Introduce a type for "platform word size", use it instead of Int

We introduce a PlatformWordSize type and use it in platformWordSize
field.

This removes to panic/error calls called when platform word size is not
32 or 64. We now check for this when reading the platform config.

3 files changed, 11 insertions, 14 deletions

diff --git a/compiler/nativeGen/Dwarf.hs b/compiler/nativeGen/Dwarf.hs
index b64b4efc33..33f1c5b2f7 100644
--- a/compiler/nativeGen/Dwarf.hs
+++ b/compiler/nativeGen/Dwarf.hs
@@ -116,7 +116,7 @@ compileUnitHeader unitU = sdocWithPlatform $ \plat ->
           , pprHalf 3                          -- DWARF version
           , sectionOffset (ptext dwarfAbbrevLabel) (ptext dwarfAbbrevLabel)
                                                -- abbrevs offset
-          , text "\t.byte " <> ppr (platformWordSize plat) -- word size
+          , text "\t.byte " <> ppr (platformWordSizeInBytes plat) -- word size
           ]
 
 -- | Compilation unit footer, mainly establishing size of debug sections
diff --git a/compiler/nativeGen/Dwarf/Types.hs b/compiler/nativeGen/Dwarf/Types.hs
index 01253544e6..a646f0bdfa 100644
--- a/compiler/nativeGen/Dwarf/Types.hs
+++ b/compiler/nativeGen/Dwarf/Types.hs
@@ -224,7 +224,7 @@ data DwarfARange
 -- address table entry.
 pprDwarfARanges :: [DwarfARange] -> Unique -> SDoc
 pprDwarfARanges arngs unitU = sdocWithPlatform $ \plat ->
-  let wordSize = platformWordSize plat
+  let wordSize = platformWordSizeInBytes plat
       paddingSize = 4 :: Int
       -- header is 12 bytes long.
       -- entry is 8 bytes (32-bit platform) or 16 bytes (64-bit platform).
@@ -293,7 +293,7 @@ pprDwarfFrame DwarfFrame{dwCieLabel=cieLabel,dwCieInit=cieInit,dwCieProcs=procs}
         length      = ppr cieEndLabel <> char '-' <> ppr cieStartLabel
         spReg       = dwarfGlobalRegNo plat Sp
         retReg      = dwarfReturnRegNo plat
-        wordSize    = platformWordSize plat
+        wordSize    = platformWordSizeInBytes plat
         pprInit :: (GlobalReg, Maybe UnwindExpr) -> SDoc
         pprInit (g, uw) = pprSetUnwind plat g (Nothing, uw)
 
@@ -454,9 +454,9 @@ pprSetUnwind plat Sp (_, Just (UwReg s' o'))
 pprSetUnwind _    Sp (_, Just uw)
   = pprByte dW_CFA_def_cfa_expression $$ pprUnwindExpr False uw
 pprSetUnwind plat g  (_, Just (UwDeref (UwReg Sp o)))
-  | o < 0 && ((-o) `mod` platformWordSize plat) == 0 -- expected case
+  | o < 0 && ((-o) `mod` platformWordSizeInBytes plat) == 0 -- expected case
   = pprByte (dW_CFA_offset + dwarfGlobalRegNo plat g) $$
-    pprLEBWord (fromIntegral ((-o) `div` platformWordSize plat))
+    pprLEBWord (fromIntegral ((-o) `div` platformWordSizeInBytes plat))
   | otherwise
   = pprByte dW_CFA_offset_extended_sf $$
     pprLEBRegNo plat g $$
@@ -517,10 +517,9 @@ wordAlign :: SDoc
 wordAlign = sdocWithPlatform $ \plat ->
   text "\t.align " <> case platformOS plat of
     OSDarwin -> case platformWordSize plat of
-      8      -> text "3"
-      4      -> text "2"
-      _other -> error "wordAlign: Unsupported word size!"
-    _other   -> ppr (platformWordSize plat)
+      PW8 -> char '3'
+      PW4 -> char '2'
+    _other   -> ppr (platformWordSizeInBytes plat)
 
 -- | Assembly for a single byte of constant DWARF data
 pprByte :: Word8 -> SDoc
@@ -552,10 +551,8 @@ pprDwWord = pprData4'
 pprWord :: SDoc -> SDoc
 pprWord s = (<> s) . sdocWithPlatform $ \plat ->
   case platformWordSize plat of
-    4 -> text "\t.long "
-    8 -> text "\t.quad "
-    n -> panic $ "pprWord: Unsupported target platform word length " ++
-                 show n ++ "!"
+    PW4 -> text "\t.long "
+    PW8 -> text "\t.quad "
 
 -- | Prints a number in "little endian base 128" format. The idea is
 -- to optimize for small numbers by stopping once all further bytes
diff --git a/compiler/nativeGen/PPC/Instr.hs b/compiler/nativeGen/PPC/Instr.hs
index b17ea32f01..ee8edd86fd 100644
--- a/compiler/nativeGen/PPC/Instr.hs
+++ b/compiler/nativeGen/PPC/Instr.hs
@@ -98,7 +98,7 @@ ppc_mkStackAllocInstr' platform amount
     , STU fmt r0 (AddrRegReg sp tmp)
     ]
   where
-    fmt = intFormat $ widthFromBytes (platformWordSize platform)
+    fmt = intFormat $ widthFromBytes (platformWordSizeInBytes platform)
     zero = ImmInt 0
     tmp = tmpReg platform
     immAmount = ImmInt amount