static u32 vfp_double_ftosi()

in vfp/vfpdouble.c [585:653]

• 56 lines of code
• 20 McCabe index (conditional complexity)

static u32 vfp_double_ftosi(int sd, int unused, int dm, u32 fpscr)
{
	struct vfp_double vdm;
	u32 d, exceptions = 0;
	int rmode = fpscr & FPSCR_RMODE_MASK;
	int tm;

	vfp_double_unpack(&vdm, vfp_get_double(dm));
	vfp_double_dump("VDM", &vdm);

	/*
	 * Do we have denormalised number?
	 */
	tm = vfp_double_type(&vdm);
	if (tm & VFP_DENORMAL)
		exceptions |= FPSCR_IDC;

	if (tm & VFP_NAN) {
		d = 0;
		exceptions |= FPSCR_IOC;
	} else if (vdm.exponent >= 1023 + 32) {
		d = 0x7fffffff;
		if (vdm.sign)
			d = ~d;
		exceptions |= FPSCR_IOC;
	} else if (vdm.exponent >= 1023 - 1) {
		int shift = 1023 + 63 - vdm.exponent;	/* 58 */
		u64 rem, incr = 0;

		d = (vdm.significand << 1) >> shift;
		rem = vdm.significand << (65 - shift);

		if (rmode == FPSCR_ROUND_NEAREST) {
			incr = 0x8000000000000000ULL;
			if ((d & 1) == 0)
				incr -= 1;
		} else if (rmode == FPSCR_ROUND_TOZERO) {
			incr = 0;
		} else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) {
			incr = ~0ULL;
		}

		if ((rem + incr) < rem && d < 0xffffffff)
			d += 1;
		if (d > 0x7fffffff + (vdm.sign != 0)) {
			d = 0x7fffffff + (vdm.sign != 0);
			exceptions |= FPSCR_IOC;
		} else if (rem)
			exceptions |= FPSCR_IXC;

		if (vdm.sign)
			d = -d;
	} else {
		d = 0;
		if (vdm.exponent | vdm.significand) {
			exceptions |= FPSCR_IXC;
			if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0)
				d = 1;
			else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign)
				d = -1;
		}
	}

	pr_debug("VFP: ftosi: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions);

	vfp_put_float((s32)d, sd);

	return exceptions;
}