GPU Calc: Optimized ATAN2

AMLOEXT-349

Change-Id: Ifd9532d7b73afee1a0d6eb8f2d4522e0356006f5
Signed-off-by: haochen <haochen@multicorewareinc.com>
Signed-off-by: Wei Wei <weiwei@multicorewareinc.com>
Signed-off-by: I-Jui (Ray) Sung <ray@multicorewareinc.com>

sc/source/core/opencl/op_math.cxx

@@ -1396,6 +1396,12 @@ void OpArcSinHyp::GenSlidingWindowFunction(std::stringstream &ss,
     ss << "    return  log( tmp + pow((pown(tmp, 2) + 1.0), 0.5));\n";
     ss << "}";
 }
+void OpArcTan2::BinInlineFun(std::set<std::string>& decls,
+    std::set<std::string>& funs)
+{
+    decls.insert(atan2Decl);
+    funs.insert(atan2Content);
+}
 void OpArcTan2::GenSlidingWindowFunction(std::stringstream &ss,
     const std::string sSymName, SubArguments &vSubArguments)
 {
@@ -1432,7 +1438,7 @@ void OpArcTan2::GenSlidingWindowFunction(std::stringstream &ss,
     ss << "    else \n    ";
 #endif
     ss << "    y_num = "<< vSubArguments[1]->GenSlidingWindowDeclRef() << ";\n";
-    ss << "    return atan2(y_num, x_num);\n";
+    ss << "    return arctan2(y_num, x_num);\n";
     ss << "}";
 }
 void OpArcTan::GenSlidingWindowFunction(std::stringstream &ss,

sc/source/core/opencl/op_math.hxx

@@ -175,6 +175,7 @@ public:
         const std::string sSymName, SubArguments &vSubArguments);
     virtual std::string GetBottom(void) { return "0.0"; }
     virtual std::string BinFuncName(void) const { return "ScATan2"; }
+    virtual void BinInlineFun(std::set<std::string>& ,std::set<std::string>&);
 };
 class OpArcTan:public Normal{
 public:

sc/source/core/opencl/opinlinefun_math.hxx

@@ -56,6 +56,35 @@ std::string local_cosh =
 "    double nVal = (exp(n) + exp(-n)) / 2;\n"
 "    return nVal;\n"
 "}\n";
+std::string atan2Decl = "double arctan2(double y, double x);\n";
+std::string atan2Content =
+"double arctan2(double y, double x)\n"
+"{\n"
+"    if(y==0.0)\n"
+"        return 0.0;\n"
+"    double a,num,den,tmpPi;\n"
+"    int flag;\n"
+"    tmpPi = 0;\n"
+"    if (fabs(x) >= fabs(y))\n"
+"    {\n"
+"        num = y;\n"
+"        den = x;\n"
+"        flag = 1;\n"
+"        if (x < 0.0)\n"
+"            tmpPi = M_PI;\n"
+"    }\n"
+"    if(fabs(x) < fabs(y))\n"
+"    {\n"
+"        num = x;\n"
+"        den = y;\n"
+"        flag = -1;\n"
+"        tmpPi = M_PI_2;\n"
+"    }\n"
+"    a = atan(num/den);\n"
+"    a = flag==1?a:-a;\n"
+"    a = a + (y >= 0.0 ? tmpPi : -tmpPi);\n"
+"    return a;\n"
+"}\n";
 
 
 #endif //SC_OPENCL_OPINLINFUN_MATH