Hello everybody,
second iteration of the div64.h cleanup + bug fixing.
Contains the following changes since the previous release:
- add likely() to the fast path (divisor>>32 == 0);
- add __attribute__((pure)) to __div64_32() prototype so
the compiler knows global memory isn't clobbered;
- export the __div64_32 symbol for modules;
The generic do_div() code is now tested on m68knommu, arm
and even i386 (by manually replacing real asm-i386/div64.h
with the generic version).
Applies to 2.5.74 and 2.5.74-bk2. I'll provide a 2.4
backport once it has been tested in 2.5.
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/
-----------------------------------------------------------------
- add generic C implementations of the do_div() for 32bit and 64bit
archs in asm-generic/div64.h;
- add generic library support function __div64_32() to handle the
full 64/32 case on 32bit archs;
- kill multiple copies of generic do_div() in architecture
specific subdirs. Most copies were either buggy or not doing
what they were supposed to do;
- ensure all surviving instances of do_div() have their parameters
correctly parenthesized to avoid funny side-effects;
include/asm-generic/div64.h | 53 ++++++++++++++++++++++++++++++++++++++++
lib/div64.c | 47 ++++++++++++++++++++++++++++++++++
include/asm-alpha/div64.h | 15 -----------
include/asm-arm26/div64.h | 15 -----------
include/asm-cris/div64.h | 17 ------------
include/asm-h8300/div64.h | 14 ----------
include/asm-ia64/div64.h | 21 ----------------
include/asm-m68k/div64.h | 9 ------
include/asm-m68knommu/div64.h | 14 ----------
include/asm-mips64/div64.h | 19 --------------
include/asm-parisc/div64.h | 55 ------------------------------------------
include/asm-ppc/div64.h | 24 ------------------
include/asm-ppc64/div64.h | 19 --------------
include/asm-s390/div64.h | 8 ------
include/asm-sh/div64.h | 21 ----------------
include/asm-sparc/div64.h | 12 ---------
include/asm-sparc64/div64.h | 15 -----------
include/asm-v850/div64.h | 12 ---------
include/asm-x86_64/div64.h | 15 -----------
lib/Makefile | 2 -
20 files changed, 115 insertions(+), 290 deletions(-)
diff -Nru linux-2.5.74-uc0/include/asm-generic/div64.h linux-2.5.74-uc0-develer/include/asm-generic/div64.h
--- linux-2.5.74-uc0/include/asm-generic/div64.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.74-uc0-develer/include/asm-generic/div64.h 2003-07-03 09:55:04.000000000 +0200
@@ -0,0 +1,53 @@
+#ifndef _ASM_GENERIC_DIV64_H
+#define _ASM_GENERIC_DIV64_H
+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
+ * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
+ *
+ * The semantics of do_div() are:
+ *
+ * uint32_t do_div(uint64_t *n, uint32_t base)
+ * {
+ * uint32_t remainder = *n % base;
+ * *n = *n / base;
+ * return remainder;
+ * }
+ *
+ * NOTE: macro parameter n is evaluated multiple times,
+ * beware of side effects!
+ */
+
+#include <linux/types.h>
+
+#if BITS_PER_LONG == 64
+
+# define do_div(n,base) ({ \
+ uint32_t __base = (base); \
+ uint32_t __rem; \
+ __rem = ((uint64_t)(n)) % __base; \
+ (n) = ((uint64_t)(n)) / __base; \
+ __rem; \
+ })
+
+#elif BITS_PER_LONG == 32
+
+extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor) __attribute__((pure));
+
+# define do_div(n,base) ({ \
+ uint32_t __base = (base); \
+ uint32_t __rem; \
+ if (likely(((n) >> 32) == 0)) { \
+ __rem = (uint32_t)(n) % __base; \
+ (n) = (uint32_t)(n) / __base; \
+ } else \
+ __rem = __div64_32(&(n), __base); \
+ __rem; \
+ })
+
+#else /* BITS_PER_LONG == ?? */
+
+# error do_div() does not yet support the C64
+
+#endif /* BITS_PER_LONG */
+
+#endif /* _ASM_GENERIC_DIV64_H */
diff -Nru linux-2.5.74-uc0/lib/div64.c linux-2.5.74-uc0-develer/lib/div64.c
--- linux-2.5.74-uc0/lib/div64.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.74-uc0-develer/lib/div64.c 2003-07-03 09:37:22.000000000 +0200
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
+ *
+ * Based on former do_div() implementation from asm-parisc/div64.h:
+ * Copyright (C) 1999 Hewlett-Packard Co
+ * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
+ *
+ *
+ * Generic C version of 64bit/32bit division and modulo, with
+ * 64bit result and 32bit remainder.
