diff options
Diffstat (limited to 'compiler/cmm')
| -rw-r--r-- | compiler/cmm/CmmOpt.hs | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs index d6fdd5a23f..403fbd946a 100644 --- a/compiler/cmm/CmmOpt.hs +++ b/compiler/cmm/CmmOpt.hs @@ -345,10 +345,10 @@ cmmMachOpFoldM dflags mop [x, (CmmLit (CmmInt n _))] = case mop of MO_Mul rep | Just p <- exactLog2 n -> - Just (cmmMachOpFold dflags (MO_Shl rep) [x, CmmLit (CmmInt p rep)]) + Just (cmmMachOpFold dflags (MO_Shl rep) [x, CmmLit (CmmInt p wordW)]) MO_U_Quot rep | Just p <- exactLog2 n -> - Just (cmmMachOpFold dflags (MO_U_Shr rep) [x, CmmLit (CmmInt p rep)]) + Just (cmmMachOpFold dflags (MO_U_Shr rep) [x, CmmLit (CmmInt p wordW)]) MO_U_Rem rep | Just _ <- exactLog2 n -> Just (cmmMachOpFold dflags (MO_And rep) [x, CmmLit (CmmInt (n - 1) rep)]) @@ -356,7 +356,7 @@ cmmMachOpFoldM dflags mop [x, (CmmLit (CmmInt n _))] | Just p <- exactLog2 n, CmmReg _ <- x -> -- We duplicate x in signedQuotRemHelper, hence require -- it is a reg. FIXME: remove this restriction. - Just (cmmMachOpFold dflags (MO_S_Shr rep) + Just (cmmMachOpFold dflags (MO_S_Shr wordW) [signedQuotRemHelper rep p, CmmLit (CmmInt p rep)]) MO_S_Rem rep | Just p <- exactLog2 n, @@ -370,6 +370,8 @@ cmmMachOpFoldM dflags mop [x, (CmmLit (CmmInt n _))] [signedQuotRemHelper rep p, CmmLit (CmmInt (- n) rep)]]) _ -> Nothing where + wordW = wordWidth dflags + -- In contrast with unsigned integers, for signed ones -- shift right is not the same as quot, because it rounds -- to minus infinity, whereas quot rounds toward zero. |