diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig | 5 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/bitmap.c | 30 | ||||
| -rw-r--r-- | lib/cpumask.c | 9 | ||||
| -rw-r--r-- | lib/dma-debug.c | 2 | ||||
| -rw-r--r-- | lib/find_bit.c | 193 | ||||
| -rw-r--r-- | lib/find_last_bit.c | 36 | ||||
| -rw-r--r-- | lib/find_next_bit.c | 285 | ||||
| -rw-r--r-- | lib/vsprintf.c | 244 |
9 files changed, 342 insertions, 464 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 87da53bb1fef..f5440221d929 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -18,9 +18,8 @@ config HAVE_ARCH_BITREVERSE default n depends on BITREVERSE help - This option provides an config for the architecture which have instruction - can do bitreverse operation, we use the hardware instruction if the architecture - have this capability. + This option enables the use of hardware bit-reversal instructions on + architectures which support such operations. config RATIONAL bool diff --git a/lib/Makefile b/lib/Makefile index 58f74d2dd396..da6116b21555 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -25,7 +25,7 @@ obj-y += lockref.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ gcd.o lcm.o list_sort.o uuid.o flex_array.o iov_iter.o clz_ctz.o \ - bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \ + bsearch.o find_bit.o llist.o memweight.o kfifo.o \ percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o diff --git a/lib/bitmap.c b/lib/bitmap.c index d456f4c15a9f..64c0926f5dd8 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -42,36 +42,6 @@ * for the best explanations of this ordering. */ -int __bitmap_empty(const unsigned long *bitmap, unsigned int bits) -{ - unsigned int k, lim = bits/BITS_PER_LONG; - for (k = 0; k < lim; ++k) - if (bitmap[k]) - return 0; - - if (bits % BITS_PER_LONG) - if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) - return 0; - - return 1; -} -EXPORT_SYMBOL(__bitmap_empty); - -int __bitmap_full(const unsigned long *bitmap, unsigned int bits) -{ - unsigned int k, lim = bits/BITS_PER_LONG; - for (k = 0; k < lim; ++k) - if (~bitmap[k]) - return 0; - - if (bits % BITS_PER_LONG) - if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) - return 0; - - return 1; -} -EXPORT_SYMBOL(__bitmap_full); - int __bitmap_equal(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { diff --git a/lib/cpumask.c b/lib/cpumask.c index b6513a9f2892..5ab1553fd076 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -37,10 +37,11 @@ EXPORT_SYMBOL(__next_cpu_nr); int cpumask_next_and(int n, const struct cpumask *src1p, const struct cpumask *src2p) { - while ((n = cpumask_next(n, src1p)) < nr_cpu_ids) - if (cpumask_test_cpu(n, src2p)) - break; - return n; + struct cpumask tmp; + + if (cpumask_and(&tmp, src1p, src2p)) + return cpumask_next(n, &tmp); + return nr_cpu_ids; } EXPORT_SYMBOL(cpumask_next_and); diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 9722bd2dbc9b..ae4b65e17e64 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -361,7 +361,7 @@ static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, unsigned int range = 0; while (range <= max_range) { - entry = __hash_bucket_find(*bucket, &index, containing_match); + entry = __hash_bucket_find(*bucket, ref, containing_match); if (entry) return entry; diff --git a/lib/find_bit.c b/lib/find_bit.c new file mode 100644 index 000000000000..18072ea9c20e --- /dev/null +++ b/lib/find_bit.c @@ -0,0 +1,193 @@ +/* bit search implementation + * + * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * Copyright (C) 2008 IBM Corporation + * 'find_last_bit' is written by Rusty Russell <rusty@rustcorp.com.au> + * (Inspired by David Howell's find_next_bit