Unverified Commit 6315730e authored by Zong Li's avatar Zong Li Committed by Palmer Dabbelt
Browse files

lib: Add umoddi3 and udivmoddi4 of GCC library routines 



Add umoddi3 and udivmoddi4 support for 32-bit.

The RV32 need the umoddi3 to do modulo when the operands are long long
type, like other libraries implementation such as ucmpdi2, lshrdi3 and
so on.

I encounter the undefined reference 'umoddi3' when I use the in
house dma driver, although it is in house driver, but I think that
umoddi3 is a common function for RV32.

The udivmoddi4 and umoddi3 are copies from libgcc in gcc. There are other
functions use the udivmoddi4 in libgcc, so I separate the umoddi3 and
udivmoddi4 for flexible extension in the future.

Signed-off-by: default avatarZong Li <zong@andestech.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent 51858aaf

lib/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -621,3 +621,6 @@ config GENERIC_LIB_CMPDI2 


config GENERIC_LIB_UCMPDI2

	bool



config GENERIC_LIB_UMODDI3

	bool

lib/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -270,3 +270,4 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o 
obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o

obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o

obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o

obj-$(CONFIG_GENERIC_LIB_UMODDI3) += umoddi3.o udivmoddi4.o

lib/udivmoddi4.c

0 → 100644
+310 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



/*

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, see the file COPYING, or write

 * to the Free Software Foundation, Inc.

 */



#include <linux/libgcc.h>



#define count_leading_zeros(COUNT, X)   ((COUNT) = __builtin_clz(X))



#define W_TYPE_SIZE 32



#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))

#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))

#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))



/* If we still don't have umul_ppmm, define it using plain C. */

#if !defined(umul_ppmm)

#define umul_ppmm(w1, w0, u, v)						\

	do {								\

		unsigned long __x0, __x1, __x2, __x3;			\

		unsigned short __ul, __vl, __uh, __vh;			\

									\

		__ul = __ll_lowpart(u);					\

		__uh = __ll_highpart(u);				\

		__vl = __ll_lowpart(v);					\

		__vh = __ll_highpart(v);				\

									\

		__x0 = (unsigned long) __ul * __vl;			\

		__x1 = (unsigned long) __ul * __vh;			\

		__x2 = (unsigned long) __uh * __vl;			\

		__x3 = (unsigned long) __uh * __vh;			\

									\

		__x1 += __ll_highpart(__x0);				\

		__x1 += __x2;						\

		if (__x1 < __x2)					\

			__x3 += __ll_B;					\

									\

		(w1) = __x3 + __ll_highpart(__x1);			\

		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\

	} while (0)

#endif



#if !defined(sub_ddmmss)

#define sub_ddmmss(sh, sl, ah, al, bh, bl)				\

	do {								\

		unsigned long __x;					\

		__x = (al) - (bl);					\

		(sh) = (ah) - (bh) - (__x > (al));			\

		(sl) = __x;						\

	} while (0)

#endif



/* Define this unconditionally, so it can be used for debugging. */

#define __udiv_qrnnd_c(q, r, n1, n0, d)					\

	do {								\

		unsigned long __d1, __d0, __q1, __q0;			\

		unsigned long __r1, __r0, __m;				\

		__d1 = __ll_highpart(d);				\

		__d0 = __ll_lowpart(d);				\

									\

		__r1 = (n1) % __d1;					\

		__q1 = (n1) / __d1;					\

		__m = (unsigned long) __q1 * __d0;			\

		__r1 = __r1 * __ll_B | __ll_highpart(n0);		\

		if (__r1 < __m) {					\

			__q1--, __r1 += (d);				\

			if (__r1 >= (d))				\

				if (__r1 < __m)				\

					__q1--, __r1 += (d);		\

		}							\

		__r1 -= __m;						\

									\

		__r0 = __r1 % __d1;					\

		__q0 = __r1 / __d1;					\

		__m = (unsigned long) __q0 * __d0;			\

		__r0 = __r0 * __ll_B | __ll_lowpart(n0);		\

		if (__r0 < __m) {					\

			__q0--, __r0 += (d);				\

			if (__r0 >= (d))				\

				if (__r0 < __m)				\

					__q0--, __r0 += (d);		\

		}							\

		__r0 -= __m;						\

									\

		(q) = (unsigned long) __q1 * __ll_B | __q0;		\

		(r) = __r0;						\

	} while (0)



/* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */

#if !defined(udiv_qrnnd)

#define UDIV_NEEDS_NORMALIZATION 1

#define udiv_qrnnd __udiv_qrnnd_c

#endif



unsigned long long __udivmoddi4(unsigned long long u, unsigned long long v,

				unsigned long long *rp)

{

	const DWunion nn = {.ll = u };

	const DWunion dd = {.ll = v };

	DWunion rr, ww;

	unsigned long d0, d1, n0, n1, n2;

	unsigned long q0 = 0, q1 = 0;

	unsigned long b, bm;



	d0 = dd.s.low;

	d1 = dd.s.high;

	n0 = nn.s.low;

	n1 = nn.s.high;



#if !UDIV_NEEDS_NORMALIZATION



	if (d1 == 0) {

		if (d0 > n1) {

			/* 0q = nn / 0D */



			udiv_qrnnd(q0, n0, n1, n0, d0);

			q1 = 0;



