@@ -1,10 +1,5 @@
/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
- with help from Dan Sahlin (dan@sics.se) and
- commentary by Jim Blandy (jimb@ai.mit.edu);
- adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
- and implemented by Roland McGrath (roland@ai.mit.edu).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -20,143 +15,36 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#ifndef _LIBC
-# include <config.h>
-#endif
-
#include <string.h>
+#include <stdlib.h>
-#include <stddef.h>
+#undef __memchr
+#undef memchr
-#include <limits.h>
+/* Return the length of the null-terminated string STR. Scan for
+ the null terminator quickly by testing four bytes at a time. */
-#undef __memchr
-#ifdef _LIBC
-# undef memchr
-#endif
+#include <string_vector.h>
+#define EXPRESSION(p, c) (bytes_equal (p, c))
+#define EXPRESSION_NOCARRY(p, c) (bytes_equal_nocarry (p, c))
-#ifndef weak_alias
-# define __memchr memchr
-#endif
+#define CHECK_N
+#include <string_vector_skeleton.h>
#ifndef MEMCHR
# define MEMCHR __memchr
#endif
-/* Search no more than N bytes of S for C. */
+#ifdef STATIC
+static __always_inline
+#endif
void *
-MEMCHR (void const *s, int c_in, size_t n)
+MEMCHR (const void *str, int c, size_t n)
{
- /* On 32-bit hardware, choosing longword to be a 32-bit unsigned
- long instead of a 64-bit uintmax_t tends to give better
- performance. On 64-bit hardware, unsigned long is generally 64
- bits already. Change this typedef to experiment with
- performance. */
- typedef unsigned long int longword;
-
- const unsigned char *char_ptr;
- const longword *longword_ptr;
- longword repeated_one;
- longword repeated_c;
- unsigned char c;
-
- c = (unsigned char) c_in;
-
- /* Handle the first few bytes by reading one byte at a time.
- Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = (const unsigned char *) s;
- n > 0 && (size_t) char_ptr % sizeof (longword) != 0;
- --n, ++char_ptr)
- if (*char_ptr == c)
- return (void *) char_ptr;
-
- longword_ptr = (const longword *) char_ptr;
-
- /* All these elucidatory comments refer to 4-byte longwords,
- but the theory applies equally well to any size longwords. */
-
- /* Compute auxiliary longword values:
- repeated_one is a value which has a 1 in every byte.
- repeated_c has c in every byte. */
- repeated_one = 0x01010101;
- repeated_c = c | (c << 8);
- repeated_c |= repeated_c << 16;
- if (0xffffffffU < (longword) -1)
- {
- repeated_one |= repeated_one << 31 << 1;
- repeated_c |= repeated_c << 31 << 1;
- if (8 < sizeof (longword))
- {
- size_t i;
-
- for (i = 64; i < sizeof (longword) * 8; i *= 2)
- {
- repeated_one |= repeated_one << i;
- repeated_c |= repeated_c << i;
- }
- }
- }
-
- /* Instead of the traditional loop which tests each byte, we will test a
- longword at a time. The tricky part is testing if *any of the four*
- bytes in the longword in question are equal to c. We first use an xor
- with repeated_c. This reduces the task to testing whether *any of the
- four* bytes in longword1 is zero.
-
- We compute tmp =
- ((longword1 - repeated_one) & ~longword1) & (repeated_one << 7).
- That is, we perform the following operations:
- 1. Subtract repeated_one.
- 2. & ~longword1.
- 3. & a mask consisting of 0x80 in every byte.
- Consider what happens in each byte:
- - If a byte of longword1 is zero, step 1 and 2 transform it into 0xff,
- and step 3 transforms it into 0x80. A carry can also be propagated
- to more significant bytes.
- - If a byte of longword1 is nonzero, let its lowest 1 bit be at
- position k (0 <= k <= 7); so the lowest k bits are 0. After step 1,
- the byte ends in a single bit of value 0 and k bits of value 1.
- After step 2, the result is just k bits of value 1: 2^k - 1. After
- step 3, the result is 0. And no carry is produced.
