summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--compiler/cmm/CmmBuildInfoTables.hs23
-rw-r--r--compiler/cmm/CmmExpr.hs12
-rw-r--r--compiler/cmm/CmmInfo.hs44
-rw-r--r--includes/rts/storage/ClosureMacros.h2
-rw-r--r--includes/rts/storage/InfoTables.h48
-rw-r--r--libraries/ghci/GHCi/InfoTable.hsc4
-rw-r--r--rts/RtsAPI.c2
-rw-r--r--rts/sm/Evac.c4
-rw-r--r--rts/sm/Scav.c6
9 files changed, 102 insertions, 43 deletions
diff --git a/compiler/cmm/CmmBuildInfoTables.hs b/compiler/cmm/CmmBuildInfoTables.hs
index 498fded724..043f62f811 100644
--- a/compiler/cmm/CmmBuildInfoTables.hs
+++ b/compiler/cmm/CmmBuildInfoTables.hs
@@ -102,8 +102,6 @@ In each case, the info table points to the SRT.
- info->srt is zero if there's no SRT, otherwise:
- info->srt == 1 and info->f.srt_offset points to the SRT
-(but see TODO below, we can improve this)
-
e.g. for a FUN with an SRT:
StgFunInfoTable +------+
@@ -115,6 +113,23 @@ StgStdInfoTable +------+
info->type | ... |
|------|
+On x86_64, we optimise the info table representation further. The
+offset to the SRT can be stored in 32 bits (all code lives within a
+2GB region in x86_64's small memory model), so we can save a word in
+the info table by storing the srt_offset in the srt field, which is
+half a word.
+
+On x86_64 with TABLES_NEXT_TO_CODE:
+
+- info->srt is zero if there's no SRT, otherwise:
+- info->srt is an offset from the info pointer to the SRT object
+
+StgStdInfoTable +------+
+ info->layout.ptrs | |
+ info->layout.nptrs | |
+ info->srt | ------------> offset to SRT object
+ |------|
+
EXAMPLE
^^^^^^^
@@ -281,9 +296,6 @@ implemented.
As an alternative to [FUN]: we could merge the FUN's SRT with the FUN
object itself.
-TODO: make info->srt be an offset to the SRT, or zero if none (save
-one word per info table that has an SRT)
-
Note that there are many other optimisations that we could do, but
aren't implemented. In general, we could omit any reference from an
SRT if everything reachable from it is also reachable from the other
@@ -297,7 +309,6 @@ B = {Y,Z}
C = {X,B}
Here we could use C = {A} and therefore [Shortcut] C = A.
-
-}
-- ---------------------------------------------------------------------
diff --git a/compiler/cmm/CmmExpr.hs b/compiler/cmm/CmmExpr.hs
index 80ca1b1ef2..46f772731b 100644
--- a/compiler/cmm/CmmExpr.hs
+++ b/compiler/cmm/CmmExpr.hs
@@ -189,9 +189,13 @@ data CmmLit
-- It is also used inside the NCG during when generating
-- position-independent code.
| CmmLabelDiffOff CLabel CLabel Int Width -- label1 - label2 + offset
- -- The supported Widths depend on the architecture. wordWidth
- -- is supported on all architectures. Additionally W32 is
- -- supported on x86_64 when using the small memory model.
+ -- In an expression, the width just has the effect of MO_SS_Conv
+ -- from wordWidth to the desired width.
+ --
+ -- In a static literal, the supported Widths depend on the
+ -- architecture: wordWidth is supported on all
+ -- architectures. Additionally W32 is supported on x86_64 when
+ -- using the small memory model.
