diff options
Diffstat (limited to 'compiler/codeGen/StgCmmPrim.hs')
| -rw-r--r-- | compiler/codeGen/StgCmmPrim.hs | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/compiler/codeGen/StgCmmPrim.hs b/compiler/codeGen/StgCmmPrim.hs index a6e13086aa..266ab3a0f6 100644 --- a/compiler/codeGen/StgCmmPrim.hs +++ b/compiler/codeGen/StgCmmPrim.hs @@ -352,14 +352,6 @@ emitPrimOp dflags [res] ByteArrayContents_Char [arg] emitPrimOp dflags [res] StableNameToIntOp [arg] = emitAssign (CmmLocal res) (cmmLoadIndexW dflags arg (fixedHdrSizeW dflags) (bWord dflags)) --- #define eqStableNamezh(r,sn1,sn2) \ --- (r = (((StgStableName *)sn1)->sn == ((StgStableName *)sn2)->sn)) -emitPrimOp dflags [res] EqStableNameOp [arg1,arg2] - = emitAssign (CmmLocal res) (CmmMachOp (mo_wordEq dflags) [ - cmmLoadIndexW dflags arg1 (fixedHdrSizeW dflags) (bWord dflags), - cmmLoadIndexW dflags arg2 (fixedHdrSizeW dflags) (bWord dflags) - ]) - emitPrimOp dflags [res] ReallyUnsafePtrEqualityOp [arg1,arg2] = emitAssign (CmmLocal res) (CmmMachOp (mo_wordEq dflags) [arg1,arg2]) @@ -1405,9 +1397,22 @@ translateOp dflags SameMutableArrayArrayOp= Just (mo_wordEq dflags) translateOp dflags SameSmallMutableArrayOp= Just (mo_wordEq dflags) translateOp dflags SameTVarOp = Just (mo_wordEq dflags) translateOp dflags EqStablePtrOp = Just (mo_wordEq dflags) +-- See Note [Comparing stable names] +translateOp dflags EqStableNameOp = Just (mo_wordEq dflags) translateOp _ _ = Nothing +-- Note [Comparing stable names] +-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +-- +-- A StableName# is actually a pointer to a stable name object (SNO) +-- containing an index into the stable name table (SNT). We +-- used to compare StableName#s by following the pointers to the +-- SNOs and checking whether they held the same SNT indices. However, +-- this is not necessary: there is a one-to-one correspondence +-- between SNOs and entries in the SNT, so simple pointer equality +-- does the trick. + -- These primops are implemented by CallishMachOps, because they sometimes -- turn into foreign calls depending on the backend. |