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| author | Thomas Miedema <thomasmiedema@gmail.com> | 2015-08-21 10:44:54 +0200 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2015-08-21 15:44:21 +0200 |
| commit | 2f29ebbb6f8c914f2bba624f3edcc259274df8af (patch) | |
| tree | c523018ed23dd32e45697fe177d6df5ad4b59b50 /compiler/cmm | |
| parent | 3452473b4bb180ba327520067b8c6f2a8d6c4f4b (diff) | |
| download | haskell-2f29ebbb6f8c914f2bba624f3edcc259274df8af.tar.gz | |
Refactor: delete most of the module FastTypes
This reverses some of the work done in #1405, and goes back to the
assumption that the bootstrap compiler understands GHC-haskell.
In particular:
* use MagicHash instead of _ILIT and _CLIT
* pattern matching on I# if possible, instead of using iUnbox
unnecessarily
* use Int#/Char#/Addr# instead of the following type synonyms:
- type FastInt = Int#
- type FastChar = Char#
- type FastPtr a = Addr#
* inline the following functions:
- iBox = I#
- cBox = C#
- fastChr = chr#
- fastOrd = ord#
- eqFastChar = eqChar#
- shiftLFastInt = uncheckedIShiftL#
- shiftR_FastInt = uncheckedIShiftRL#
- shiftRLFastInt = uncheckedIShiftRL#
* delete the following unused functions:
- minFastInt
- maxFastInt
- uncheckedIShiftRA#
- castFastPtr
- panicDocFastInt and pprPanicFastInt
* rename panicFastInt back to panic#
These functions remain, since they actually do something:
* iUnbox
* bitAndFastInt
* bitOrFastInt
Test Plan: validate
Reviewers: austin, bgamari
Subscribers: rwbarton
Differential Revision: https://phabricator.haskell.org/D1141
GHC Trac Issues: #1405
Diffstat (limited to 'compiler/cmm')
| -rw-r--r-- | compiler/cmm/CmmOpt.hs | 24 |
1 files changed, 6 insertions, 18 deletions
diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs index 84499b97de..7c634c2201 100644 --- a/compiler/cmm/CmmOpt.hs +++ b/compiler/cmm/CmmOpt.hs @@ -21,7 +21,6 @@ import CmmUtils import Cmm import DynFlags -import FastTypes import Outputable import Platform @@ -376,30 +375,19 @@ cmmMachOpFoldM _ _ _ = Nothing -- This algorithm for determining the $\log_2$ of exact powers of 2 comes -- from GCC. It requires bit manipulation primitives, and we use GHC -- extensions. Tough. --- --- Used to be in MachInstrs --SDM. --- ToDo: remove use of unboxery --SDM. - --- Unboxery removed in favor of FastInt; but is the function supposed to fail --- on inputs >= 2147483648, or was that just an implementation artifact? --- And is this speed-critical, or can we just use Integer operations --- (including Data.Bits)? --- --Isaac Dupree exactLog2 :: Integer -> Maybe Integer -exactLog2 x_ - = if (x_ <= 0 || x_ >= 2147483648) then +exactLog2 x + = if (x <= 0 || x >= 2147483648) then Nothing else - case iUnbox (fromInteger x_) of { x -> - if (x `bitAndFastInt` negateFastInt x) /=# x then + if (x .&. (-x)) /= x then Nothing else - Just (toInteger (iBox (pow2 x))) - } + Just (pow2 x) where - pow2 x | x ==# _ILIT(1) = _ILIT(0) - | otherwise = _ILIT(1) +# pow2 (x `shiftR_FastInt` _ILIT(1)) + pow2 x | x == 1 = 0 + | otherwise = 1 + pow2 (x `shiftR` 1) -- ----------------------------------------------------------------------------- -- Utils |