| CmmBlock {-# UNPACK #-} !BlockId -- Code label
-- Invariant: must be a continuation BlockId
@@ -224,7 +228,7 @@ cmmLitType cflags (CmmVec (l:ls)) = let ty = cmmLitType cflags l
else panic "cmmLitType: CmmVec"
cmmLitType dflags (CmmLabel lbl) = cmmLabelType dflags lbl
cmmLitType dflags (CmmLabelOff lbl _) = cmmLabelType dflags lbl
-cmmLitType dflags (CmmLabelDiffOff _ _ _ width) = cmmBits width
+cmmLitType _ (CmmLabelDiffOff _ _ _ width) = cmmBits width
cmmLitType dflags (CmmBlock _) = bWord dflags
cmmLitType dflags (CmmHighStackMark) = bWord dflags
diff --git a/compiler/cmm/CmmInfo.hs b/compiler/cmm/CmmInfo.hs
index ea7923264f..4201fda36a 100644
--- a/compiler/cmm/CmmInfo.hs
+++ b/compiler/cmm/CmmInfo.hs
@@ -45,6 +45,7 @@ import Stream (Stream)
import qualified Stream
import Hoopl.Collections
+import Platform
import Maybes
import DynFlags
import Panic
@@ -188,7 +189,7 @@ mkInfoTableContents dflags
| StackRep frame <- smrep
= do { (prof_lits, prof_data) <- mkProfLits dflags prof
- ; let (srt_label, srt_bitmap) = mkSRTLit dflags srt
+ ; let (srt_label, srt_bitmap) = mkSRTLit dflags info_lbl srt
; (liveness_lit, liveness_data) <- mkLivenessBits dflags frame
; let
std_info = mkStdInfoTable dflags prof_lits rts_tag srt_bitmap liveness_lit
@@ -201,7 +202,7 @@ mkInfoTableContents dflags
| HeapRep _ ptrs nonptrs closure_type <- smrep
= do { let layout = packIntsCLit dflags ptrs nonptrs
; (prof_lits, prof_data) <- mkProfLits dflags prof
- ; let (srt_label, srt_bitmap) = mkSRTLit dflags srt
+ ; let (srt_label, srt_bitmap) = mkSRTLit dflags info_lbl srt
; (mb_srt_field, mb_layout, extra_bits, ct_data)
<- mk_pieces closure_type srt_label
; let std_info = mkStdInfoTable dflags prof_lits
@@ -211,20 +212,22 @@ mkInfoTableContents dflags
; return (prof_data ++ ct_data, (std_info, extra_bits)) }
where
mk_pieces :: ClosureTypeInfo -> [CmmLit]
- -> UniqSM ( Maybe StgHalfWord -- Override the SRT field with this
- , Maybe CmmLit -- Override the layout field with this
+ -> UniqSM ( Maybe CmmLit -- Override the SRT field with this
+ , Maybe CmmLit -- Override the layout field with this
, [CmmLit] -- "Extra bits" for info table
, [RawCmmDecl]) -- Auxiliary data decls
mk_pieces (Constr con_tag con_descr) _no_srt -- A data constructor
= do { (descr_lit, decl) <- newStringLit con_descr
- ; return ( Just (toStgHalfWord dflags (fromIntegral con_tag))
+ ; return ( Just (CmmInt (fromIntegral con_tag)
+ (halfWordWidth dflags))
, Nothing, [descr_lit], [decl]) }
mk_pieces Thunk srt_label
= return (Nothing, Nothing, srt_label, [])
mk_pieces (ThunkSelector offset) _no_srt
- = return (Just (toStgHalfWord dflags 0), Just (mkWordCLit dflags (fromIntegral offset)), [], [])
+ = return (Just (CmmInt 0 (halfWordWidth dflags)),
+ Just (mkWordCLit dflags (fromIntegral offset)), [], [])
-- Layout known (one free var); we use the layout field for offset
mk_pieces (Fun arity (ArgSpec fun_type)) srt_label
@@ -235,8 +238,9 @@ mkInfoTableContents dflags
= do { (liveness_lit, liveness_data) <- mkLivenessBits dflags arg_bits
; let fun_type | null liveness_data = aRG_GEN