implementation) + * + * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease + * size and improve performance, 2015. + * + * 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. + */ + +#include <linux/bitops.h> +#include <linux/bitmap.h> +#include <linux/export.h> +#include <linux/kernel.h> + +#if !defined(find_next_bit) || !defined(find_next_zero_bit) + +/* + * This is a common helper function for find_next_bit and + * find_next_zero_bit. The difference is the "invert" argument, which + * is XORed with each fetched word before searching it for one bits. + */ +static unsigned long _find_next_bit(const unsigned long *addr, + unsigned long nbits, unsigned long start, unsigned long invert) +{ + unsigned long tmp; + + if (!nbits || start >= nbits) + return nbits; + + tmp = addr[start / BITS_PER_LONG] ^ invert; + + /* Handle 1st word. */ + tmp &= BITMAP_FIRST_WORD_MASK(start); + start = round_down(start, BITS_PER_LONG); + + while (!tmp) { + start += BITS_PER_LONG; + if (start >= nbits) + return nbits; + + tmp = addr[start / BITS_PER_LONG] ^ invert; + } + + return min(start + __ffs(tmp), nbits); +} +#endif + +#ifndef find_next_bit +/* + * Find the next set bit in a memory region. + */ +unsigned long find_next_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + return _find_next_bit(addr, size, offset, 0UL); +} +EXPORT_SYMBOL(find_next_bit); +#endif + +#ifndef find_next_zero_bit +unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, + unsigned long offset) +{ + return _find_next_bit(addr, size, offset, ~0UL); +} +EXPORT_SYMBOL(find_next_zero_bit); +#endif + +#ifndef find_first_bit +/* + * Find the first set bit in a memory region. + */ +unsigned long find_first_bit(const unsigned long *addr, unsigned long size) +{ + unsigned long idx; + + for (idx = 0; idx * BITS_PER_LONG < size; idx++) { + if (addr[idx]) + return min(idx * BITS_PER_LONG + __ffs(addr[idx]), size); + } + + return size; +} +EXPORT_SYMBOL(find_first_bit); +#endif + +#ifndef find_first_zero_bit +/* + * Find the first cleared bit in a memory region. + */ +unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) +{ + unsigned long idx; + + for (idx = 0; idx * BITS_PER_LONG < size; idx++) { + if (addr[idx] != ~0UL) + return min(idx * BITS_PER_LONG + ffz(addr[idx]), size); + } + + return size; +} +EXPORT_SYMBOL(find_first_zero_bit); +#endif + +#ifndef find_last_bit +unsigned long find_last_bit(const unsigned long *addr, unsigned long size) +{ + if (size) { + unsigned long val = BITMAP_LAST_WORD_MASK(size); + unsigned long idx = (size-1) / BITS_PER_LONG; + + do { + val &= addr[idx]; + if (val) + return idx * BITS_PER_LONG + __fls(val); + + val = ~0ul; + } while (idx--); + } + return size; +} +EXPORT_SYMBOL(find_last_bit); +#endif + +#ifdef __BIG_ENDIAN + +/* include/linux/byteorder does not support "unsigned long" type */ +static inline unsigned long ext2_swab(const unsigned long y) +{ +#if BITS_PER_LONG == 64 + return (unsigned long) __swab64((u64) y); +#elif BITS_PER_LONG == 32 + return (unsigned long) __swab32((u32) y); +#else +#error BITS_PER_LONG not defined +#endif +} + +#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le) +static unsigned long _find_next_bit_le(const unsigned long *addr, + unsigned long nbits, unsigned long start, unsigned long invert) +{ + unsigned long tmp; + + if (!nbits || start >= nbits) + return nbits; + + tmp = addr[start / BITS_PER_LONG] ^ invert; + + /* Handle 1st word. */ + tmp &= ext2_swab(BITMAP_FIRST_WORD_MASK(start)); + start = round_down(start, BITS_PER_LONG); + + while (!tmp) { + start += BITS_PER_LONG; + if (start >= nbits) + return nbits; + + tmp = addr[start / BITS_PER_LONG] ^ invert; + } + + return min(start + __ffs(ext2_swab(tmp)), nbits); +} +#endif + +#ifndef