+ *
+ * The fast case for (n>>32 == 0) is handled inline by do_div().
+ *
+ * Code generated for this function might be very inefficient
+ * for some CPUs. __div64_32() can be overridden by linking arch-specific
+ * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <asm/div64.h>
+
+uint32_t __div64_32(uint64_t *n, uint32_t base)
+{
+ uint32_t low, low2, high, rem;
+
+ low = *n & 0xffffffff;
+ high = *n >> 32;
+ rem = high % (uint32_t)base;
+ high = high / (uint32_t)base;
+ low2 = low >> 16;
+ low2 += rem << 16;
+ rem = low2 % (uint32_t)base;
+ low2 = low2 / (uint32_t)base;
+ low = low & 0xffff;
+ low += rem << 16;
+ rem = low % (uint32_t)base;
+ low = low / (uint32_t)base;
+
+ *n = low +
+ ((uint64_t)low2 << 16) +
+ ((uint64_t)high << 32);
+
+ return rem;
+}
+
+EXPORT_SYMBOL(__div64_32);
diff -Nru linux-2.5.74-uc0/include/asm-alpha/div64.h linux-2.5.74-uc0-develer/include/asm-alpha/div64.h
--- linux-2.5.74-uc0/include/asm-alpha/div64.h 2003-07-02 22:54:43.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-alpha/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,14 +1 @@
-#ifndef __ALPHA_DIV64
-#define __ALPHA_DIV64
-
-/*
- * Hey, we're already 64-bit, no
- * need to play games..
- */
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) (n)) % (unsigned) (base); \
- (n) = ((unsigned long) (n)) / (unsigned) (base); \
- __res; })
-
-#endif
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-arm26/div64.h linux-2.5.74-uc0-develer/include/asm-arm26/div64.h
--- linux-2.5.74-uc0/include/asm-arm26/div64.h 2003-07-02 22:42:11.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-arm26/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,14 +1 @@
-#ifndef __ASM_ARM_DIV64
-#define __ASM_ARM_DIV64
-
-/* We're not 64-bit, but... */
-#define do_div(n,base) \
-({ \
- int __res; \
- __res = ((unsigned long)n) % (unsigned int)base; \
- n = ((unsigned long)n) / (unsigned int)base; \
- __res; \
-})
-
-#endif
-
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-cris/div64.h linux-2.5.74-uc0-develer/include/asm-cris/div64.h
--- linux-2.5.74-uc0/include/asm-cris/div64.h 2003-07-02 22:42:06.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-cris/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,16 +1 @@
-#ifndef __ASM_CRIS_DIV64
-#define __ASM_CRIS_DIV64
-
-/* copy from asm-arm */
-
-/* We're not 64-bit, but... */
-#define do_div(n,base) \
-({ \
- int __res; \
- __res = ((unsigned long)n) % (unsigned int)base; \
- n = ((unsigned long)n) / (unsigned int)base; \
- __res; \
-})
-
-#endif
-
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-h8300/div64.h linux-2.5.74-uc0-develer/include/asm-h8300/div64.h
--- linux-2.5.74-uc0/include/asm-h8300/div64.h 2003-07-02 22:39:25.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-h8300/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,13 +1 @@
-#ifndef H8300_DIV64_H
-#define H8300_DIV64_H
-
-/* n = n / base; return rem; */
-
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) n) % (unsigned) base; \
- n = ((unsigned long) n) / (unsigned) base; \
- __res; \
-})
-
-#endif /* _H8300_DIV64_H */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-ia64/div64.h linux-2.5.74-uc0-develer/include/asm-ia64/div64.h
--- linux-2.5.74-uc0/include/asm-ia64/div64.h 2003-07-02 22:58:14.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-ia64/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,20 +1 @@
-#ifndef _ASM_IA64_DIV64_H
-#define _ASM_IA64_DIV64_H
-
-/*
- * Copyright (C) 1999 Hewlett-Packard Co
- * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
- *
- * vsprintf uses this to divide a 64-bit integer N by a small integer BASE.
