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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 /compiler/codeGen | |
| 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.
Diffstat (limited to 'compiler/codeGen')
| -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 |