diff options
| author |   miod <miod@openbsd.org> | 2004-04-01 20:39:55 +0000 |
|---|---|---|
| committer | miod <miod@openbsd.org> | 2004-04-01 20:39:55 +0000 |
| commit | d84580875301d99e4ccd8f1d9f79a515bdec1167 (patch) | |
| tree | 998cb9b1ed71dba764dcc29855b69b3809d7b4d2 /sys/lib/libkern/arch | |
| parent | audio/x-vorbis, ok henning@ (diff) | |
| download | wireguard-openbsd-d84580875301d99e4ccd8f1d9f79a515bdec1167.tar.xz wireguard-openbsd-d84580875301d99e4ccd8f1d9f79a515bdec1167.zip | |
It turns out that the so-called fast ffs(3) routines were wrong, as soon as
more than one bit is set, as the ff1 instruction counts from the highest
order.
However, gcc/m88k with optimization enabled would use a correct, short
sequence based upon ff1 and tweaks, to achieve the intended result, hence
i did not catch this flaw initially.
So revert to the C implementation - it is correct, still decently fast, and
will only be used when compiling at -O0.
Diffstat (limited to 'sys/lib/libkern/arch')
| -rw-r--r-- | sys/lib/libkern/arch/m88k/Makefile.inc | 4 | ||||
| -rw-r--r-- | sys/lib/libkern/arch/m88k/ffs.S | 16 |
2 files changed, 2 insertions, 18 deletions
diff --git a/sys/lib/libkern/arch/m88k/Makefile.inc b/sys/lib/libkern/arch/m88k/Makefile.inc index 953cb7d5684..d34437d10d7 100644 --- a/sys/lib/libkern/arch/m88k/Makefile.inc +++ b/sys/lib/libkern/arch/m88k/Makefile.inc @@ -1,6 +1,6 @@ -# $OpenBSD: Makefile.inc,v 1.7 2004/01/21 14:28:36 miod Exp $ +# $OpenBSD: Makefile.inc,v 1.8 2004/04/01 20:39:59 miod Exp $ SRCS+= __main.c imax.c imin.c lmax.c lmin.c max.c min.c ulmax.c ulmin.c \ memchr.c memcmp.c memset.c bcmp.c random.c \ strcmp.c strlcat.c strlcpy.c strlen.c strncmp.c \ - strncpy.c scanc.c skpc.c strncasecmp.c ffs.S + strncpy.c scanc.c skpc.c strncasecmp.c ffs.c diff --git a/sys/lib/libkern/arch/m88k/ffs.S b/sys/lib/libkern/arch/m88k/ffs.S deleted file mode 100644 index aca0ca50381..00000000000 --- a/sys/lib/libkern/arch/m88k/ffs.S +++ /dev/null @@ -1,16 +0,0 @@ -/* $OpenBSD: ffs.S,v 1.2 2004/01/22 20:39:06 deraadt Exp $ */ - -/* - * Written by Miodrag Vallat, 2004 - Public Domain - */ - -#include <machine/asm.h> - -ENTRY(ffs) - bcnd eq0, r2, 1f /* ff1(0) = 32, treat differently */ - ff1 r3, r2 - jmp.n r1 - add r2, r3, 1 /* ff1 returns 0-31, need to increment */ -1: - jmp.n r1 - or r2, r0, r0 |