop"#
+
+-- RHS size: {terms: 2, types: 2, coercions: 0, joins: 0/0}
+lvl1 :: ()
+[GblId, Str=b, Cpr=b]
+lvl1 = Control.Exception.Base.patError @GHC.Types.LiftedRep @() lvl
+
+Rec {
+-- RHS size: {terms: 20, types: 13, coercions: 0, joins: 0/0}
+loop [InlPrag=OPAQUE, Occ=LoopBreaker]
+ :: SPEC -> [Int] -> [Int] -> [Int]
+[GblId, Arity=3, Str=<1L><L><1L>, Unf=OtherCon []]
+loop
+ = \ (ds :: SPEC) (z :: [Int]) (ds1 :: [Int]) ->
+ case ds of {
+ SPEC ->
+ case ds1 of {
+ [] -> z;
+ : x xs -> loop OpaqueNoSpecConstr.SPEC (GHC.Types.: @Int x z) xs
+ };
+ SPEC2 -> case lvl1 of wild1 { }
+ }
+end Rec }
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoSpecConstr.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$trModule3
+ = GHC.Types.TrNameS OpaqueNoSpecConstr.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 60 0}]
+OpaqueNoSpecConstr.$trModule2 = "OpaqueNoSpecConstr"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$trModule1
+ = GHC.Types.TrNameS OpaqueNoSpecConstr.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$trModule
+ = GHC.Types.Module
+ OpaqueNoSpecConstr.$trModule3 OpaqueNoSpecConstr.$trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tcSPEC2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoSpecConstr.$tcSPEC2 = "SPEC"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tcSPEC1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$tcSPEC1
+ = GHC.Types.TrNameS OpaqueNoSpecConstr.$tcSPEC2
+
+-- RHS size: {terms: 7, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tcSPEC :: GHC.Types.TyCon
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$tcSPEC
+ = GHC.Types.TyCon
+ 1794519131116102988##
+ 1536993820726345194##
+ OpaqueNoSpecConstr.$trModule
+ OpaqueNoSpecConstr.$tcSPEC1
+ 0#
+ GHC.Types.krep$*
+
+-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC1 [InlPrag=[~]] :: GHC.Types.KindRep
+[GblId, Unf=OtherCon []]
+OpaqueNoSpecConstr.$tc'SPEC1
+ = GHC.Types.KindRepTyConApp
+ OpaqueNoSpecConstr.$tcSPEC (GHC.Types.[] @GHC.Types.KindRep)
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+OpaqueNoSpecConstr.$tc'SPEC4 = "'SPEC"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$tc'SPEC3
+ = GHC.Types.TrNameS OpaqueNoSpecConstr.$tc'SPEC4
+
+-- RHS size: {terms: 7, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC :: GHC.Types.TyCon
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$tc'SPEC
+ = GHC.Types.TyCon
+ 9648911419523887824##
+ 4100179153648933145##
+ OpaqueNoSpecConstr.$trModule
+ OpaqueNoSpecConstr.$tc'SPEC3
+ 0#
+ OpaqueNoSpecConstr.$tc'SPEC1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC6 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+OpaqueNoSpecConstr.$tc'SPEC6 = "'SPEC2"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC5 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$tc'SPEC5
+ = GHC.Types.TrNameS OpaqueNoSpecConstr.$tc'SPEC6
+
+-- RHS size: {terms: 7, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecConstr.$tc'SPEC2 :: GHC.Types.TyCon
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecConstr.$tc'SPEC2
+ = GHC.Types.TyCon
+ 4214136204857816792##
+ 17253701793498718125##
+ OpaqueNoSpecConstr.$trModule
+ OpaqueNoSpecConstr.$tc'SPEC5
+ 0#
+ OpaqueNoSpecConstr.$tc'SPEC1
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.hs
new file mode 100644
index 0000000000..cc538980b1
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.hs
@@ -0,0 +1,7 @@
+module OpaqueNoSpecialise where
+
+f x = x : f (x-1)
+{-# OPAQUE f #-}
+
+-- This would normally induce a specialisation of f on Int
+g (x :: Int) = f x
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.stderr
new file mode 100644
index 0000000000..b3d76cde24
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoSpecialise.stderr
@@ -0,0 +1,74 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 41, types: 29, coercions: 0, joins: 0/2}
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl :: Integer
+[GblId, Unf=OtherCon []]
+lvl = GHC.Num.Integer.IS 1#
+
+-- RHS size: {terms: 18, types: 12, coercions: 0, joins: 0/2}
+f [InlPrag=OPAQUE] :: forall {t}. Num t => t -> [t]
+[GblId,
+ Arity=2,
+ Str=<LP(A,LCL(C1(L)),A,A,A,A,MCM(L))><L>,
+ Unf=OtherCon []]
+f = \ (@t) ($dNum :: Num t) (eta :: t) ->
+ let {
+ lvl1 :: t
+ [LclId]
+ lvl1 = fromInteger @t $dNum lvl } in
+ letrec {
+ f1 [Occ=LoopBreaker, Dmd=SCS(L)] :: t -> [t]
+ [LclId, Arity=1, Str=<L>, Unf=OtherCon []]
+ f1 = \ (x :: t) -> GHC.Types.: @t x (f1 (- @t $dNum x lvl1)); } in
+ f1 eta
+
+-- RHS size: {terms: 4, types: 2, coercions: 0, joins: 0/0}
+g :: Int -> [Int]
+[GblId,
+ Arity=1,
+ Str=<L>,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [0] 30 0}]
+g = \ (ds :: Int) -> f @Int GHC.Num.$fNumInt ds
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecialise.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoSpecialise.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecialise.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecialise.$trModule3
+ = GHC.Types.TrNameS OpaqueNoSpecialise.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecialise.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 60 0}]
+OpaqueNoSpecialise.$trModule2 = "OpaqueNoSpecialise"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecialise.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecialise.$trModule1
+ = GHC.Types.TrNameS OpaqueNoSpecialise.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoSpecialise.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoSpecialise.$trModule
+ = GHC.Types.Module
