Commit ca43c4f5 authored by Manuel Jander's avatar Manuel Jander
Browse files

Issue #1010 : Add output normalization and x==0 handling to BASOP_Util_Inv32... 

Issue #1010 : Add output normalization and x==0 handling to BASOP_Util_Inv32 to prevent instabilities for some operating points.
parent 5aae8ccc

lib_com/basop_util.c

+11 −2
Original line number Diff line number Diff line
@@ -1044,7 +1044,14 @@ Word32 div_w( Word32 L_num, Word32 L_den ) 
static

Word32 BASOP_Util_Inv32(Word32 x, Word16 *px_e)

{

    Word16 sign, shift;

    Word16 sign, shift, shift2;



    /* Avoid result 0 with inconvenient exponent returned. */

    IF( x == (Word32) 0 )

    {

        *px_e = 0;

        return ( (Word32) 0 );

    }



    sign = 0;

    move16();
@@ -1061,7 +1068,9 @@ Word32 BASOP_Util_Inv32(Word32 x, Word16 *px_e) 
    move16();

    x = ISqrt32norm(x, px_e);

    x = Mpy_32_32(x, x);

    *px_e = add(shl(*px_e, 1), shift);

    shift2 = norm_l(x);

    x = L_shl(x, shift2);

    *px_e = add(shl(*px_e, 1), sub(shift, shift2));

    move16();



    if (sign) {