diff options
| author | Alexey Brodkin <abrodkin@synopsys.com> | 2018-01-24 23:22:33 +0300 |
|---|---|---|
| committer | Alexey Brodkin <abrodkin@synopsys.com> | 2018-03-21 16:21:34 +0300 |
| commit | 2178817c4a105ead044e054bf902f256e6d589c2 (patch) | |
| tree | b8fd816159aa1c08cdd29dad6fa69a8b3d5075cc /arch/arc/lib/strlen.S | |
| parent | 9c0e2f6ed391f199ba1bf30c7d0b71123a012958 (diff) | |
arc: Get rid of handwritten string routines
U-Boot is a bit special piese of software because it is being
only executed once on power-on as compared to operating system
for example. That's why we don't care much about performance
optimizations instead we're more concerned about size. And up-to-date
compilers might produce much smaller code compared to
performance-optimized routines copy-pasted from the Linux kernel.
Here's an example:
------------------------------->8--------------------------
--- size_asm_strings.txt
+++ size_c_strings.txt
@@ -1,2 +1,2 @@
text data bss dec hex filename
- 121260 3784 3308 128352 1f560 u-boot
+ 120448 3784 3308 127540 1f234 u-boot
------------------------------->8--------------------------
See we were able to shave off ~800 bytes of .text section.
Also usage of string routines implemented in C gives us an ability
to support more HW flavors for free: generated instructions will match
our target as long as correct compiler option is used.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Diffstat (limited to 'arch/arc/lib/strlen.S')
| -rw-r--r-- | arch/arc/lib/strlen.S | 80 |
1 files changed, 0 insertions, 80 deletions
diff --git a/arch/arc/lib/strlen.S b/arch/arc/lib/strlen.S deleted file mode 100644 index 666e22c0d5..0000000000 --- a/arch/arc/lib/strlen.S +++ /dev/null @@ -1,80 +0,0 @@ -/* - * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved. - * - * SPDX-License-Identifier: GPL-2.0+ - */ - -.global strlen -.align 4 -strlen: - or %r3, %r0, 7 - ld %r2, [%r3, -7] - ld.a %r6, [%r3, -3] - mov %r4, 0x01010101 - /* uses long immediate */ -#ifdef __LITTLE_ENDIAN__ - asl_s %r1, %r0, 3 - btst_s %r0, 2 - asl %r7, %r4, %r1 - ror %r5, %r4 - sub %r1, %r2, %r7 - bic_s %r1, %r1, %r2 - mov.eq %r7, %r4 - sub %r12, %r6, %r7 - bic %r12, %r12, %r6 - or.eq %r12, %r12, %r1 - and %r12, %r12, %r5 - brne %r12, 0, .Learly_end -#else /* __BIG_ENDIAN__ */ - ror %r5, %r4 - btst_s %r0, 2 - mov_s %r1, 31 - sub3 %r7, %r1, %r0 - sub %r1, %r2, %r4 - bic_s %r1, %r1, %r2 - bmsk %r1, %r1, %r7 - sub %r12, %r6, %r4 - bic %r12, %r12, %r6 - bmsk.ne %r12, %r12, %r7 - or.eq %r12, %r12, %r1 - and %r12, %r12, %r5 - brne %r12, 0, .Learly_end -#endif /* _ENDIAN__ */ - -.Loop: - ld_s %r2, [%r3, 4] - ld.a %r6, [%r3, 8] - /* stall for load result */ - sub %r1, %r2, %r4 - bic_s %r1, %r1, %r2 - sub %r12, %r6, %r4 - bic %r12, %r12, %r6 - or %r12, %r12, %r1 - and %r12, %r12, %r5 - breq %r12, 0, .Loop -.Lend: - and.f %r1, %r1, %r5 - sub.ne %r3, %r3, 4 - mov.eq %r1, %r12 -#ifdef __LITTLE_ENDIAN__ - sub_s %r2, %r1, 1 - bic_s %r2, %r2, %r1 - norm %r1, %r2 - sub_s %r0, %r0, 3 - lsr_s %r1, %r1, 3 - sub %r0, %r3, %r0 - j_s.d [%blink] - sub %r0, %r0, %r1 -#else /* __BIG_ENDIAN__ */ - lsr_s %r1, %r1, 7 - mov.eq %r2, %r6 - bic_s %r1, %r1, %r2 - norm %r1, %r1 - sub %r0, %r3, %r0 - lsr_s %r1, %r1, 3 - j_s.d [%blink] - add %r0, %r0, %r1 -#endif /* _ENDIAN */ -.Learly_end: - b.d .Lend - sub_s.ne %r1, %r1, %r1 |