+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
-----------------------------------------------------------------------------
--
-- Cmm optimisation
--
-----------------------------------------------------------------------------
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module CmmOpt (
cmmMiniInline,
cmmMachOpFold,
cmmMiniInlineStmts :: UniqFM Int -> [CmmStmt] -> [CmmStmt]
cmmMiniInlineStmts uses [] = []
cmmMiniInlineStmts uses (stmt@(CmmAssign (CmmLocal (LocalReg u _ _)) expr) : stmts)
+ -- not used at all: just discard this assignment
+ | Nothing <- lookupUFM uses u
+ = cmmMiniInlineStmts uses stmts
+
+ -- used once: try to inline at the use site
| Just 1 <- lookupUFM uses u,
Just stmts' <- lookForInline u expr stmts
=
= cmmMachOpFold narrow_cmp [x, CmmLit (CmmInt narrow_i rep)]
where
maybe_conversion (MO_U_Conv from _) = Just (from, narrowU)
- maybe_conversion (MO_S_Conv from _) = Just (from, narrowS)
+ maybe_conversion (MO_S_Conv from _)
+ | not (isFloatingRep from) = Just (from, narrowS)
+ -- don't attempt to apply this optimisation when the source
+ -- is a float; see #1916
maybe_conversion _ = Nothing
maybe_comparison (MO_U_Gt _) rep = Just (MO_U_Gt rep)