mtlb_uint64

Description

Matlab and Scilab uint64 behave differently :

• Beyong the main interval bounds, Scilab's uint64() wraps, while Matlab's mtlb_uint64() saturates.
• For non integer values, Scilab's uint64() truncates the fractional part, while Matlab's mtlb_uint64() rounds to the nearest integer.

Let imax = 2^64 - 1 = 18 446 744 073 709 551 615.

x	uint64(x)	mtlb_uint64(x)
%nan	0	0
-%inf	0	0
-2	imax-1	0
-1	imax	0
0	0	0
1	1	1
10.2	10	10
10.5	10	11
10.51	10	11
...	...	...
imax	imax	imax
imax+1	0	imax
imax+1	1	imax
%inf	imax	imax

mtlb_uint64 has not to be used for hand coded functions. The function mtlb_uint64(A) is used by mfile2sci to replace uint64(A) when it is not possible to know what is the input while porting Matlab code to Scilab. This function then determines the correct semantic at run time.