[clang] Add __bf16 Type Support Macros With Literal Suffix Support

clang/docs/ReleaseNotes.rst

@@ -459,6 +459,26 @@ DWARF Support in Clang
 
 Floating Point Support in Clang
 -------------------------------
+- Added 15 ``__BFLT16_`` macros to indicate support of ``__bf16`` type. The new macros are:
+
+ + ``__BFLT16_DECIMAL_DIG__``
+ + ``__BFLT16_DENORM_MIN__``
+ + ``__BFLT16_DIG__``
+ + ``__BFLT16_EPSILON__``
+ + ``__BFLT16_HAS_DENORM__``
+ + ``__BFLT16_HAS_INFINITY__``
+ + ``__BFLT16_HAS_QUIET_NAN__``
+ + ``__BFLT16_MANT_DIG__``
+ + ``__BFLT16_MAX_10_EXP__``
+ + ``__BFLT16_MAX_EXP__``
+ + ``__BFLT16_MAX__``
+ + ``__BFLT16_MIN_10_EXP__``
+ + ``__BFLT16_MIN_EXP__``
+ + ``__BFLT16_MIN__``
+ + ``__BFLT16_NORM_MAX__``
+
+- Added brain float literal suffix (``1.0bf16`` and ``1.0BF16``).
+
 
 Fixed Point Support in Clang
 ----------------------------

clang/include/clang/Lex/LiteralSupport.h

@@ -77,6 +77,7 @@ class NumericLiteralParser {
   bool isFloat : 1;         // 1.0f
   bool isImaginary : 1;     // 1.0i
   bool isFloat16 : 1;       // 1.0f16
+  bool isBFloat16 : 1;      // 1.0bf16
   bool isFloat128 : 1;      // 1.0q
   bool isFract : 1;         // 1.0hr/r/lr/uhr/ur/ulr
   bool isAccum : 1;         // 1.0hk/k/lk/uhk/uk/ulk

clang/lib/Basic/Targets/AMDGPU.cpp

@@ -365,11 +365,13 @@ void AMDGPUTargetInfo::setAuxTarget(const TargetInfo *Aux) {
   // not supported by AMDGPU. 128-bit floating point format is also not
   // supported by AMDGPU. Therefore keep its own format for these two types.
   auto SaveLongDoubleFormat = LongDoubleFormat;
+  auto SaveBFloat16Format = BFloat16Format;
   auto SaveFloat128Format = Float128Format;
   auto SaveLongDoubleWidth = LongDoubleWidth;
   auto SaveLongDoubleAlign = LongDoubleAlign;
   copyAuxTarget(Aux);
   LongDoubleFormat = SaveLongDoubleFormat;
+  BFloat16Format = SaveBFloat16Format;
   Float128Format = SaveFloat128Format;
   LongDoubleWidth = SaveLongDoubleWidth;
   LongDoubleAlign = SaveLongDoubleAlign;