- So, if longword1 has only non-zero bytes, tmp is zero.
- Whereas if longword1 has a zero byte, call j the position of the least
- significant zero byte. Then the result has a zero at positions 0, ...,
- j-1 and a 0x80 at position j. We cannot predict the result at the more
- significant bytes (positions j+1..3), but it does not matter since we
- already have a non-zero bit at position 8*j+7.
-
- So, the test whether any byte in longword1 is zero is equivalent to
- testing whether tmp is nonzero. */
-
- while (n >= sizeof (longword))
- {
- longword longword1 = *longword_ptr ^ repeated_c;
-
- if ((((longword1 - repeated_one) & ~longword1)
- & (repeated_one << 7)) != 0)
- break;
- longword_ptr++;
- n -= sizeof (longword);
- }
-
- char_ptr = (const unsigned char *) longword_ptr;
-
- /* At this point, we know that either n < sizeof (longword), or one of the
- sizeof (longword) bytes starting at char_ptr is == c. On little-endian
- machines, we could determine the first such byte without any further
- memory accesses, just by looking at the tmp result from the last loop
- iteration. But this does not work on big-endian machines. Choose code
- that works in both cases. */
-
- for (; n > 0; --n, ++char_ptr)
- {
- if (*char_ptr == c)
- return (void *) char_ptr;
- }
-
- return NULL;
+ return (void *) string_skeleton ((char *) str, c, n);
}
-#ifdef weak_alias
+
+#ifndef STATIC
weak_alias (__memchr, memchr)
-#endif
libc_hidden_builtin_def (memchr)
+#endif
@@ -1,10 +1,5 @@
/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
- with help from Dan Sahlin (dan@sics.se) and
- commentary by Jim Blandy (jimb@ai.mit.edu);
- adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
- and implemented by Roland McGrath (roland@ai.mit.edu).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -20,166 +15,25 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
+#include <string.h>
+#include <stdlib.h>
-#undef __ptr_t
-#define __ptr_t void *
+#undef rawmemchr
+#undef __rawmemchr
-#if defined (_LIBC)
-# include <string.h>
-# include <memcopy.h>
-# include <stdlib.h>
-#endif
-#if defined (HAVE_LIMITS_H) || defined (_LIBC)
-# include <limits.h>
-#endif
+#include <string_vector.h>
+#define EXPRESSION(p, c) (bytes_equal (p, c))
+#define EXPRESSION_NOCARRY(p, c) (bytes_equal_nocarry (p, c))
-#define LONG_MAX_32_BITS 2147483647
+#include <string_vector_skeleton.h>
-#ifndef LONG_MAX
-#define LONG_MAX LONG_MAX_32_BITS
-#endif
-
-#include <sys/types.h>
-
-#undef memchr
-
-#ifndef RAWMEMCHR
-# define RAWMEMCHR __rawmemchr
-#endif
-
-/* Find the first occurrence of C in S. */
-__ptr_t
-RAWMEMCHR (s, c_in)
- const __ptr_t s;
- int c_in;
+void *
+__rawmemchr (const void *s, int c)
{
- const unsigned char *char_ptr;
- const unsigned long int *longword_ptr;
- unsigned long int longword, magic_bits, charmask;
- unsigned char c;
-
- c = (unsigned char) c_in;
-
- /* Handle the first few characters by reading one character at a time.
- Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = (const unsigned char *) s;
- ((unsigned long int) char_ptr & (sizeof (longword) - 1)) != 0;
- ++char_ptr)
- if (*char_ptr == c)
- return (__ptr_t) char_ptr;
-
- /* All these elucidatory comments refer to 4-byte longwords,
- but the theory applies equally well to 8-byte longwords. */
-
- longword_ptr = (unsigned long int *) char_ptr;
-
- /* Bits 31, 24, 16, and 8 of this number are zero. Call these bits
- the "holes." Note that there is a hole just to the left of
- each byte, with an extra at the end:
-
- bits: 01111110 11111110 11111110 11111111
- bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
-
- The 1-bits make sure that carries propagate to the next 0-bit.
