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| author | Johan Tibell <johan.tibell@gmail.com> | 2014-08-12 20:28:14 +0200 |
|---|---|---|
| committer | Johan Tibell <johan.tibell@gmail.com> | 2014-08-12 22:13:21 +0200 |
| commit | 434204975bb6e25a3ec0d32fc225effb8eceb0c3 (patch) | |
| tree | fe651c778b6b8fb103fb15a59fb626eebf50cb5e | |
| parent | a6fd7b5c4b8439bfcc56bf6924de64f4f32e7211 (diff) | |
| download | haskell-434204975bb6e25a3ec0d32fc225effb8eceb0c3.tar.gz | |
StgCmmPrim: add note to stop using fixed size signed types for sizes
We use fixed size signed types to e.g. represent array sizes. This
means that the size can overflow.
| -rw-r--r-- | compiler/codeGen/StgCmmPrim.hs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/codeGen/StgCmmPrim.hs b/compiler/codeGen/StgCmmPrim.hs index 2fa1b85a03..77739fe0fb 100644 --- a/compiler/codeGen/StgCmmPrim.hs +++ b/compiler/codeGen/StgCmmPrim.hs @@ -137,6 +137,11 @@ cgOpApp (StgPrimCallOp primcall) args _res_ty asUnsigned :: Width -> Integer -> Integer asUnsigned w n = n .&. (bit (widthInBits w) - 1) +-- TODO: Several primop implementations (e.g. 'doNewByteArrayOp') use +-- ByteOff (or some other fixed width signed type) to represent +-- array sizes or indices. This means that these will overflow for +-- large enough sizes. + -- | Decide whether an out-of-line primop should be replaced by an -- inline implementation. This might happen e.g. if there's enough -- static information, such as statically know arguments, to emit a |