[PATCH] ARM: 2723/2: remove __udivdi3 and __umoddi3 from the kernel

Patch from Nicolas Pitre

Those are big, slow and generally not recommended for kernel code.
They are even not present on i386.  So it should be concluded that
one could as well get away with do_div() alone.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 1 insertions, 412 deletions

diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 4c38bd8bc29..b713c44c6fb 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -30,9 +30,6 @@ extern void __lshrdi3(void);
 extern void __modsi3(void);
 extern void __muldi3(void);
 extern void __ucmpdi2(void);
-extern void __udivdi3(void);
-extern void __umoddi3(void);
-extern void __udivmoddi4(void);
 extern void __udivsi3(void);
 extern void __umodsi3(void);
 extern void __do_div64(void);
@@ -134,9 +131,6 @@ EXPORT_SYMBOL(__lshrdi3);
 EXPORT_SYMBOL(__modsi3);
 EXPORT_SYMBOL(__muldi3);
 EXPORT_SYMBOL(__ucmpdi2);
-EXPORT_SYMBOL(__udivdi3);
-EXPORT_SYMBOL(__umoddi3);
-EXPORT_SYMBOL(__udivmoddi4);
 EXPORT_SYMBOL(__udivsi3);
 EXPORT_SYMBOL(__umodsi3);
 EXPORT_SYMBOL(__do_div64);
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index c0e65833ffc..8725d63e421 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -11,7 +11,7 @@ lib-y		:= backtrace.o changebit.o csumipv6.o csumpartial.o   \
 		   strnlen_user.o strchr.o strrchr.o testchangebit.o  \
 		   testclearbit.o testsetbit.o uaccess.o getuser.o    \
 		   putuser.o ashldi3.o ashrdi3.o lshrdi3.o muldi3.o   \
-		   ucmpdi2.o udivdi3.o lib1funcs.o div64.o	      \
+		   ucmpdi2.o lib1funcs.o div64.o	              \
 		   io-readsb.o io-writesb.o io-readsl.o io-writesl.o
 
 ifeq ($(CONFIG_CPU_32v3),y)
diff --git a/arch/arm/lib/longlong.h b/arch/arm/lib/longlong.h
deleted file mode 100644
index 90ae647e4d7..00000000000
--- a/arch/arm/lib/longlong.h
+++ /dev/null
@@ -1,183 +0,0 @@
-/* longlong.h -- based on code from gcc-2.95.3
-
-   definitions for mixed size 32/64 bit arithmetic.
-   Copyright (C) 1991, 92, 94, 95, 96, 1997, 1998 Free Software Foundation, Inc.
-
-   This definition file 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, or (at your option) any later version.
-
-   This definition file 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, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
-
-/* Borrowed from GCC 2.95.3, I Molton 29/07/01 */
-
-#ifndef SI_TYPE_SIZE
-#define SI_TYPE_SIZE 32
-#endif
-
-#define __BITS4 (SI_TYPE_SIZE / 4)
-#define __ll_B (1L << (SI_TYPE_SIZE / 2))
-#define __ll_lowpart(t) ((u32) (t) % __ll_B)
-#define __ll_highpart(t) ((u32) (t) / __ll_B)
-
-/* Define auxiliary asm macros.
-
-   1) umul_ppmm(high_prod, low_prod, multipler, multiplicand)
-   multiplies two u32 integers MULTIPLER and MULTIPLICAND,
-   and generates a two-part u32 product in HIGH_PROD and
-   LOW_PROD.
-
-   2) __umulsidi3(a,b) multiplies two u32 integers A and B,
-   and returns a u64 product.  This is just a variant of umul_ppmm.
-
-   3) udiv_qrnnd(quotient, remainder, high_numerator, low_numerator,
-   denominator) divides a two-word unsigned integer, composed by the
-   integers HIGH_NUMERATOR and LOW_NUMERATOR, by DENOMINATOR and
-   places the quotient in QUOTIENT and the remainder in REMAINDER.
-   HIGH_NUMERATOR must be less than DENOMINATOR for correct operation.
-   If, in addition, the most significant bit of DENOMINATOR must be 1,
-   then the pre-processor symbol UDIV_NEEDS_NORMALIZATION is defined to 1.
-
-   4) sdiv_qrnnd(quotient, remainder, high_numerator, low_numerator,
-   denominator).  Like udiv_qrnnd but the numbers are signed.  The
-   quotient is rounded towards 0.
