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authorMikael Starvik <mikael.starvik@axis.com>2005-07-27 14:44:44 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-27 19:26:01 -0400
commit51533b615e605d86154ec1b4e585c8ca1b0b15b7 (patch)
tree4a6d7d8494d2017632d83624fb71b36031e0e7e5 /arch/cris/arch-v32/lib/memset.c
parent5d01e6ce785884a5db5792cd2e5bb36fa82fe23c (diff)
[PATCH] CRIS update: new subarchitecture v32
New CRIS sub architecture named v32. From: Dave Jones <davej@redhat.com> Fix swapped kmalloc args Signed-off-by: Mikael Starvik <starvik@axis.com> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/cris/arch-v32/lib/memset.c')
-rw-r--r--arch/cris/arch-v32/lib/memset.c253
1 files changed, 253 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/lib/memset.c b/arch/cris/arch-v32/lib/memset.c
new file mode 100644
index 000000000000..ffca1214674e
--- /dev/null
+++ b/arch/cris/arch-v32/lib/memset.c
@@ -0,0 +1,253 @@
1/*#************************************************************************#*/
2/*#-------------------------------------------------------------------------*/
3/*# */
4/*# FUNCTION NAME: memset() */
5/*# */
6/*# PARAMETERS: void* dst; Destination address. */
7/*# int c; Value of byte to write. */
8/*# int len; Number of bytes to write. */
9/*# */
10/*# RETURNS: dst. */
11/*# */
12/*# DESCRIPTION: Sets the memory dst of length len bytes to c, as standard. */
13/*# Framework taken from memcpy. This routine is */
14/*# very sensitive to compiler changes in register allocation. */
15/*# Should really be rewritten to avoid this problem. */
16/*# */
17/*#-------------------------------------------------------------------------*/
18/*# */
19/*# HISTORY */
20/*# */
21/*# DATE NAME CHANGES */
22/*# ---- ---- ------- */
23/*# 990713 HP Tired of watching this function (or */
24/*# really, the nonoptimized generic */
25/*# implementation) take up 90% of simulator */
26/*# output. Measurements needed. */
27/*# */
28/*#-------------------------------------------------------------------------*/
29
30#include <linux/types.h>
31
32/* No, there's no macro saying 12*4, since it is "hard" to get it into
33 the asm in a good way. Thus better to expose the problem everywhere.
34 */
35
36/* Assuming 1 cycle per dword written or read (ok, not really true), and
37 one per instruction, then 43+3*(n/48-1) <= 24+24*(n/48-1)
38 so n >= 45.7; n >= 0.9; we win on the first full 48-byte block to set. */
39
40#define ZERO_BLOCK_SIZE (1*12*4)
41
42void *memset(void *pdst,
43 int c,
44 size_t plen)
45{
46 /* Ok. Now we want the parameters put in special registers.
47 Make sure the compiler is able to make something useful of this. */
48
49 register char *return_dst __asm__ ("r10") = pdst;
50 register int n __asm__ ("r12") = plen;
51 register int lc __asm__ ("r11") = c;
52
53 /* Most apps use memset sanely. Only those memsetting about 3..4
54 bytes or less get penalized compared to the generic implementation
55 - and that's not really sane use. */
56
57 /* Ugh. This is fragile at best. Check with newer GCC releases, if
58 they compile cascaded "x |= x << 8" sanely! */
59 __asm__("movu.b %0,$r13 \n\
60 lslq 8,$r13 \n\
61 move.b %0,$r13 \n\
62 move.d $r13,%0 \n\
63 lslq 16,$r13 \n\
64 or.d $r13,%0"
65 : "=r" (lc) : "0" (lc) : "r13");
66
67 {
68 register char *dst __asm__ ("r13") = pdst;
69
70 /* This is NONPORTABLE, but since this whole routine is */
71 /* grossly nonportable that doesn't matter. */
72
73 if (((unsigned long) pdst & 3) != 0
74 /* Oops! n=0 must be a legal call, regardless of alignment. */
75 && n >= 3)
76 {
77 if ((unsigned long)dst & 1)
78 {
79 *dst = (char) lc;
80 n--;
81 dst++;
82 }
83
84 if ((unsigned long)dst & 2)
85 {
86 *(short *)dst = lc;
87 n -= 2;
88 dst += 2;
89 }
90 }
91
92 /* Now the fun part. For the threshold value of this, check the equation
93 above. */
94 /* Decide which copying method to use. */
95 if (n >= ZERO_BLOCK_SIZE)
96 {
97 /* For large copies we use 'movem' */
98
99 /* It is not optimal to tell the compiler about clobbering any
100 registers; that will move the saving/restoring of those registers
101 to the function prologue/epilogue, and make non-movem sizes
102 suboptimal.
103
104 This method is not foolproof; it assumes that the "asm reg"
105 declarations at the beginning of the function really are used
106 here (beware: they may be moved to temporary registers).
