PICA f32 -> f31/f24 conversion

gistfile1.c

u32 f31FromFloat(float f) {
	u32 i;
	memcpy(&i, &f, 4);

	u32 mantissa = (i << 9) >>  9;
	s32 exponent = (i << 1) >> 24;
	u32 sign     = (i << 0) >> 31;

	// Re-bias exponent
	exponent = exponent - 127 + 63;
	if (exponent < 0) {
		// Underflow
		return sign << 30;
	} else if (exponent > 0x7F) {
		// Overflow: saturate to infinity
		return sign << 30 | 0x7F << 23;
	}

	return sign << 30 | exponent << 23 | mantissa;
}

u32 f32tof31(float fval) {
	u32 tmp1,tmp2;
	u32 tmp3;
	memcpy(&tmp3, &fval, 4);
	tmp1=(tmp3<<9)>>9;
	tmp2=tmp3&(~0x80000000);
	if(tmp2){
		tmp1=(tmp3<<9)>>9;
		int tmp=((tmp3<<1)>>24)-0x40;
		if(tmp<0)return ((tmp3>>31)<<30);
		else tmp2=tmp;
	}
	tmp3>>=31;
	return (tmp1|(tmp2<<23)|(tmp3<<30));
}

u32 f24FromFloat(float f) {
	u32 i;
	memcpy(&i, &f, 4);

	u32 mantissa = (i << 9) >>  9;
	s32 exponent = (i << 1) >> 24;
	u32 sign     = (i << 0) >> 31;

	// Truncate mantissa
	mantissa >>= 7;

	// Re-bias exponent
	exponent = exponent - 127 + 63;
	if (exponent < 0) {
		// Underflow: flush to zero
		return sign << 23;
	} else if (exponent > 0x7F) {
		// Overflow: saturate to infinity
		return sign << 23 | 0x7F << 16;
	}

	return sign << 23 | exponent << 16 | mantissa;
}

u32 f32tof24(float f)
{
	//if(!f)return 0;

	u32 v;
	memcpy(&v, &f, 4);

	u8 s=v>>31;
	s32 exp=((v>>23)&0xFF)-0x40;
	u32 man=(v>>7)&0xFFFF;

	if(exp>=0)return man|(exp<<16)|(s<<23);
	else return s<<23;
}