Fix #98: Add support for 16-bit floating point numbers

ChangeLog.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.10.0
+
+- Support for half-precision floating point `__fp16`, `_Float16`, and `_Float16x`.
+- Support for bfloat16 `__bf16`.
+
 ## 0.9.4
 
 - Support `happy-2.1`.

language-c.cabal

@@ -1,6 +1,6 @@
 cabal-version:   2.2
 name:            language-c
-version:         0.9.4
+version:         0.10.0
 license:         BSD-3-Clause
 license-file:    LICENSE
 copyright:       LICENSE

scripts/tokenlist.txt

@@ -29,6 +29,10 @@ void,
 volatile @__,
 while,
 label __label__
+BFloat16 __bf16
+(CTokFloatN 16 False) __fp16
+(CTokFloatN 16 False) _Float16
+(CTokFloatN 16 True) _Float16x
 (CTokFloatN 32 False) _Float32
 (CTokFloatN 32 True) _Float32x
 (CTokFloatN 64 False) _Float64

src/Language/C/Analysis/DeclAnalysis.hs

@@ -395,6 +395,7 @@ tNumType (NumTypeSpec basetype sgn sz iscomplex) =
         (BaseFloat, NoSignSpec, NoSizeMod)  -> floatType TyFloat
         (BaseDouble, NoSignSpec, NoSizeMod) -> floatType TyDouble
         (BaseDouble, NoSignSpec, LongMod)   -> floatType TyLDouble
+        (BaseBFloat16, NoSignSpec, NoSizeMod)   -> floatType TyBFloat16
         (BaseFloatN n x, NoSignSpec, NoSizeMod) -> floatType (TyFloatN n x)
         -- TODO: error analysis
         (_,_,_)   -> error "Bad AST analysis"
@@ -431,7 +432,7 @@ tTypeQuals = foldrM go (noTypeQuals,[]) where
 To canoicalize type specifiers, we define a canonical form:
 void | bool | (char|int|int128|float|double|floatNx)? (signed|unsigned)? (long long?)? complex? | othertype
 -}
-data NumBaseType = NoBaseType | BaseChar | BaseInt | BaseInt128 | BaseFloat |
+data NumBaseType = NoBaseType | BaseChar | BaseInt | BaseInt128 | BaseFloat | BaseBFloat16 |
                    BaseFloatN Int Bool | BaseDouble deriving (Eq,Ord)
 data SignSpec    = NoSignSpec | Signed | Unsigned deriving (Eq,Ord)
 data SizeMod     = NoSizeMod | ShortMod | LongMod | LongLongMod deriving (Eq,Ord)
@@ -461,6 +462,8 @@ canonicalTypeSpec = foldrM go TSNone where
                             = return$  TSNum$ nts { base = BaseInt128 }
     go (CFloatType _)   tsa | (Just nts@(NumTypeSpec { base = NoBaseType })) <- getNTS tsa
                             = return$  TSNum$ nts { base = BaseFloat }
+    go (CBFloat16Type _) tsa | (Just nts@(NumTypeSpec { base = NoBaseType })) <- getNTS tsa
+                            = return$  TSNum$ nts { base = BaseBFloat16 }
     go (CFloatNType n x _) tsa | (Just nts@(NumTypeSpec { base = NoBaseType })) <- getNTS tsa
                             = return$  TSNum$ nts { base = BaseFloatN n x }
     go (CDoubleType _)  tsa | (Just nts@(NumTypeSpec { base = NoBaseType })) <- getNTS tsa

src/Language/C/Analysis/Export.hs

@@ -177,6 +177,7 @@ exportFloatType ty =
       TyFloat    -> [CFloatType ni]
       TyDouble   -> [CDoubleType ni]
       TyLDouble  -> [CLongType ni, CDoubleType ni]
+      TyBFloat16 -> [CBFloat16Type ni]
       TyFloatN n x -> [CFloatNType n x ni]
 
 exportComplexType :: FloatType -> [CTypeSpec]

src/Language/C/Analysis/MachineDescs.hs

@@ -27,6 +27,7 @@ x86_64 =
         TyFloat    -> 4
         TyDouble   -> 8
         TyLDouble  -> 16
+        TyBFloat16 -> error "TyBFloat16"
         TyFloatN{} -> error "TyFloatN"
       builtinSize = \case
         TyVaList -> 24
@@ -52,6 +53,7 @@ x86_64 =
         TyFloat    -> 4
         TyDouble   -> 8
         TyLDouble  -> 16
+        TyBFloat16{} -> error "TyBFloat16"
         TyFloatN{} -> error "TyFloatN"
       builtinAlign = \case
         TyVaList -> 8
@@ -81,6 +83,7 @@ armv7l =
         TyFloat    -> 4
         TyDouble   -> 8
         TyLDouble  -> 8
+        TyBFloat16 -> 2
         TyFloatN{} -> error "TyFloatN"
       builtinSize = \case
         TyVaList -> 4
@@ -106,6 +109,7 @@ armv7l =
         TyFloat    -> 4
         TyDouble   -> 8
         TyLDouble  -> 8
+        TyBFloat16 -> 2
         TyFloatN{} -> error "TyFloatN"
       builtinAlign = \case
         TyVaList -> 4

