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author | Zong Li <zongbox@gmail.com> | 2018-10-02 16:52:29 +0800 |
---|---|---|
committer | Palmer Dabbelt <palmer@sifive.com> | 2018-10-22 17:02:56 -0700 |
commit | 6315730e9eab7de5fa9864bb13a352713f48aef1 (patch) | |
tree | 8971b00693f003a5e5b71d57b40fd5d91de11879 | |
parent | 51858aaf9bea3ddf166bf9d252a1fc351260b497 (diff) | |
download | op-kernel-dev-6315730e9eab7de5fa9864bb13a352713f48aef1.zip op-kernel-dev-6315730e9eab7de5fa9864bb13a352713f48aef1.tar.gz |
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: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
-rw-r--r-- | lib/Kconfig | 3 | ||||
-rw-r--r-- | lib/Makefile | 1 | ||||
-rw-r--r-- | lib/udivmoddi4.c | 310 | ||||
-rw-r--r-- | lib/umoddi3.c | 32 |
4 files changed, 346 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index a3928d4..d82f206 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -621,3 +621,6 @@ config GENERIC_LIB_CMPDI2 config GENERIC_LIB_UCMPDI2 bool + +config GENERIC_LIB_UMODDI3 + bool diff --git a/lib/Makefile b/lib/Makefile index 4238764..56a8d9c 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -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 diff --git a/lib/udivmoddi4.c b/lib/udivmoddi4.c new file mode 100644 index 0000000..c08bc8a --- /dev/null +++ b/lib/udivmoddi4.c @@ -0,0 +1,310 @@ +// 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; +} diff --git a/lib/umoddi3.c b/lib/umoddi3.c new file mode 100644 index 0000000..d7bbf0f --- /dev/null +++ b/lib/umoddi3.c @@ -0,0 +1,32 @@ +// 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); |