X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmOpt.hs;h=df0555fe58f027e963e283196e31c64d5830ddf6;hb=9176377bf7d989919fe7d27cad1f56bd9c4e7b6b;hp=0e35cc10b93ca33582774395b33ec3011d792592;hpb=6b89acb468c0db3337b831790f96bee4d9b54bfe;p=ghc-hetmet.git diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs index 0e35cc1..df0555f 100644 --- a/compiler/cmm/CmmOpt.hs +++ b/compiler/cmm/CmmOpt.hs @@ -306,9 +306,18 @@ cmmMachOpFold op [x@(CmmLit _), y] -- PicBaseReg from the corresponding label (or label difference). -- cmmMachOpFold mop1 [CmmMachOp mop2 [arg1,arg2], arg3] - | mop1 == mop2 && isAssociativeMachOp mop1 + | mop2 `associates_with` mop1 && not (isLit arg1) && not (isPicReg arg1) - = cmmMachOpFold mop1 [arg1, cmmMachOpFold mop2 [arg2,arg3]] + = cmmMachOpFold mop2 [arg1, cmmMachOpFold mop1 [arg2,arg3]] + where + MO_Add{} `associates_with` MO_Sub{} = True + mop1 `associates_with` mop2 = + mop1 == mop2 && isAssociativeMachOp mop1 + +-- special case: (a - b) + c ==> a + (c - b) +cmmMachOpFold mop1@(MO_Add{}) [CmmMachOp mop2@(MO_Sub{}) [arg1,arg2], arg3] + | not (isLit arg1) && not (isPicReg arg1) + = cmmMachOpFold mop1 [arg1, cmmMachOpFold mop2 [arg3,arg2]] -- Make a RegOff if we can cmmMachOpFold (MO_Add _) [CmmReg reg, CmmLit (CmmInt n rep)]