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Use stosl in memset; makes boot time bearable

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This commit is contained in:
Austin Clements 2011-09-01 10:41:21 -04:00
parent e25b74ca80
commit d0f3efca65
2 changed files with 14 additions and 1 deletions
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4
string.c
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@ -4,6 +4,10 @@
void* void*
memset(void *dst, int c, uint n) memset(void *dst, int c, uint 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); stosb(dst, c, n);
return dst; return dst;
} }

9
x86.h
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@ -48,6 +48,15 @@ stosb(void *addr, int data, int cnt)
"memory", "cc"); "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; struct segdesc;
static inline void static inline void