fast memcpy() using x86 asm or mmxext

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@359 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 98 insertions, 0 deletions

diff --git a/libvo/fastmemcpy.h b/libvo/fastmemcpy.h
new file mode 100644
index 0000000000..bd6d4c255a
--- /dev/null
+++ b/libvo/fastmemcpy.h
@@ -0,0 +1,98 @@
+/*
+ This part of code was taken by from Linux-2.4.3 and slightly modified
+for MMX2 instruction set. I have done it since linux uses page aligned
+blocks but mplayer uses weakly ordered data and original sources can not
+speedup their. Only using prefetch and movntq together have effect! 
+If you have questions please contact with me: Nick Kurshev: nickols_k@mail.ru.
+*/
+
+#ifndef HAVE_MMX2
+//static inline void * __memcpy(void * to, const void * from, unsigned n)
+inline static void * memcpy(void * to, const void * from, unsigned n)
+{
+int d0, d1, d2;
+__asm__ __volatile__(
+	"rep ; movsl\n\t"
+	"testb $2,%b4\n\t"
+	"je 1f\n\t"
+	"movsw\n"
+	"1:\ttestb $1,%b4\n\t"
+	"je 2f\n\t"
+	"movsb\n"
+	"2:"
+	: "=&c" (d0), "=&D" (d1), "=&S" (d2)
+	:"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
+	: "memory");
+return (to);
+}
+#else
+//inline static void *__memcpy_mmx2(void *to, const void *from, unsigned len)
+inline static void * memcpy(void * to, const void * from, unsigned n)
+{
+	void *p;
+	int i;
+
+        if(len >= 0x200) /* 512-byte blocks */
+	{
+  	  p = to;
+	  i = len >> 6; /* len/64 */
+	__asm__ __volatile__ (
+		"1: prefetch (%0)\n"		/* This set is 28 bytes */
+		"   prefetch 64(%0)\n"
+		"   prefetch 128(%0)\n"
+		"   prefetch 192(%0)\n"
+		"   prefetch 256(%0)\n"
+		"2:  \n"
+		".section .fixup, \"ax\"\n"
+		"3: movw $0x1AEB, 1b\n"	/* jmp on 26 bytes */
+		"   jmp 2b\n"
+		".previous\n"
+		".section __ex_table,\"a\"\n"
+		"	.align 4\n"
+		"	.long 1b, 3b\n"
+		".previous"
+		: : "r" (from) );
+		
+	
+	for(; i>0; i--)
+	{
+		__asm__ __volatile__ (
+		"1:  prefetch 320(%0)\n"
+		"2:  movq (%0), %%mm0\n"
+		"  movq 8(%0), %%mm1\n"
+		"  movq 16(%0), %%mm2\n"
+		"  movq 24(%0), %%mm3\n"
+		"  movntq %%mm0, (%1)\n"
+		"  movntq %%mm1, 8(%1)\n"
+		"  movntq %%mm2, 16(%1)\n"
+		"  movntq %%mm3, 24(%1)\n"
+		"  movq 32(%0), %%mm0\n"
+		"  movq 40(%0), %%mm1\n"
+		"  movq 48(%0), %%mm2\n"
+		"  movq 56(%0), %%mm3\n"
+		"  movntq %%mm0, 32(%1)\n"
+		"  movntq %%mm1, 40(%1)\n"
+		"  movntq %%mm2, 48(%1)\n"
+		"  movntq %%mm3, 56(%1)\n"
+		".section .fixup, \"ax\"\n"
+		"3: movw $0x05EB, 1b\n"	/* jmp on 5 bytes */
+		"   jmp 2b\n"
+		".previous\n"
+		".section __ex_table,\"a\"\n"
+		"	.align 4\n"
+		"	.long 1b, 3b\n"
+		".previous"
+		: : "r" (from), "r" (to) : "memory");
+		from+=64;
+		to+=64;
+	}
+	        __asm__ __volatile__ ("emms":::"memory");
+	}
+	/*
+	 *	Now do the tail of the block
+	 */
+	__memcpy(to, from, len&63);
+	return p;
+}
+#endif
+