clang/lib/Frontend/InitPreprocessor.cpp

@@ -94,11 +94,13 @@ static void AddImplicitIncludePCH(MacroBuilder &Builder, Preprocessor &PP,
 /// PickFP - This is used to pick a value based on the FP semantics of the
 /// specified FP model.
 template <typename T>
-static T PickFP(const llvm::fltSemantics *Sem, T IEEEHalfVal, T IEEESingleVal,
-                T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
-                T IEEEQuadVal) {
+static T PickFP(const llvm::fltSemantics *Sem, T IEEEHalfVal, T BFloatVal,
+                T IEEESingleVal, T IEEEDoubleVal, T X87DoubleExtendedVal,
+                T PPCDoubleDoubleVal, T IEEEQuadVal) {
   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEhalf())
     return IEEEHalfVal;
+  if (Sem == (const llvm::fltSemantics *)&llvm::APFloat::BFloat())
+    return BFloatVal;
   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle())
     return IEEESingleVal;
   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble())
@@ -114,30 +116,34 @@ static T PickFP(const llvm::fltSemantics *Sem, T IEEEHalfVal, T IEEESingleVal,
 static void DefineFloatMacros(MacroBuilder &Builder, StringRef Prefix,
                               const llvm::fltSemantics *Sem, StringRef Ext) {
   const char *DenormMin, *NormMax, *Epsilon, *Max, *Min;
-  NormMax = PickFP(Sem, "6.5504e+4", "3.40282347e+38",
-                   "1.7976931348623157e+308", "1.18973149535723176502e+4932",
-                   "8.98846567431157953864652595394501e+307",
-                   "1.18973149535723176508575932662800702e+4932");
-  DenormMin = PickFP(Sem, "5.9604644775390625e-8", "1.40129846e-45",
-                     "4.9406564584124654e-324", "3.64519953188247460253e-4951",
-                     "4.94065645841246544176568792868221e-324",
-                     "6.47517511943802511092443895822764655e-4966");
-  int Digits = PickFP(Sem, 3, 6, 15, 18, 31, 33);
-  int DecimalDigits = PickFP(Sem, 5, 9, 17, 21, 33, 36);
-  Epsilon = PickFP(Sem, "9.765625e-4", "1.19209290e-7",
+  NormMax = PickFP(
+      Sem, "6.5504e+4", "3.38953138925153547590470800371487867e+38",
+      "3.40282347e+38", "1.7976931348623157e+308",
+      "1.18973149535723176502e+4932", "8.98846567431157953864652595394501e+307",
+      "1.18973149535723176508575932662800702e+4932");
+  DenormMin = PickFP(
+      Sem, "5.9604644775390625e-8", "9.18354961579912115600575419704879436e-41",
+      "1.40129846e-45", "4.9406564584124654e-324",
+      "3.64519953188247460253e-4951", "4.94065645841246544176568792868221e-324",
+      "6.47517511943802511092443895822764655e-4966");
+  int Digits = PickFP(Sem, 3, 2, 6, 15, 18, 31, 33);
+  int DecimalDigits = PickFP(Sem, 5, 4, 9, 17, 21, 33, 36);
+  Epsilon = PickFP(Sem, "9.765625e-4", "7.8125e-3", "1.19209290e-7",
                    "2.2204460492503131e-16", "1.08420217248550443401e-19",
                    "4.94065645841246544176568792868221e-324",
                    "1.92592994438723585305597794258492732e-34");
-  int MantissaDigits = PickFP(Sem, 11, 24, 53, 64, 106, 113);
-  int Min10Exp = PickFP(Sem, -4, -37, -307, -4931, -291, -4931);
-  int Max10Exp = PickFP(Sem, 4, 38, 308, 4932, 308, 4932);
-  int MinExp = PickFP(Sem, -13, -125, -1021, -16381, -968, -16381);
-  int MaxExp = PickFP(Sem, 16, 128, 1024, 16384, 1024, 16384);
-  Min = PickFP(Sem, "6.103515625e-5", "1.17549435e-38", "2.2250738585072014e-308",
-               "3.36210314311209350626e-4932",
+  int MantissaDigits = PickFP(Sem, 11, 8, 24, 53, 64, 106, 113);
+  int Min10Exp = PickFP(Sem, -4, -37, -37, -307, -4931, -291, -4931);
+  int Max10Exp = PickFP(Sem, 4, 38, 38, 308, 4932, 308, 4932);
+  int MinExp = PickFP(Sem, -13, -125, -125, -1021, -16381, -968, -16381);
+  int MaxExp = PickFP(Sem, 16, 128, 128, 1024, 16384, 1024, 16384);
+  Min = PickFP(Sem, "6.103515625e-5",
+               "1.17549435082228750796873653722224568e-38", "1.17549435e-38",
+               "2.2250738585072014e-308", "3.36210314311209350626e-4932",
                "2.00416836000897277799610805135016e-292",
                "3.36210314311209350626267781732175260e-4932");
-  Max = PickFP(Sem, "6.5504e+4", "3.40282347e+38", "1.7976931348623157e+308",
+  Max = PickFP(Sem, "6.5504e+4", "3.38953138925153547590470800371487867e+38",
+               "3.40282347e+38", "1.7976931348623157e+308",
                "1.18973149535723176502e+4932",
                "1.79769313486231580793728971405301e+308",
                "1.18973149535723176508575932662800702e+4932");
@@ -1250,6 +1256,8 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
 
   if (TI.hasFloat16Type())
     DefineFloatMacros(Builder, "FLT16", &TI.getHalfFormat(), "F16");
+  if (TI.hasBFloat16Type())
+    DefineFloatMacros(Builder, "BFLT16", &TI.getBFloat16Format(), "BF16");
   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat(), "F");
   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat(), "");
   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat(), "L");

clang/lib/Lex/LiteralSupport.cpp

@@ -917,6 +917,7 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
   isFloat = false;
   isImaginary = false;
   isFloat16 = false;
+  isBFloat16 = false;
   isFloat128 = false;
   MicrosoftInteger = 0;
   isFract = false;
@@ -978,6 +979,24 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
   // we break out of the loop.
   for (; s != ThisTokEnd; ++s) {
     switch (*s) {
+    case 'b': // FP Suffix for "__bf16"
+    case 'B':
+      if (!Target.hasBFloat16Type())
+        break;
+      if (!isFPConstant)
+        break; // Error for integer constant.
+      if (HasSize)
+        break;
+      HasSize = true;
+
+      if ((Target.hasBFloat16Type()) && s + 3 < ThisTokEnd &&
+          ((s[0] == 'b' && s[1] == 'f') || (s[0] == 'B' && s[1] == 'F')) &&
+          s[2] == '1' && s[3] == '6') {
+        s += 3; // success, eat up 3 characters.
+        isBFloat16 = true;
+        continue;
+      }
+      break;
     case 'R':
     case 'r':
       if (!LangOpts.FixedPoint)
@@ -1183,6 +1202,7 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
         isSizeT = false;
         isFloat = false;
         isFloat16 = false;
+        isBFloat16 = false;
         isHalf = false;
         isImaginary = false;
         isBitInt = false;