| otherwise = aRG_GEN_BIG
- extra_bits = [ packIntsCLit dflags fun_type arity
- , srt_lit, liveness_lit, slow_entry ]
+ extra_bits = [ packIntsCLit dflags fun_type arity ]
+ ++ (if inlineSRT dflags then [] else [ srt_lit ])
+ ++ [ liveness_lit, slow_entry ]
; return (Nothing, Nothing, extra_bits, liveness_data) }
where
slow_entry = CmmLabel (toSlowEntryLbl info_lbl)
@@ -255,11 +259,21 @@ packIntsCLit dflags a b = packHalfWordsCLit dflags
mkSRTLit :: DynFlags
+ -> CLabel
-> Maybe CLabel
-> ([CmmLit], -- srt_label, if any
- StgHalfWord) -- srt_bitmap
-mkSRTLit dflags Nothing = ([], toStgHalfWord dflags 0)
-mkSRTLit dflags (Just lbl) = ([CmmLabel lbl], toStgHalfWord dflags 1)
+ CmmLit) -- srt_bitmap
+mkSRTLit dflags info_lbl (Just lbl)
+ | inlineSRT dflags
+ = ([], CmmLabelDiffOff lbl info_lbl 0 (halfWordWidth dflags))
+mkSRTLit dflags _ Nothing = ([], CmmInt 0 (halfWordWidth dflags))
+mkSRTLit dflags _ (Just lbl) = ([CmmLabel lbl], CmmInt 1 (halfWordWidth dflags))
+
+
+-- | is the SRT offset field inline in the info table on this platform?
+inlineSRT :: DynFlags -> Bool
+inlineSRT dflags = platformArch (targetPlatform dflags) == ArchX86_64
+ && tablesNextToCode dflags
-------------------------------------------------------------------------
--
@@ -367,23 +381,23 @@ mkStdInfoTable
:: DynFlags
-> (CmmLit,CmmLit) -- Closure type descr and closure descr (profiling)
-> Int -- Closure RTS tag
- -> StgHalfWord -- SRT length
+ -> CmmLit -- SRT length
-> CmmLit -- layout field
-> [CmmLit]
-mkStdInfoTable dflags (type_descr, closure_descr) cl_type srt_len layout_lit
+mkStdInfoTable dflags (type_descr, closure_descr) cl_type srt layout_lit
= -- Parallel revertible-black hole field
prof_info
-- Ticky info (none at present)
-- Debug info (none at present)
- ++ [layout_lit, type_lit]
+ ++ [layout_lit, tag, srt]
where
prof_info
| gopt Opt_SccProfilingOn dflags = [type_descr, closure_descr]
| otherwise = []
- type_lit = packHalfWordsCLit dflags (toStgHalfWord dflags (fromIntegral cl_type)) srt_len
+ tag = CmmInt (fromIntegral cl_type) (halfWordWidth dflags)
-------------------------------------------------------------------------
--
diff --git a/includes/rts/storage/ClosureMacros.h b/includes/rts/storage/ClosureMacros.h
index 2b78ab44b8..7a3ecaa1d2 100644
--- a/includes/rts/storage/ClosureMacros.h
+++ b/includes/rts/storage/ClosureMacros.h
@@ -109,7 +109,7 @@ INLINE_HEADER const StgConInfoTable *get_con_itbl(const StgClosure *c)
INLINE_HEADER StgHalfWord GET_TAG(const StgClosure *con)
{
- return get_itbl(con)->has_srt;
+ return get_itbl(con)->srt;
}
/* -----------------------------------------------------------------------------
diff --git a/includes/rts/storage/InfoTables.h b/includes/rts/storage/InfoTables.h
index 0e25e14c8e..8107510321 100644
--- a/includes/rts/storage/InfoTables.h
+++ b/includes/rts/storage/InfoTables.h
@@ -153,6 +153,21 @@ typedef union {
} StgClosureInfo;
+#if defined(x86_64_TARGET_ARCH) && defined(TABLES_NEXT_TO_CODE)
+// On x86_64 we can fit a pointer offset in half a word, so put the SRT offset
+// in the info->srt field directly.