107 This way, we do not have to save/move the registers around into
108 temporaries; we can safely use them straight away.
109
110 If you want to check that the allocation was right; then
111 check the equalities in the first comment. It should say
112 "r13=r13, r12=r12, r11=r11" */
113 __asm__ volatile (" \n\
114 ;; Check that the register asm declaration got right. \n\
115 ;; The GCC manual says it will work, but there *has* been bugs. \n\
116 .ifnc %0-%1-%4,$r13-$r12-$r11 \n\
117 .err \n\
118 .endif \n\
119 \n\
120 ;; Save the registers we'll clobber in the movem process \n\
121 ;; on the stack. Don't mention them to gcc, it will only be \n\
122 ;; upset. \n\
123 subq 11*4,$sp \n\
124 movem $r10,[$sp] \n\
125 \n\
126 move.d $r11,$r0 \n\
127 move.d $r11,$r1 \n\
128 move.d $r11,$r2 \n\
129 move.d $r11,$r3 \n\
130 move.d $r11,$r4 \n\
131 move.d $r11,$r5 \n\
132 move.d $r11,$r6 \n\
133 move.d $r11,$r7 \n\
134 move.d $r11,$r8 \n\
135 move.d $r11,$r9 \n\
136 move.d $r11,$r10 \n\
137 \n\
138 ;; Now we've got this: \n\
139 ;; r13 - dst \n\
140 ;; r12 - n \n\
141 \n\
142 ;; Update n for the first loop \n\
143 subq 12*4,$r12 \n\
1440: \n\
145 subq 12*4,$r12 \n\
146 bge 0b \n\
147 movem $r11,[$r13+] \n\
148 \n\
149 addq 12*4,$r12 ;; compensate for last loop underflowing n \n\
150 \n\
151 ;; Restore registers from stack \n\
152 movem [$sp+],$r10"
153
154 /* Outputs */ : "=r" (dst), "=r" (n)
155 /* Inputs */ : "0" (dst), "1" (n), "r" (lc));
156 }
157
158 /* Either we directly starts copying, using dword copying
159 in a loop, or we copy as much as possible with 'movem'
160 and then the last block (<44 bytes) is copied here.
161 This will work since 'movem' will have updated src,dst,n. */
162
163 while ( n >= 16 )
164 {
165 *((long*)dst)++ = lc;
166 *((long*)dst)++ = lc;
167 *((long*)dst)++ = lc;
168 *((long*)dst)++ = lc;
169 n -= 16;
170 }
171
172 /* A switch() is definitely the fastest although it takes a LOT of code.
173 * Particularly if you inline code this.
174 */
175 switch (n)
176 {
177 case 0:
178 break;
179 case 1:
180 *(char*)dst = (char) lc;
181 break;
182 case 2:
183 *(short*)dst = (short) lc;
184 break;
185 case 3:
186 *((short*)dst)++ = (short) lc;
187 *(char*)dst = (char) lc;
188 break;
189 case 4:
190 *((long*)dst)++ = lc;
191 break;
192 case 5:
193 *((long*)dst)++ = lc;
194 *(char*)dst = (char) lc;
195 break;
196 case 6:
197 *((long*)dst)++ = lc;
198 *(short*)dst = (short) lc;
199 break;
200 case 7:
201 *((long*)dst)++ = lc;
202 *((short*)dst)++ = (short) lc;
203 *(char*)dst = (char) lc;
204 break;
205 case 8:
206 *((long*)dst)++ = lc;
207 *((long*)dst)++ = lc;
208 break;
209 case 9:
210 *((long*)dst)++ = lc;
211 *((long*)dst)++ = lc;
212 *(char*)dst = (char) lc;
213 break;
214 case 10:
215 *((long*)dst)++ = lc;
216 *((long*)dst)++ = lc;
217 *(short*)dst = (short) lc;
218 break;
219 case 11:
220 *((long*)dst)++ = lc;
221 *((long*)dst)++ = lc;
222 *((short*)dst)++ = (short) lc;
223 *(char*)dst = (char) lc;
224 break;
225 case 12:
226 *((long*)dst)++ = lc;
227 *((long*)dst)++ = lc;
228 *((long*)dst)++ = lc;
229 break;
230 case 13:
231 *((long*)dst)++ = lc;
232 *((long*)dst)++ = lc;
233 *((long*)dst)++ = lc;
234 *(char*)dst = (char) lc;
235 break;
236 case 14:
237 *((long*)dst)++ = lc;
238 *((long*)dst)++ = lc;
239 *((long*)dst)++ = lc;
240 *(short*)dst = (short) lc;
241 break;
242 case 15:
243 *((long*)dst)++ = lc;
244 *((long*)dst)++ = lc;
245 *((long*)dst)++ = lc;
246 *((short*)dst)++ = (short) lc;
247 *(char*)dst = (char) lc;
248 break;
249 }
250 }
251
252 return return_dst; /* destination pointer. */
253} /* memset() */
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