aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/powerpc/powerpc32/405/strlen.S
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/powerpc32/405/strlen.S')
-rw-r--r--sysdeps/powerpc/powerpc32/405/strlen.S75
1 files changed, 75 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/405/strlen.S b/sysdeps/powerpc/powerpc32/405/strlen.S
new file mode 100644
index 0000000000..77d22ea673
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/405/strlen.S
@@ -0,0 +1,75 @@
+/* Optimized strlen implementation for PowerPC476.
+ Copyright (C) 2010-2013 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+/* strlen
+
+ Register Use
+ r3:source address and return length of string
+ r4:byte counter
+
+ Implementation description
+ Load 2 words at a time and count bytes, if we find null we subtract one from
+ the count and return the count value. We need to subtract one because
+ we don't count the null character as a byte. */
+
+EALIGN (strlen,5,0)
+ neg r7,r3
+ clrlwi. r8,r7,29
+ addi r4,0,0
+ beq L(byte_count_loop)
+ mtctr r8
+
+L(loop):
+ lbz r5,0(r3)
+ cmpi cr5,r5,0x0
+ addi r3,r3,0x1
+ addi r4,r4,0x1
+ beq cr5,L(end_strlen)
+ bdnz L(loop)
+
+L(byte_count_loop):
+ lwz r5,0(r3)
+ lwz r6,4(r3)
+ dlmzb. r12,r5,r6
+ add r4,r4,r12
+ bne L(end_strlen)
+ lwz r5,8(r3)
+ lwz r6,12(r3)
+ dlmzb. r12,r5,r6
+ add r4,r4,r12
+ bne L(end_strlen)
+ lwz r5,16(r3)
+ lwz r6,20(r3)
+ dlmzb. r12,r5,r6
+ add r4,r4,r12
+ bne L(end_strlen)
+ lwz r5,24(r3)
+ lwz r6,28(r3)
+ addi r3,r3,0x20
+ dlmzb. r12,r5,r6
+ add r4,r4,r12
+ bne L(end_strlen)
+ b L(byte_count_loop)
+
+L(end_strlen):
+ addi r3,r4,-1
+ blr
+END (strlen)
+libc_hidden_builtin_def (strlen)