libkern pica stuff

1 files changed, 35 insertions, 0 deletions

diff --git a/sys/lib/libkern/arch/mips/bzero.S b/sys/lib/libkern/arch/mips/bzero.S
new file mode 100644
index 00000000000..07fae64f768
--- /dev/null
+++ b/sys/lib/libkern/arch/mips/bzero.S
@@ -0,0 +1,35 @@
+#include "DEFS.h"
+
+/*
+ * bzero(s1, n)
+ */
+LEAF(bzero)
+ALEAF(blkclr)
+	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 does not help
+	sw	zero, -4(a0)		#  since we are 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)
+