-
-   5) count_leading_zeros(count, x) counts the number of zero-bits from
-   the msb to the first non-zero bit.  This is the number of steps X
-   needs to be shifted left to set the msb.  Undefined for X == 0.
-
-   6) add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1,
-   high_addend_2, low_addend_2) adds two two-word unsigned integers,
-   composed by HIGH_ADDEND_1 and LOW_ADDEND_1, and HIGH_ADDEND_2 and
-   LOW_ADDEND_2 respectively.  The result is placed in HIGH_SUM and
-   LOW_SUM.  Overflow (i.e. carry out) is not stored anywhere, and is
-   lost.
-
-   7) sub_ddmmss(high_difference, low_difference, high_minuend,
-   low_minuend, high_subtrahend, low_subtrahend) subtracts two
-   two-word unsigned integers, composed by HIGH_MINUEND_1 and
-   LOW_MINUEND_1, and HIGH_SUBTRAHEND_2 and LOW_SUBTRAHEND_2
-   respectively.  The result is placed in HIGH_DIFFERENCE and
-   LOW_DIFFERENCE.  Overflow (i.e. carry out) is not stored anywhere,
-   and is lost.
-
-   If any of these macros are left undefined for a particular CPU,
-   C macros are used.  */
-
-#if defined (__arm__)
-#define add_ssaaaa(sh, sl, ah, al, bh, bl) \
-  __asm__ ("adds	%1, %4, %5					\n\
-	adc	%0, %2, %3"						\
-	   : "=r" ((u32) (sh)),					\
-	     "=&r" ((u32) (sl))					\
-	   : "%r" ((u32) (ah)),					\
-	     "rI" ((u32) (bh)),					\
-	     "%r" ((u32) (al)),					\
-	     "rI" ((u32) (bl)))
-#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
-  __asm__ ("subs	%1, %4, %5					\n\
-	sbc	%0, %2, %3"						\
-	   : "=r" ((u32) (sh)),					\
-	     "=&r" ((u32) (sl))					\
-	   : "r" ((u32) (ah)),					\
-	     "rI" ((u32) (bh)),					\
-	     "r" ((u32) (al)),					\
-	     "rI" ((u32) (bl)))
-#define umul_ppmm(xh, xl, a, b) \
-{register u32 __t0, __t1, __t2;					\
-  __asm__ ("%@ Inlined umul_ppmm					\n\
-	mov	%2, %5, lsr #16						\n\
-	mov	%0, %6, lsr #16						\n\
-	bic	%3, %5, %2, lsl #16					\n\
-	bic	%4, %6, %0, lsl #16					\n\
-	mul	%1, %3, %4						\n\
-	mul	%4, %2, %4						\n\
-	mul	%3, %0, %3						\n\
-	mul	%0, %2, %0						\n\
-	adds	%3, %4, %3						\n\
-	addcs	%0, %0, #65536						\n\
-	adds	%1, %1, %3, lsl #16					\n\
-	adc	%0, %0, %3, lsr #16"					\
-	   : "=&r" ((u32) (xh)),					\
-	     "=r" ((u32) (xl)),					\
-	     "=&r" (__t0), "=&r" (__t1), "=r" (__t2)			\
-	   : "r" ((u32) (a)),					\
-	     "r" ((u32) (b)));}
-#define UMUL_TIME 20
-#define UDIV_TIME 100
-#endif				/* __arm__ */
-
-#define __umulsidi3(u, v) \
-  ({DIunion __w;							\
-    umul_ppmm (__w.s.high, __w.s.low, u, v);				\
-    __w.ll; })
-
-#define __udiv_qrnnd_c(q, r, n1, n0, d) \
-  do {									\
-    u32 __d1, __d0, __q1, __q0;					\
-    u32 __r1, __r0, __m;						\
-    __d1 = __ll_highpart (d);						\
-    __d0 = __ll_lowpart (d);						\
-									\
-    __r1 = (n1) % __d1;							\
-    __q1 = (n1) / __d1;							\
-    __m = (u32) __q1 * __d0;					\
-    __r1 = __r1 * __ll_B | __ll_highpart (n0);				\
-    if (__r1 < __m)							\
-      {									\
-	__q1--, __r1 += (d);						\
-	if (__r1 >= (d)) /* i.e. we didn't get carry when adding to __r1 */\
-	  if (__r1 < __m)						\
-	    __q1--, __r1 += (d);					\
-      }									\
-    __r1 -= __m;							\
-									\
-    __r0 = __r1 % __d1;							\
-    __q0 = __r1 / __d1;							\
-    __m = (u32) __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) = (u32) __q1 * __ll_B | __q0;				\
-    (r) = __r0;								\
-  } while (0)
-
-#define UDIV_NEEDS_NORMALIZATION 1
-#define udiv_qrnnd __udiv_qrnnd_c
-
-#define count_leading_zeros(count, x) \
-  do {									\