find_next_zero_bit_le +unsigned long find_next_zero_bit_le(const void *addr, unsigned + long size, unsigned long offset) +{ + return _find_next_bit_le(addr, size, offset, ~0UL); +} +EXPORT_SYMBOL(find_next_zero_bit_le); +#endif + +#ifndef find_next_bit_le +unsigned long find_next_bit_le(const void *addr, unsigned + long size, unsigned long offset) +{ + return _find_next_bit_le(addr, size, offset, 0UL); +} +EXPORT_SYMBOL(find_next_bit_le); +#endif + +#endif /* __BIG_ENDIAN */ diff --git a/lib/find_last_bit.c b/lib/find_last_bit.c index 91ca09fbf6f9..3e3be40c6a6e 100644 --- a/lib/find_last_bit.c +++ b/lib/find_last_bit.c @@ -4,6 +4,9 @@ * Written by Rusty Russell <rusty@rustcorp.com.au> * (Inspired by David Howell's find_next_bit implementation) * + * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease + * size and improve performance, 2015. + * * 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 @@ -11,37 +14,26 @@ */ #include <linux/bitops.h> +#include <linux/bitmap.h> #include <linux/export.h> -#include <asm/types.h> -#include <asm/byteorder.h> +#include <linux/kernel.h> #ifndef find_last_bit unsigned long find_last_bit(const unsigned long *addr, unsigned long size) { - unsigned long words; - unsigned long tmp; - - /* Start at final word. */ - words = size / BITS_PER_LONG; + if (size) { + unsigned long val = BITMAP_LAST_WORD_MASK(size); + unsigned long idx = (size-1) / BITS_PER_LONG; - /* Partial final word? */ - if (size & (BITS_PER_LONG-1)) { - tmp = (addr[words] & (~0UL >> (BITS_PER_LONG - - (size & (BITS_PER_LONG-1))))); - if (tmp) - goto found; - } + do { + val &= addr[idx]; + if (val) + return idx * BITS_PER_LONG + __fls(val); - while (words) { - tmp = addr[--words]; - if (tmp) { -found: - return words * BITS_PER_LONG + __fls(tmp); - } + val = ~0ul; + } while (idx--); } - - /* Not found */ return size; } EXPORT_SYMBOL(find_last_bit); diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c deleted file mode 100644 index 0cbfc0b4398f..000000000000 --- a/lib/find_next_bit.c +++ /dev/null @@ -1,285 +0,0 @@ -/* find_next_bit.c: fallback find next bit implementation - * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * 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. - */ - -#include <linux/bitops.h> -#include <linux/export.h> -#include <asm/types.h> -#include <asm/byteorder.h> - -#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) - -#ifndef find_next_bit -/* - * Find the next set bit in a memory region. - */ -unsigned long find_next_bit(const unsigned long *addr, unsigned long size, - unsigned long offset) -{ - const unsigned long *p = addr + BITOP_WORD(offset); - unsigned long result = offset & ~(BITS_PER_LONG-1); - unsigned long tmp; - - if (offset >= size) - return size; - size -= result; - offset %= BITS_PER_LONG; - if (offset) { - tmp = *(p++); - tmp &= (~0UL << offset); - if (size < BITS_PER_LONG) - goto found_first; - if (tmp) - goto found_middle; - size -= BITS_PER_LONG; - result += BITS_PER_LONG; - } - while (size & ~(BITS_PER_LONG-1)) { - if ((tmp = *(p++))) - goto found_middle; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - tmp = *p; - -found_first: - tmp &= (~0UL >> (BITS_PER_LONG - size)); - if (tmp == 0UL) /* Are any bits set? */ - return result + size; /* Nope. */ -found_middle: - return result + __ffs(tmp); -} -EXPORT_SYMBOL(find_next_bit); -#endif - -#ifndef find_next_zero_bit -/* - * This implementation of find_{first,next}_zero_bit was stolen from - * Linus' asm-alpha/bitops.h. - */ -unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, - unsigned long offset) -{ - const unsigned long *p = addr + BITOP_WORD(offset); - unsigned long result = offset & ~(BITS_PER_LONG-1); - unsigned long