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authorTaru Karttunen <taruti@taruti.net>2011-03-30 15:46:40 +0300
committerTaru Karttunen <taruti@taruti.net>2011-03-30 15:46:40 +0300
commite5888a1ffdae813d7575f5fb02275c6bb07e5199 (patch)
treed8d51eac403f07814b9e936eed0c9a79195e2450 /sys/src/libc/68020/memset.s
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/libc/68020/memset.s')
-rwxr-xr-xsys/src/libc/68020/memset.s47
1 files changed, 47 insertions, 0 deletions
diff --git a/sys/src/libc/68020/memset.s b/sys/src/libc/68020/memset.s
new file mode 100755
index 000000000..d4b773416
--- /dev/null
+++ b/sys/src/libc/68020/memset.s
@@ -0,0 +1,47 @@
+ TEXT memset(SB), $0
+ MOVL n+8(FP), R0
+ BLE return
+ MOVL s1+0(FP), A1
+ CLRL R1
+ MOVB c+7(FP), R1
+ BEQ l1
+
+/*
+ * create 4 replicated copies
+ * of the byte in R1
+ */
+ MOVL R1, R2
+ ASLL $8, R2
+ ORL R2, R1
+ MOVL R1, R2
+ SWAP R2
+ ORL R2, R1
+
+/*
+ * quad-long-at-a-time set
+ * destination allignment is not
+ * very important.
+ */
+l1:
+ SUBL $16, R0
+ BLT l2
+ MOVL R1, (A1)+
+ MOVL R1, (A1)+
+ MOVL R1, (A1)+
+ MOVL R1, (A1)+
+ BRA l1
+
+/*
+ * cleanup byte-at-a-time
+ */
+l2:
+ ADDL $15, R0
+ BLT return
+l3:
+ MOVB R1, (A1)+
+ SUBL $1, R0
+ BGE l3
+
+return:
+ MOVL s1+0(FP),R0
+ RTS