[PATCH v2 1/1] ARM : missing corrupted reg in __div64_32
Chen Gang
chengang_rda at 163.com
Thu Mar 31 04:41:05 PDT 2016
__xl(R0 in little endian system, or R1 in big endian system) is corrupted
after calling __do_div64 and compiler is not informed about this.
If n is used again afterwards, __xl won't be reloaded and n will
contain incorrect value.
Signed-off-by: Chen Gang <gangchen at rdamicro.com>
Signed-off-by: Chen Gang <chengang_rda at 163.com>
---
arch/arm/include/asm/div64.h | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)
diff --git a/arch/arm/include/asm/div64.h b/arch/arm/include/asm/div64.h
index e1f0776..ba3f36c 100644
--- a/arch/arm/include/asm/div64.h
+++ b/arch/arm/include/asm/div64.h
@@ -21,30 +21,22 @@
* for arguments and results (beware).
*/
-#ifdef __ARMEB__
-#define __xh "r0"
-#define __xl "r1"
-#else
-#define __xl "r0"
-#define __xh "r1"
-#endif
static inline uint32_t __div64_32(uint64_t *n, uint32_t base)
{
register unsigned int __base asm("r4") = base;
register unsigned long long __n asm("r0") = *n;
register unsigned long long __res asm("r2");
- register unsigned int __rem asm(__xh);
- asm( __asmeq("%0", __xh)
+ asm(
+ __asmeq("%0", "r0")
__asmeq("%1", "r2")
- __asmeq("%2", "r0")
- __asmeq("%3", "r4")
+ __asmeq("%2", "r4")
"bl __do_div64"
- : "=r" (__rem), "=r" (__res)
- : "r" (__n), "r" (__base)
+ : "+r" (__n), "=r" (__res)
+ : "r" (__base)
: "ip", "lr", "cc");
*n = __res;
- return __rem;
+ return __n >> 32;
}
#define __div64_32 __div64_32
--
2.4.3
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