diff options
| -rw-r--r-- | arch/mn10300/include/asm/div64.h | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/mn10300/include/asm/div64.h b/arch/mn10300/include/asm/div64.h index 34dcb8e6830..503efab2a51 100644 --- a/arch/mn10300/include/asm/div64.h +++ b/arch/mn10300/include/asm/div64.h @@ -16,6 +16,19 @@ extern void ____unhandled_size_in_do_div___(void); /* + * Beginning with gcc 4.6, the MDR register is represented explicitly. We + * must, therefore, at least explicitly clobber the register when we make + * changes to it. The following assembly fragments *could* be rearranged in + * order to leave the moves to/from the MDR register to the compiler, but the + * gains would be minimal at best. + */ +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) +# define CLOBBER_MDR_CC "mdr", "cc" +#else +# define CLOBBER_MDR_CC "cc" +#endif + +/* * divide n by base, leaving the result in n and returning the remainder * - we can do this quite efficiently on the MN10300 by cascading the divides * through the MDR register @@ -29,7 +42,7 @@ extern void ____unhandled_size_in_do_div___(void); "mov mdr,%1 \n" \ : "+r"(n), "=d"(__rem) \ : "r"(base), "1"(__rem) \ - : "cc" \ + : CLOBBER_MDR_CC \ ); \ } else if (sizeof(n) <= 8) { \ union { \ @@ -48,7 +61,7 @@ extern void ____unhandled_size_in_do_div___(void); : "=d"(__rem), "=r"(__quot.w[1]), "=r"(__quot.w[0]) \ : "r"(base), "0"(__rem), "1"(__quot.w[1]), \ "2"(__quot.w[0]) \ - : "cc" \ + : CLOBBER_MDR_CC \ ); \ n = __quot.l; \ } else { \ @@ -72,7 +85,7 @@ unsigned __muldiv64u(unsigned val, unsigned mult, unsigned div) * MDR = MDR:val%div */ : "=r"(result) : "0"(val), "ir"(mult), "r"(div) - : "cc" + : CLOBBER_MDR_CC ); return result; @@ -93,7 +106,7 @@ signed __muldiv64s(signed val, signed mult, signed div) * MDR = MDR:val%div */ : "=r"(result) : "0"(val), "ir"(mult), "r"(div) - : "cc" + : CLOBBER_MDR_CC ); return result; |