Commit 0931ce84 authored by Mike Frysinger's avatar Mike Frysinger Committed by Bryan Wu
Browse files

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: default avatarMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: default avatarBryan Wu <bryan.wu@analog.com>
parent e62687f9

include/asm-blackfin/string.h

+80 −49
Original line number Diff line number Diff line
@@ -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"

	__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");

		:

		: "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"

	__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");

		:

		: "memory", "CC");



	return xdest;

}



#define __HAVE_ARCH_STRCMP

extern inline int strcmp(const char *cs, const char *ct)

{

	char __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"

	/* 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__ __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)

      : :	"CC");

		:

		: "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 */



	__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)

      : :	"CC");

		:

		: "memory", "CC");



	return __res1;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE