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authorUlrich Drepper <drepper@redhat.com>1998-07-30 12:47:25 +0000
committerUlrich Drepper <drepper@redhat.com>1998-07-30 12:47:25 +0000
commitbdd421cc6d055af6a1a561344b2fa56267cad617 (patch)
treebe16db84076d9a9aa58deed3f7452fabc5fa4d04 /sysdeps/alpha/ffs.S
parentccd17b3265ed22f6add55b574b684f6e11a2ea8c (diff)
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Update.
1998-07-30 12:38 Ulrich Drepper <drepper@cygnus.com> * sysdeps/i386/ffs.c: Add ffsl entry point. * sysdeps/i386/i686/ffs.c: Likewise. * sysdeps/m68k/ffs.c: Likewise. * sysdeps/powerpc/ffs.c: Likewise. * sysdeps/i386/i486/bits/string.h: Add optimizations for ffs/ffsl on i686. 1998-07-30 Richard Henderson <rth@cygnus.com> * elf/Makefile (ld-map): Move initialization below Makeconfig include. * sysdeps/libm-ieee754/k_standard.c (zero): Make non-const to work around gcc bug. * string/string.h (ffsl, ffsll): Prototype. * string/Version (GLIBC_2.1): Add them. * sysdeps/alpha/ffs.S: Schedule for EV5. Add ffsl and ffsll entry points. * sysdeps/alpha/ffsll.S: New file. Empty. * sysdeps/generic/ffs.c: Add ffsl and ffsll entry points. * sysdeps/generic/ffsll.c: New file. * string/Makefile (routines): Add ffsll. 1998-07-30 10:03 Ulrich Drepper <drepper@cygnus.com> * sysdeps/unix/sysv/linux/alpha/bits/time.h: Don't define CLK_TCK for strictly ISO C compliant programs. * sysdeps/unix/sysv/linux/mips/bits/time.h: Likewise. 1998-07-22 Andreas Jaeger <aj@arthur.rhein-neckar.de> * inet/protocols/rwhod.h: Correct typo in comment. * configure.in: Use better regex for gettext.
Diffstat (limited to 'sysdeps/alpha/ffs.S')
-rw-r--r--sysdeps/alpha/ffs.S87
1 files changed, 52 insertions, 35 deletions
diff --git a/sysdeps/alpha/ffs.S b/sysdeps/alpha/ffs.S
index 6eb3afdff7..91cce4182b 100644
--- a/sysdeps/alpha/ffs.S
+++ b/sysdeps/alpha/ffs.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
Contributed by David Mosberger (davidm@cs.arizona.edu).
This file is part of the GNU C Library.
@@ -25,49 +25,66 @@
.set noreorder
.set noat
+
ENTRY(__ffs)
#ifdef PROF
ldgp gp, 0(pv)
lda AT, _mcount
jsr AT, (AT), _mcount
.prologue 1
+ zap $16, 0xF0, $16
+ br $ffsl..ng
#else
.prologue 0
+ zap $16, 0xF0, $16
+ # FALLTHRU
#endif
+END(__ffs)
- ldq_u zero, 0(sp) # on the 21064, this helps dual-issuing
- addl a0, zero, a0 # the last insn and reduces the stall
- negq a0, t0 # due to the srl instruction
- and a0, t0, t0
- clr v0
- beq a0, $done
-
- # now do binary search for first non-zero bit
-
- zapnot t0, 0x03, t2
- addq v0, 16, t3
- cmoveq t2, t3, v0
-
- zapnot t0, 0x05, t2
- addq v0, 8, t3
- cmoveq t2, t3, v0
-
- srl t0, v0, t0
- addq v0, 1, v0
-
- and t0, 0x0f, t2
- addq v0, 4, t3
- cmoveq t2, t3, v0
-
- and t0, 0x33, t2
- addq v0, 2, t3
- cmoveq t2, t3, v0
-
- and t0, 0x55, t2
- addq v0, 1, t3
- cmoveq t2, t3, v0
-
-$done: ret
+ .align 4
+ENTRY(ffsl)
+#ifdef PROF
+ ldgp gp, 0(pv)
+ lda AT, _mcount
+ jsr AT, (AT), _mcount
+ .prologue 1
+$ffsl..ng:
+#else
+ .prologue 0
+#endif
+ not $16, $1 # e0 :
+ ldi $2, -1 # .. e1 :
+ cmpbge $1, $2, $3 # e0 : bit N == 1 for byte N == 0
+ clr $0 # .. e1 :
+ addq $3, 1, $4 # e0 :
+ bic $4, $3, $3 # e1 : bit N == 1 for first byte N != 0
+ and $3, 0xF0, $4 # e0 :
+ and $3, 0xCC, $5 # .. e1 :
+ and $3, 0xAA, $6 # e0 :
+ cmovne $4, 4, $0 # .. e1 :
+ cmovne $5, 2, $5 # e0 :
+ cmovne $6, 1, $6 # .. e1 :
+ addl $0, $5, $0 # e0 :
+ addl $0, $6, $0 # e1 : $0 == N
+ extbl $16, $0, $1 # e0 : $1 == byte N
+ ldi $2, 1 # .. e1 :
+ negq $1, $3 # e0 :
+ and $3, $1, $3 # e1 : bit N == least bit set of byte N
+ and $3, 0xF0, $4 # e0 :
+ and $3, 0xCC, $5 # .. e1 :
+ and $3, 0xAA, $6 # e0 :
+ cmovne $4, 5, $2 # .. e1 :
+ cmovne $5, 2, $5 # e0 :
+ cmovne $6, 1, $6 # .. e1 :
+ s8addl $0, $2, $0 # e0 : mult byte ofs by 8 and sum
+ addl $5, $6, $5 # .. e1 :
+ addl $0, $5, $0 # e0 :
+ nop # .. e1 :
+ cmoveq $16, 0, $0 # e0 : trap input == 0 case.
+ ret # .. e1 : 18
+
+END(ffsl)
- END(__ffs)
weak_alias (__ffs, ffs)
+weak_extern (ffsl)
+weak_alias (ffsl, ffsll)