clang/lib/Sema/SemaExpr.cpp

@@ -3878,6 +3878,8 @@ ExprResult Sema::ActOnNumericConstant(const Token &Tok, Scope *UDLScope) {
       Ty = !getLangOpts().HLSL ? Context.LongDoubleTy : Context.DoubleTy;
     else if (Literal.isFloat16)
       Ty = Context.Float16Ty;
+    else if (Literal.isBFloat16)
+      Ty = Context.BFloat16Ty;
     else if (Literal.isFloat128)
       Ty = Context.Float128Ty;
     else if (getLangOpts().HLSL)

clang/test/Lexer/bfloat-literal.cpp

@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -pedantic %s
+__bf16 a = 1.b; // expected-error{{invalid suffix 'b' on floating constant}}
+__bf16 b = 1.bf; // expected-error{{invalid suffix 'bf' on floating constant}}
+__bf16 c = 1.bf166; // expected-error{{invalid suffix 'bf166' on floating constant}}
+__bf16 d = 1.bf1; // expected-error{{invalid suffix 'bf1' on floating constant}}
+
+__bf16 e = 1.B; // expected-error{{invalid suffix 'B' on floating constant}}
+__bf16 f = 1.BF; // expected-error{{invalid suffix 'BF' on floating constant}}
+__bf16 g = 1.BF166; // expected-error{{invalid suffix 'BF166' on floating constant}}
+__bf16 h = 1.BF1; // expected-error{{invalid suffix 'BF1' on floating constant}}
+
+__bf16 i = 1.bf16; // expect-success
+__bf16 j = 1.BF16; // expect-success
+
+__bf16 k = 1B; // expected-error{{invalid digit 'B' in decimal constant}}
+__bf16 l = 1BF; // expected-error{{invalid digit 'B' in decimal constant}}
+__bf16 m = 1BF166; // expected-error{{invalid digit 'B' in decimal constant}}
+__bf16 n = 1BF1; // expected-error{{invalid digit 'B' in decimal constant}}
+
+__bf16 o = 1b; // expected-error{{invalid digit 'b' in decimal constant}}
+__bf16 p = 1bf; // expected-error{{invalid digit 'b' in decimal constant}}
+__bf16 q = 1bf166; // expected-error{{invalid digit 'b' in decimal constant}}
+__bf16 r = 1bf1; // expected-error{{invalid digit 'b' in decimal constant}}
+
+__bf16 s = 1bf16; // expected-error{{invalid digit 'b' in decimal constant}}
+__bf16 t = 1BF16; // expected-error{{invalid digit 'B' in decimal constant}}
+
+__bf16 u = 1.bf16F16; // expected-error{{invalid suffix 'bf16F16' on floating constant}}
+__bf16 v = 1.BF16f16; // expected-error{{invalid suffix 'BF16f16' on floating constant}}
+__bf16 w = 1.F16bf16; // expected-error{{invalid suffix 'F16bf16' on floating constant}}

clang/test/Preprocessor/bfloat16-macros.c

@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -E -dM -ffreestanding < /dev/null | FileCheck -match-full-lines -check-prefix BFLT16 %s
+
+// BFLT16: #define __BFLT16_DECIMAL_DIG__ 4
+// BFLT16: #define __BFLT16_DENORM_MIN__ 9.18354961579912115600575419704879436e-41BF16
+// BFLT16: #define __BFLT16_DIG__ 2
+// BFLT16: #define __BFLT16_EPSILON__ 7.8125e-3BF16
+// BFLT16: #define __BFLT16_HAS_DENORM__ 1
+// BFLT16: #define __BFLT16_HAS_INFINITY__ 1
+// BFLT16: #define __BFLT16_HAS_QUIET_NAN__ 1
+// BFLT16: #define __BFLT16_MANT_DIG__ 8
+// BFLT16: #define __BFLT16_MAX_10_EXP__ 38
+// BFLT16: #define __BFLT16_MAX_EXP__ 128
+// BFLT16: #define __BFLT16_MAX__ 3.38953138925153547590470800371487867e+38BF16
+// BFLT16: #define __BFLT16_MIN_10_EXP__ (-37)
+// BFLT16: #define __BFLT16_MIN_EXP__ (-125)
+// BFLT16: #define __BFLT16_MIN__ 1.17549435082228750796873653722224568e-38BF16
+// BFLT16: #define __BFLT16_NORM_MAX__ 3.38953138925153547590470800371487867e+38BF16