+#define USE_INLINE_SRT_FIELD
+#endif
+
+#if defined(USE_INLINE_SRT_FIELD)
+// offset to the SRT / closure, or zero if there's no SRT
+typedef StgHalfInt StgSRTField;
+#else
+// non-zero if there is an SRT, the offset is in the optional srt field.
+typedef StgHalfWord StgSRTField;
+#endif
+
+
/*
* The "standard" part of an info table. Every info table has this bit.
*/
@@ -169,11 +184,14 @@ typedef struct StgInfoTable_ {
StgClosureInfo layout; /* closure layout info (one word) */
StgHalfWord type; /* closure type */
- StgHalfWord has_srt;
+ StgSRTField srt;
/* In a CONSTR:
- the constructor tag
In a FUN/THUNK
- - non-zero if there is an SRT
+ - if USE_INLINE_SRT_FIELD
+ - offset to the SRT (or zero if no SRT)
+ - otherwise
+ - non-zero if there is an SRT, offset is in srt_offset
*/
#if defined(TABLES_NEXT_TO_CODE)
@@ -214,7 +232,9 @@ typedef struct StgFunInfoExtraRev_ {
StgWord bitmap;
OFFSET_FIELD(bitmap_offset); /* arg ptr/nonptr bitmap */
} b;
+#if !defined(USE_INLINE_SRT_FIELD)
OFFSET_FIELD(srt_offset); /* pointer to the SRT closure */
+#endif
StgHalfWord fun_type; /* function type */
StgHalfWord arity; /* function arity */
} StgFunInfoExtraRev;
@@ -253,7 +273,9 @@ extern const StgWord stg_arg_bitmaps[];
typedef struct {
#if defined(TABLES_NEXT_TO_CODE)
+#if !defined(USE_INLINE_SRT_FIELD)
OFFSET_FIELD(srt_offset); /* offset to the SRT closure */
+#endif
StgInfoTable i;
#else
StgInfoTable i;
@@ -271,16 +293,14 @@ typedef struct {
*/
typedef struct StgThunkInfoTable_ {
-#if !defined(TABLES_NEXT_TO_CODE)
- StgInfoTable i;
-#endif
#if defined(TABLES_NEXT_TO_CODE)
+#if !defined(USE_INLINE_SRT_FIELD)
OFFSET_FIELD(srt_offset); /* offset to the SRT closure */
-#else
- StgClosure *srt; /* pointer to the SRT closure */
#endif
-#if defined(TABLES_NEXT_TO_CODE)
StgInfoTable i;
+#else
+ StgInfoTable i;
+ StgClosure *srt; /* pointer to the SRT closure */
#endif
} StgThunkInfoTable;
@@ -315,9 +335,14 @@ typedef struct StgConInfoTable_ {
* info must be a Stg[Ret|Thunk]InfoTable* (an info table that has a SRT)
*/
#if defined(TABLES_NEXT_TO_CODE)
+#if x86_64_TARGET_ARCH
#define GET_SRT(info) \
- ((StgClosure*) (((StgWord) ((info)+1)) + (info)->srt_offset))
+ ((StgClosure*) (((StgWord) ((info)+1)) + (info)->i.srt))
#else
+#define GET_SRT(info) \
+ ((StgClosure*) (((StgWord) ((info)+1)) + (info)->srt_offset))
+#endif
+#else // !TABLES_NEXT_TO_CODE
#define GET_SRT(info) ((info)->srt)
#endif
@@ -337,8 +362,13 @@ typedef struct StgConInfoTable_ {
* info must be a StgFunInfoTable*
*/
#if defined(TABLES_NEXT_TO_CODE)
+#if x86_64_TARGET_ARCH
+#define GET_FUN_SRT(info) \
+ ((StgClosure*) (((StgWord) ((info)+1)) + (info)->i.srt))
+#else
#define GET_FUN_SRT(info) \
