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authorFenghua Yu <fenghua.yu@intel.com>2011-01-17 20:39:15 -0500
committerH. Peter Anvin <hpa@linux.intel.com>2011-01-25 19:58:39 -0500
commit9599ec0471deae24044241e2173090d2cbc0e899 (patch)
tree7ff508aefdb075ce62ef59e6218588eacedeff7f /arch/x86/lib/memmove_64.c
parent1bae4ce27c9c90344f23c65ea6966c50ffeae2f5 (diff)
x86-64, mem: Convert memmove() to assembly file and fix return value bug
memmove_64.c only implements memmove() function which is completely written in inline assembly code. Therefore it doesn't make sense to keep the assembly code in .c file. Currently memmove() doesn't store return value to rax. This may cause issue if caller uses the return value. The patch fixes this issue. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> LKML-Reference: <1295314755-6625-1-git-send-email-fenghua.yu@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/lib/memmove_64.c')
-rw-r--r--arch/x86/lib/memmove_64.c192
1 files changed, 0 insertions, 192 deletions
diff --git a/arch/x86/lib/memmove_64.c b/arch/x86/lib/memmove_64.c
deleted file mode 100644
index 6d0f0ec41b3..00000000000
--- a/arch/x86/lib/memmove_64.c
+++ /dev/null
@@ -1,192 +0,0 @@
1/* Normally compiler builtins are used, but sometimes the compiler calls out
2 of line code. Based on asm-i386/string.h.
3 */
4#define _STRING_C
5#include <linux/string.h>
6#include <linux/module.h>
7
8#undef memmove
9void *memmove(void *dest, const void *src, size_t count)
10{
11 unsigned long d0,d1,d2,d3,d4,d5,d6,d7;
12 char *ret;
13
14 __asm__ __volatile__(
15 /* Handle more 32bytes in loop */
16 "mov %2, %3\n\t"
17 "cmp $0x20, %0\n\t"
18 "jb 1f\n\t"
19
20 /* Decide forward/backward copy mode */
21 "cmp %2, %1\n\t"
22 "jb 2f\n\t"
23
24 /*
25 * movsq instruction have many startup latency
26 * so we handle small size by general register.
27 */
28 "cmp $680, %0\n\t"
29 "jb 3f\n\t"
30 /*
31 * movsq instruction is only good for aligned case.
32 */
33 "cmpb %%dil, %%sil\n\t"
34 "je 4f\n\t"
35 "3:\n\t"
36 "sub $0x20, %0\n\t"
37 /*
38 * We gobble 32byts forward in each loop.
39 */
40 "5:\n\t"
41 "sub $0x20, %0\n\t"
42 "movq 0*8(%1), %4\n\t"
43 "movq 1*8(%1), %5\n\t"
44 "movq 2*8(%1), %6\n\t"
45 "movq 3*8(%1), %7\n\t"
46 "leaq 4*8(%1), %1\n\t"
47
48 "movq %4, 0*8(%2)\n\t"
49 "movq %5, 1*8(%2)\n\t"
50 "movq %6, 2*8(%2)\n\t"
51 "movq %7, 3*8(%2)\n\t"
52 "leaq 4*8(%2), %2\n\t"
53 "jae 5b\n\t"
54 "addq $0x20, %0\n\t"
55 "jmp 1f\n\t"
56 /*
57 * Handle data forward by movsq.
58 */
59 ".p2align 4\n\t"
60 "4:\n\t"
61 "movq %0, %8\n\t"
62 "movq -8(%1, %0), %4\n\t"
63 "lea -8(%2, %0), %5\n\t"
64 "shrq $3, %8\n\t"
65 "rep movsq\n\t"
66 "movq %4, (%5)\n\t"
67 "jmp 13f\n\t"
68 /*
69 * Handle data backward by movsq.
70 */
71 ".p2align 4\n\t"
72 "7:\n\t"
73 "movq %0, %8\n\t"
74 "movq (%1), %4\n\t"
75 "movq %2, %5\n\t"
76 "leaq -8(%1, %0), %1\n\t"
77 "leaq -8(%2, %0), %2\n\t"
78 "shrq $3, %8\n\t"
79 "std\n\t"
80 "rep movsq\n\t"
81 "cld\n\t"
82 "movq %4, (%5)\n\t"
83 "jmp 13f\n\t"
84
85 /*
86 * Start to prepare for backward copy.