src/Language/C/Analysis/SemRep.hs

@@ -431,13 +431,15 @@ data FloatType =
       TyFloat
     | TyDouble
     | TyLDouble
+    | TyBFloat16
     | TyFloatN Int Bool
     deriving (Typeable, Data, Eq, Ord)
 
 instance Show FloatType where
     show TyFloat = "float"
     show TyDouble = "double"
     show TyLDouble = "long double"
+    show TyBFloat16 = "__bf16"
     show (TyFloatN n x) = "_Float" ++ (show n) ++ (if x then "x" else "")
 
 -- | composite type declarations

src/Language/C/Parser/Lexer.x

@@ -311,6 +311,10 @@ void,
 volatile @__,
 while,
 label __label__
+BFloat16 __bf16
+(CTokFloatN 16 False) __fp16
+(CTokFloatN 16 False) _Float16
+(CTokFloatN 16 True) _Float16x
 (CTokFloatN 32 False) _Float32
 (CTokFloatN 32 True) _Float32x
 (CTokFloatN 64 False) _Float64
@@ -328,13 +332,17 @@ label __label__
 (flip CTokClangC ClangBuiltinConvertVector) __builtin_convertvector
 -}
 
--- Tokens: _Alignas _Alignof __alignof alignof __alignof__ __asm asm __asm__ _Atomic auto break _Bool case char __const const __const__ continue _Complex __complex__ default do double else enum extern float for _Generic goto if __inline inline __inline__ int __int128_t long _Noreturn _Nullable __nullable _Nonnull __nonnull register __restrict restrict __restrict__ return short __signed signed __signed__ sizeof static _Static_assert struct switch typedef __typeof typeof __typeof__ __thread _Thread_local __uint128 __uint128_t union unsigned void __volatile volatile __volatile__ while __label__ _Float32 _Float32x _Float64 _Float64x _Float128 __float128 _Float128x __attribute __attribute__ __extension__ __real __real__ __imag __imag__ __builtin_va_arg __builtin_offsetof __builtin_types_compatible_p __builtin_bit_cast __builtin_convertvector
+-- Tokens: _Alignas _Alignof __alignof alignof __alignof__ __asm asm __asm__ _Atomic auto break _Bool case char __const const __const__ continue _Complex __complex__ default do double else enum extern float for _Generic goto if __inline inline __inline__ int __int128_t long _Noreturn _Nullable __nullable _Nonnull __nonnull register __restrict restrict __restrict__ return short __signed signed __signed__ sizeof static _Static_assert struct switch typedef __typeof typeof __typeof__ __thread _Thread_local __uint128 __uint128_t union unsigned void __volatile volatile __volatile__ while __label__ _Float16 _Float16x _Float32 _Float32x _Float64 _Float64x _Float128 __float128 _Float128x __attribute __attribute__ __extension__ __real __real__ __imag __imag__ __builtin_va_arg __builtin_offsetof __builtin_types_compatible_p __builtin_bit_cast __builtin_convertvector
 idkwtok ('_' : 'A' : 'l' : 'i' : 'g' : 'n' : 'a' : 's' : []) = tok 8 CTokAlignas
 idkwtok ('_' : 'A' : 'l' : 'i' : 'g' : 'n' : 'o' : 'f' : []) = tok 8 CTokAlignof
 idkwtok ('_' : 'A' : 't' : 'o' : 'm' : 'i' : 'c' : []) = tok 7 CTokAtomic
 idkwtok ('_' : 'B' : 'o' : 'o' : 'l' : []) = tok 5 CTokBool
 idkwtok ('_' : 'C' : 'o' : 'm' : 'p' : 'l' : 'e' : 'x' : []) = tok 8 CTokComplex
+idkwtok ('_' : '_' : 'b' : 'f' : '1' : '6' : []) = tok 6 CTokBFloat16
+idkwtok ('_' : '_' : 'f' : 'p' : '1' : '6' : []) = tok 6 (CTokFloatN 16 False)
 #ifdef IEC_60559_TYPES_EXT
+idkwtok ('_' : 'F' : 'l' : 'o' : 'a' : 't' : '1' : '6' : []) = tok 8 (CTokFloatN 16 False)
+idkwtok ('_' : 'F' : 'l' : 'o' : 'a' : 't' : '1' : '6' : 'x' : []) = tok 9 (CTokFloatN 16 True)
 idkwtok ('_' : 'F' : 'l' : 'o' : 'a' : 't' : '1' : '2' : '8' : []) = tok 9 (CTokFloatN 128 False)
 idkwtok ('_' : 'F' : 'l' : 'o' : 'a' : 't' : '1' : '2' : '8' : 'x' : []) = tok 10 (CTokFloatN 128 True)
 idkwtok ('_' : 'F' : 'l' : 'o' : 'a' : 't' : '3' : '2' : []) = tok 8 (CTokFloatN 32 False)

