[Fixed Point Arithmetic] Fixed Point to Boolean Cast

This patch is a part of https://reviews.llvm.org/D48456 in an attempt to split
the casting logic up into smaller patches. This contains the code for casting
from fixed point types to boolean types.

Differential Revision: https://reviews.llvm.org/D53308

llvm-svn: 345063

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index a7da24db6a2..c64e335255e 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -9590,6 +9590,14 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
     return Success(IntResult, E);
   }
 
+  case CK_FixedPointToBoolean: {
+    // Unsigned padding does not affect this.
+    APValue Val;
+    if (!Evaluate(Val, Info, SubExpr))
+      return false;
+    return Success(Val.getInt().getBoolValue(), E);
+  }
+
   case CK_IntegralCast: {
     if (!Visit(SubExpr))
       return false;
@@ -10090,6 +10098,7 @@ bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
   case CK_AddressSpaceConversion:
   case CK_IntToOCLSampler:
   case CK_FixedPointCast:
+  case CK_FixedPointToBoolean:
     llvm_unreachable("invalid cast kind for complex value");
 
   case CK_LValueToRValue: