What's the most efficient way to split two integral values and get a floating point factor in .NET?
Consider the following signature in C #:
double Divide(int numerator, int denominator);
Is there a performance difference between the following implementations?
return (double)numerator / denominator;
return numerator / (double)denominator;
return (double)numerator / (double)denominator;
I guess both of them will return the same answer.
Have I missed any other equivalent solution?
+1
Drew noakes
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2 answers
Have you tried comparing IL (with Reflector for example )?
static double A(int numerator, int denominator)
{ return (double)numerator / denominator; }
static double B(int numerator, int denominator)
{ return numerator / (double)denominator; }
static double C(int numerator, int denominator)
{ return (double)numerator / (double)denominator; }
All three become (give or take a name):
.method private hidebysig static float64 A(int32 numerator, int32 denominator) cil managed
{
.maxstack 8
L_0000: ldarg.0 // pushes numerator onto the stack
L_0001: conv.r8 // converts the value at the top of the stack to double
L_0002: ldarg.1 // pushes denominator onto the stack
L_0003: conv.r8 // converts the value at the top of the stack to double
L_0004: div // pops two values, divides, and pushes the result
L_0005: ret // pops the value from the top of the stack as the return value
}
No, no: the difference is exactly zero.
+5
Marc gravell
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Even if you are using VB.NET, both the numerator and denominator are converted to doubles before doing the actual division, so your examples are the same.
+1
Maxam
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