[Fixed Point Arithmetic] Fixed Point Precision Bits and Fixed Point Literals

This diff includes the logic for setting the precision bits for each primary fixed point type in the target info and logic for initializing a fixed point literal.

Fixed point literals are declared using the suffixes

```
hr: short _Fract
uhr: unsigned short _Fract
r: _Fract
ur: unsigned _Fract
lr: long _Fract
ulr: unsigned long _Fract
hk: short _Accum
uhk: unsigned short _Accum
k: _Accum
uk: unsigned _Accum
```
Errors are also thrown for illegal literal values

```
unsigned short _Accum u_short_accum = 256.0uhk;   // expected-error{{the integral part of this literal is too large for this unsigned _Accum type}}
```

Differential Revision: https://reviews.llvm.org/D46915

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@335148 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 3 deletions

diff --git a/include/clang/Lex/LiteralSupport.h b/include/clang/Lex/LiteralSupport.h
index 4f32fa8e73..1b6bf6bcff 100644
--- a/include/clang/Lex/LiteralSupport.h
+++ b/include/clang/Lex/LiteralSupport.h
@@ -50,7 +50,7 @@ class NumericLiteralParser {
 
   unsigned radix;
 
-  bool saw_exponent, saw_period, saw_ud_suffix;
+  bool saw_exponent, saw_period, saw_ud_suffix, saw_fixed_point_suffix;
 
   SmallString<32> UDSuffixBuf;
 
@@ -69,11 +69,16 @@ public:
   bool isFloat128 : 1;      // 1.0q
   uint8_t MicrosoftInteger; // Microsoft suffix extension i8, i16, i32, or i64.
 
+  bool isFract : 1;         // 1.0hr/r/lr/uhr/ur/ulr
+  bool isAccum : 1;         // 1.0hk/k/lk/uhk/uk/ulk
+
+  bool isFixedPointLiteral() const { return saw_fixed_point_suffix; }
+
   bool isIntegerLiteral() const {
-    return !saw_period && !saw_exponent;
+    return !saw_period && !saw_exponent && !isFixedPointLiteral();
   }
   bool isFloatingLiteral() const {
-    return saw_period || saw_exponent;
+    return (saw_period || saw_exponent) && !isFixedPointLiteral();
   }
 
   bool hasUDSuffix() const {
@@ -105,6 +110,12 @@ public:
   /// literal exactly, and false otherwise.
   llvm::APFloat::opStatus GetFloatValue(llvm::APFloat &Result);
 
+  /// GetFixedPointValue - Convert this numeric literal value into a
+  /// scaled integer that represents this value. Returns true if an overflow
+  /// occurred when calculating the integral part of the scaled integer or
+  /// calculating the digit sequence of the exponent.
+  bool GetFixedPointValue(llvm::APInt &StoreVal, unsigned Scale);
+
 private:
 
   void ParseNumberStartingWithZero(SourceLocation TokLoc);