87 */
88 ".p2align 4\n\t"
89 "2:\n\t"
90 "cmp $680, %0\n\t"
91 "jb 6f \n\t"
92 "cmp %%dil, %%sil\n\t"
93 "je 7b \n\t"
94 "6:\n\t"
95 /*
96 * Calculate copy position to tail.
97 */
98 "addq %0, %1\n\t"
99 "addq %0, %2\n\t"
100 "subq $0x20, %0\n\t"
101 /*
102 * We gobble 32byts backward in each loop.
103 */
104 "8:\n\t"
105 "subq $0x20, %0\n\t"
106 "movq -1*8(%1), %4\n\t"
107 "movq -2*8(%1), %5\n\t"
108 "movq -3*8(%1), %6\n\t"
109 "movq -4*8(%1), %7\n\t"
110 "leaq -4*8(%1), %1\n\t"
111
112 "movq %4, -1*8(%2)\n\t"
113 "movq %5, -2*8(%2)\n\t"
114 "movq %6, -3*8(%2)\n\t"
115 "movq %7, -4*8(%2)\n\t"
116 "leaq -4*8(%2), %2\n\t"
117 "jae 8b\n\t"
118 /*
119 * Calculate copy position to head.
120 */
121 "addq $0x20, %0\n\t"
122 "subq %0, %1\n\t"
123 "subq %0, %2\n\t"
124 "1:\n\t"
125 "cmpq $16, %0\n\t"
126 "jb 9f\n\t"
127 /*
128 * Move data from 16 bytes to 31 bytes.
129 */
130 "movq 0*8(%1), %4\n\t"
131 "movq 1*8(%1), %5\n\t"
132 "movq -2*8(%1, %0), %6\n\t"
133 "movq -1*8(%1, %0), %7\n\t"
134 "movq %4, 0*8(%2)\n\t"
135 "movq %5, 1*8(%2)\n\t"
136 "movq %6, -2*8(%2, %0)\n\t"
137 "movq %7, -1*8(%2, %0)\n\t"
138 "jmp 13f\n\t"
139 ".p2align 4\n\t"
140 "9:\n\t"
141 "cmpq $8, %0\n\t"
142 "jb 10f\n\t"
143 /*
144 * Move data from 8 bytes to 15 bytes.
145 */
146 "movq 0*8(%1), %4\n\t"
147 "movq -1*8(%1, %0), %5\n\t"
148 "movq %4, 0*8(%2)\n\t"
149 "movq %5, -1*8(%2, %0)\n\t"
150 "jmp 13f\n\t"
151 "10:\n\t"
152 "cmpq $4, %0\n\t"
153 "jb 11f\n\t"
154 /*
155 * Move data from 4 bytes to 7 bytes.
156 */
157 "movl (%1), %4d\n\t"
158 "movl -4(%1, %0), %5d\n\t"
159 "movl %4d, (%2)\n\t"
160 "movl %5d, -4(%2, %0)\n\t"
161 "jmp 13f\n\t"
162 "11:\n\t"
163 "cmp $2, %0\n\t"
164 "jb 12f\n\t"
165 /*
166 * Move data from 2 bytes to 3 bytes.
167 */
168 "movw (%1), %4w\n\t"
169 "movw -2(%1, %0), %5w\n\t"
170 "movw %4w, (%2)\n\t"
171 "movw %5w, -2(%2, %0)\n\t"
172 "jmp 13f\n\t"
173 "12:\n\t"
174 "cmp $1, %0\n\t"
175 "jb 13f\n\t"
176 /*
177 * Move data for 1 byte.
178 */
179 "movb (%1), %4b\n\t"
180 "movb %4b, (%2)\n\t"
181 "13:\n\t"
182 : "=&d" (d0), "=&S" (d1), "=&D" (d2), "=&a" (ret) ,
183 "=r"(d3), "=r"(d4), "=r"(d5), "=r"(d6), "=&c" (d7)
184 :"0" (count),
185 "1" (src),
186 "2" (dest)
187 :"memory");
188
189 return ret;
190
191}
192EXPORT_SYMBOL(memmove);
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