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>
diff --git a/include/asm-blackfin/string.h b/include/asm-blackfin/string.h
index 6f1eb7d..e8ada91 100644
--- a/include/asm-blackfin/string.h
+++ b/include/asm-blackfin/string.h
@@ -9,13 +9,16 @@
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 @@
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 @@
#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;
}