[RISC-V] Use standard NaNs in FP ops for cross-compiling RISC-V on x86 (dotnet#93098)

Author: tomeksowi

src/coreclr/jit/valuenum.cpp

@@ -106,7 +106,7 @@ struct DoubleTraits
 template <typename TFp, typename TFpTraits>
 TFp FpAdd(TFp value1, TFp value2)
 {
-#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64)
+#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64) || defined(TARGET_RISCV64)
     // If [value1] is negative infinity and [value2] is positive infinity
     //   the result is NaN.
     // If [value1] is positive infinity and [value2] is negative infinity
@@ -124,7 +124,7 @@ TFp FpAdd(TFp value1, TFp value2)
             return TFpTraits::NaN();
         }
     }
-#endif // TARGET_ARMARCH || TARGET_LOONGARCH64
+#endif // TARGET_ARMARCH || TARGET_LOONGARCH64 || TARGET_RISCV64
 
     return value1 + value2;
 }
@@ -142,7 +142,7 @@ TFp FpAdd(TFp value1, TFp value2)
 template <typename TFp, typename TFpTraits>
 TFp FpSub(TFp value1, TFp value2)
 {
-#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64)
+#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64) || defined(TARGET_RISCV64)
     // If [value1] is positive infinity and [value2] is positive infinity
     //   the result is NaN.
     // If [value1] is negative infinity and [value2] is negative infinity
@@ -160,7 +160,7 @@ TFp FpSub(TFp value1, TFp value2)
             return TFpTraits::NaN();
         }
     }
-#endif // TARGET_ARMARCH || TARGET_LOONGARCH64
+#endif // TARGET_ARMARCH || TARGET_LOONGARCH64 || TARGET_RISCV64
 
     return value1 - value2;
 }
@@ -178,7 +178,7 @@ TFp FpSub(TFp value1, TFp value2)
 template <typename TFp, typename TFpTraits>
 TFp FpMul(TFp value1, TFp value2)
 {
-#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64)
+#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64) || defined(TARGET_RISCV64)
     // From the ECMA standard:
     //
     // If [value1] is zero and [value2] is infinity
@@ -194,7 +194,7 @@ TFp FpMul(TFp value1, TFp value2)
     {
         return TFpTraits::NaN();
     }
-#endif // TARGET_ARMARCH || TARGET_LOONGARCH64
+#endif // TARGET_ARMARCH || TARGET_LOONGARCH64 || TARGET_RISCV64
 
     return value1 * value2;
 }
@@ -212,7 +212,7 @@ TFp FpMul(TFp value1, TFp value2)
 template <typename TFp, typename TFpTraits>
 TFp FpDiv(TFp dividend, TFp divisor)
 {
-#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64)
+#if defined(TARGET_ARMARCH) || defined(TARGET_LOONGARCH64) || defined(TARGET_RISCV64)
     // From the ECMA standard:
     //
     // If [dividend] is zero and [divisor] is zero
@@ -228,7 +228,7 @@ TFp FpDiv(TFp dividend, TFp divisor)
     {
         return TFpTraits::NaN();
     }
-#endif // TARGET_ARMARCH || TARGET_LOONGARCH64
+#endif // TARGET_ARMARCH || TARGET_LOONGARCH64 || TARGET_RISCV64
 
     return dividend / divisor;
 }