tmp; - - if (offset >= size) - return size; - size -= result; - offset %= BITS_PER_LONG; - if (offset) { - tmp = *(p++); - tmp |= ~0UL >> (BITS_PER_LONG - offset); - if (size < BITS_PER_LONG) - goto found_first; - if (~tmp) - goto found_middle; - size -= BITS_PER_LONG; - result += BITS_PER_LONG; - } - while (size & ~(BITS_PER_LONG-1)) { - if (~(tmp = *(p++))) - goto found_middle; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - tmp = *p; - -found_first: - tmp |= ~0UL << size; - if (tmp == ~0UL) /* Are any bits zero? */ - return result + size; /* Nope. */ -found_middle: - return result + ffz(tmp); -} -EXPORT_SYMBOL(find_next_zero_bit); -#endif - -#ifndef find_first_bit -/* - * Find the first set bit in a memory region. - */ -unsigned long find_first_bit(const unsigned long *addr, unsigned long size) -{ - const unsigned long *p = addr; - unsigned long result = 0; - unsigned long tmp; - - while (size & ~(BITS_PER_LONG-1)) { - if ((tmp = *(p++))) - goto found; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - - tmp = (*p) & (~0UL >> (BITS_PER_LONG - size)); - if (tmp == 0UL) /* Are any bits set? */ - return result + size; /* Nope. */ -found: - return result + __ffs(tmp); -} -EXPORT_SYMBOL(find_first_bit); -#endif - -#ifndef find_first_zero_bit -/* - * Find the first cleared bit in a memory region. - */ -unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) -{ - const unsigned long *p = addr; - unsigned long result = 0; - unsigned long tmp; - - while (size & ~(BITS_PER_LONG-1)) { - if (~(tmp = *(p++))) - goto found; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - - tmp = (*p) | (~0UL << size); - if (tmp == ~0UL) /* Are any bits zero? */ - return result + size; /* Nope. */ -found: - return result + ffz(tmp); -} -EXPORT_SYMBOL(find_first_zero_bit); -#endif - -#ifdef __BIG_ENDIAN - -/* include/linux/byteorder does not support "unsigned long" type */ -static inline unsigned long ext2_swabp(const unsigned long * x) -{ -#if BITS_PER_LONG == 64 - return (unsigned long) __swab64p((u64 *) x); -#elif BITS_PER_LONG == 32 - return (unsigned long) __swab32p((u32 *) x); -#else -#error BITS_PER_LONG not defined -#endif -} - -/* include/linux/byteorder doesn't support "unsigned long" type */ -static inline unsigned long ext2_swab(const unsigned long y) -{ -#if BITS_PER_LONG == 64 - return (unsigned long) __swab64((u64) y); -#elif BITS_PER_LONG == 32 - return (unsigned long) __swab32((u32) y); -#else -#error BITS_PER_LONG not defined -#endif -} - -#ifndef find_next_zero_bit_le -unsigned long find_next_zero_bit_le(const void *addr, unsigned - long size, unsigned long offset) -{ - const unsigned long *p = addr; - unsigned long result = offset & ~(BITS_PER_LONG - 1); - unsigned long tmp; - - if (offset >= size) - return size; - p += BITOP_WORD(offset); - size -= result; - offset &= (BITS_PER_LONG - 1UL); - if (offset) { - tmp = ext2_swabp(p++); - tmp |= (~0UL >> (BITS_PER_LONG - offset)); - if (size < BITS_PER_LONG) - goto found_first; - if (~tmp) - goto found_middle; - size -= BITS_PER_LONG; - result += BITS_PER_LONG; - } - - while (size & ~(BITS_PER_LONG - 1)) { - if (~(tmp = *(p++))) - goto found_middle_swap; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - tmp = ext2_swabp(p); -found_first: - tmp |= ~0UL << size; - if (tmp == ~0UL) /* Are any bits zero? */ - return result + size; /* Nope. Skip ffz */ -found_middle: - return result + ffz(tmp); - -found_middle_swap: - return result + ffz(ext2_swab(tmp)); -} -EXPORT_SYMBOL(find_next_zero_bit_le); -#endif - -#ifndef find_next_bit_le -unsigned long find_next_bit_le(const void *addr, unsigned - long size, unsigned long offset) -{ - const unsigned long *p = addr; - unsigned long result = offset & ~(BITS_PER_LONG - 1); - unsigned long tmp; - - if (offset >= size) - return size; - p += BITOP_WORD(offset); - size -= result; - offset &= (BITS_PER_LONG - 1UL); - if (offset) { - tmp = ext2_swabp(p++); - tmp &= (~0UL << offset); - if (size < BITS_PER_LONG) - goto found_first; - if (tmp) - goto found_middle; - size -= BITS_PER_LONG; - result += BITS_PER_LONG; - } - - while (size & ~(BITS_PER_LONG - 1)) { - tmp = *(p++); - if (tmp) - goto found_middle_swap; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - tmp = ext2_swabp(p); -found_first: - tmp &= (~0UL >> (BITS_PER_LONG - size)); - if (tmp == 0UL) /* Are any bits set? */ - return result + size; /* Nope. */ -found_middle: - return result + __ffs(tmp); - -found_middle_swap: - return result + __ffs(ext2_swab(tmp)); -} -EXPORT_SYMBOL(find_next_bit_le); -#endif - -#endif /* __BIG_ENDIAN */ diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 3a1e0843f9a2..da39c608a28c 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -33,6 +33,7 @@ #include <asm/page.h> /* for PAGE_SIZE */ #include <asm/sections.h> /* for dereference_function_descriptor() */ +#include <asm/byteorder.h> /* cpu_to_le16 */ #include <linux/string_helpers.h> #include "kstrtox.h" @@ -122,142 +123,145 @@ int skip_atoi(const char **s) return i; } -/* Decimal conversion is by far the most typical, and is used - * for /proc and /sys data. This directly impacts e.g. top performance - * with many processes running. We optimize it for speed - * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html> - * (with permission from the author, Douglas W. Jones). +/* + * Decimal conversion is by far the most typical, and is used for + * /proc and /sys data. This directly impacts e.g. top performance + * with many processes running. We optimize it for speed by emitting + * two characters at a time, using a 200 byte lookup table. This + * roughly halves the number of multiplications compared to computing + * the digits one at a time. Implementation strongly inspired by the + * previous version, which in turn used ideas described at + * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission + * from the author, Douglas W. Jones). + * + * It turns out there is precisely one 26 bit fixed-point + * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 + * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual + * range happens to be somewhat larger (x <= 1073741898), but that's + * irrelevant for our purpose. + * + * For dividing a number in the range [10^4, 10^6-1] by 100, we still + * need a 32x32->64 bit multiply, so we simply use the same constant. + * + * For dividing a number in the range [100, 10^4-1] by 100, there are + * several options. The simplest is (x * 0x147b) >> 19, which is valid + * for all x <= 43698. */ -#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 -/* Formats correctly any integer in [0, 999999999] */ +static const u16 decpair[100] = { +#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) + _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), + _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), + _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), + _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), + _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), + _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), + _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), + _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), + _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), + _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), +#undef _ +}; + +/* + * This will print a single '0' even if r == 0, since we would + * immediately jump to out_r where two 0s would be