static u32 vfp_single_ftosi()

in vfp/vfpsingle.c [627:699]

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

static u32 vfp_single_ftosi(int sd, int unused, s32 m, u32 fpscr)
{
	struct vfp_single vsm;
	u32 d, exceptions = 0;
	int rmode = fpscr & FPSCR_RMODE_MASK;
	int tm;

	vfp_single_unpack(&vsm, m);
	vfp_single_dump("VSM", &vsm);

	/*
	 * Do we have a denormalised number?
	 */
	tm = vfp_single_type(&vsm);
	if (vfp_single_type(&vsm) & VFP_DENORMAL)
		exceptions |= FPSCR_IDC;

	if (tm & VFP_NAN) {
		d = 0;
		exceptions |= FPSCR_IOC;
	} else if (vsm.exponent >= 127 + 32) {
		/*
		 * m >= 2^31-2^7: invalid
		 */
		d = 0x7fffffff;
		if (vsm.sign)
			d = ~d;
		exceptions |= FPSCR_IOC;
	} else if (vsm.exponent >= 127 - 1) {
		int shift = 127 + 31 - vsm.exponent;
		u32 rem, incr = 0;

		/* 2^0 <= m <= 2^31-2^7 */
		d = (vsm.significand << 1) >> shift;
		rem = vsm.significand << (33 - shift);

		if (rmode == FPSCR_ROUND_NEAREST) {
			incr = 0x80000000;
			if ((d & 1) == 0)
				incr -= 1;
		} else if (rmode == FPSCR_ROUND_TOZERO) {
			incr = 0;
		} else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vsm.sign != 0)) {
			incr = ~0;
		}

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

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