src/Language/C/Parser/Parser.y

@@ -202,6 +202,10 @@ else		{ CTokElse	_ }
 enum		{ CTokEnum	_ }
 extern		{ CTokExtern	_ }
 float		{ CTokFloat	_ }
+"__bf16"	{ CTokBFloat16	_ }
+"__fp16"	{ CTokFloatN  16 False _ }
+"_Float16"	{ CTokFloatN  16 False _ }
+"_Float16x"	{ CTokFloatN  16 True _ }
 "_Float32"	{ CTokFloatN  32 False _ }
 "_Float32x"	{ CTokFloatN  32 True _ }
 "_Float64"	{ CTokFloatN  64 False _ }
@@ -898,6 +902,10 @@ basic_type_name
   | "_Complex"			{% withNodeInfo $1 $ CComplexType }
   | "__int128"                  {% withNodeInfo $1 $ CInt128Type }
   | "__uint128"                 {% withNodeInfo $1 $ CUInt128Type }
+  | "__bf16"                    {% withNodeInfo $1 $ CBFloat16Type }
+  | "__fp16"                    {% withNodeInfo $1 $ (CFloatNType 16 False) }
+  | "_Float16"                  {% withNodeInfo $1 $ (CFloatNType 16 False) }
+  | "_Float16x"                 {% withNodeInfo $1 $ (CFloatNType 16 True) }
   | "_Float32"                  {% withNodeInfo $1 $ (CFloatNType 32 False) }
   | "_Float32x"                 {% withNodeInfo $1 $ (CFloatNType 32 True) }
   | "_Float64"                  {% withNodeInfo $1 $ (CFloatNType 64 False) }

src/Language/C/Parser/Tokens.hs

@@ -92,7 +92,10 @@ data CToken = CTokLParen   !PosLength            -- `('
             | CTokEnum     !PosLength            -- `enum'
             | CTokExtern   !PosLength            -- `extern'
             | CTokFloat    !PosLength            -- `float'
-            | CTokFloatN !Int !Bool !PosLength   -- `__float128' or `_Float{32,64,128}{,x}`
+            | CTokBFloat16 !PosLength            -- `__bf16'
+            | CTokFloatN !Int !Bool !PosLength   -- (or `__float128',
+                                                 -- `__fp16',
+                                                 -- `_Float{16,32,64,128}{,x}`)
             | CTokFor      !PosLength            -- `for'
             | CTokGeneric  !PosLength            -- `_Generic'
             | CTokGoto     !PosLength            -- `goto'
@@ -235,6 +238,7 @@ posLenOfTok (CTokElse     pos  ) = pos
 posLenOfTok (CTokEnum     pos  ) = pos
 posLenOfTok (CTokExtern   pos  ) = pos
 posLenOfTok (CTokFloat    pos  ) = pos
+posLenOfTok (CTokBFloat16 pos  ) = pos
 posLenOfTok (CTokFloatN _ _ pos) = pos
 posLenOfTok (CTokFor      pos  ) = pos
 posLenOfTok (CTokGeneric  pos  ) = pos
@@ -348,6 +352,7 @@ instance Show CToken where
   showsPrec _ (CTokEnum     _  ) = showString "enum"
   showsPrec _ (CTokExtern   _  ) = showString "extern"
   showsPrec _ (CTokFloat    _  ) = showString "float"
+  showsPrec _ (CTokBFloat16 _  ) = showString "__bf16"
   showsPrec _ (CTokFloatN n x _) = showString "_Float" . shows n .
                                    showString (if x then "x" else "")
   showsPrec _ (CTokFor      _  ) = showString "for"

src/Language/C/Pretty.hs

@@ -248,6 +248,7 @@ instance Pretty CTypeSpec where
     pretty (CIntType _)         = text "int"
     pretty (CLongType _)        = text "long"
     pretty (CFloatType _)       = text "float"
+    pretty (CBFloat16Type _)    = text "__bf16"
     pretty (CFloatNType n x _)  = text "_Float" <> text (show n) <>
                                   (if x then text "x" else empty)
     pretty (CDoubleType _)      = text "double"

