Blackfin arch: fix some bugs in lib/string.h functions found by our string testing modules

- use ints for the return value rather than char since we actually return
   an int and we dont want it improperly being sign extended during the reload
   http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3525

 - if src is shorter than the requested number of copy bytes, we need to null
   pad the rest
   http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3524

 - mark these as __volatile__ and add memory to the clobber list so gcc does
   not optimize buffers around on us we may be using

 - rewrite asm code to be readable/maintainable

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
This commit is contained in:
Mike Frysinger 2007-09-12 16:30:15 +08:00 committed by Bryan Wu
parent e62687f995
commit 0931ce8439

View File

@ -9,13 +9,16 @@ extern inline char *strcpy(char *dest, const char *src)
char *xdest = dest;
char temp = 0;
__asm__ __volatile__
("1:\t%2 = B [%1++] (Z);\n\t"
"B [%0++] = %2;\n\t"
"CC = %2;\n\t"
"if cc jump 1b (bp);\n"
: "+&a" (dest), "+&a" (src), "=&d" (temp)
::"memory", "CC");
__asm__ __volatile__ (
"1:"
"%2 = B [%1++] (Z);"
"B [%0++] = %2;"
"CC = %2;"
"if cc jump 1b (bp);"
: "+&a" (dest), "+&a" (src), "=&d" (temp)
:
: "memory", "CC");
return xdest;
}
@ -28,37 +31,56 @@ extern inline char *strncpy(char *dest, const char *src, size_t n)
if (n == 0)
return xdest;
__asm__ __volatile__
("1:\t%3 = B [%1++] (Z);\n\t"
"B [%0++] = %3;\n\t"
"CC = %3;\n\t"
"if ! cc jump 2f;\n\t"
"%2 += -1;\n\t"
"CC = %2 == 0;\n\t"
"if ! cc jump 1b (bp);\n"
"2:\n"
: "+&a" (dest), "+&a" (src), "+&da" (n), "=&d" (temp)
::"memory", "CC");
__asm__ __volatile__ (
"1:"
"%3 = B [%1++] (Z);"
"B [%0++] = %3;"
"CC = %3;"
"if ! cc jump 2f;"
"%2 += -1;"
"CC = %2 == 0;"
"if ! cc jump 1b (bp);"
"jump 4f;"
"2:"
/* if src is shorter than n, we need to null pad bytes now */
"%3 = 0;"
"3:"
"%2 += -1;"
"CC = %2 == 0;"
"if cc jump 4f;"
"B [%0++] = %3;"
"jump 3b;"
"4:"
: "+&a" (dest), "+&a" (src), "+&da" (n), "=&d" (temp)
:
: "memory", "CC");
return xdest;
}
#define __HAVE_ARCH_STRCMP
extern inline int strcmp(const char *cs, const char *ct)
{
char __res1, __res2;
/* need to use int's here so the char's in the assembly don't get
* sign extended incorrectly when we don't want them to be
*/
int __res1, __res2;
__asm__
("1:\t%2 = B[%0++] (Z);\n\t" /* get *cs */
"%3 = B[%1++] (Z);\n\t" /* get *ct */
"CC = %2 == %3;\n\t" /* compare a byte */
"if ! cc jump 2f;\n\t" /* not equal, break out */
"CC = %2;\n\t" /* at end of cs? */
"if cc jump 1b (bp);\n\t" /* no, keep going */
"jump.s 3f;\n" /* strings are equal */
"2:\t%2 = %2 - %3;\n" /* *cs - *ct */
"3:\n"
: "+&a" (cs), "+&a" (ct), "=&d" (__res1), "=&d" (__res2)
: : "CC");
__asm__ __volatile__ (
"1:"
"%2 = B[%0++] (Z);" /* get *cs */
"%3 = B[%1++] (Z);" /* get *ct */
"CC = %2 == %3;" /* compare a byte */
"if ! cc jump 2f;" /* not equal, break out */
"CC = %2;" /* at end of cs? */
"if cc jump 1b (bp);" /* no, keep going */
"jump.s 3f;" /* strings are equal */
"2:"
"%2 = %2 - %3;" /* *cs - *ct */
"3:"
: "+&a" (cs), "+&a" (ct), "=&d" (__res1), "=&d" (__res2)
:
: "memory", "CC");
return __res1;
}
@ -66,26 +88,35 @@ extern inline int strcmp(const char *cs, const char *ct)
#define __HAVE_ARCH_STRNCMP
extern inline int strncmp(const char *cs, const char *ct, size_t count)
{
char __res1, __res2;
/* need to use int's here so the char's in the assembly don't get
* sign extended incorrectly when we don't want them to be
*/
int __res1, __res2;
if (!count)
return 0;
__asm__
("1:\t%3 = B[%0++] (Z);\n\t" /* get *cs */
"%4 = B[%1++] (Z);\n\t" /* get *ct */
"CC = %3 == %4;\n\t" /* compare a byte */
"if ! cc jump 3f;\n\t" /* not equal, break out */
"CC = %3;\n\t" /* at end of cs? */
"if ! cc jump 4f;\n\t" /* yes, all done */
"%2 += -1;\n\t" /* no, adjust count */
"CC = %2 == 0;\n\t"
"if ! cc jump 1b;\n" /* more to do, keep going */
"2:\t%3 = 0;\n\t" /* strings are equal */
"jump.s 4f;\n"
"3:\t%3 = %3 - %4;\n" /* *cs - *ct */
"4:"
: "+&a" (cs), "+&a" (ct), "+&da" (count), "=&d" (__res1), "=&d" (__res2)
: : "CC");
__asm__ __volatile__ (
"1:"
"%3 = B[%0++] (Z);" /* get *cs */
"%4 = B[%1++] (Z);" /* get *ct */
"CC = %3 == %4;" /* compare a byte */
"if ! cc jump 3f;" /* not equal, break out */
"CC = %3;" /* at end of cs? */
"if ! cc jump 4f;" /* yes, all done */
"%2 += -1;" /* no, adjust count */
"CC = %2 == 0;"
"if ! cc jump 1b;" /* more to do, keep going */
"2:"
"%3 = 0;" /* strings are equal */
"jump.s 4f;"
"3:"
"%3 = %3 - %4;" /* *cs - *ct */
"4:"
: "+&a" (cs), "+&a" (ct), "+&da" (count), "=&d" (__res1), "=&d" (__res2)
:
: "memory", "CC");
return __res1;
}