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authorRoland McGrath <roland@gnu.org>1996-03-17 01:58:17 +0000
committerRoland McGrath <roland@gnu.org>1996-03-17 01:58:17 +0000
commit6025c399e9fd73efeb5b93db78ec021d3fce2b1c (patch)
treee213f46f05f3cb8638d22a81d437a32754062173 /sysdeps/alpha/memchr.S
parentd3b7d2ac93ed6fce3f7cb8e567d2b96719dde01a (diff)
Sat Mar 16 20:08:22 1996 David Mosberger-Tang <davidm@azstarnet.com>
* sysdeps/alpha/memchr.S: new file. * sysdeps/alpha/memchr.c: obsolete file removed. Sat Mar 16 16:26:09 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> * misc/Makefile (headers): Add sysexits.h. * misc/sysexits.h: New file. Thu Mar 14 15:20:45 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/libm-ieee754/e_atan2.c (__ieee754_atan2): Change atan call to __atan. * sysdeps/libm-ieee754/e_atan2f.c (__ieee754_atan2f): Change atanf call to __atanf. * sysdeps/m68k/fpu/e_acos.c, sysdeps/m68k/fpu/e_acosf.c, sysdeps/m68k/fpu/e_asin.c, sysdeps/m68k/fpu/e_asinf.c, sysdeps/m68k/fpu/e_atanh.c, sysdeps/m68k/fpu/e_atanhf.c, sysdeps/m68k/fpu/e_cosh.c, sysdeps/m68k/fpu/e_coshf.c, sysdeps/m68k/fpu/e_exp.c, sysdeps/m68k/fpu/e_expf.c, sysdeps/m68k/fpu/e_fmod.c, sysdeps/m68k/fpu/e_fmodf.c, sysdeps/m68k/fpu/e_log.c, sysdeps/m68k/fpu/e_log10.c, sysdeps/m68k/fpu/e_log10f.c, sysdeps/m68k/fpu/e_logf.c, sysdeps/m68k/fpu/e_pow.c, sysdeps/m68k/fpu/e_powf.c, sysdeps/m68k/fpu/e_remainder.c, sysdeps/m68k/fpu/e_remainderf.c, sysdeps/m68k/fpu/e_scalb.c, sysdeps/m68k/fpu/e_scalbf.c, sysdeps/m68k/fpu/e_sinh.c, sysdeps/m68k/fpu/e_sinhf.c, sysdeps/m68k/fpu/e_sqrt.c, sysdeps/m68k/fpu/e_sqrtf.c, sysdeps/m68k/fpu/k_cos.c, sysdeps/m68k/fpu/k_cosf.c, sysdeps/m68k/fpu/k_sin.c, sysdeps/m68k/fpu/k_sinf.c, sysdeps/m68k/fpu/k_tan.c, sysdeps/m68k/fpu/k_tanf.c, sysdeps/m68k/fpu/s_atan.c, sysdeps/m68k/fpu/s_atanf.c, sysdeps/m68k/fpu/s_ceil.c, sysdeps/m68k/fpu/s_ceilf.c, sysdeps/m68k/fpu/s_cos.c, sysdeps/m68k/fpu/s_cosf.c, sysdeps/m68k/fpu/s_expm1.c, sysdeps/m68k/fpu/s_expm1f.c, sysdeps/m68k/fpu/s_fabs.c, sysdeps/m68k/fpu/s_fabsf.c, sysdeps/m68k/fpu/s_finite.c, sysdeps/m68k/fpu/s_finitef.c, sysdeps/m68k/fpu/s_floor.c, sysdeps/m68k/fpu/s_floorf.c, sysdeps/m68k/fpu/s_frexp.c, sysdeps/m68k/fpu/s_frexpf.c, sysdeps/m68k/fpu/s_ilogb.c, sysdeps/m68k/fpu/s_ilogbf.c, sysdeps/m68k/fpu/s_isinf.c, sysdeps/m68k/fpu/s_isinff.c, sysdeps/m68k/fpu/s_isnan.c, sysdeps/m68k/fpu/s_isnanf.c, sysdeps/m68k/fpu/s_ldexp.c, sysdeps/m68k/fpu/s_ldexpf.c, sysdeps/m68k/fpu/s_log1p.c, sysdeps/m68k/fpu/s_log1pf.c, sysdeps/m68k/fpu/s_logb.c, sysdeps/m68k/fpu/s_logbf.c, sysdeps/m68k/fpu/s_modf.c, sysdeps/m68k/fpu/s_modff.c, sysdeps/m68k/fpu/s_rint.c, sysdeps/m68k/fpu/s_rintf.c, sysdeps/m68k/fpu/s_scalbn.c, sysdeps/m68k/fpu/s_scalbnf.c, sysdeps/m68k/fpu/s_significand.c, sysdeps/m68k/fpu/s_significandf.c, sysdeps/m68k/fpu/s_sin.c, sysdeps/m68k/fpu/s_sinf.c, sysdeps/m68k/fpu/s_tan.c, sysdeps/m68k/fpu/s_tanf.c, sysdeps/m68k/fpu/s_tanh.c, sysdeps/m68k/fpu/s_tanhf.c: New files, for m68881 port of fdlibm. * sysdeps/m68k/fpu/__math.h: Rewritten for fdlibm. * sysdeps/m68k/fpu/isinfl.c: Rewritten to get argument type right. * sysdeps/m68k/fpu/isnanl.c: Likewise. Thu Mar 14 06:01:07 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> * posix/glob.c (glob): In GLOB_BRACE brace expansion, fix buffer size calculation to include trailing invariant portion. Don't use alloca; instead use a dynamic auto array for GCC, malloc for non-GCC. Handle nested braces properly. * elf/elf.h (Elf32_auxv_t): Specify prototype (void) for `a_un.a_fcn'. * libc-symbols.h (lint): New macro. Fri Mar 15 01:18:00 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * libio/iosetvbuf.c: Add weak alias setvbuf.
