mtlb_int64

Description

Matlab and Scilab int64 behave differently :

• Beyong the main interval bounds, Scilab's int64() wraps, while Matlab's mtlb_int64() saturates.
• For non integer values, Scilab's int64() truncates the fractional part, while Matlab's mtlb_int64() rounds to the nearest integer.

Let imin = -(2^32) = -9223372036854775808 and imax = 2^32 - 1 = 9223372036854775807.

x	int64(x)	mtlb_int64(x)
%nan	0	0
-%inf	imin	imin
imin-2	imax-1	imin
imin-1	imax	imin
imin	imin	imin
-80.7	-80	-81
-80.5	-80	-81
-80.4	-80	-80
10.2	10	10
10.5	10	11
10.51	10	11
imax	imax	imax
imax+1	imin	imax
imax+2	imin+1	imax
imax+3	imin+2	imax
%inf	imax	imax

mtlb_int64 has not to be used for hand coded functions. The function mtlb_int64(A) is used by mfile2sci to replace int64(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.