written but only + * one of them accounted for in buf. This is needed by ip4_string + * below. All other callers pass a non-zero value of r. +*/ static noinline_for_stack -char *put_dec_full9(char *buf, unsigned q) +char *put_dec_trunc8(char *buf, unsigned r) { - unsigned r; + unsigned q; - /* - * Possible ways to approx. divide by 10 - * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit) - * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul) - * (x * 0x6667) >> 18 x < 43699 - * (x * 0x3334) >> 17 x < 16389 - * (x * 0x199a) >> 16 x < 16389 - * (x * 0x0ccd) >> 15 x < 16389 - * (x * 0x0667) >> 14 x < 2739 - * (x * 0x0334) >> 13 x < 1029 - * (x * 0x019a) >> 12 x < 1029 - * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386) - * (x * 0x0067) >> 10 x < 179 - * (x * 0x0034) >> 9 x < 69 same - * (x * 0x001a) >> 8 x < 69 same - * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386) - * (x * 0x0007) >> 6 x < 19 - * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html> - */ - r = (q * (uint64_t)0x1999999a) >> 32; - *buf++ = (q - 10 * r) + '0'; /* 1 */ - q = (r * (uint64_t)0x1999999a) >> 32; - *buf++ = (r - 10 * q) + '0'; /* 2 */ - r = (q * (uint64_t)0x1999999a) >> 32; - *buf++ = (q - 10 * r) + '0'; /* 3 */ - q = (r * (uint64_t)0x1999999a) >> 32; - *buf++ = (r - 10 * q) + '0'; /* 4 */ - r = (q * (uint64_t)0x1999999a) >> 32; - *buf++ = (q - 10 * r) + '0'; /* 5 */ - /* Now value is under 10000, can avoid 64-bit multiply */ - q = (r * 0x199a) >> 16; - *buf++ = (r - 10 * q) + '0'; /* 6 */ - r = (q * 0xcd) >> 11; - *buf++ = (q - 10 * r) + '0'; /* 7 */ - q = (r * 0xcd) >> 11; - *buf++ = (r - 10 * q) + '0'; /* 8 */ - *buf++ = q + '0'; /* 9 */ + /* 1 <= r < 10^8 */ + if (r < 100) + goto out_r; + + /* 100 <= r < 10^8 */ + q = (r * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; + + /* 1 <= q < 10^6 */ + if (q < 100) + goto out_q; + + /* 100 <= q < 10^6 */ + r = (q * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[q - 100*r]; + buf += 2; + + /* 1 <= r < 10^4 */ + if (r < 100) + goto out_r; + + /* 100 <= r < 10^4 */ + q = (r * 0x147b) >> 19; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; +out_q: + /* 1 <= q < 100 */ + r = q; +out_r: + /* 1 <= r < 100 */ + *((u16 *)buf) = decpair[r]; + buf += r < 10 ? 1 : 2; return buf; } -#endif -/* Similar to above but do not pad with zeros. - * Code can be easily arranged to print 9 digits too, but our callers - * always call put_dec_full9() instead when the number has 9 decimal digits. - */ +#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 static noinline_for_stack -char *put_dec_trunc8(char *buf, unsigned r) +char *put_dec_full8(char *buf, unsigned r) { unsigned q; - /* Copy of previous function's body with added early returns */ - while (r >= 10000) { - q = r + '0'; - r = (r * (uint64_t)0x1999999a) >> 32; - *buf++ = q - 10*r; - } + /* 0 <= r < 10^8 */ + q = (r * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; - q = (r * 0x199a) >> 16; /* r <= 9999 */ - *buf++ = (r - 10 * q) + '0'; - if (q == 0) - return buf; - r = (q * 0xcd) >> 11; /* q <= 999 */ - *buf++ = (q - 10 * r) + '0'; - if (r == 0) - return buf; - q = (r * 0xcd) >> 11; /* r <= 99 */ - *buf++ = (r - 10 * q) + '0'; - if (q == 0) - return buf; - *buf++ = q + '0'; /* q <= 9 */ - return buf; -} + /* 0 <= q < 10^6 */ + r = (q * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[q - 100*r]; + buf += 2; -/* There are two algorithms to print larger numbers. - * One is generic: divide by 1000000000 and repeatedly print - * groups of (up to) 9 digits. It's conceptually simple, - * but requires a (unsigned long long) / 1000000000 division. - * - * Second algorithm splits 64-bit unsigned long long into 16-bit chunks, - * manipulates