an amd64 arch support.

hacked by art@ from netbsd sources and then later debugged
by me into the shape where it can host itself.
no bootloader yet as needs redoing from the
recent advanced i386 sources (anyone? ;)

1 files changed, 65 insertions, 0 deletions

diff --git a/sys/lib/libkern/arch/amd64/strcat.S b/sys/lib/libkern/arch/amd64/strcat.S
new file mode 100644
index 00000000000..7dc71244312
--- /dev/null
+++ b/sys/lib/libkern/arch/amd64/strcat.S
@@ -0,0 +1,65 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ * Adapted for NetBSD/x86_64 by Frank van der Linden <fvdl@wasabisystems.com>
+ */
+
+#include <machine/asm.h>
+
+#if defined(LIBC_SCCS)
+	RCSID("$NetBSD: strcat.S,v 1.1 2001/06/19 00:22:47 fvdl Exp $")
+#endif
+
+/*
+ * NOTE: I've unrolled the loop eight times: large enough to make a
+ * significant difference, and small enough not to totally trash the
+ * cache.
+ */
+
+ENTRY(strcat)
+	movq	%rdi,%r11
+
+	cld				/* set search forward */
+	xorl	%eax,%eax		/* set search for null terminator */
+	movq	$-1,%rcx		/* set search for lots of characters */
+	repne				/* search! */
+	scasb
+
+	decq	%rdi
+
+L1:	movb	(%rsi),%al		/* unroll loop, but not too much */
+	movb	%al,(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	1(%rsi),%al
+	movb	%al,1(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	2(%rsi),%al
+	movb	%al,2(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	3(%rsi),%al
+	movb	%al,3(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	4(%rsi),%al
+	movb	%al,4(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	5(%rsi),%al
+	movb	%al,5(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	6(%rsi),%al
+	movb	%al,6(%rdi)
+	testb	%al,%al
+	jz	L2
+	movb	7(%rsi),%al
+	movb	%al,7(%rdi)
+	addq	$8,%rsi
+	addq	$8,%rdi
+	testb	%al,%al
+	jnz	L1
+L2:	movq	%r11,%rax
+	ret