Make round function to behave consistently on non-x86_64

src/Common/ErrorCodes.cpp

@@ -547,6 +547,7 @@
     M(577, INVALID_SHARD_ID) \
     M(578, INVALID_FORMAT_INSERT_QUERY_WITH_DATA) \
     M(579, INCORRECT_PART_TYPE) \
+    M(580, CANNOT_SET_ROUNDING_MODE) \
     \
     M(998, POSTGRESQL_CONNECTION_FAILURE) \
     M(999, KEEPER_EXCEPTION) \

src/Functions/FunctionsRound.h

@@ -21,6 +21,8 @@
 
 #ifdef __SSE4_1__
     #include <smmintrin.h>
+#else
+    #include <fenv.h>
 #endif
 
 
@@ -34,6 +36,7 @@ namespace ErrorCodes
     extern const int ARGUMENT_OUT_OF_BOUND;
     extern const int ILLEGAL_COLUMN;
     extern const int BAD_ARGUMENTS;
+    extern const int CANNOT_SET_ROUNDING_MODE;
 }
 
 
@@ -231,7 +234,7 @@ inline float roundWithMode(float x, RoundingMode mode)
 {
     switch (mode)
     {
-        case RoundingMode::Round: return roundf(x);
+        case RoundingMode::Round: return nearbyintf(x);
         case RoundingMode::Floor: return floorf(x);
         case RoundingMode::Ceil: return ceilf(x);
         case RoundingMode::Trunc: return truncf(x);
@@ -244,7 +247,7 @@ inline double roundWithMode(double x, RoundingMode mode)
 {
     switch (mode)
     {
-        case RoundingMode::Round: return round(x);
+        case RoundingMode::Round: return nearbyint(x);
         case RoundingMode::Floor: return floor(x);
         case RoundingMode::Ceil: return ceil(x);
         case RoundingMode::Trunc: return trunc(x);
@@ -595,6 +598,15 @@ public:
             return false;
         };
 
+#if !defined(__SSE4_1__)
+        /// In case of "nearbyint" function is used, we should ensure the expected rounding mode for the Banker's rounding.
+        /// Actually it is by default. But we will set it just in case.
+
+        if constexpr (rounding_mode == RoundingMode::Round)
+            if (0 != fesetround(FE_TONEAREST))
+                throw Exception("Cannot set floating point rounding mode", ErrorCodes::CANNOT_SET_ROUNDING_MODE);
+#endif
+
         if (!callOnIndexAndDataType<void>(column.type->getTypeId(), call))
         {
             throw Exception("Illegal column " + column.name + " of argument of function " + getName(),