- The 0-bits provide holes for carries to fall into. */
-
- if (sizeof (longword) != 4 && sizeof (longword) != 8)
- abort ();
-
-#if LONG_MAX <= LONG_MAX_32_BITS
- magic_bits = 0x7efefeff;
-#else
- magic_bits = ((unsigned long int) 0x7efefefe << 32) | 0xfefefeff;
-#endif
-
- /* Set up a longword, each of whose bytes is C. */
- charmask = c | (c << 8);
- charmask |= charmask << 16;
-#if LONG_MAX > LONG_MAX_32_BITS
- charmask |= charmask << 32;
-#endif
-
- /* Instead of the traditional loop which tests each character,
- we will test a longword at a time. The tricky part is testing
- if *any of the four* bytes in the longword in question are zero. */
- while (1)
- {
- /* We tentatively exit the loop if adding MAGIC_BITS to
- LONGWORD fails to change any of the hole bits of LONGWORD.
-
- 1) Is this safe? Will it catch all the zero bytes?
- Suppose there is a byte with all zeros. Any carry bits
- propagating from its left will fall into the hole at its
- least significant bit and stop. Since there will be no
- carry from its most significant bit, the LSB of the
- byte to the left will be unchanged, and the zero will be
- detected.
-
- 2) Is this worthwhile? Will it ignore everything except
- zero bytes? Suppose every byte of LONGWORD has a bit set
- somewhere. There will be a carry into bit 8. If bit 8
- is set, this will carry into bit 16. If bit 8 is clear,
- one of bits 9-15 must be set, so there will be a carry
- into bit 16. Similarly, there will be a carry into bit
- 24. If one of bits 24-30 is set, there will be a carry
- into bit 31, so all of the hole bits will be changed.
-
- The one misfire occurs when bits 24-30 are clear and bit
- 31 is set; in this case, the hole at bit 31 is not
- changed. If we had access to the processor carry flag,
- we could close this loophole by putting the fourth hole
- at bit 32!
-
- So it ignores everything except 128's, when they're aligned
- properly.
-
- 3) But wait! Aren't we looking for C, not zero?
- Good point. So what we do is XOR LONGWORD with a longword,
- each of whose bytes is C. This turns each byte that is C
- into a zero. */
-
- longword = *longword_ptr++ ^ charmask;
-
- /* Add MAGIC_BITS to LONGWORD. */
- if ((((longword + magic_bits)
-
- /* Set those bits that were unchanged by the addition. */
- ^ ~longword)
-
- /* Look at only the hole bits. If any of the hole bits
- are unchanged, most likely one of the bytes was a
- zero. */
- & ~magic_bits) != 0)
- {
- /* Which of the bytes was C? If none of them were, it was
- a misfire; continue the search. */
-
- const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
-
- if (cp[0] == c)
- return (__ptr_t) cp;
- if (cp[1] == c)
- return (__ptr_t) &cp[1];
- if (cp[2] == c)
- return (__ptr_t) &cp[2];
- if (cp[3] == c)
- return (__ptr_t) &cp[3];
-#if LONG_MAX > 2147483647
- if (cp[4] == c)
- return (__ptr_t) &cp[4];
- if (cp[5] == c)
- return (__ptr_t) &cp[5];
- if (cp[6] == c)
- return (__ptr_t) &cp[6];
- if (cp[7] == c)
- return (__ptr_t) &cp[7];
-#endif
- }
- }
+ return (void *) string_skeleton (s, c, 0);
}
+
libc_hidden_def (__rawmemchr)
weak_alias (__rawmemchr, rawmemchr)
+
@@ -1,10 +1,5 @@
/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
- with help from Dan Sahlin (dan@sics.se) and
- bug fix and commentary by Jim Blandy (jimb@ai.mit.edu);
- adaptation to strchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
- and implemented by Roland McGrath (roland@ai.mit.edu).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -21,166 +16,21 @@
<http://www.gnu.org/licenses/>. */
#include <string.h>
-#include <stdlib.h>
-
#undef strchr
+#undef index
+
+#define AS_STRCHR
+#define STRCHRNUL strchrnul_static
+#include "string/strchrnul.c"
+
-/* Find the first occurrence of C in S. */
char *
strchr (const char *s, int c_in)
{
- const unsigned char *char_ptr;
- const unsigned long int *longword_ptr;
- unsigned long int longword, magic_bits, charmask;
- unsigned char c;
-
- c = (unsigned char) c_in;
-
- /* Handle the first few characters by reading one character at a time.
- Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = (const unsigned char *) s;
- ((unsigned long int) char_ptr & (sizeof (longword) - 1)) != 0;
- ++char_ptr)
- if (*char_ptr == c)
- return (void *) char_ptr;
- else if (*char_ptr == '\0')
- return NULL;
-
- /* All these elucidatory comments refer to 4-byte longwords,
- but the theory applies equally well to 8-byte longwords. */
-
- longword_ptr = (unsigned long int *) char_ptr;
-
- /* Bits 31, 24, 16, and 8 of this number are zero. Call these bits
- the "holes." Note that there is a hole just to the left of
- each byte, with an extra at the end:
-
- bits: 01111110 11111110 11111110 11111111
- bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
-
- The 1-bits make sure that carries propagate to the next 0-bit.
- The 0-bits provide holes for carries to fall into. */
- switch (sizeof (longword))
- {
- case 4: magic_bits = 0x7efefeffL; break;
- case 8: magic_bits = ((0x7efefefeL << 16) << 16) | 0xfefefeffL; break;
- default:
- abort ();
- }
-
- /* Set up a longword, each of whose bytes is C. */
- charmask = c | (c << 8);
- charmask |= charmask << 16;
- if (sizeof (longword) > 4)
- /* Do the shift in two steps to avoid a warning if long has 32 bits. */
- charmask |= (charmask << 16) << 16;
- if (sizeof (longword) > 8)
- abort ();
-
- /* Instead of the traditional loop which tests each character,
- we will test a longword at a time. The tricky part is testing
- if *any of the four* bytes in the longword in question are zero. */
- for (;;)
- {
- /* We tentatively exit the loop if adding MAGIC_BITS to
- LONGWORD fails to change any of the hole bits of LONGWORD.
-
- 1) Is this safe? Will it catch all the zero bytes?
- Suppose there is a byte with all zeros. Any carry bits
- propagating from its left will fall into the hole at its
- least significant bit and stop. Since there will be no
- carry from its most significant bit, the LSB of the
- byte to the left will be unchanged, and the zero will be
- detected.
-
- 2) Is this worthwhile? Will it ignore everything except
- zero bytes? Suppose every byte of LONGWORD has a bit set
- somewhere. There will be a carry into bit 8. If bit 8
- is set, this will carry into bit 16. If bit 8 is clear,
- one of bits 9-15 must be set, so there will be a carry
- into bit 16. Similarly, there will be a carry into bit
- 24. If one of bits 24-30 is set, there will be a carry
- into bit 31, so all of the hole bits will be changed.
-
- The one misfire occurs when bits 24-30 are clear and bit
- 31 is set; in this case, the hole at bit 31 is not
- changed. If we had access to the processor carry flag,
- we could close this loophole by putting the fourth hole
- at bit 32!
-
- So it ignores everything except 128's, when they're aligned
- properly.
-
- 3) But wait! Aren't we looking for C as well as zero?
- Good point. So what we do is XOR LONGWORD with a longword,
- each of whose bytes is C. This turns each byte that is C
- into a zero. */
-
- longword = *longword_ptr++;
-
- /* Add MAGIC_BITS to LONGWORD. */
- if ((((longword + magic_bits)
-
- /* Set those bits that were unchanged by the addition. */
- ^ ~longword)
-
- /* Look at only the hole bits. If any of the hole bits
- are unchanged, most likely one of the bytes was a
- zero. */
- & ~magic_bits) != 0 ||
-
- /* That caught zeroes. Now test for C. */
- ((((longword ^ charmask) + magic_bits) ^ ~(longword ^ charmask))
- & ~magic_bits) != 0)
- {
- /* Which of the bytes was C or zero?
