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authorZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
committerZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
commit5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch)
tree4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/sysdeps/alpha/alphaev67/strchr.S
parent199fc19d3aaaf57944ef036e15904febe877fc93 (diff)
downloadglibc-zack/build-layout-experiment.tar.gz
glibc-zack/build-layout-experiment.tar.xz
glibc-zack/build-layout-experiment.zip
Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/sysdeps/alpha/alphaev67/strchr.S')
-rw-r--r--REORG.TODO/sysdeps/alpha/alphaev67/strchr.S100
1 files changed, 100 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/alpha/alphaev67/strchr.S b/REORG.TODO/sysdeps/alpha/alphaev67/strchr.S
new file mode 100644
index 0000000000..ac1886eb55
--- /dev/null
+++ b/REORG.TODO/sysdeps/alpha/alphaev67/strchr.S
@@ -0,0 +1,100 @@
+/* Copyright (C) 2000-2017 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@tamu.edu>, 1996.
+   EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.
+   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/>.  */
+
+/* Return the address of a given character within a null-terminated
+   string, or null if it is not found.  */
+
+#include <sysdep.h>
+
+	.arch ev6
+	.set noreorder
+	.set noat
+
+ENTRY(strchr)
+#ifdef PROF
+	ldgp	gp, 0(pv)
+	lda	AT, _mcount
+	jsr	AT, (AT), _mcount
+	.prologue 1
+#else
+	.prologue 0
+#endif
+
+	ldq_u   t0, 0(a0)	# L : load first quadword Latency=3
+	and	a1, 0xff, t3	# E : 00000000000000ch
+	insbl	a1, 1, t5	# U : 000000000000ch00
+	insbl	a1, 7, a2	# U : ch00000000000000
+
+	insbl	t3, 6, a3	# U : 00ch000000000000
+	or	t5, t3, a1	# E : 000000000000chch
+	andnot  a0, 7, v0	# E : align our loop pointer
+	lda	t4, -1		# E : build garbage mask
+
+	mskqh	t4, a0, t4	# U : only want relevant part of first quad
+	or	a2, a3, a2	# E : chch000000000000
+	inswl	a1, 2, t5	# E : 00000000chch0000
+	inswl	a1, 4, a3	# E : 0000chch00000000
+
+	or	a1, a2, a1	# E : chch00000000chch
+	or	a3, t5, t5	# E : 0000chchchch0000
+	cmpbge  zero, t0, t2	# E : bits set iff byte == zero
+	cmpbge	zero, t4, t4	# E : bits set iff byte is garbage
+
+	/* This quad is _very_ serialized.  Lots of stalling happens */
+	or	t5, a1, a1	# E : chchchchchchchch
+	xor	t0, a1, t1	# E : make bytes == c zero
+	cmpbge  zero, t1, t3	# E : bits set iff byte == c
+	or	t2, t3, t0	# E : bits set iff char match or zero match
+
+	andnot	t0, t4, t0	# E : clear garbage bits
+	cttz	t0, a2		# U0 : speculative (in case we get a match)
+	nop			# E :
+	bne	t0, $found	# U :
+
+	/*
+	 * Yuk.  This loop is going to stall like crazy waiting for the
+	 * data to be loaded.  Not much can be done about it unless it's
+	 * unrolled multiple times, which is generally unsafe.
+	 */
+$loop:
+	ldq	t0, 8(v0)	# L : Latency=3
+	addq	v0, 8, v0	# E :
+	xor	t0, a1, t1	# E :
+	cmpbge	zero, t0, t2	# E : bits set iff byte == 0
+
+	cmpbge	zero, t1, t3	# E : bits set iff byte == c
+	or	t2, t3, t0	# E :
+	cttz	t3, a2		# U0 : speculative (in case we get a match)
+	beq	t0, $loop	# U :
+
+$found:
+	negq    t0, t1		# E : clear all but least set bit
+	and     t0, t1, t0	# E :
+	and	t0, t3, t1	# E : bit set iff byte was the char
+	addq	v0, a2, v0	# E : Add in the bit number from above
+
+	cmoveq	t1, $31, v0	# E : Two mapping slots, latency = 2
+	nop
+	nop
+	ret			# L0 :
+
+	END(strchr)
+
+weak_alias (strchr, index)
+libc_hidden_builtin_def (strchr)