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Diffstat (limited to 'cyclone/sickle/bitshift.c')
| -rw-r--r-- | cyclone/sickle/bitshift.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/cyclone/sickle/bitshift.c b/cyclone/sickle/bitshift.c new file mode 100644 index 0000000..db30fcd --- /dev/null +++ b/cyclone/sickle/bitshift.c @@ -0,0 +1,130 @@ +/* Copyright (c) 2002-2003 krzYszcz and others. + * For information on usage and redistribution, and for a DISCLAIMER OF ALL + * WARRANTIES, see the file, "LICENSE.txt," in this distribution. */ + +/* When bit-shifting 32-bit values, gcc (intel?) bashes the second operand + modulo 32. In msp x << 32 gives 0, x >> 32 gives a propagated sign bit + (as expected). Mimicking that is clumsy. LATER consider making the calcs + more generic (use long long values?) */ + +#include "m_pd.h" +#include "sickle/sic.h" + +//#define BITSHIFT_DEBUG + +typedef struct _bitshift +{ + t_sic x_sic; + int x_convert1; + int x_lshift; + int x_rshift; + int x_lover; +} t_bitshift; + +static t_class *bitshift_class; + +static t_int *bitshift_perform(t_int *w) +{ + t_bitshift *x = (t_bitshift *)(w[1]); + int nblock = (int)(w[2]); + t_float *in = (t_float *)(w[3]); + t_float *out = (t_float *)(w[4]); + /* LATER think about performance */ + if (x->x_lshift) + { + unsigned int shift = x->x_lshift; + if (x->x_convert1) while (nblock--) + { + /* CHECKED */ + t_int i = ((t_int)*in++ << shift); + *out++ = (t_float)i; + } + else while (nblock--) + { + /* CHECKED */ + t_int i = (*(t_int *)(t_float *)in++ << shift); + *out++ = *(t_float *)&i; + } + } + else if (x->x_rshift) + { + unsigned int shift = x->x_rshift; + if (x->x_convert1) while (nblock--) + { + /* CHECKME */ + t_int i = ((t_int)*in++ >> shift); + *out++ = (t_float)i; + } + else while (nblock--) + { + /* CHECKME */ + t_int i = (*(t_int *)(t_float *)in++ >> shift); + *out++ = *(t_float *)&i; + } + } + else if (x->x_lover) + while (nblock--) *out++ = 0; /* CHECKED both modes */ + else + while (nblock--) *out++ = *in++; /* CHECKED both modes */ + return (w + 5); +} + +static void bitshift_dsp(t_bitshift *x, t_signal **sp) +{ + dsp_add(bitshift_perform, 4, x, sp[0]->s_n, sp[0]->s_vec, sp[1]->s_vec); +} + +static void bitshift_mode(t_bitshift *x, t_floatarg f) +{ + int i = (int)f; + x->x_convert1 = (i > 0); /* CHECKED */ +} + +static void bitshift_shift(t_bitshift *x, t_floatarg f) +{ + int i = (int)f; + int nbits = sizeof(t_int) * 8; + x->x_lshift = x->x_rshift = 0; + x->x_lover = 0; + if (i > 0) + { +#ifdef BITSHIFT_DEBUG + post("%.8x << %d == %.8x, %.8x << %d == %.8x", + 1, i, 1 << i, -1, i, -1 << i); +#endif + if (i < nbits) + x->x_lshift = i; + else + x->x_lover = 1; + } + else if (i < 0) + { +#ifdef BITSHIFT_DEBUG + post("%.8x >> %d == %.8x, %.8x >> %d == %.8x", + 0x7fffffff, -i, 0x7fffffff >> -i, -1, -i, -1 >> -i); +#endif + x->x_rshift = (i <= -nbits ? nbits - 1 : -i); + } +} + +static void *bitshift_new(t_floatarg f1, t_floatarg f2) +{ + t_bitshift *x = (t_bitshift *)pd_new(bitshift_class); + outlet_new((t_object *)x, &s_signal); + bitshift_shift(x, f1); + bitshift_mode(x, f2); + return (x); +} + +void bitshift_tilde_setup(void) +{ + bitshift_class = class_new(gensym("bitshift~"), + (t_newmethod)bitshift_new, 0, + sizeof(t_bitshift), 0, + A_DEFFLOAT, A_DEFFLOAT, 0); + sic_setup(bitshift_class, bitshift_dsp, SIC_FLOATTOSIGNAL); + class_addmethod(bitshift_class, (t_method)bitshift_mode, + gensym("mode"), A_FLOAT, 0); + class_addmethod(bitshift_class, (t_method)bitshift_shift, + gensym("shift"), A_FLOAT, 0); +} |