- * This is incredibly hard on IA-64...
- */
-
-#define do_div(n,base) \
-({ \
- int _res; \
- _res = ((unsigned long) (n)) % (unsigned) (base); \
- (n) = ((unsigned long) (n)) / (unsigned) (base); \
- _res; \
-})
-
-#endif /* _ASM_IA64_DIV64_H */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-m68k/div64.h linux-2.5.74-uc0-develer/include/asm-m68k/div64.h
--- linux-2.5.74-uc0/include/asm-m68k/div64.h 2003-07-02 22:55:53.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-m68k/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -3,7 +3,6 @@
/* n = n / base; return rem; */
-#if 1
#define do_div(n, base) ({ \
union { \
unsigned long n32[2]; \
@@ -23,13 +22,5 @@
(n) = __n.n64; \
__rem; \
})
-#else
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) n) % (unsigned) base; \
- n = ((unsigned long) n) / (unsigned) base; \
- __res; \
-})
-#endif
#endif /* _M68K_DIV64_H */
diff -Nru linux-2.5.74-uc0/include/asm-m68knommu/div64.h linux-2.5.74-uc0-develer/include/asm-m68knommu/div64.h
--- linux-2.5.74-uc0/include/asm-m68knommu/div64.h 2003-07-03 10:40:35.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-m68knommu/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,13 +1 @@
-#ifndef _M68KNOMMU_DIV64_H
-#define _M68KNOMMU_DIV64_H
-
-/* n = n / base; return rem; */
-
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) n) % (unsigned) base; \
- n = ((unsigned long) n) / (unsigned) base; \
- __res; \
-})
-
-#endif /* _M68K_DIV64_H */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-mips64/div64.h linux-2.5.74-uc0-develer/include/asm-mips64/div64.h
--- linux-2.5.74-uc0/include/asm-mips64/div64.h 2003-07-02 22:47:26.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-mips64/div64.h 2003-07-03 09:39:28.000000000 +0200
@@ -27,23 +27,6 @@
(res) = __quot; \
__mod; })
-/*
- * Hey, we're already 64-bit, no
- * need to play games..
- */
-#define do_div(n, base) ({ \
- unsigned long __quot; \
- unsigned int __mod; \
- unsigned long __div; \
- unsigned int __base; \
- \
- __div = (n); \
- __base = (base); \
- \
- __mod = __div % __base; \
- __quot = __div / __base; \
- \
- (n) = __quot; \
- __mod; })
+#include <asm-generic.h>
#endif /* _ASM_DIV64_H */
diff -Nru linux-2.5.74-uc0/include/asm-parisc/div64.h linux-2.5.74-uc0-develer/include/asm-parisc/div64.h
--- linux-2.5.74-uc0/include/asm-parisc/div64.h 2003-07-02 22:48:40.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-parisc/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,54 +1 @@
-#ifndef __ASM_PARISC_DIV64
-#define __ASM_PARISC_DIV64
-
-#ifdef __LP64__
-
-/*
- * Copyright (C) 1999 Hewlett-Packard Co
- * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
- *
- * vsprintf uses this to divide a 64-bit integer N by a small integer BASE.
