date and time created 92/02/29 12:48:57 by bostic

SCCS-vsn: lib/libc/mips/string/bzero.s 5.1

diff --git a/usr/src/lib/libc/mips/string/bzero.s b/usr/src/lib/libc/mips/string/bzero.s
new file mode 100644 (file)
index 0000000..a8779c3
--- /dev/null
+++ b/usr/src/lib/libc/mips/string/bzero.s
@@ -0,0 +1,47 @@
+/*-
+ * Copyright (c) 1991 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Ralph Campbell.
+ *
+ * %sccs.include.redist.c%
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+       ASMSTR("@(#)bzero.s     5.1 (Berkeley) %G%")
+#endif /* LIBC_SCCS and not lint */
+
+#include "DEFS.h"
+
+/* bzero(s1, n) */
+
+LEAF(bzero)
+       .set    noreorder
+       blt     a1, 12, smallclr        # small amount to clear?
+       subu    a3, zero, a0            # compute # bytes to word align address
+       and     a3, a3, 3
+       beq     a3, zero, 1f            # skip if word aligned
+       subu    a1, a1, a3              # subtract from remaining count
+       swr     zero, 0(a0)             # clear 1, 2, or 3 bytes to align
+       addu    a0, a0, a3
+1:
+       and     v0, a1, 3               # compute number of words left
+       subu    a3, a1, v0
+       move    a1, v0
+       addu    a3, a3, a0              # compute ending address
+2:
+       addu    a0, a0, 4               # clear words
+       bne     a0, a3, 2b              #   unrolling loop doesn't help
+       sw      zero, -4(a0)            #   since we're limited by memory speed
+smallclr:
+       ble     a1, zero, 2f
+       addu    a3, a1, a0              # compute ending address
+1:
+       addu    a0, a0, 1               # clear bytes
+       bne     a0, a3, 1b
+       sb      zero, -1(a0)
+2:
+       j       ra
+       nop
+END(bzero)