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| author | Simon Marlow <marlowsd@gmail.com> | 2009-12-17 22:42:28 +0000 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2009-12-17 22:42:28 +0000 |
| commit | 0417404f5d1230c9d291ea9f73e2831121c8ec99 (patch) | |
| tree | 609f1be77f63606772e71ad84c7a92b205baaa9e /compiler/codeGen | |
| parent | fb783aeaa5bc1cc60e6bb551c1cd01a097b84fad (diff) | |
| download | haskell-0417404f5d1230c9d291ea9f73e2831121c8ec99.tar.gz | |
Fix #650: use a card table to mark dirty sections of mutable arrays
The card table is an array of bytes, placed directly following the
actual array data. This means that array reading is unaffected, but
array writing needs to read the array size from the header in order to
find the card table.
We use a bytemap rather than a bitmap, because updating the card table
must be multi-thread safe. Each byte refers to 128 entries of the
array, but this is tunable by changing the constant
MUT_ARR_PTRS_CARD_BITS in includes/Constants.h.
Diffstat (limited to 'compiler/codeGen')
| -rw-r--r-- | compiler/codeGen/CgPrimOp.hs | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/compiler/codeGen/CgPrimOp.hs b/compiler/codeGen/CgPrimOp.hs index 7f100e283b..c99bdb4a74 100644 --- a/compiler/codeGen/CgPrimOp.hs +++ b/compiler/codeGen/CgPrimOp.hs @@ -571,9 +571,21 @@ doWriteByteArrayOp _ _ _ _ doWritePtrArrayOp :: CmmExpr -> CmmExpr -> CmmExpr -> Code doWritePtrArrayOp addr idx val - = do stmtC (setInfo addr (CmmLit (CmmLabel mkMAP_DIRTY_infoLabel))) - mkBasicIndexedWrite arrPtrsHdrSize Nothing bWord addr idx val - + = do mkBasicIndexedWrite arrPtrsHdrSize Nothing bWord addr idx val + stmtC (setInfo addr (CmmLit (CmmLabel mkMAP_DIRTY_infoLabel))) + -- the write barrier. We must write a byte into the mark table: + -- bits8[a + header_size + StgMutArrPtrs_size(a) + x >> N] + stmtC $ CmmStore ( + cmmOffsetExpr + (cmmOffsetExprW (cmmOffsetB addr arrPtrsHdrSize) + (loadArrPtrsSize addr)) + (CmmMachOp mo_wordUShr [idx, + CmmLit (mkIntCLit mUT_ARR_PTRS_CARD_BITS)]) + ) (CmmLit (CmmInt 1 W8)) + +loadArrPtrsSize :: CmmExpr -> CmmExpr +loadArrPtrsSize addr = CmmLoad (cmmOffsetB addr off) bWord + where off = fixedHdrSize*wORD_SIZE + oFFSET_StgMutArrPtrs_ptrs mkBasicIndexedRead :: ByteOff -> Maybe MachOp -> CmmType -> LocalReg -> CmmExpr -> CmmExpr -> Code |