Diffstat (limited to 'sysdeps/alpha/memchr.S')
-rw-r--r--sysdeps/alpha/memchr.S163
1 files changed, 163 insertions, 0 deletions
diff --git a/sysdeps/alpha/memchr.S b/sysdeps/alpha/memchr.S
new file mode 100644
index 0000000000..118a1f13d1
--- /dev/null
+++ b/sysdeps/alpha/memchr.S
@@ -0,0 +1,163 @@
+/* Copyright (C) 1996 Free Software Foundation, Inc.
+ Contributed by David Mosberger (davidm@cs.arizona.edu).
+
+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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+/* Finds characters in a memory area. Optimized for the Alpha
+architecture:
+
+ - memory accessed as aligned quadwords only
+ - uses cmpbge to compare 8 bytes in parallel
+ - does binary search to find 0 byte in last
+ quadword (HAKMEM needed 12 instructions to
+ do this instead of the 9 instructions that
+ binary search needs).
+
+For correctness consider that:
+
+ - only minimum number of quadwords may be accessed
+ - the third argument is an unsigned long
+*/
+
+#include <sysdep.h>
+#ifdef __linux__
+# include <alpha/regdef.h>
+#else
+#include <regdef.h>
+#endif
+
+ .set noreorder
+ .set noat
+
+ENTRY(memchr)
+ beq a2, not_found
+ ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned)
+ addq a0, a2, t4
+ and a1, 0xff, a1 # a1 = 00000000000000ch
+ ldq_u t5, -1(t4)
+ sll a1, 8, t1 # t1 = 000000000000ch00
+ cmpult a2, 9, t3
+ or t1, a1, a1 # a1 = 000000000000chch
+ sll a1, 16, t1 # t1 = 00000000chch0000
+ lda t2, -1(zero)
+ or t1, a1, a1 # a1 = 00000000chchchch
+ sll a1, 32, t1 # t1 = chchchch00000000
+ extql t0, a0, t6
+ or t1, a1, a1 # a1 = chchchchchchchch
+
+ beq t3, first_quad
+
+ extqh t5, a0, t5
+ mov a0, v0
+ or t6, t5, t0 # t0 = quadword starting at a0
+
+ #
+ # Deal with the case where at most 8 bytes remain to be searched
+ # in t0. E.g.:
+ # a2 = 6
+ # t0 = ????c6c5c4c3c2c1
+last_quad:
+ negq a2, t5
+ srl t2, t5, t5 # t5 = mask of a2 bits set
+ xor a1, t0, t0
+ cmpbge zero, t0, t1
+ and t1, t5, t1
+ beq t1, not_found
+
+found_it:
+ # now, determine which byte matched:
+ negq t1, t2
+ and t1, t2, t1
+
+ and t1, 0x0f, t0
+ addq v0, 4, t2
+ cmoveq t0, t2, v0
+
+ and t1, 0x33, t0
+ addq v0, 2, t2
+ cmoveq t0, t2, v0
+
+ and t1, 0x55, t0
+ addq v0, 1, t2
+ cmoveq t0, t2, v0
+
+done: ret
+
+
+ #
+ # Deal with the case where a2 > 8 bytes remain to be
+ # searched. a0 may not be aligned.
+ #
+first_quad:
+ andnot a0, 0x7, v0
+ insqh t2, a0, t1 # t1 = 0000ffffffffffff (a0<0:2> ff bytes)
+ xor t0, a1, t0
+ or t0, t1, t0 # t0 = ====ffffffffffff
+ cmpbge zero, t0, t1
+ bne t1, found_it
+
+ /* at least one byte left to process */
+
+ ldq t0, 8(v0)
+ addq v0, 8, v0
+ /*
+ * Make a2 point to last quad to be accessed (the
+ * last quad may or may not be partial).
+ */
+ subq t4, 1, a2
+ andnot a2, 0x7, a2
+ cmpult v0, a2, t1
+ beq t1, final
+
+ /* at least two quads remain to be accessed */
+
+ subq a2, v0, t3 # t3 <- number of quads to be processed in loop
+ and t3, 8, t3 # odd number of quads?
+ bne t3, odd_quad_count
+
+ /* at least three quads remain to be accessed */
+
+ mov t0, t3 # move prefetched value into correct register
+
+ .align 3
+unrolled_loop:
+ ldq t0, 8(v0) # prefetch t0
+ xor a1, t3, t1
+ cmpbge zero, t1, t1
+ bne t1, found_it
+
+ addq v0, 8, v0
+odd_quad_count:
+ xor a1, t0, t1
+ ldq t3, 8(v0) # prefetch t3
+ cmpbge zero, t1, t1
+ bne t1, found_it
+
+ addq v0, 8, v0
+ cmpult v0, a2, t5
+ bne t5, unrolled_loop
+
+ mov t3, t0 # move prefetched value into t0
+final: subq t4, v0, a2 # a2 <- number of bytes left to do
+ bne a2, last_quad
+
+not_found:
+ mov zero, v0
+ ret
+
+ .end memchr