Mirrors/libhermit
1
0
Fork 0
mirror of https://github.com/hermitcore/libhermit.git synced 2025-03-09 00:00:03 +01:00
Code Issues Releases Wiki Activity

minor improvements in memset (usage of stosq instead of stosb)

Browse source
This commit is contained in:
Stefan Lankes 2016-10-04 16:45:42 +02:00
parent c5f2c1f0b7
commit a2819c6874
1 changed files with 13 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
hermit/arch/x86/include/asm/string.h
View file

@ -66,9 +66,19 @@ inline static void *memset(void* dest, int val, size_t count)
if (BUILTIN_EXPECT(!dest, 0))
return dest;
asm volatile ("cld; rep stosb"
: "=&c"(i), "=&D"(j)
: "a"(val), "1"(dest), "0"(count) : "memory","cc");
if (val) {
asm volatile ("cld; rep stosb"
: "=&c"(i), "=&D"(j)
: "a"(val), "1"(dest), "0"(count) : "memory","cc");
} else {
asm volatile (
"cld; rep stosq\n\t"
"movq %5, %%rcx\n\t"
"andq $7, %%rcx\n\t"
"rep stosb\n\t"
: "=&c"(i), "=&D"(j)
: "a"((size_t)val), "1"(dest), "0"(count/8), "g"(count): "memory","cc");
}
return dest;
}