How to assign INFINITY to variables in CUDA code?

Accelerated Computing CUDA CUDA Programming and Performance
1

Is there a good method of declaring a float variable to be positive or negative INFINITY?

The generally accepted C++ method

#include
const float blah = std::numeric_limits::infinity();

produces an error message in device code because the infinity() function is not a device function.

Christian

2

I dont know… float a = 1.0f/0.0f?

3

From the math_constants.h file:

#define CUDART_INF_F __int_as_float(0x7f800000)

So, I guess you can just define your own constants that way if you’re using the driver, with:

0x7f800000 = infinity
0xff800000 = -infinity

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4

These conform to the ieee floating point specification. You can use the values:

0x7ff0000000000000 = infinity

0xfff0000000000000 = -infinity

for doubles

5

You can use the C INFINITY macro

#include <cmath>
const float blah = INFINITY;
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