[Fixed Point Arithmetic] Fixed Point and Integer Conversions

This patch includes the necessary code for converting between a fixed point type and integer.
This also includes constant expression evaluation for conversions with these types.

Differential Revision: https://reviews.llvm.org/D56900

llvm-svn: 355462

1 files changed, 30 insertions, 0 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 44ccb74e3f7..1a21ad2539d 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -9776,6 +9776,7 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
   case CK_AddressSpaceConversion:
   case CK_IntToOCLSampler:
   case CK_FixedPointCast:
+  case CK_IntegralToFixedPoint:
     llvm_unreachable("invalid cast kind for integral value");
 
   case CK_BitCast:
@@ -9810,6 +9811,19 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
     return Success(IntResult, E);
   }
 
+  case CK_FixedPointToIntegral: {
+    APFixedPoint Src(Info.Ctx.getFixedPointSemantics(SrcType));
+    if (!EvaluateFixedPoint(SubExpr, Src, Info))
+      return false;
+    bool Overflowed;
+    llvm::APSInt Result = Src.convertToInt(
+        Info.Ctx.getIntWidth(DestType),
+        DestType->isSignedIntegerOrEnumerationType(), &Overflowed);
+    if (Overflowed && !HandleOverflow(Info, E, Result, DestType))
+      return false;
+    return Success(Result, E);
+  }
+
   case CK_FixedPointToBoolean: {
     // Unsigned padding does not affect this.
     APValue Val;
@@ -9970,6 +9984,20 @@ bool FixedPointExprEvaluator::VisitCastExpr(const CastExpr *E) {
       return false;
     return Success(Result, E);
   }
+  case CK_IntegralToFixedPoint: {
+    APSInt Src;
+    if (!EvaluateInteger(SubExpr, Src, Info))
+      return false;
+
+    bool Overflowed;
+    APFixedPoint IntResult = APFixedPoint::getFromIntValue(
+        Src, Info.Ctx.getFixedPointSemantics(DestType), &Overflowed);
+
+    if (Overflowed && !HandleOverflow(Info, E, IntResult, DestType))
+      return false;
+
+    return Success(IntResult, E);
+  }
   case CK_NoOp:
   case CK_LValueToRValue:
     return ExprEvaluatorBaseTy::VisitCastExpr(E);
@@ -10371,6 +10399,8 @@ bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
   case CK_IntToOCLSampler:
   case CK_FixedPointCast:
   case CK_FixedPointToBoolean:
+  case CK_FixedPointToIntegral:
+  case CK_IntegralToFixedPoint:
     llvm_unreachable("invalid cast kind for complex value");
 
   case CK_LValueToRValue: