1 files changed, 59 insertions, 10 deletions
diff --git a/flang/lib/Evaluate/fold-logical.cpp b/flang/lib/Evaluate/fold-logical.cpp
index a7c655b..ee6655f 100644
--- a/flang/lib/Evaluate/fold-logical.cpp
+++ b/flang/lib/Evaluate/fold-logical.cpp
@@ -620,6 +620,24 @@ static Expr<Type<TypeCategory::Logical, KIND>> RewriteOutOfRange(
   return AsExpr(std::move(funcRef));
 }
 
+static std::optional<common::RoundingMode> GetRoundingMode(
+    const std::optional<ActualArgument> &arg) {
+  if (arg) {
+    if (const auto *cst{UnwrapExpr<Constant<SomeDerived>>(*arg)}) {
+      if (auto constr{cst->GetScalarValue()}) {
+        if (StructureConstructorValues & values{constr->values()};
+            values.size() == 1) {
+          const Expr<SomeType> &value{values.begin()->second.value()};
+          if (auto code{ToInt64(value)}) {
+            return static_cast<common::RoundingMode>(*code);
+          }
+        }
+      }
+    }
+  }
+  return std::nullopt;
+}
+
 template <int KIND>
 Expr<Type<TypeCategory::Logical, KIND>> FoldIntrinsicFunction(
     FoldingContext &context,
@@ -831,17 +849,48 @@ Expr<Type<TypeCategory::Logical, KIND>> FoldIntrinsicFunction(
         }
       }
     }
-  } else if (name == "__builtin_ieee_support_datatype" ||
-      name == "__builtin_ieee_support_denormal" ||
-      name == "__builtin_ieee_support_divide" ||
-      name == "__builtin_ieee_support_inf" ||
-      name == "__builtin_ieee_support_io" ||
-      name == "__builtin_ieee_support_nan" ||
-      name == "__builtin_ieee_support_sqrt" ||
-      name == "__builtin_ieee_support_standard" ||
-      name == "__builtin_ieee_support_subnormal" ||
-      name == "__builtin_ieee_support_underflow_control") {
+  } else if (name == "__builtin_ieee_support_datatype") {
     return Expr<T>{true};
+  } else if (name == "__builtin_ieee_support_denormal") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::Denormal)};
+  } else if (name == "__builtin_ieee_support_divide") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::Divide)};
+  } else if (name == "__builtin_ieee_support_flag") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::Flags)};
+  } else if (name == "__builtin_ieee_support_halting") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::Halting)};
+  } else if (name == "__builtin_ieee_support_inf") {
+    return Expr<T>{
+        context.targetCharacteristics().ieeeFeatures().test(IeeeFeature::Inf)};
+  } else if (name == "__builtin_ieee_support_io") {
+    return Expr<T>{
+        context.targetCharacteristics().ieeeFeatures().test(IeeeFeature::Io)};
+  } else if (name == "__builtin_ieee_support_nan") {
+    return Expr<T>{
+        context.targetCharacteristics().ieeeFeatures().test(IeeeFeature::NaN)};
+  } else if (name == "__builtin_ieee_support_rounding") {
+    if (context.targetCharacteristics().ieeeFeatures().test(
+            IeeeFeature::Rounding)) {
+      if (auto mode{GetRoundingMode(args[0])}) {
+        return Expr<T>{mode != common::RoundingMode::TiesAwayFromZero};
+      }
+    }
+  } else if (name == "__builtin_ieee_support_sqrt") {
+    return Expr<T>{
+        context.targetCharacteristics().ieeeFeatures().test(IeeeFeature::Sqrt)};
+  } else if (name == "__builtin_ieee_support_standard") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::Standard)};
+  } else if (name == "__builtin_ieee_support_subnormal") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::Subnormal)};
+  } else if (name == "__builtin_ieee_support_underflow_control") {
+    return Expr<T>{context.targetCharacteristics().ieeeFeatures().test(
+        IeeeFeature::UnderflowControl)};
   }
   return Expr<T>{std::move(funcRef)};
 }