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-rw-r--r--lib/libc/amd64/string/strcpy.S112
1 files changed, 0 insertions, 112 deletions
diff --git a/lib/libc/amd64/string/strcpy.S b/lib/libc/amd64/string/strcpy.S
deleted file mode 100644
index 8cafa12..0000000
--- a/lib/libc/amd64/string/strcpy.S
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
- * Written by J.T. Conklin <jtc@acorntoolworks.com>
- * Public domain.
- */
-
-#include <machine/asm.h>
-__FBSDID("$FreeBSD$");
-
-#if 0
- RCSID("$NetBSD: strcpy.S,v 1.3 2004/07/19 20:04:41 drochner Exp $")
-#endif
-
-/*
- * This strcpy implementation copies a byte at a time until the
- * source pointer is aligned to a word boundary, it then copies by
- * words until it finds a word containing a zero byte, and finally
- * copies by bytes until the end of the string is reached.
- *
- * While this may result in unaligned stores if the source and
- * destination pointers are unaligned with respect to each other,
- * it is still faster than either byte copies or the overhead of
- * an implementation suitable for machines with strict alignment
- * requirements.
- */
-
-ENTRY(strcpy)
- movq %rdi,%rax
- movabsq $0x0101010101010101,%r8
- movabsq $0x8080808080808080,%r9
-
- /*
- * Align source to a word boundary.
- * Consider unrolling loop?
- */
-.Lalign:
- testb $7,%sil
- je .Lword_aligned
- movb (%rsi),%dl
- incq %rsi
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl
- jne .Lalign
- ret
-
- .p2align 4
-.Lloop:
- movq %rdx,(%rdi)
- addq $8,%rdi
-.Lword_aligned:
- movq (%rsi),%rdx
- movq %rdx,%rcx
- addq $8,%rsi
- subq %r8,%rcx
- testq %r9,%rcx
- je .Lloop
-
- /*
- * In rare cases, the above loop may exit prematurely. We must
- * return to the loop if none of the bytes in the word equal 0.
- */
-
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 1st byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 2nd byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 3rd byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 4th byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 5th byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 6th byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 7th byte == 0? */
- je .Ldone
-
- shrq $8,%rdx
- movb %dl,(%rdi)
- incq %rdi
- testb %dl,%dl /* 8th byte == 0? */
- jne .Lword_aligned
-
-.Ldone:
- ret
-END(strcpy)
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