[Fixed Point Arithmetic] Addition of the remaining fixed point types and their saturated equivalents

This diff includes changes for the remaining _Fract and _Sat fixed point types.

```
signed short _Fract s_short_fract;
signed _Fract s_fract;
signed long _Fract s_long_fract;
unsigned short _Fract u_short_fract;
unsigned _Fract u_fract;
unsigned long _Fract u_long_fract;

// Aliased fixed point types
short _Accum short_accum;
_Accum accum;
long _Accum long_accum;
short _Fract short_fract;
_Fract fract;
long _Fract long_fract;

// Saturated fixed point types
_Sat signed short _Accum sat_s_short_accum;
_Sat signed _Accum sat_s_accum;
_Sat signed long _Accum sat_s_long_accum;
_Sat unsigned short _Accum sat_u_short_accum;
_Sat unsigned _Accum sat_u_accum;
_Sat unsigned long _Accum sat_u_long_accum;
_Sat signed short _Fract sat_s_short_fract;
_Sat signed _Fract sat_s_fract;
_Sat signed long _Fract sat_s_long_fract;
_Sat unsigned short _Fract sat_u_short_fract;
_Sat unsigned _Fract sat_u_fract;
_Sat unsigned long _Fract sat_u_long_fract;

// Aliased saturated fixed point types
_Sat short _Accum sat_short_accum;
_Sat _Accum sat_accum;
_Sat long _Accum sat_long_accum;
_Sat short _Fract sat_short_fract;
_Sat _Fract sat_fract;
_Sat long _Fract sat_long_fract;
```

This diff only allows for declaration of these fixed point types. Assignment and other operations done on fixed point types according to http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1169.pdf will be added in future patches.

Differential Revision: https://reviews.llvm.org/D46911

llvm-svn: 334718

3 files changed, 75 insertions, 32 deletions

diff --git a/clang/lib/Sema/DeclSpec.cpp b/clang/lib/Sema/DeclSpec.cpp
index aa5f197b541..fe111a5ddea 100644
--- a/clang/lib/Sema/DeclSpec.cpp
+++ b/clang/lib/Sema/DeclSpec.cpp
@@ -340,6 +340,7 @@ bool Declarator::isDeclarationOfFunction() const {
     case TST_decimal64:
     case TST_double:
     case TST_Accum:
+    case TST_Fract:
     case TST_Float16:
     case TST_float128:
     case TST_enum:
@@ -512,6 +513,7 @@ const char *DeclSpec::getSpecifierName(DeclSpec::TST T,
   case DeclSpec::TST_float:       return "float";
   case DeclSpec::TST_double:      return "double";
   case DeclSpec::TST_accum:       return "_Accum";
+  case DeclSpec::TST_fract:       return "_Fract";
   case DeclSpec::TST_float16:     return "_Float16";
   case DeclSpec::TST_float128:    return "__float128";
   case DeclSpec::TST_bool:        return Policy.Bool ? "bool" : "_Bool";
@@ -767,6 +769,19 @@ bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
   return false;
 }
 
+bool DeclSpec::SetTypeSpecSat(SourceLocation Loc, const char *&PrevSpec,
+                              unsigned &DiagID) {
+  // Cannot set twice
+  if (TypeSpecSat) {
+    DiagID = diag::warn_duplicate_declspec;
+    PrevSpec = "_Sat";
+    return true;
+  }
+  TypeSpecSat = true;
+  TSSatLoc = Loc;
+  return false;
+}
+
 bool DeclSpec::SetTypeAltiVecVector(bool isAltiVecVector, SourceLocation Loc,
                           const char *&PrevSpec, unsigned &DiagID,
                           const PrintingPolicy &Policy) {
@@ -1102,13 +1117,16 @@ void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
     }
   }
 
