pcsx2/common/x86/MemcpyFast.cpp

// GH: AMD memcpy was removed. The remaining part (memcmp_mmx) is likely from Zerofrog.
// Hopefully memcmp_mmx will be dropped in the future.

#if defined(_WIN32) && !defined(_M_AMD64)
#include "common/MemcpyFast.h"
#include "common/Assertions.h"

#ifdef _MSC_VER
#pragma warning(disable : 4414)
#endif

// Inline assembly syntax for use with Visual C++

// mmx mem-compare implementation, size has to be a multiple of 8
// returns 0 is equal, nonzero value if not equal
// ~10 times faster than standard memcmp
// (zerofrog)
u8 memcmp_mmx(const void *src1, const void *src2, int cmpsize)
{
    pxAssert((cmpsize & 7) == 0);

    __asm {
		mov ecx, cmpsize
		mov edx, src1
		mov esi, src2

		cmp ecx, 32
		jl Done4

        // custom test first 8 to make sure things are ok
		movq mm0, [esi]
		movq mm1, [esi+8]
		pcmpeqd mm0, [edx]
		pcmpeqd mm1, [edx+8]
		pand mm0, mm1
		movq mm2, [esi+16]
		pmovmskb eax, mm0
		movq mm3, [esi+24]

        // check if eq
		cmp eax, 0xff
		je NextComp
		mov eax, 1
		jmp End

NextComp:
		pcmpeqd mm2, [edx+16]
		pcmpeqd mm3, [edx+24]
		pand mm2, mm3
		pmovmskb eax, mm2

		sub ecx, 32
		add esi, 32
		add edx, 32

        // check if eq
		cmp eax, 0xff
		je ContinueTest
		mov eax, 1
		jmp End

		cmp ecx, 64
		jl Done8

Cmp8:
		movq mm0, [esi]
		movq mm1, [esi+8]
		movq mm2, [esi+16]
		movq mm3, [esi+24]
		movq mm4, [esi+32]
		movq mm5, [esi+40]
		movq mm6, [esi+48]
		movq mm7, [esi+56]
		pcmpeqd mm0, [edx]
		pcmpeqd mm1, [edx+8]
		pcmpeqd mm2, [edx+16]
		pcmpeqd mm3, [edx+24]
		pand mm0, mm1
		pcmpeqd mm4, [edx+32]
		pand mm0, mm2
		pcmpeqd mm5, [edx+40]
		pand mm0, mm3
		pcmpeqd mm6, [edx+48]
		pand mm0, mm4
		pcmpeqd mm7, [edx+56]
		pand mm0, mm5
		pand mm0, mm6
		pand mm0, mm7
		pmovmskb eax, mm0

        // check if eq
		cmp eax, 0xff
		je Continue
		mov eax, 1
		jmp End

Continue:
		sub ecx, 64
		add esi, 64
		add edx, 64
ContinueTest:
		cmp ecx, 64
		jge Cmp8

Done8:
		test ecx, 0x20
		jz Done4
		movq mm0, [esi]
		movq mm1, [esi+8]
		movq mm2, [esi+16]
		movq mm3, [esi+24]
		pcmpeqd mm0, [edx]
		pcmpeqd mm1, [edx+8]
		pcmpeqd mm2, [edx+16]
		pcmpeqd mm3, [edx+24]
		pand mm0, mm1
		pand mm0, mm2
		pand mm0, mm3
		pmovmskb eax, mm0
		sub ecx, 32
		add esi, 32
		add edx, 32

        // check if eq
		cmp eax, 0xff
		je Done4
		mov eax, 1
		jmp End

Done4:
		cmp ecx, 24
		jne Done2
		movq mm0, [esi]
		movq mm1, [esi+8]
		movq mm2, [esi+16]
		pcmpeqd mm0, [edx]
		pcmpeqd mm1, [edx+8]
		pcmpeqd mm2, [edx+16]
		pand mm0, mm1
		pand mm0, mm2
		pmovmskb eax, mm0

        // check if eq
		cmp eax, 0xff
		setne al
		jmp End

Done2:
		cmp ecx, 16
		jne Done1

		movq mm0, [esi]
		movq mm1, [esi+8]
		pcmpeqd mm0, [edx]
		pcmpeqd mm1, [edx+8]
		pand mm0, mm1
		pmovmskb eax, mm0

        // check if eq
		cmp eax, 0xff
		setne al
		jmp End

Done1:
		cmp ecx, 8
		jne Done

		mov eax, [esi]
		mov esi, [esi+4]
		cmp eax, [edx]
		je Next
		mov eax, 1
		jmp End

Next:
		cmp esi, [edx+4]
		setne al
		jmp End

Done:
		xor eax, eax

End:
		emms
    }
}

#endif