diff options
Diffstat (limited to 'compiler/codeGen')
| -rw-r--r-- | compiler/codeGen/StgCmmExpr.hs | 32 | ||||
| -rw-r--r-- | compiler/codeGen/StgCmmPrim.hs | 9 |
2 files changed, 18 insertions, 23 deletions
diff --git a/compiler/codeGen/StgCmmExpr.hs b/compiler/codeGen/StgCmmExpr.hs index 3d60def450..20b65ba4c7 100644 --- a/compiler/codeGen/StgCmmExpr.hs +++ b/compiler/codeGen/StgCmmExpr.hs @@ -141,9 +141,9 @@ cgLetNoEscapeRhsBody local_cc bndr (StgRhsClosure cc _bi _ _upd _ args body) = cgLetNoEscapeClosure bndr local_cc cc (nonVoidIds args) body cgLetNoEscapeRhsBody local_cc bndr (StgRhsCon cc con args) = cgLetNoEscapeClosure bndr local_cc cc [] (StgConApp con args) - -- For a constructor RHS we want to generate a single chunk of - -- code which can be jumped to from many places, which will - -- return the constructor. It's easy; just behave as if it + -- For a constructor RHS we want to generate a single chunk of + -- code which can be jumped to from many places, which will + -- return the constructor. It's easy; just behave as if it -- was an StgRhsClosure with a ConApp inside! ------------------------- @@ -193,9 +193,9 @@ heapcheck will take their worst case into account. In favour of omitting !Q!, !R!: - *May* save a heap overflow test, - if ...P... allocates anything. + if ...P... allocates anything. - - We can use relative addressing from a single Hp to + - We can use relative addressing from a single Hp to get at all the closures so allocated. - No need to save volatile vars etc across heap checks @@ -203,7 +203,7 @@ In favour of omitting !Q!, !R!: Against omitting !Q!, !R! - - May put a heap-check into the inner loop. Suppose + - May put a heap-check into the inner loop. Suppose the main loop is P -> R -> P -> R... Q is the loop exit, and only it does allocation. This only hurts us if P does no allocation. If P allocates, @@ -212,7 +212,7 @@ Against omitting !Q!, !R! - May do more allocation than reqd. This sometimes bites us badly. For example, nfib (ha!) allocates about 30\% more space if the worst-casing is done, because many many calls to nfib are leaf calls - which don't need to allocate anything. + which don't need to allocate anything. We can un-allocate, but that costs an instruction @@ -248,7 +248,7 @@ Hence: two basic plans for ...save current cost centre... - ...code for e, + ...code for e, with sequel (SetLocals r) ...restore current cost centre... @@ -338,8 +338,12 @@ So we add a special case to generate and later optimisations will further improve this. -We should really change all these primops to return Int# instead, that -would make this special case go away. +Now that #6135 has been resolved it should be possible to remove that +special case. The idea behind this special case and pre-6135 implementation +of Bool-returning primops was that tagToEnum# was added implicitly in the +codegen and then optimized away. Now the call to tagToEnum# is explicit +in the source code, which allows to optimize it away at the earlier stages +of compilation (i.e. at the Core level). -} @@ -498,7 +502,7 @@ cgAlts gc_plan bndr (PrimAlt _) alts -- PrimAlts always have a DEFAULT case -- and it always comes first - tagged_cmms' = [(lit,code) + tagged_cmms' = [(lit,code) | (LitAlt lit, code) <- tagged_cmms] ; emitCmmLitSwitch (CmmReg bndr_reg) tagged_cmms' deflt ; return AssignedDirectly } @@ -637,7 +641,7 @@ cgLneJump blk_id lne_regs args -- Join point; discard sequel ; emitMultiAssign lne_regs cmm_args ; emit (mkBranch blk_id) ; return AssignedDirectly } - + cgTailCall :: Id -> CgIdInfo -> [StgArg] -> FCode ReturnKind cgTailCall fun_id fun_info args = do dflags <- getDynFlags @@ -645,7 +649,7 @@ cgTailCall fun_id fun_info args = do -- A value in WHNF, so we can just return it. ReturnIt -> emitReturn [fun] -- ToDo: does ReturnIt guarantee tagged? - + EnterIt -> ASSERT( null args ) -- Discarding arguments emitEnter fun @@ -653,7 +657,7 @@ cgTailCall fun_id fun_info args = do { tickySlowCall lf_info args ; emitComment $ mkFastString "slowCall" ; slowCall fun args } - + -- A direct function call (possibly with some left-over arguments) DirectEntry lbl arity -> do { tickyDirectCall arity args diff --git a/compiler/codeGen/StgCmmPrim.hs b/compiler/codeGen/StgCmmPrim.hs index 7ce329a707..2c044faa42 100644 --- a/compiler/codeGen/StgCmmPrim.hs +++ b/compiler/codeGen/StgCmmPrim.hs @@ -107,15 +107,6 @@ cgOpApp (StgPrimOp primop) args res_ty cgPrimOp regs primop args emitReturn (map (CmmReg . CmmLocal) regs) - | ReturnsAlg tycon <- result_info - , isEnumerationTyCon tycon - -- c.f. cgExpr (...TagToEnumOp...) - = do dflags <- getDynFlags - tag_reg <- newTemp (bWord dflags) - cgPrimOp [tag_reg] primop args - emitReturn [tagToClosure dflags tycon - (CmmReg (CmmLocal tag_reg))] - | otherwise = panic "cgPrimop" where result_info = getPrimOpResultInfo primop |