File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/alpha/lib/strcat.S b/arch/alpha/lib/strcat.S
new file mode 100644
index 0000000..393f503
--- /dev/null
+++ b/arch/alpha/lib/strcat.S
@@ -0,0 +1,52 @@
+/*
+ * arch/alpha/lib/strcat.S
+ * Contributed by Richard Henderson (rth@tamu.edu)
+ *
+ * Append a null-terminated string from SRC to DST.
+ */
+
+ .text
+
+ .align 3
+ .globl strcat
+ .ent strcat
+strcat:
+ .frame $30, 0, $26
+ .prologue 0
+
+ mov $16, $0 # set up return value
+
+ /* Find the end of the string. */
+
+ ldq_u $1, 0($16) # load first quadword (a0 may be misaligned)
+ lda $2, -1
+ insqh $2, $16, $2
+ andnot $16, 7, $16
+ or $2, $1, $1
+ cmpbge $31, $1, $2 # bits set iff byte == 0
+ bne $2, $found
+
+$loop: ldq $1, 8($16)
+ addq $16, 8, $16
+ cmpbge $31, $1, $2
+ beq $2, $loop
+
+$found: negq $2, $3 # clear all but least set bit
+ and $2, $3, $2
+
+ and $2, 0xf0, $3 # binary search for that set bit
+ and $2, 0xcc, $4
+ and $2, 0xaa, $5
+ cmovne $3, 4, $3
+ cmovne $4, 2, $4
+ cmovne $5, 1, $5
+ addq $3, $4, $3
+ addq $16, $5, $16
+ addq $16, $3, $16
+
+ /* Now do the append. */
+
+ mov $26, $23
+ br __stxcpy
+
+ .end strcat