+  bool IsFixedPointType =
+      TypeSpecType == TST_accum || TypeSpecType == TST_fract;
+
   // signed/unsigned are only valid with int/char/wchar_t/_Accum.
   if (TypeSpecSign != TSS_unspecified) {
     if (TypeSpecType == TST_unspecified)
       TypeSpecType = TST_int; // unsigned -> unsigned int, signed -> signed int.
     else if (TypeSpecType != TST_int && TypeSpecType != TST_int128 &&
              TypeSpecType != TST_char && TypeSpecType != TST_wchar &&
-             TypeSpecType != TST_accum) {
+             !IsFixedPointType) {
       S.Diag(TSSLoc, diag::err_invalid_sign_spec)
         << getSpecifierName((TST)TypeSpecType, Policy);
       // signed double -> double.
@@ -1124,10 +1142,11 @@ void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
     if (TypeSpecType == TST_unspecified)
       TypeSpecType = TST_int; // short -> short int, long long -> long long int.
     else if (!(TypeSpecType == TST_int ||
-               (TypeSpecType == TST_accum && TypeSpecWidth != TSW_longlong))) {
+               (IsFixedPointType && TypeSpecWidth != TSW_longlong))) {
       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
       TypeSpecType = TST_int;
+      TypeSpecSat = false;
       TypeSpecOwned = false;
     }
     break;
@@ -1135,10 +1154,11 @@ void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
     if (TypeSpecType == TST_unspecified)
       TypeSpecType = TST_int;  // long -> long int.
     else if (TypeSpecType != TST_int && TypeSpecType != TST_double &&
-             TypeSpecType != TST_accum) {
+             !IsFixedPointType) {
       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
       TypeSpecType = TST_int;
+      TypeSpecSat = false;
       TypeSpecOwned = false;
     }
     break;
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index dc67c8ef19a..71c583367bd 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -831,6 +831,7 @@ bool Sema::containsUnexpandedParameterPacks(Declarator &D) {
   case TST_float:
   case TST_double:
   case TST_Accum:
+  case TST_Fract:
   case TST_Float16:
   case TST_float128:
   case TST_bool:
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 1f6034a07d3..9ee947b80a3 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -1392,36 +1392,49 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
     break;
   }
   case DeclSpec::TST_accum: {
-    if (DS.getTypeSpecSign() != DeclSpec::TSS_unsigned) {
-      switch (DS.getTypeSpecWidth()) {
-        case DeclSpec::TSW_short:
-          Result = Context.ShortAccumTy;
-          break;
-        case DeclSpec::TSW_unspecified:
-          Result = Context.AccumTy;
-          break;
-        case DeclSpec::TSW_long:
-          Result = Context.LongAccumTy;
-          break;
-        case DeclSpec::TSW_longlong:
-          // Unreachable b/c this is caught in final analysis of the DeclSpec.
-          llvm_unreachable("Unable to specify long long as _Accum width");
-      }
-    } else {
-      switch (DS.getTypeSpecWidth()) {
-        case DeclSpec::TSW_short:
-          Result = Context.UnsignedShortAccumTy;
-          break;
-        case DeclSpec::TSW_unspecified:
-          Result = Context.UnsignedAccumTy;
-          break;
-        case DeclSpec::TSW_long:
-          Result = Context.UnsignedLongAccumTy;
-          break;
-        case DeclSpec::TSW_longlong:
-          llvm_unreachable("Unable to specify long long as _Accum width");
-      }
+    switch (DS.getTypeSpecWidth()) {
+      case DeclSpec::TSW_short:
+        Result = Context.ShortAccumTy;
+        break;
+      case DeclSpec::TSW_unspecified:
+        Result = Context.AccumTy;
+        break;
+      case DeclSpec::TSW_long:
+        Result = Context.LongAccumTy;
+        break;
+      case DeclSpec::TSW_longlong:
+        llvm_unreachable("Unable to specify long long as _Accum width");
     }
+
+    if (DS.getTypeSpecSign() == DeclSpec::TSS_unsigned)
+      Result = Context.getCorrespondingUnsignedType(Result);
+
+    if (DS.isTypeSpecSat())
+      Result = Context.getCorrespondingSaturatedType(Result);
+
+    break;
+  }
+  case DeclSpec::TST_fract: {
+    switch (DS.getTypeSpecWidth()) {
+      case DeclSpec::TSW_short:
+        Result = Context.ShortFractTy;
+        break;
+      case DeclSpec::TSW_unspecified:
+        Result = Context.FractTy;
+        break;
+      case DeclSpec::TSW_long:
+        Result = Context.LongFractTy;
+        break;
+      case DeclSpec::TSW_longlong:
+        llvm_unreachable("Unable to specify long long as _Fract width");
+    }
+
+    if (DS.getTypeSpecSign() == DeclSpec::TSS_unsigned)
+      Result = Context.getCorrespondingUnsignedType(Result);
+
+    if (DS.isTypeSpecSat())
+      Result = Context.getCorrespondingSaturatedType(Result);
+
     break;
   }
   case DeclSpec::TST_int128:
@@ -1592,6 +1605,15 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
       S.checkOpenCLDisabledTypeDeclSpec(DS, Result))
     declarator.setInvalidType(true);
 
+  bool IsFixedPointType = DS.getTypeSpecType() == DeclSpec::TST_accum ||
+                          DS.getTypeSpecType() == DeclSpec::TST_fract;
+
+  // Only fixed point types can be saturated
+  if (DS.isTypeSpecSat() && !IsFixedPointType)
+    S.Diag(DS.getTypeSpecSatLoc(), diag::err_invalid_saturation_spec)
+        << DS.getSpecifierName(DS.getTypeSpecType(),
+                               Context.getPrintingPolicy());
+
   // Handle complex types.
   if (DS.getTypeSpecComplex() == DeclSpec::TSC_complex) {
     if (S.getLangOpts().Freestanding)