Moving parts of System.Math and System.MathF to be shared with Co…

…reRT. (#14119)

* Moving parts of `System.MathF` to be shared with CoreRT.

* Moving parts of `System.Math` to be shared with CoreRT.

* Updating the new 'Round' named intrinsic to map to the legacy 'Round' intrinsic.

* Adding back the case statement for CORINFO_INTRINSIC_Round, since it is required for Desktop compat.

src/classlibnative/float/floatdouble.cpp

@@ -132,6 +132,15 @@ FCIMPL1_V(double, COMDouble::Floor, double x)
     return (double)floor(x);
 FCIMPLEND
 
+/*=====================================FMod=====================================
+**
+==============================================================================*/
+FCIMPL2_VV(double, COMDouble::FMod, double x, double y)
+    FCALL_CONTRACT;
+
+    return (double)fmod(x, y);
+FCIMPLEND
+
 /*=====================================Log======================================
 **
 ==============================================================================*/
@@ -153,10 +162,10 @@ FCIMPLEND
 /*=====================================ModF=====================================
 **
 ==============================================================================*/
-FCIMPL1(double, COMDouble::ModF, double* iptr)
+FCIMPL2_VV(double, COMDouble::ModF, double x, double* intptr)
     FCALL_CONTRACT;
 
-    return (double)modf(*iptr, iptr);
+    return (double)modf(x, intptr);
 FCIMPLEND
 
 /*=====================================Pow======================================
@@ -168,30 +177,6 @@ FCIMPL2_VV(double, COMDouble::Pow, double x, double y)
     return (double)pow(x, y);
 FCIMPLEND
 
-/*====================================Round=====================================
-**
-==============================================================================*/
-FCIMPL1_V(double, COMDouble::Round, double x)
-    FCALL_CONTRACT;
-
-    // If the number has no fractional part do nothing
-    // This shortcut is necessary to workaround precision loss in borderline cases on some platforms
-    if (x == (double)((INT64)x)) {
-        return x;
-    }
-
-    // We had a number that was equally close to 2 integers.
-    // We need to return the even one.
-
-    double flrTempVal = floor(x + 0.5);
-
-    if ((x == (floor(x) + 0.5)) && (fmod(flrTempVal, 2.0) != 0)) {
-        flrTempVal -= 1.0;
-    }
-
-    return _copysign(flrTempVal, x);
-FCIMPLEND
-
 /*=====================================Sin======================================
 **
 ==============================================================================*/

src/classlibnative/float/floatsingle.cpp

@@ -130,6 +130,15 @@ FCIMPL1_V(float, COMSingle::Floor, float x)
     return (float)floorf(x);
 FCIMPLEND
 
+/*=====================================FMod=====================================
+**
+==============================================================================*/
+FCIMPL2_VV(float, COMSingle::FMod, float x, float y)
+    FCALL_CONTRACT;
+
+    return (float)fmodf(x, y);
+FCIMPLEND
+
 /*=====================================Log======================================
 **
 ==============================================================================*/
@@ -151,10 +160,10 @@ FCIMPLEND
 /*=====================================ModF=====================================
 **
 ==============================================================================*/
-FCIMPL1(float, COMSingle::ModF, float* iptr)
+FCIMPL2_VV(float, COMSingle::ModF, float x, float* intptr)
     FCALL_CONTRACT;
 
-    return (float)modff(*iptr, iptr);
+    return (float)modff(x, intptr);
 FCIMPLEND
 
 /*=====================================Pow======================================
@@ -166,30 +175,6 @@ FCIMPL2_VV(float, COMSingle::Pow, float x, float y)
     return (float)powf(x, y);
 FCIMPLEND
 
-/*====================================Round=====================================
-**
-==============================================================================*/
-FCIMPL1_V(float, COMSingle::Round, float x)
-    FCALL_CONTRACT;
-
-    // If the number has no fractional part do nothing
-    // This shortcut is necessary to workaround precision loss in borderline cases on some platforms
-    if (x == (float)((INT32)x)) {
-        return x;
-    }
-
-    // We had a number that was equally close to 2 integers.
-    // We need to return the even one.
-
-    float flrTempVal = floorf(x + 0.5f);
-
-    if ((x == (floorf(x) + 0.5f)) && (fmod(flrTempVal, 2.0f) != 0)) {
-        flrTempVal -= 1.0f;
-    }
-
-    return _copysignf(flrTempVal, x);
-FCIMPLEND
-
 /*=====================================Sin======================================
 **
 ==============================================================================*/

src/classlibnative/inc/floatdouble.h

@@ -20,11 +20,11 @@ class COMDouble {
     FCDECL1_V(static double, Cosh, double x);
     FCDECL1_V(static double, Exp, double x);
     FCDECL1_V(static double, Floor, double x);
+    FCDECL2_VV(static double, FMod, double x, double y);
     FCDECL1_V(static double, Log, double x);
     FCDECL1_V(static double, Log10, double x);
-    FCDECL1(static double, ModF, double* iptr);
+    FCDECL2_VV(static double, ModF, double x, double* intptr);
     FCDECL2_VV(static double, Pow, double x, double y);
-    FCDECL1_V(static double, Round, double x);
     FCDECL1_V(static double, Sin, double x);
     FCDECL1_V(static double, Sinh, double x);
     FCDECL1_V(static double, Sqrt, double x);

src/classlibnative/inc/floatsingle.h

@@ -20,11 +20,11 @@ class COMSingle {
     FCDECL1_V(static float, Cosh, float x);
     FCDECL1_V(static float, Exp, float x);
     FCDECL1_V(static float, Floor, float x);
+    FCDECL2_VV(static float, FMod, float x, float y);
     FCDECL1_V(static float, Log, float x);
     FCDECL1_V(static float, Log10, float x);
-    FCDECL1(static float, ModF, float* iptr);
+    FCDECL2_VV(static float, ModF, float x, float* intptr);
     FCDECL2_VV(static float, Pow, float x, float y);
-    FCDECL1_V(static float, Round, float x);
     FCDECL1_V(static float, Sin, float x);
     FCDECL1_V(static float, Sinh, float x);
     FCDECL1_V(static float, Sqrt, float x);

src/jit/compiler.h

@@ -3007,6 +3007,11 @@ class Compiler
                             bool                  isJitIntrinsic,
                             CorInfoIntrinsics*    pIntrinsicID,
                             bool*                 isSpecialIntrinsic = nullptr);
+    GenTree* impMathIntrinsic(CORINFO_METHOD_HANDLE method,
+                              CORINFO_SIG_INFO*     sig,
+                              var_types             callType,
+                              CorInfoIntrinsics     intrinsicID,
+                              bool                  tailCall);
     NamedIntrinsic lookupNamedIntrinsic(CORINFO_METHOD_HANDLE method);
     GenTreePtr impArrayAccessIntrinsic(CORINFO_CLASS_HANDLE clsHnd,
                                        CORINFO_SIG_INFO*    sig,