((StgClosure*) (((StgWord) ((info)+1)) + (info)->f.srt_offset))
+#endif
#else
#define GET_FUN_SRT(info) ((info)->f.srt)
#endif
diff --git a/libraries/ghci/GHCi/InfoTable.hsc b/libraries/ghci/GHCi/InfoTable.hsc
index d5e50c2dff..afcfefc7fa 100644
--- a/libraries/ghci/GHCi/InfoTable.hsc
+++ b/libraries/ghci/GHCi/InfoTable.hsc
@@ -58,7 +58,7 @@ peekItbl a0 = do
nptrs' <- (#peek StgInfoTable, layout.payload.nptrs) a0
tipe' <- (#peek StgInfoTable, type) a0
#if __GLASGOW_HASKELL__ > 804
- srtlen' <- (#peek StgInfoTable, has_srt) a0
+ srtlen' <- (#peek StgInfoTable, srt) a0
#else
srtlen' <- (#peek StgInfoTable, srt_bitmap) a0
#endif
@@ -398,7 +398,7 @@ pokeItbl a0 itbl = do
(#poke StgInfoTable, layout.payload.nptrs) a0 (nptrs itbl)
(#poke StgInfoTable, type) a0 (tipe itbl)
#if __GLASGOW_HASKELL__ > 804
- (#poke StgInfoTable, has_srt) a0 (srtlen itbl)
+ (#poke StgInfoTable, srt) a0 (srtlen itbl)
#else
(#poke StgInfoTable, srt_bitmap) a0 (srtlen itbl)
#endif
diff --git a/rts/RtsAPI.c b/rts/RtsAPI.c
index 8946f9d840..8fd1917392 100644
--- a/rts/RtsAPI.c
+++ b/rts/RtsAPI.c
@@ -367,7 +367,7 @@ rts_getBool (HaskellObj p)
const StgInfoTable *info;
info = get_itbl((const StgClosure *)UNTAG_CONST_CLOSURE(p));
- if (info->has_srt == 0) { // has_srt is the constructor tag
+ if (info->srt == 0) { // srt is the constructor tag
return 0;
} else {
return 1;
diff --git a/rts/sm/Evac.c b/rts/sm/Evac.c
index 198c37d5a9..a8559e7e00 100644
--- a/rts/sm/Evac.c
+++ b/rts/sm/Evac.c
@@ -536,13 +536,13 @@ loop:
switch (info->type) {
case THUNK_STATIC:
- if (info->has_srt != 0) {
+ if (info->srt != 0) {
evacuate_static_object(THUNK_STATIC_LINK((StgClosure *)q), q);
}
return;
case FUN_STATIC:
- if (info->has_srt != 0) {
+ if (info->srt != 0) {
evacuate_static_object(FUN_STATIC_LINK((StgClosure *)q), q);
}
return;
diff --git a/rts/sm/Scav.c b/rts/sm/Scav.c
index 1bee05221a..79adcaa826 100644
--- a/rts/sm/Scav.c
+++ b/rts/sm/Scav.c
@@ -337,7 +337,7 @@ scavenge_thunk_srt(const StgInfoTable *info)
if (!major_gc) return;
thunk_info = itbl_to_thunk_itbl(info);
- if (thunk_info->i.has_srt) {
+ if (thunk_info->i.srt) {
StgClosure *srt = (StgClosure*)GET_SRT(thunk_info);
evacuate(&srt);
}
@@ -351,7 +351,7 @@ scavenge_fun_srt(const StgInfoTable *info)
if (!major_gc) return;
fun_info = itbl_to_fun_itbl(info);
- if (fun_info->i.has_srt) {
+ if (fun_info->i.srt) {
StgClosure *srt = (StgClosure*)GET_FUN_SRT(fun_info);
evacuate(&srt);
}
@@ -1888,7 +1888,7 @@ scavenge_stack(StgPtr p, StgPtr stack_end)
p = scavenge_small_bitmap(p, size, bitmap);
follow_srt:
- if (major_gc && info->i.has_srt) {
+ if (major_gc && info->i.srt) {
StgClosure *srt = (StgClosure*)GET_SRT(info);
evacuate(&srt);
}
View Lorry Controller Status