src/Language/C/Syntax/AST.hs

@@ -469,6 +469,7 @@ data CTypeSpecifier a
   | CComplexType a
   | CInt128Type  a
   | CUInt128Type a
+  | CBFloat16Type a
   | CFloatNType Int Bool a           -- ^ IEC 60227: width (32,64,128), extended flag
   | CSUType      (CStructureUnion a) a      -- ^ Struct or Union specifier
   | CEnumType    (CEnumeration a)    a      -- ^ Enumeration specifier
@@ -1090,6 +1091,7 @@ instance CNode t1 => CNode (CTypeSpecifier t1) where
         nodeInfo (CShortType d) = nodeInfo d
         nodeInfo (CIntType d) = nodeInfo d
         nodeInfo (CLongType d) = nodeInfo d
+        nodeInfo (CBFloat16Type d) = nodeInfo d
         nodeInfo (CFloatType d) = nodeInfo d
         nodeInfo (CFloatNType _ _ d) = nodeInfo d
         nodeInfo (CDoubleType d) = nodeInfo d
@@ -1115,6 +1117,7 @@ instance Functor CTypeSpecifier where
         fmap _f (CIntType a1) = CIntType (_f a1)
         fmap _f (CLongType a1) = CLongType (_f a1)
         fmap _f (CFloatType a1) = CFloatType (_f a1)
+        fmap _f (CBFloat16Type a1) = CBFloat16Type (_f a1)
         fmap _f (CFloatNType n x a1) = CFloatNType n x (_f a1)
         fmap _f (CDoubleType a1) = CDoubleType (_f a1)
         fmap _f (CSignedType a1) = CSignedType (_f a1)
@@ -1137,6 +1140,7 @@ instance Annotated CTypeSpecifier where
         annotation (CIntType n) = n
         annotation (CLongType n) = n
         annotation (CFloatType n) = n
+        annotation (CBFloat16Type n) = n
         annotation (CFloatNType _ _ n) = n
         annotation (CDoubleType n) = n
         annotation (CSignedType n) = n
@@ -1157,6 +1161,7 @@ instance Annotated CTypeSpecifier where
         amap f (CIntType a_1) = CIntType (f a_1)
         amap f (CLongType a_1) = CLongType (f a_1)
         amap f (CFloatType a_1) = CFloatType (f a_1)
+        amap f (CBFloat16Type a_1) = CBFloat16Type (f a_1)
         amap f (CFloatNType n x a_1) = CFloatNType n x (f a_1)
         amap f (CDoubleType a_1) = CDoubleType (f a_1)
         amap f (CSignedType a_1) = CSignedType (f a_1)

test/harness/arm_float16/Makefile

@@ -0,0 +1,12 @@
+PP=../../../examples/ParseAndPrint
+TY=../../../examples/TypeCheck
+all: parse
+parse:
+#	gcc -c -Wall test.c
+	$(PP) test.c > test.out
+	diff -u test.expect test.out
+	$(TY) test.c
+clean:
+	rm -f *.out
+gcc_check:
+	gcc -fsyntax-only -c test.c

test/harness/arm_float16/test.c

@@ -0,0 +1,6 @@
+/* extended floating point types */
+static void f(void)
+{
+    __fp16 a1 = 2.0;
+    __bf16 b1 = 2.0;
+}

test/harness/arm_float16/test.expect

@@ -0,0 +1,5 @@
+static void f(void)
+{
+    _Float16 a1 = 2.0;
+    __bf16 b1 = 2.0;
+}

test/harness/iec_60559/test.c

@@ -7,6 +7,8 @@ static void f(void)
     _Float64x d1 = 2.0;
     _Float128 e1 = 2.0;
     __float128 g1 = 2.0 + e1;
+    _Float16 h1 = 2.0;
+    _Float16x i1 = 2.0;
 
     _Float32 a = 2.0f32;
     _Float32x b = 2.0if32x;
@@ -18,4 +20,5 @@ static void f(void)
     _Float128x f = 2.0f128x;
     _Float128x f1 = 2.0 + d1 + e1;
 #endif
+
 }

test/harness/iec_60559/test.expect

@@ -6,6 +6,8 @@ static void f(void)
     _Float64x d1 = 2.0;
     _Float128 e1 = 2.0;
     _Float128 g1 = 2.0 + e1;
+    _Float16 h1 = 2.0;
+    _Float16x i1 = 2.0;
     _Float32 a = 2.0f32;
     _Float32x b = 2.0if32x;
     _Float64 c = 2.0f64;