them cleverly and generates groups of 4 decimal digits. - * It so happens that it does NOT require long long division. - * - * If long is > 32 bits, division of 64-bit values is relatively easy, - * and we will use the first algorithm. - * If long long is > 64 bits (strange architecture with VERY large long long), - * second algorithm can't be used, and we again use the first one. - * - * Else (if long is 32 bits and long long is 64 bits) we use second one. - */ + /* 0 <= r < 10^4 */ + q = (r * 0x147b) >> 19; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; -#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 - -/* First algorithm: generic */ + /* 0 <= q < 100 */ + *((u16 *)buf) = decpair[q]; + buf += 2; + return buf; +} -static +static noinline_for_stack char *put_dec(char *buf, unsigned long long n) { - if (n >= 100*1000*1000) { - while (n >= 1000*1000*1000) - buf = put_dec_full9(buf, do_div(n, 1000*1000*1000)); - if (n >= 100*1000*1000) - return put_dec_full9(buf, n); - } + if (n >= 100*1000*1000) + buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); + /* 1 <= n <= 1.6e11 */ + if (n >= 100*1000*1000) + buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); + /* 1 <= n < 1e8 */ return put_dec_trunc8(buf, n); } -#else +#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 -/* Second algorithm: valid only for 64-bit long longs */ - -/* See comment in put_dec_full9 for choice of constants */ -static noinline_for_stack -void put_dec_full4(char *buf, unsigned q) +static void +put_dec_full4(char *buf, unsigned r) { - unsigned r; - r = (q * 0xccd) >> 15; - buf[0] = (q - 10 * r) + '0'; - q = (r * 0xcd) >> 11; - buf[1] = (r - 10 * q) + '0'; - r = (q * 0xcd) >> 11; - buf[2] = (q - 10 * r) + '0'; - buf[3] = r + '0'; + unsigned q; + + /* 0 <= r < 10^4 */ + q = (r * 0x147b) >> 19; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; + /* 0 <= q < 100 */ + *((u16 *)buf) = decpair[q]; } /* @@ -265,9 +269,9 @@ void put_dec_full4(char *buf, unsigned q) * The approximation x/10000 == (x * 0x346DC5D7) >> 43 * holds for all x < 1,128,869,999. The largest value this * helper will ever be asked to convert is 1,125,520,955. - * (d1 in the put_dec code, assuming n is all-ones). + * (second call in the put_dec code, assuming n is all-ones). */ -static +static noinline_for_stack unsigned put_dec_helper4(char *buf, unsigned x) { uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; @@ -294,6 +298,8 @@ char *put_dec(char *buf, unsigned long long n) d2 = (h ) & 0xffff; d3 = (h >> 16); /* implicit "& 0xffff" */ + /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 + = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); q = put_dec_helper4(buf, q); @@ -323,7 +329,8 @@ char *put_dec(char *buf, unsigned long long n) */ int num_to_str(char *buf, int size, unsigned long long num) { - char tmp[sizeof(num) * 3]; + /* put_dec requires 2-byte alignment of the buffer. */ + char tmp[sizeof(num) * 3] __aligned(2); int idx, len; /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ @@ -384,7 +391,8 @@ static noinline_for_stack char *number(char *buf, char *end, unsigned long long num, struct printf_spec spec) { - char tmp[3 * sizeof(num)]; + /* put_dec requires 2-byte alignment of the buffer. */ + char tmp[3 * sizeof(num)] __aligned(2); char sign; char locase; int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); @@ -944,7 +952,7 @@ char *ip4_string(char *p, const u8 *addr, const char *fmt) break; } for (i = 0; i < 4; i++) { - char temp[3]; /* hold each IP quad in reverse order */ + char temp[4] __aligned(2); /* hold each IP quad in reverse order */ int digits = put_dec_trunc8(temp, addr[index]) - temp; if (leading_zeros) { if (digits < 3) |