- * This is incredibly hard on IA-64 and HPPA
- */
-
-#define do_div(n,base) \
-({ \
- int _res; \
- _res = ((unsigned long) (n)) % (unsigned) (base); \
- (n) = ((unsigned long) (n)) / (unsigned) (base); \
- _res; \
-})
-
-#else
-/*
- * unsigned long long division. Yuck Yuck! What is Linux coming to?
- * This is 100% disgusting
- */
-#define do_div(n,base) \
-({ \
- unsigned long __low, __low2, __high, __rem; \
- __low = (n) & 0xffffffff; \
- __high = (n) >> 32; \
- if (__high) { \
- __rem = __high % (unsigned long)base; \
- __high = __high / (unsigned long)base; \
- __low2 = __low >> 16; \
- __low2 += __rem << 16; \
- __rem = __low2 % (unsigned long)base; \
- __low2 = __low2 / (unsigned long)base; \
- __low = __low & 0xffff; \
- __low += __rem << 16; \
- __rem = __low % (unsigned long)base; \
- __low = __low / (unsigned long)base; \
- n = __low + ((long long)__low2 << 16) + \
- ((long long) __high << 32); \
- } else { \
- __rem = __low % (unsigned long)base; \
- n = (__low / (unsigned long)base); \
- } \
- __rem; \
-})
-#endif
-
-#endif
-
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-ppc/div64.h linux-2.5.74-uc0-develer/include/asm-ppc/div64.h
--- linux-2.5.74-uc0/include/asm-ppc/div64.h 2003-07-02 22:57:06.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-ppc/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,23 +1 @@
-#ifndef __PPC_DIV64
-#define __PPC_DIV64
-
-#include <linux/types.h>
-
-extern u32 __div64_32(u64 *dividend, u32 div);
-
-#define do_div(n, div) ({ \
- u64 __n = (n); \
- u32 __d = (div); \
- u32 __q, __r; \
- if ((__n >> 32) == 0) { \
- __q = (u32)__n / __d; \
- __r = (u32)__n - __q * __d; \
- (n) = __q; \
- } else { \
- __r = __div64_32(&__n, __d); \
- (n) = __n; \
- } \
- __r; \
-})
-
-#endif
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-ppc64/div64.h linux-2.5.74-uc0-develer/include/asm-ppc64/div64.h
--- linux-2.5.74-uc0/include/asm-ppc64/div64.h 2003-07-02 22:39:34.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-ppc64/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,18 +1 @@
-#ifndef __PPC_DIV64
-#define __PPC_DIV64
-
-/* Copyright 2001 PPC64 Team, IBM Corp
- *
- * 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.