			/* Remainder in n0. */

		} else {

			/* qq = NN / 0d */



			if (d0 == 0)

				/* Divide intentionally by zero. */

				d0 = 1 / d0;



			udiv_qrnnd(q1, n1, 0, n1, d0);

			udiv_qrnnd(q0, n0, n1, n0, d0);



			/* Remainder in n0. */

		}



		if (rp != 0) {

			rr.s.low = n0;

			rr.s.high = 0;

			*rp = rr.ll;

		}



#else /* UDIV_NEEDS_NORMALIZATION */



	if (d1 == 0) {

		if (d0 > n1) {

			/* 0q = nn / 0D */



			count_leading_zeros(bm, d0);



			if (bm != 0) {

				/*

				 * Normalize, i.e. make the most significant bit

				 * of the denominator set.

				 */



				d0 = d0 << bm;

				n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));

				n0 = n0 << bm;

			}



			udiv_qrnnd(q0, n0, n1, n0, d0);

			q1 = 0;



			/* Remainder in n0 >> bm. */

		} else {

			/* qq = NN / 0d */



			if (d0 == 0)

				/* Divide intentionally by zero. */

				d0 = 1 / d0;



			count_leading_zeros(bm, d0);



			if (bm == 0) {

				/*

				 * From (n1 >= d0) /\ (the most significant bit

				 * of d0 is set), conclude (the most significant

				 * bit of n1 is set) /\ (theleading quotient

				 * digit q1 = 1).

				 *

				 * This special case is necessary, not an

				 * optimization. (Shifts counts of W_TYPE_SIZE

				 * are undefined.)

				 */



				n1 -= d0;

				q1 = 1;

			} else {

				/* Normalize. */



				b = W_TYPE_SIZE - bm;



				d0 = d0 << bm;

				n2 = n1 >> b;

				n1 = (n1 << bm) | (n0 >> b);

				n0 = n0 << bm;



				udiv_qrnnd(q1, n1, n2, n1, d0);

			}



			/* n1 != d0... */



			udiv_qrnnd(q0, n0, n1, n0, d0);



			/* Remainder in n0 >> bm. */

		}



		if (rp != 0) {

			rr.s.low = n0 >> bm;

			rr.s.high = 0;

			*rp = rr.ll;

		}



#endif /* UDIV_NEEDS_NORMALIZATION */



	} else {

		if (d1 > n1) {

			/* 00 = nn / DD */



			q0 = 0;

			q1 = 0;



			/* Remainder in n1n0. */

			if (rp != 0) {

				rr.s.low = n0;

				rr.s.high = n1;

				*rp = rr.ll;

			}

		} else {

			/* 0q = NN / dd */



			count_leading_zeros(bm, d1);

			if (bm == 0) {

				/*

				 * From (n1 >= d1) /\ (the most significant bit

				 * of d1 is set), conclude (the most significant

				 * bit of n1 is set) /\ (the quotient digit q0 =

				 * 0 or 1).

				 *

				 * This special case is necessary, not an

				 * optimization.

				 */



				/*

				 * The condition on the next line takes

				 * advantage of that n1 >= d1 (true due to

				 * program flow).

				 */

				if (n1 > d1 || n0 >= d0) {

					q0 = 1;

					sub_ddmmss(n1, n0, n1, n0, d1, d0);

				} else {

					q0 = 0;

				}



				q1 = 0;



				if (rp != 0) {

					rr.s.low = n0;

					rr.s.high = n1;

					*rp = rr.ll;

				}

			} else {

				unsigned long m1, m0;

				/* Normalize. */



				b = W_TYPE_SIZE - bm;



				d1 = (d1 << bm) | (d0 >> b);

				d0 = d0 << bm;

				n2 = n1 >> b;

				n1 = (n1 << bm) | (n0 >> b);

				n0 = n0 << bm;



				udiv_qrnnd(q0, n1, n2, n1, d1);

				umul_ppmm(m1, m0, q0, d0);



				if (m1 > n1 || (m1 == n1 && m0 > n0)) {

					q0--;

					sub_ddmmss(m1, m0, m1, m0, d1, d0);

				}



				q1 = 0;



				/* Remainder in (n1n0 - m1m0) >> bm. */

				if (rp != 0) {

					sub_ddmmss(n1, n0, n1, n0, m1, m0);

					rr.s.low = (n1 << b) | (n0 >> bm);

					rr.s.high = n1 >> bm;

					*rp = rr.ll;

				}

			}

		}

	}



	ww.s.low = q0;

	ww.s.high = q1;



	return ww.ll;

}

lib/umoddi3.c

0 → 100644
+32 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



/*

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, see the file COPYING, or write

 * to the Free Software Foundation, Inc.

 */



#include <linux/module.h>

#include <linux/libgcc.h>



extern unsigned long long __udivmoddi4(unsigned long long u,

				       unsigned long long v,

				       unsigned long long *rp);



unsigned long long __umoddi3(unsigned long long u, unsigned long long v)

{

	unsigned long long w;

	(void)__udivmoddi4(u, v, &w);

	return w;

}

EXPORT_SYMBOL(__umoddi3);

CRA Git | Maintained and supported by SUSTech CRA and CCSE