+ OpaqueNoSpecialise.$trModule3 OpaqueNoSpecialise.$trModule1
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.hs
new file mode 100644
index 0000000000..d4112cf12e
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.hs
@@ -0,0 +1,5 @@
+module OpaqueNoStrictArgWW where
+
+f :: Int -> Int
+f x = x + 1
+{-# OPAQUE f #-}
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.stderr
new file mode 100644
index 0000000000..c99e729976
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoStrictArgWW.stderr
@@ -0,0 +1,49 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 23, types: 10, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoStrictArgWW.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoStrictArgWW.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoStrictArgWW.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoStrictArgWW.$trModule3
+ = GHC.Types.TrNameS OpaqueNoStrictArgWW.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoStrictArgWW.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 60 0}]
+OpaqueNoStrictArgWW.$trModule2 = "OpaqueNoStrictArgWW"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoStrictArgWW.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoStrictArgWW.$trModule1
+ = GHC.Types.TrNameS OpaqueNoStrictArgWW.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoStrictArgWW.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoStrictArgWW.$trModule
+ = GHC.Types.Module
+ OpaqueNoStrictArgWW.$trModule3 OpaqueNoStrictArgWW.$trModule1
+
+-- RHS size: {terms: 8, types: 3, coercions: 0, joins: 0/0}
+f [InlPrag=OPAQUE] :: Int -> Int
+[GblId, Arity=1, Str=<1L>, Unf=OtherCon []]
+f = / (x :: Int) ->
+ case x of { GHC.Types.I# x1 -> GHC.Types.I# (GHC.Prim.+# x1 1#) } \ No newline at end of file
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoWW.hs b/testsuite/tests/simplCore/should_compile/OpaqueNoWW.hs
new file mode 100644
index 0000000000..7d617e891f
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoWW.hs
@@ -0,0 +1,12 @@
+module OpaqueNoWW where
+
+-- Would normally result in a worker of type Int# -> Int#
+f :: Int -> Int
+f 0 = 0
+f x = f (x + 1)
+{-# OPAQUE f #-}
+
+g :: Bool -> Bool -> Int -> Int
+g True True p = f p
+g False True p = p + 1
+g b False p = g b True p
diff --git a/testsuite/tests/simplCore/should_compile/OpaqueNoWW.stderr b/testsuite/tests/simplCore/should_compile/OpaqueNoWW.stderr
new file mode 100644
index 0000000000..77d820f9dd
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/OpaqueNoWW.stderr
@@ -0,0 +1,78 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 65, types: 24, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoWW.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+OpaqueNoWW.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoWW.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoWW.$trModule3 = GHC.Types.TrNameS OpaqueNoWW.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoWW.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 0}]
+OpaqueNoWW.$trModule2 = "OpaqueNoWW"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoWW.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoWW.$trModule1 = GHC.Types.TrNameS OpaqueNoWW.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+OpaqueNoWW.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+OpaqueNoWW.$trModule
+ = GHC.Types.Module OpaqueNoWW.$trModule3 OpaqueNoWW.$trModule1
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl :: Int
+[GblId, Unf=OtherCon []]
+lvl = GHC.Types.I# 0#
+
+Rec {
+-- RHS size: {terms: 14, types: 4, coercions: 0, joins: 0/0}
+f [InlPrag=OPAQUE, Occ=LoopBreaker] :: Int -> Int
+[GblId, Arity=1, Str=<1P(1L)>, Unf=OtherCon []]
+f = / (ds :: Int) ->
+ case ds of { GHC.Types.I# ds1 ->
+ case ds1 of ds2 {
+ __DEFAULT -> f (GHC.Types.I# (GHC.Prim.+# ds2 1#));
+ 0# -> lvl
+ }
+ }
+end Rec }
+
+Rec {
+-- RHS size: {terms: 32, types: 8, coercions: 0, joins: 0/0}
+g [Occ=LoopBreaker] :: Bool -> Bool -> Int -> Int
+[GblId, Arity=3, Str=<1L><1L><1L>, Unf=OtherCon []]
+g = / (ds :: Bool) (ds1 :: Bool) (p :: Int) ->
+ case ds of {
+ False ->
+ case ds1 of {
+ False -> g GHC.Types.False GHC.Types.True p;
+ True ->
+ case p of { GHC.Types.I# x -> GHC.Types.I# (GHC.Prim.+# x 1#) }
+ };
+ True ->
+ case ds1 of {
+ False -> g GHC.Types.True GHC.Types.True p;
+ True -> f p
+ }
+ }
+end Rec } \ No newline at end of file
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index 034a76fadd..f0b361b3f8 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -379,3 +379,13 @@ test('T19790', normal, compile, ['-O -ddump-rule-firings'])
# -O0 is needed to trigger it because that switches rules off,
# which (before the fix) lost crucial dependencies
test('T20820', normal, compile, ['-O0'])
+
+test('OpaqueNoAbsentArgWW', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoCastWW', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoRebox', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoRebox2', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoRebox3', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoSpecConstr', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoSpecialise', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoStrictArgWW', normal, compile, ['-O -fworker-wrapper-cbv -ddump-simpl -dsuppress-uniques'])
+test('OpaqueNoWW', normal, compile, ['-O -ddump-simpl -dsuppress-uniques'])
diff --git a/utils/haddock b/utils/haddock
-Subproject d2779a3e659d4e9f7044c346a566e5fe4edbdb9
+Subproject 559e41505e81d93939e9afa6aa9793b0a428924