- If none of them were, it was a misfire; continue the search. */
-
- const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
-
- if (*cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (sizeof (longword) > 4)
- {
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- if (*++cp == c)
- return (char *) cp;
- else if (*cp == '\0')
- return NULL;
- }
- }
- }
-
- return NULL;
+ unsigned char c = (unsigned char) c_in;
+ unsigned char *r = (unsigned char *) STRCHRNUL (s, c);
+ return (*r == c) ? (char *) r : NULL;
}
-#ifdef weak_alias
-#undef index
weak_alias (strchr, index)
-#endif
libc_hidden_builtin_def (strchr)
@@ -1,10 +1,5 @@
/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
- with help from Dan Sahlin (dan@sics.se) and
- bug fix and commentary by Jim Blandy (jimb@ai.mit.edu);
- adaptation to strchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
- and implemented by Roland McGrath (roland@ai.mit.edu).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -21,153 +16,69 @@
<http://www.gnu.org/licenses/>. */
#include <string.h>
-#include <memcopy.h>
#include <stdlib.h>
-#undef __strchrnul
#undef strchrnul
+#undef __strchrnul
-#ifndef STRCHRNUL
-# define STRCHRNUL __strchrnul
-#endif
-
-/* Find the first occurrence of C in S or the final NUL byte. */
-char *
-STRCHRNUL (s, c_in)
- const char *s;
- int c_in;
-{
- const unsigned char *char_ptr;
- const unsigned long int *longword_ptr;
- unsigned long int longword, magic_bits, charmask;
- unsigned char c;
-
- c = (unsigned char) c_in;
+/* Return the length of the null-terminated string STR. Scan for
+ the null terminator quickly by testing four bytes at a time. */
- /* Handle the first few characters by reading one character at a time.
- Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = (const unsigned char *) s;
- ((unsigned long int) char_ptr & (sizeof (longword) - 1)) != 0;
- ++char_ptr)
- if (*char_ptr == c || *char_ptr == '\0')
- return (void *) char_ptr;
+/* Here idea is still use the result of expression
+ contains_zero (*p) | contains_zero (*p ^ cmask)
+ but we can optimize it by using commutativity of operations. */
- /* All these elucidatory comments refer to 4-byte longwords,
- but the theory applies equally well to 8-byte longwords. */
+#include <string_vector.h>
+#define EXPRESSION(s, cmask) ((((s) - ones) | (((s) ^ cmask) - ones)) \
+ & high_bits & (~s))
- longword_ptr = (unsigned long int *) char_ptr;
+/* TODO simplify. */
+#define EXPRESSION_NOCARRY(s, cmask) contains_zero_nocarry (s) \
+ | bytes_equal_nocarry (s, cmask)
- /* Bits 31, 24, 16, and 8 of this number are zero. Call these bits
- the "holes." Note that there is a hole just to the left of
- each byte, with an extra at the end:
- bits: 01111110 11111110 11111110 11111111
- bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
+#include <string_vector_skeleton.h>
- The 1-bits make sure that carries propagate to the next 0-bit.
- The 0-bits provide holes for carries to fall into. */
- switch (sizeof (longword))
- {
- case 4: magic_bits = 0x7efefeffL; break;
- case 8: magic_bits = ((0x7efefefeL << 16) << 16) | 0xfefefeffL; break;
- default:
- abort ();
- }
+#ifndef STRCHRNUL
+# define STRCHRNUL __strchrnul
+#endif
- /* Set up a longword, each of whose bytes is C. */
- charmask = c | (c << 8);
- charmask |= charmask << 16;
- if (sizeof (longword) > 4)
- /* Do the shift in two steps to avoid a warning if long has 32 bits. */
- charmask |= (charmask << 16) << 16;
- if (sizeof (longword) > 8)
- abort ();
-
- /* Instead of the traditional loop which tests each character,
- we will test a longword at a time. The tricky part is testing
- if *any of the four* bytes in the longword in question are zero. */
- for (;;)
+#ifdef AS_STRCHR
+static __always_inline
+#endif
+char *
+STRCHRNUL (const char *s_in, int c_in)
+{
+ char *s_aligned;
+ vector_int mask;
+ const vector_int *lptr;
+ char *s = (char *) s_in;
+ unsigned char c = (unsigned char) c_in;
+ vector_int cmask = broadcast (c);
+ if (__glibc_unlikely (c > 127))
{
- /* We tentatively exit the loop if adding MAGIC_BITS to
- LONGWORD fails to change any of the hole bits of LONGWORD.
