Handle zero and empty cells (which also means zero) in OpenCL for division

Not sure if it makes sense to keep having OpDiv a subclass of Reduction. There
is no DIV() function that would take a range of cells, so it isn't really
comparable to the other Reducion subclasses. But let's keep that as it is for
now.

We need to handle three cases specially in the OpenCL: Dividing by an empty
cell which should produce an #DIV/0! error, dividing an empty cell by zero
which also should produce #DIV/0!, and dividing an empty cell with anything
else number which should produce 0.

Change-Id: I86d86f652047d6f9e3c095c3ef135a8f5396b000

sc/source/core/opencl/formulagroupcl.cxx

@@ -1661,6 +1661,11 @@ public:
     typedef DynamicKernelSlidingArgument<DynamicKernelStringArgument> StringRange;
     typedef ParallelReductionVectorRef<VectorRef> ParallelNumericRange;
 
+    virtual bool HandleNaNArgument( std::stringstream&, unsigned, SubArguments& ) const
+    {
+        return false;
+    }
+
     virtual void GenSlidingWindowFunction( std::stringstream& ss,
         const std::string& sSymName, SubArguments& vSubArguments ) SAL_OVERRIDE
     {
@@ -1724,18 +1729,25 @@ public:
             }
             if (ocPush == vSubArguments[i]->GetFormulaToken()->GetOpCode())
             {
+                bool bNanHandled = HandleNaNArgument(ss, i, vSubArguments);
+
                 ss << "tmpBottom = " << GetBottom() << ";\n";
-                ss << "if (isNan(";
-                ss << vSubArguments[i]->GenSlidingWindowDeclRef();
-                ss << "))\n";
-                if (ZeroReturnZero())
-                    ss << "    return 0;\n";
-                else
+
+                if (!bNanHandled)
                 {
-                    ss << "    tmp = ";
-                    ss << Gen2("tmpBottom", "tmp") << ";\n";
+                    ss << "if (isNan(";
+                    ss << vSubArguments[i]->GenSlidingWindowDeclRef();
+                    ss << "))\n";
+                    if (ZeroReturnZero())
+                        ss << "    return 0;\n";
+                    else
+                    {
+                        ss << "    tmp = ";
+                        ss << Gen2("tmpBottom", "tmp") << ";\n";
+                    }
+                    ss << "else\n";
                 }
-                ss << "else{\n";
+                ss << "{";
                 ss << "        tmp = ";
                 ss << Gen2(vSubArguments[i]->GenSlidingWindowDeclRef(), "tmp");
                 ss << ";\n";
@@ -2147,6 +2159,32 @@ public:
         return "(" + rhs + "==0 ? CreateDoubleError(errDivisionByZero) : (" + lhs + "/" + rhs + ") )";
     }
     virtual std::string BinFuncName() const SAL_OVERRIDE { return "fdiv"; }
+
+    virtual bool HandleNaNArgument( std::stringstream& ss, unsigned argno, SubArguments& vSubArguments ) const SAL_OVERRIDE
+    {
+        if (argno == 1)
+        {
+            ss <<
+                "if (isnan(" << vSubArguments[argno]->GetName() << "[gid0])) {\n"
+                "    if (GetDoubleErrorValue(" << vSubArguments[argno]->GetName() << "[gid0]) == errNoValue)\n"
+                "        return CreateDoubleError(errDivisionByZero);\n"
+                "}\n";
+            return true;
+        }
+        else if (argno == 0)
+        {
+            ss <<
+                "if (isnan(" << vSubArguments[argno]->GetName() << "[gid0])) {\n"
+                "    if (GetDoubleErrorValue(" << vSubArguments[argno]->GetName() << "[gid0]) == errNoValue) {\n"
+                "        if (" << vSubArguments[1]->GetName() << "[gid0] == 0)\n"
+                "            return CreateDoubleError(errDivisionByZero);\n"
+                "        return 0;\n"
+                "    }\n"
+                "}\n";
+        }
+        return false;
+    }
+
 };
 
 class OpMin : public Reduction