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author | Austin Clements <[email protected]> | 2011-09-01 10:41:21 -0400 |
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committer | Austin Clements <[email protected]> | 2011-09-01 10:41:27 -0400 |
commit | d0f3efca650eccd5179e045cd07f7d723037defc (patch) | |
tree | f28734b5ac99749ebb0927e079a4c656f6e0d847 | |
parent | e25b74ca8069e340c3f2c267d09beed6d9328250 (diff) | |
download | xv6-labs-d0f3efca650eccd5179e045cd07f7d723037defc.tar.gz xv6-labs-d0f3efca650eccd5179e045cd07f7d723037defc.tar.bz2 xv6-labs-d0f3efca650eccd5179e045cd07f7d723037defc.zip |
Use stosl in memset; makes boot time bearable
-rw-r--r-- | string.c | 6 | ||||
-rw-r--r-- | x86.h | 9 |
2 files changed, 14 insertions, 1 deletions
@@ -4,7 +4,11 @@ void* memset(void *dst, int c, uint n) { - stosb(dst, c, n); + if ((int)dst%4 == 0 && n%4 == 0){ + c &= 0xFF; + stosl(dst, (c<<24)|(c<<16)|(c<<8)|c, n/4); + } else + stosb(dst, c, n); return dst; } @@ -48,6 +48,15 @@ stosb(void *addr, int data, int cnt) "memory", "cc"); } +static inline void +stosl(void *addr, int data, int cnt) +{ + asm volatile("cld; rep stosl" : + "=D" (addr), "=c" (cnt) : + "0" (addr), "1" (cnt), "a" (data) : + "memory", "cc"); +} + struct segdesc; static inline void |