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authorPikalaxALT <pikalaxalt@gmail.com>2017-12-15 09:38:53 -0500
committerPikalaxALT <pikalaxalt@gmail.com>2017-12-15 09:39:34 -0500
commitf95a4a932476be2ba99e2fd081e8d2bc6ea12813 (patch)
tree75f67192cb2d7b7b575c94edda318e475239b63c /newlib/libc/machine/i386/memmove.S
parentf60aca96985e68c7d8a52eb7bc955fb80e132f73 (diff)
Import newlib and create makefile
Diffstat (limited to 'newlib/libc/machine/i386/memmove.S')
-rw-r--r--newlib/libc/machine/i386/memmove.S74
1 files changed, 74 insertions, 0 deletions
diff --git a/newlib/libc/machine/i386/memmove.S b/newlib/libc/machine/i386/memmove.S
new file mode 100644
index 0000000..e1aca0d
--- /dev/null
+++ b/newlib/libc/machine/i386/memmove.S
@@ -0,0 +1,74 @@
+/*
+ * ====================================================
+ * Copyright (C) 1998 by Cygnus Solutions. All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+ #include "i386mach.h"
+
+ .global SYM (memmove)
+
+SYM (memmove):
+
+ pushl ebp
+ movl esp,ebp
+ pushl esi
+ pushl edi
+ pushl ebx
+ movl 8(ebp),edi
+ movl 16(ebp),ecx
+ movl 12(ebp),esi
+
+/* check for destructive overlap (src < dst && dst < src + length) */
+
+ cld
+ cmpl edi,esi
+ jae .L2
+ leal -1(ecx,esi),ebx
+ cmpl ebx,edi
+ ja .L2
+
+/* destructive overlap, must copy backwards...do it a byte at a time since it is uncommon */
+
+ decl edi
+ movl ebx,esi
+ addl ecx,edi
+ std
+ jmp BYTEMOVE
+.L2:
+#ifndef __OPTIMIZE_SIZE__
+/* non-destructive overlap so we can try and move 4 bytes at a time */
+
+ movl esi,eax
+ orl edi,eax
+ testb $3,al
+ jne BYTEMOVE
+ shrl $2,ecx
+ rep
+ movsl
+
+/* calculate any remainder bytes after moving doublewords */
+
+ movl 16(ebp),ecx
+ andl $3,ecx
+
+#endif /* not __OPTIMIZE_SIZE__ */
+
+/* move any unaligned bytes or remainder bytes, one at a time */
+
+BYTEMOVE:
+ rep
+ movsb
+
+ movl 8(ebp),eax
+
+ leal -12(ebp),esp
+ popl ebx
+ popl edi
+ popl esi
+ leave
+ ret