patch-2.3.43 linux/arch/ia64/lib/strnlen_user.S

• Lines: 56
• Date: Sun Feb 6 18:42:40 2000
• Orig file: v2.3.42/linux/arch/ia64/lib/strnlen_user.S
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.42/linux/arch/ia64/lib/strnlen_user.S linux/arch/ia64/lib/strnlen_user.S
@@ -0,0 +1,55 @@
+/*
+ * Returns 0 if exception before NUL or reaching the supplied limit (N),
+ * a value greater than N if the string is longer than the limit, else
+ * strlen.
+ *
+ * Inputs:
+ *	in0:	address of buffer
+ *	in1:	string length limit N
+ * Outputs:
+ *	r8:	0 in case of fault, strlen(buffer)+1 otherwise
+ * 
+ * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+/* If a fault occurs, r8 gets set to -EFAULT and r9 gets cleared.  */
+#define EX(x...)				\
+	.section __ex_table,"a";		\
+	data4 @gprel(99f);			\
+	data4 (.Lexit-99f)|1;			\
+	.previous				\
+99:	x;
+
+	.text
+	.psr abi64
+	.psr lsb
+	.lsb
+
+	.align 32
+	.global __strnlen_user
+	.proc __strnlen_user
+__strnlen_user:
+	alloc r2=ar.pfs,2,0,0,0
+	mov r16=ar.lc			// preserve ar.lc
+	add r3=-1,in1
+	;;
+	mov ar.lc=r3
+	mov r9=0
+
+	// XXX braindead strlen loop---this needs to be optimized
+.Loop1:
+	EX(ld1 r8=[in0],1)
+	add r9=1,r9
+	;;
+	cmp.eq p6,p0=r8,r0
+(p6)	br.dpnt.few .Lexit
+	br.cloop.dptk.few .Loop1
+
+	add r9=1,in1			// NUL not found---return N+1
+	;;
+.Lexit:
+	mov r8=r9
+	mov ar.lc=r16			// restore ar.lc
+	br.ret.sptk.few rp
+
+	.endp __strnlen_user