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lib: Add shared copies of some GCC library routines
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Many ports (m32r, microblaze, mips, parisc, score, and sparc) use
functionally identical copies of various GCC library routine files,
which came up as we were submitting the RISC-V port (which also uses
some of these).

This patch adds a new copy of these library routine files, which are
functionally identical to the various other copies.  These are
availiable via Kconfig as CONFIG_GENERIC_$ROUTINE, which currently isn't
used anywhere.

Reviewed-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Palmer Dabbelt <[email protected]>
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palmer-dabbelt committed Sep 25, 2017
1 parent c98cfe4 commit b35cd98
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43 changes: 43 additions & 0 deletions include/lib/libgcc.h
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/*
* include/lib/libgcc.h
*
* 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.
*/

#ifndef __LIB_LIBGCC_H
#define __LIB_LIBGCC_H

#include <asm/byteorder.h>

typedef int word_type __attribute__ ((mode (__word__)));

#ifdef __BIG_ENDIAN
struct DWstruct {
int high, low;
};
#elif defined(__LITTLE_ENDIAN)
struct DWstruct {
int low, high;
};
#else
#error I feel sick.
#endif

typedef union {
struct DWstruct s;
long long ll;
} DWunion;

#endif /* __ASM_LIBGCC_H */
18 changes: 18 additions & 0 deletions lib/Kconfig
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Expand Up @@ -587,3 +587,21 @@ config STRING_SELFTEST
bool "Test string functions"

endmenu

config GENERIC_ASHLDI3
bool

config GENERIC_ASHRDI3
bool

config GENERIC_LSHRDI3
bool

config GENERIC_MULDI3
bool

config GENERIC_CMPDI2
bool

config GENERIC_UCMPDI2
bool
8 changes: 8 additions & 0 deletions lib/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -247,3 +247,11 @@ UBSAN_SANITIZE_ubsan.o := n
obj-$(CONFIG_SBITMAP) += sbitmap.o

obj-$(CONFIG_PARMAN) += parman.o

# GCC library routines
obj-$(CONFIG_GENERIC_ASHLDI3) += ashldi3.o
obj-$(CONFIG_GENERIC_ASHRDI3) += ashrdi3.o
obj-$(CONFIG_GENERIC_LSHRDI3) += lshrdi3.o
obj-$(CONFIG_GENERIC_MULDI3) += muldi3.o
obj-$(CONFIG_GENERIC_CMPDI2) += cmpdi2.o
obj-$(CONFIG_GENERIC_UCMPDI2) += ucmpdi2.o
44 changes: 44 additions & 0 deletions lib/ashldi3.c
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/*
* 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/export.h>

#include <lib/libgcc.h>

long long notrace __ashldi3(long long u, word_type b)
{
DWunion uu, w;
word_type bm;

if (b == 0)
return u;

uu.ll = u;
bm = 32 - b;

if (bm <= 0) {
w.s.low = 0;
w.s.high = (unsigned int) uu.s.low << -bm;
} else {
const unsigned int carries = (unsigned int) uu.s.low >> bm;

w.s.low = (unsigned int) uu.s.low << b;
w.s.high = ((unsigned int) uu.s.high << b) | carries;
}

return w.ll;
}
EXPORT_SYMBOL(__ashldi3);
46 changes: 46 additions & 0 deletions lib/ashrdi3.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,46 @@
/*
* 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/export.h>

#include <lib/libgcc.h>

long long notrace __ashrdi3(long long u, word_type b)
{
DWunion uu, w;
word_type bm;

if (b == 0)
return u;

uu.ll = u;
bm = 32 - b;

if (bm <= 0) {
/* w.s.high = 1..1 or 0..0 */
w.s.high =
uu.s.high >> 31;
w.s.low = uu.s.high >> -bm;
} else {
const unsigned int carries = (unsigned int) uu.s.high << bm;

w.s.high = uu.s.high >> b;
w.s.low = ((unsigned int) uu.s.low >> b) | carries;
}

return w.ll;
}
EXPORT_SYMBOL(__ashrdi3);
42 changes: 42 additions & 0 deletions lib/cmpdi2.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,42 @@
/*
* 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/export.h>

#include <lib/libgcc.h>

word_type notrace __cmpdi2(long long a, long long b)
{
const DWunion au = {
.ll = a
};
const DWunion bu = {
.ll = b
};

if (au.s.high < bu.s.high)
return 0;
else if (au.s.high > bu.s.high)
return 2;

if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
return 0;
else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
return 2;

return 1;
}
EXPORT_SYMBOL(__cmpdi2);
45 changes: 45 additions & 0 deletions lib/lshrdi3.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,45 @@
/*
* lib/lshrdi3.c
*
* 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 <lib/libgcc.h>

long long notrace __lshrdi3(long long u, word_type b)
{
DWunion uu, w;
word_type bm;

if (b == 0)
return u;

uu.ll = u;
bm = 32 - b;

if (bm <= 0) {
w.s.high = 0;
w.s.low = (unsigned int) uu.s.high >> -bm;
} else {
const unsigned int carries = (unsigned int) uu.s.high << bm;

w.s.high = (unsigned int) uu.s.high >> b;
w.s.low = ((unsigned int) uu.s.low >> b) | carries;
}

return w.ll;
}
EXPORT_SYMBOL(__lshrdi3);
72 changes: 72 additions & 0 deletions lib/muldi3.c
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@@ -0,0 +1,72 @@
/*
* 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/export.h>
#include <lib/libgcc.h>

#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); /* this can't give carry */\
__x1 += __x2; /* but this indeed can */ \
if (__x1 < __x2) /* did we get it? */ \
__x3 += __ll_B; /* yes, add it in the proper pos */ \
\
(w1) = __x3 + __ll_highpart(__x1); \
(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
} while (0)
#endif

#if !defined(__umulsidi3)
#define __umulsidi3(u, v) ({ \
DWunion __w; \
umul_ppmm(__w.s.high, __w.s.low, u, v); \
__w.ll; \
})
#endif

long long notrace __muldi3(long long u, long long v)
{
const DWunion uu = {.ll = u};
const DWunion vv = {.ll = v};
DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};

w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
+ (unsigned long) uu.s.high * (unsigned long) vv.s.low);

return w.ll;
}
EXPORT_SYMBOL(__muldi3);
35 changes: 35 additions & 0 deletions lib/ucmpdi2.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,35 @@
/*
* 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 <lib/libgcc.h>

word_type __ucmpdi2(unsigned long long a, unsigned long long b)
{
const DWunion au = {.ll = a};
const DWunion bu = {.ll = b};

if ((unsigned int) au.s.high < (unsigned int) bu.s.high)
return 0;
else if ((unsigned int) au.s.high > (unsigned int) bu.s.high)
return 2;
if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
return 0;
else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
return 2;
return 1;
}
EXPORT_SYMBOL(__ucmpdi2);

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