What does the numerical literal 0.e0f mean?

I am currently trying to debug an uninitialized memory error. I have now come across the numerical literal 0.e0f in the OpenBlas source code (which is what the debugger is currently at) what does that mean?

The context is this:

if ((alpha_r == 0.e0f) && (alpha_i == 0.e0f)) return;

The 0.e0f evaluates to 0 apparently.

Solution

A floating-point literals have two syntaxes. The first one consists of the following parts:

nonempty sequence of decimal digits containing a decimal point character (defines significand)
(optional) e or E followed with optional minus or plus sign and nonempty sequence of decimal digits (defines exponent)
(optional) a suffix type specifier as a l, f, L or F

The second one consists of the following parts:

nonempty sequence of decimal digits (defines significant)
e or E followed with optional minus or plus sign and nonempty sequence of decimal digits (defines exponent)
(optional) a suffix type specifier as a l, f, L or F

The suffix type specifier defines the actual type of the floating-point literal:

(no suffix) defines double
f F defines float
l L defines long double