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Add a fast memcpy() using MMX when we're moving >= 1KB.

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This is a nice speedup for WindowServer. I'll eventually have to do this
with SSE but the kernel doesn't support SSE yet so this is it for now.
This commit is contained in:
Andreas Kling 2019-02-07 08:46:52 +01:00
parent e29060620f
commit 1f159eaab0
6 changed files with 70 additions and 3 deletions
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6
AK/StdLibExtras.h
View file

@ -9,8 +9,14 @@
#include <AK/Types.h>
void* mmx_memcpy(void* to, const void* from, size_t);
ALWAYS_INLINE void fast_dword_copy(dword* dest, const dword* src, size_t count)
{
if (count >= 256) {
mmx_memcpy(dest, src, count * sizeof(count));
return;
}
asm volatile(
"rep movsl\n"
: "=S"(src), "=D"(dest), "=c"(count)