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authorCharles.Forsyth <devnull@localhost>2006-12-22 17:07:39 +0000
committerCharles.Forsyth <devnull@localhost>2006-12-22 17:07:39 +0000
commit37da2899f40661e3e9631e497da8dc59b971cbd0 (patch)
treecbc6d4680e347d906f5fa7fca73214418741df72 /libkern/strchr-arm.s
parent54bc8ff236ac10b3eaa928fd6bcfc0cdb2ba46ae (diff)
20060303a
Diffstat (limited to 'libkern/strchr-arm.s')
-rw-r--r--libkern/strchr-arm.s52
1 files changed, 52 insertions, 0 deletions
diff --git a/libkern/strchr-arm.s b/libkern/strchr-arm.s
new file mode 100644
index 00000000..9c04273c
--- /dev/null
+++ b/libkern/strchr-arm.s
@@ -0,0 +1,52 @@
+TEXT strchr(SB), $-4
+ MOVBU c+4(FP), R1
+ CMP $0, R1
+ BEQ _null
+
+_strchr: /* not looking for a null, byte at a time */
+ MOVBU.P 1(R0), R2
+ CMP R1, R2
+ BEQ _sub1
+
+ CMP $0, R2
+ BNE _strchr
+
+_return0: /* character not found in string, return 0 */
+ MOVW $0, R0
+ RET
+
+_null: /* looking for null, align */
+ AND.S $3, R0, R2
+ BEQ _aligned
+
+ MOVBU.P 1(R0), R4
+ CMP $0, R4
+ BEQ _sub1
+ B _null
+
+_aligned:
+ MOVW $0xFF, R3 /* mask */
+
+_loop:
+ MOVW.P 4(R0), R4 /* 4 at a time */
+ TST R4, R3 /* AND.S R2, R3, Rx */
+ BEQ _sub4
+ TST R4>>8, R3
+ BEQ _sub3
+ TST R4>>16, R3
+ BEQ _sub2
+ TST R4>>24, R3
+ BNE _loop
+
+_sub1: /* compensate for pointer increment */
+ SUB $1, R0
+ RET
+_sub2:
+ SUB $2, R0
+ RET
+_sub3:
+ SUB $3, R0
+ RET
+_sub4:
+ SUB $4, R0
+ RET