- */
-
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) (n)) % (unsigned) (base); \
- (n) = ((unsigned long) (n)) / (unsigned) (base); \
- __res; })
-
-#endif
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-s390/div64.h linux-2.5.74-uc0-develer/include/asm-s390/div64.h
--- linux-2.5.74-uc0/include/asm-s390/div64.h 2003-07-02 22:50:17.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-s390/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -43,13 +43,7 @@
})
#else /* __s390x__ */
-
-#define do_div(n,base) ({ \
-int __res; \
-__res = ((unsigned long) n) % (unsigned) base; \
-n = ((unsigned long) n) / (unsigned) base; \
-__res; })
-
+#include <asm-generic/div64.h>
#endif /* __s390x__ */
#endif
diff -Nru linux-2.5.74-uc0/include/asm-sh/div64.h linux-2.5.74-uc0-develer/include/asm-sh/div64.h
--- linux-2.5.74-uc0/include/asm-sh/div64.h 2003-07-02 22:39:36.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-sh/div64.h 2003-07-03 09:38:59.000000000 +0200
@@ -1,20 +1 @@
-#ifndef __ASM_SH_DIV64
-#define __ASM_SH_DIV64
-
-extern u64 __div64_32(u64 n, u32 d);
-
-#define do_div(n,base) ({ \
-u64 __n = (n), __q; \
-u32 __base = (base); \
-u32 __res; \
-if ((__n >> 32) == 0) { \
- __res = ((unsigned long) __n) % (unsigned) __base; \
- (n) = ((unsigned long) __n) / (unsigned) __base; \
-} else { \
- __q = __div64_32(__n, __base); \
- __res = __n - __q * __base; \
- (n) = __q; \
-} \
-__res; })
-
-#endif /* __ASM_SH_DIV64 */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-sparc/div64.h linux-2.5.74-uc0-develer/include/asm-sparc/div64.h
--- linux-2.5.74-uc0/include/asm-sparc/div64.h 2003-07-02 22:51:01.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-sparc/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,11 +1 @@
-#ifndef __SPARC_DIV64
-#define __SPARC_DIV64
-
-/* We're not 64-bit, but... */
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) n) % (unsigned) base; \
- n = ((unsigned long) n) / (unsigned) base; \
- __res; })
-
-#endif /* __SPARC_DIV64 */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-sparc64/div64.h linux-2.5.74-uc0-develer/include/asm-sparc64/div64.h
--- linux-2.5.74-uc0/include/asm-sparc64/div64.h 2003-07-02 22:46:06.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-sparc64/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,14 +1 @@
-#ifndef __SPARC64_DIV64
-#define __SPARC64_DIV64
-
-/*
- * Hey, we're already 64-bit, no
- * need to play games..
- */
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) n) % (unsigned) base; \
- n = ((unsigned long) n) / (unsigned) base; \
- __res; })
-
-#endif /* __SPARC64_DIV64 */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-v850/div64.h linux-2.5.74-uc0-develer/include/asm-v850/div64.h
--- linux-2.5.74-uc0/include/asm-v850/div64.h 2003-07-02 22:53:46.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-v850/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,11 +1 @@
-#ifndef __V850_DIV64_H__
-#define __V850_DIV64_H__
-
-/* We're not 64-bit, but... */
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) n) % (unsigned) base; \
- n = ((unsigned long) n) / (unsigned) base; \
- __res; })
-
-#endif /* __V850_DIV64_H__ */
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/include/asm-x86_64/div64.h linux-2.5.74-uc0-develer/include/asm-x86_64/div64.h
--- linux-2.5.74-uc0/include/asm-x86_64/div64.h 2003-07-02 22:54:30.000000000 +0200
+++ linux-2.5.74-uc0-develer/include/asm-x86_64/div64.h 2003-07-03 09:37:22.000000000 +0200
@@ -1,14 +1 @@
-#ifndef __X86_64_DIV64
-#define __X86_64_DIV64
-
-/*
- * Hey, we're already 64-bit, no
- * need to play games..
- */
-#define do_div(n,base) ({ \
- int __res; \
- __res = ((unsigned long) (n)) % (unsigned) (base); \
- (n) = ((unsigned long) (n)) / (unsigned) (base); \
- __res; })
-
-#endif
+#include <asm-generic/div64.h>
diff -Nru linux-2.5.74-uc0/lib/Makefile linux-2.5.74-uc0-develer/lib/Makefile
--- linux-2.5.74-uc0/lib/Makefile 2003-07-02 22:40:29.000000000 +0200
+++ linux-2.5.74-uc0-develer/lib/Makefile 2003-07-03 09:37:22.000000000 +0200
@@ -5,7 +5,7 @@
lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
bust_spinlocks.o rbtree.o radix-tree.o dump_stack.o \
- kobject.o idr.o
+ kobject.o idr.o div64.o
lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
-
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This archive was generated by hypermail 2b29 : Mon Jul 07 2003 - 22:00:26 EST