-
- 1) Is this safe? Will it catch all the zero bytes?
- Suppose there is a byte with all zeros. Any carry bits
- propagating from its left will fall into the hole at its
- least significant bit and stop. Since there will be no
- carry from its most significant bit, the LSB of the
- byte to the left will be unchanged, and the zero will be
- detected.
-
- 2) Is this worthwhile? Will it ignore everything except
- zero bytes? Suppose every byte of LONGWORD has a bit set
- somewhere. There will be a carry into bit 8. If bit 8
- is set, this will carry into bit 16. If bit 8 is clear,
- one of bits 9-15 must be set, so there will be a carry
- into bit 16. Similarly, there will be a carry into bit
- 24. If one of bits 24-30 is set, there will be a carry
- into bit 31, so all of the hole bits will be changed.
-
- The one misfire occurs when bits 24-30 are clear and bit
- 31 is set; in this case, the hole at bit 31 is not
- changed. If we had access to the processor carry flag,
- we could close this loophole by putting the fourth hole
- at bit 32!
-
- So it ignores everything except 128's, when they're aligned
- properly.
-
- 3) But wait! Aren't we looking for C as well as zero?
- Good point. So what we do is XOR LONGWORD with a longword,
- each of whose bytes is C. This turns each byte that is C
- into a zero. */
-
- longword = *longword_ptr++;
-
- /* Add MAGIC_BITS to LONGWORD. */
- if ((((longword + magic_bits)
-
- /* Set those bits that were unchanged by the addition. */
- ^ ~longword)
-
- /* Look at only the hole bits. If any of the hole bits
- are unchanged, most likely one of the bytes was a
- zero. */
- & ~magic_bits) != 0 ||
-
- /* That caught zeroes. Now test for C. */
- ((((longword ^ charmask) + magic_bits) ^ ~(longword ^ charmask))
- & ~magic_bits) != 0)
- {
- /* Which of the bytes was C or zero?
- If none of them were, it was a misfire; continue the search. */
-
- const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
-
- if (*cp == c || *cp == '\0')
- return (char *) cp;
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- if (sizeof (longword) > 4)
- {
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- if (*++cp == c || *cp == '\0')
- return (char *) cp;
- }
- }
+ s_aligned = PTR_ALIGN_DOWN (s, LSIZE);
+ lptr = (const vector_int *) s_aligned;
+ mask = SHIFT_BYTES (contains_zero_nocarry (*lptr)
+ | bytes_equal_nocarry (*lptr, cmask),
+ s - s_aligned);
+
+ if (mask)
+ return s + first_nonzero_byte (mask);
+
+ while (1)
+ {
+ s_aligned += LSIZE;
+ lptr = (const vector_int *) s_aligned;
+ mask = contains_zero(*lptr) | bytes_equal (*lptr, cmask);
+ if (mask)
+ return s_aligned + first_nonzero_byte (mask);
+ }
}
-
- /* This should never happen. */
- return NULL;
+ else
+ return string_skeleton (s, c, 0);
}
+#ifndef AS_STRCHR
weak_alias (__strchrnul, strchrnul)
+#endif
@@ -1,8 +1,5 @@
/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Written by Torbjorn Granlund (tege@sics.se),
- with help from Dan Sahlin (dan@sics.se);
- commentary by Jim Blandy (jimb@ai.mit.edu).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -25,81 +22,16 @@
/* Return the length of the null-terminated string STR. Scan for
the null terminator quickly by testing four bytes at a time. */
+
+#include <string_vector.h>
+#define EXPRESSION(p, c) (contains_zero (p))
+#define EXPRESSION_NOCARRY(p, c) (contains_zero_nocarry (p))
+#include <string_vector_skeleton.h>
+
size_t
strlen (const char *str)
{
- const char *char_ptr;
- const unsigned long int *longword_ptr;
- unsigned long int longword, himagic, lomagic;
-
- /* Handle the first few characters by reading one character at a time.
- Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = str; ((unsigned long int) char_ptr
- & (sizeof (longword) - 1)) != 0;
- ++char_ptr)
- if (*char_ptr == '\0')
- return char_ptr - str;
-
- /* All these elucidatory comments refer to 4-byte longwords,
- but the theory applies equally well to 8-byte longwords. */
-
- longword_ptr = (unsigned long int *) char_ptr;
-
- /* Bits 31, 24, 16, and 8 of this number are zero. Call these bits
- the "holes." Note that there is a hole just to the left of
- each byte, with an extra at the end:
-
- bits: 01111110 11111110 11111110 11111111
- bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
-
- The 1-bits make sure that carries propagate to the next 0-bit.
- The 0-bits provide holes for carries to fall into. */
- himagic = 0x80808080L;
- lomagic = 0x01010101L;
- if (sizeof (longword) > 4)
- {
- /* 64-bit version of the magic. */
- /* Do the shift in two steps to avoid a warning if long has 32 bits. */
- himagic = ((himagic << 16) << 16) | himagic;
- lomagic = ((lomagic << 16) << 16) | lomagic;
- }
- if (sizeof (longword) > 8)
- abort ();
-
- /* Instead of the traditional loop which tests each character,
- we will test a longword at a time. The tricky part is testing
- if *any of the four* bytes in the longword in question are zero. */
- for (;;)
- {
- longword = *longword_ptr++;
-
- if (((longword - lomagic) & ~longword & himagic) != 0)
- {
- /* Which of the bytes was the zero? If none of them were, it was
- a misfire; continue the search. */
-
- const char *cp = (const char *) (longword_ptr - 1);
-
- if (cp[0] == 0)
- return cp - str;
- if (cp[1] == 0)
- return cp - str + 1;
- if (cp[2] == 0)
- return cp - str + 2;
- if (cp[3] == 0)
- return cp - str + 3;
- if (sizeof (longword) > 4)
- {
- if (cp[4] == 0)
- return cp - str + 4;
- if (cp[5] == 0)
- return cp - str + 5;
- if (cp[6] == 0)
- return cp - str + 6;
- if (cp[7] == 0)
- return cp - str + 7;
- }
- }
- }
+ return string_skeleton (str, 0, 0) - str;
}
+
libc_hidden_builtin_def (strlen)
@@ -1,15 +1,10 @@
-/* Find the length of STRING, but scan at most MAXLEN characters.
- Copyright (C) 1991-2015 Free Software Foundation, Inc.
- Contributed by Jakub Jelinek <jakub@redhat.com>.
-
- Based on strlen written by Torbjorn Granlund (tege@sics.se),
- with help from Dan Sahlin (dan@sics.se);
- commentary by Jim Blandy (jimb@ai.mit.edu).
+/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public License as
- published by the Free Software Foundation; either version 2.1 of the
- License, or (at your option) any later version.
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -17,149 +12,27 @@
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; see the file COPYING.LIB. If
- not, see <http://www.gnu.org/licenses/>. */
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
#include <string.h>
#include <stdlib.h>
-/* Find the length of S, but scan at most MAXLEN characters. If no
- '\0' terminator is found in that many characters, return MAXLEN. */
+#undef strlen
+
+/* Return the length of the null-terminated string STR. Scan for
+ the null terminator quickly by testing four bytes at a time. */
-#ifdef STRNLEN
-# define __strnlen STRNLEN
-#endif
+#define STATIC
+#define MEMCHR memchr_static
+#include "string/memchr.c"
size_t
-__strnlen (const char *str, size_t maxlen)
+__strnlen (const char *str, size_t n)
{
- const char *char_ptr, *end_ptr = str + maxlen;
- const unsigned long int *longword_ptr;
- unsigned long int longword, himagic, lomagic;
-
- if (maxlen == 0)
- return 0;
-
- if (__glibc_unlikely (end_ptr < str))
- end_ptr = (const char *) ~0UL;
-
- /* Handle the first few characters by reading one character at a time.
- Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = str; ((unsigned long int) char_ptr
- & (sizeof (longword) - 1)) != 0;
- ++char_ptr)
- if (*char_ptr == '\0')
- {
- if (char_ptr > end_ptr)
- char_ptr = end_ptr;
- return char_ptr - str;
- }
-
- /* All these elucidatory comments refer to 4-byte longwords,
- but the theory applies equally well to 8-byte longwords. */
-
- longword_ptr = (unsigned long int *) char_ptr;
-
- /* Bits 31, 24, 16, and 8 of this number are zero. Call these bits
- the "holes." Note that there is a hole just to the left of
- each byte, with an extra at the end:
-
- bits: 01111110 11111110 11111110 11111111
- bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
-
- The 1-bits make sure that carries propagate to the next 0-bit.
- The 0-bits provide holes for carries to fall into. */
- himagic = 0x80808080L;
- lomagic = 0x01010101L;
- if (sizeof (longword) > 4)
- {
- /* 64-bit version of the magic. */
- /* Do the shift in two steps to avoid a warning if long has 32 bits. */
- himagic = ((himagic << 16) << 16) | himagic;
- lomagic = ((lomagic << 16) << 16) | lomagic;
- }
- if (sizeof (longword) > 8)
- abort ();
-
- /* Instead of the traditional loop which tests each character,
- we will test a longword at a time. The tricky part is testing
- if *any of the four* bytes in the longword in question are zero. */
- while (longword_ptr < (unsigned long int *) end_ptr)
- {
- /* We tentatively exit the loop if adding MAGIC_BITS to
- LONGWORD fails to change any of the hole bits of LONGWORD.
-
- 1) Is this safe? Will it catch all the zero bytes?
- Suppose there is a byte with all zeros. Any carry bits
- propagating from its left will fall into the hole at its
- least significant bit and stop. Since there will be no
- carry from its most significant bit, the LSB of the
- byte to the left will be unchanged, and the zero will be
- detected.
-
- 2) Is this worthwhile? Will it ignore everything except
- zero bytes? Suppose every byte of LONGWORD has a bit set
- somewhere. There will be a carry into bit 8. If bit 8
- is set, this will carry into bit 16. If bit 8 is clear,
- one of bits 9-15 must be set, so there will be a carry
- into bit 16. Similarly, there will be a carry into bit
- 24. If one of bits 24-30 is set, there will be a carry
- into bit 31, so all of the hole bits will be changed.
-
- The one misfire occurs when bits 24-30 are clear and bit
- 31 is set; in this case, the hole at bit 31 is not
- changed. If we had access to the processor carry flag,
- we could close this loophole by putting the fourth hole
- at bit 32!
-
- So it ignores everything except 128's, when they're aligned
- properly. */
-
- longword = *longword_ptr++;
-
- if ((longword - lomagic) & himagic)
- {
- /* Which of the bytes was the zero? If none of them were, it was
- a misfire; continue the search. */
-
- const char *cp = (const char *) (longword_ptr - 1);
-
- char_ptr = cp;
- if (cp[0] == 0)
- break;
- char_ptr = cp + 1;
- if (cp[1] == 0)
- break;
- char_ptr = cp + 2;
- if (cp[2] == 0)
- break;
- char_ptr = cp + 3;
- if (cp[3] == 0)
- break;
- if (sizeof (longword) > 4)
- {
- char_ptr = cp + 4;
- if (cp[4] == 0)
- break;
- char_ptr = cp + 5;
- if (cp[5] == 0)
- break;
- char_ptr = cp + 6;
- if (cp[6] == 0)
- break;
- char_ptr = cp + 7;
- if (cp[7] == 0)
- break;
- }
- }
- char_ptr = end_ptr;
- }
-
- if (char_ptr > end_ptr)
- char_ptr = end_ptr;
- return char_ptr - str;
+ char *ret = MEMCHR (str, 0, n);
+ return ret ? ret - str : n;
}
-#ifndef STRNLEN
+
weak_alias (__strnlen, strnlen)
-#endif
libc_hidden_def (strnlen)