-    u32 __xr = (x);							\
-    u32 __a;							\
-									\
-    if (SI_TYPE_SIZE <= 32)						\
-      {									\
-	__a = __xr < ((u32)1<<2*__BITS4)				\
-	  ? (__xr < ((u32)1<<__BITS4) ? 0 : __BITS4)		\
-	  : (__xr < ((u32)1<<3*__BITS4) ?  2*__BITS4 : 3*__BITS4);	\
-      }									\
-    else								\
-      {									\
-	for (__a = SI_TYPE_SIZE - 8; __a > 0; __a -= 8)			\
-	  if (((__xr >> __a) & 0xff) != 0)				\
-	    break;							\
-      }									\
-									\
-    (count) = SI_TYPE_SIZE - (__clz_tab[__xr >> __a] + __a);		\
-  } while (0)
diff --git a/arch/arm/lib/udivdi3.c b/arch/arm/lib/udivdi3.c
deleted file mode 100644
index e343be4c664..00000000000
--- a/arch/arm/lib/udivdi3.c
+++ /dev/null
@@ -1,222 +0,0 @@
-/* More subroutines needed by GCC output code on some machines.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
-
-This file is part of GNU CC.
-
-GNU CC 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, or (at your option)
-any later version.
-
-GNU CC 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 GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
-
-/* As a special exception, if you link this library with other files,
-   some of which are compiled with GCC, to produce an executable,
-   this library does not by itself cause the resulting executable
-   to be covered by the GNU General Public License.
-   This exception does not however invalidate any other reasons why
-   the executable file might be covered by the GNU General Public License.
- */
-/* support functions required by the kernel. based on code from gcc-2.95.3 */
-/* I Molton     29/07/01 */
-
-#include "gcclib.h"
-#include "longlong.h"
-
-static const u8 __clz_tab[] = {
-	0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
-	    5, 5, 5, 5, 5, 5, 5, 5,
-	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
-	    6, 6, 6, 6, 6, 6, 6, 6,
-	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-	    7, 7, 7, 7, 7, 7, 7, 7,
-	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-	    7, 7, 7, 7, 7, 7, 7, 7,
-	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
-	    8, 8, 8, 8, 8, 8, 8, 8,
-	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
-	    8, 8, 8, 8, 8, 8, 8, 8,
-	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
-	    8, 8, 8, 8, 8, 8, 8, 8,
-	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
-	    8, 8, 8, 8, 8, 8, 8, 8,
-};
-
-u64 __udivmoddi4(u64 n, u64 d, u64 * rp)
-{
-	DIunion ww;
-	DIunion nn, dd;
-	DIunion rr;
-	u32 d0, d1, n0, n1, n2;
-	u32 q0, q1;
-	u32 b, bm;
-
-	nn.ll = n;
-	dd.ll = d;
-
-	d0 = dd.s.low;
-	d1 = dd.s.high;
-	n0 = nn.s.low;
-	n1 = nn.s.high;
-
-	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 >> (SI_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)
-				d0 = 1 / d0;	/* Divide intentionally by zero.  */
-
-			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) /\ (the
-				   leading quotient digit q1 = 1).
-
-				   This special case is necessary, not an optimization.
-				   (Shifts counts of SI_TYPE_SIZE are undefined.)  */
-
-				n1 -= d0;
-				q1 = 1;
-			} else {
-				/* Normalize.  */
-
-				b = SI_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;
-		}
-	} 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 {
-				u32 m1, m0;
-				/* Normalize.  */
-
-				b = SI_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;
-}
-
-u64 __udivdi3(u64 n, u64 d)
-{
-	return __udivmoddi4(n, d, (u64 *) 0);
-}
-
-u64 __umoddi3(u64 u, u64 v)
-{
-	u64 w;
-
-	(void)__udivmoddi4(u, v, &w);
-
-	return w;
-}