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-rw-r--r--libc/string/ia64/strchr.S112
1 files changed, 112 insertions, 0 deletions
diff --git a/libc/string/ia64/strchr.S b/libc/string/ia64/strchr.S
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+++ b/libc/string/ia64/strchr.S
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+/* Optimized version of the standard strchr() function.
+ This file is part of the GNU C Library.
+ Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
+ Contributed by Dan Pop <Dan.Pop@cern.ch>.
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* Return: the address of the first occurence of chr in str or NULL
+
+ Inputs:
+ in0: str
+ in1: chr
+
+ A modified version of memchr.S, the search ends when the character is
+ found or the terminating null character is encountered.
+
+ This implementation assumes little endian mode. For big endian mode,
+ the instruction czx1.r should be replaced by czx1.l. */
+
+#include <sysdep.h>
+#undef ret
+
+#define saved_lc r18
+#define poschr r19
+#define pos0 r20
+#define val1 r21
+#define val2 r22
+#define tmp r24
+#define chrx8 r25
+#define loopcnt r30
+
+#define str in0
+#define chr in1
+
+ENTRY(strchr)
+ .prologue
+ alloc r2 = ar.pfs, 2, 0, 0, 0
+ .save ar.lc, saved_lc
+ mov saved_lc = ar.lc // save the loop counter
+ .body
+ mov ret0 = str
+ and tmp = 7, str // tmp = str % 8
+ mux1 chrx8 = chr, @brcst
+ extr.u chr = chr, 0, 8 // retain only the last byte
+ cmp.ne p8, p0 = r0, r0 // clear p8
+ ;;
+ sub loopcnt = 8, tmp // loopcnt = 8 - tmp
+ cmp.eq p6, p0 = tmp, r0
+(p6) br.cond.sptk .str_aligned;;
+ adds loopcnt = -1, loopcnt;;
+ mov ar.lc = loopcnt
+.l1:
+ ld1 val2 = [ret0], 1
+ ;;
+ cmp.eq p6, p0 = val2, chr
+ cmp.eq p7, p0 = val2, r0
+(p6) br.cond.spnt .restore_and_exit
+(p7) br.cond.spnt .notfound
+ br.cloop.sptk .l1
+.str_aligned:
+ ld8 val1 = [ret0], 8;;
+ nop.b 0
+ nop.b 0
+.l2:
+ ld8.s val2 = [ret0], 8 // don't bomb out here
+ czx1.r pos0 = val1
+ xor tmp = val1, chrx8 // if val1 contains chr, tmp will
+ ;; // contain a zero in its position
+ czx1.r poschr = tmp
+ cmp.ne p6, p0 = 8, pos0
+ ;;
+ cmp.ne p7, p0 = 8, poschr
+(p7) br.cond.spnt .foundit
+(p6) br.cond.spnt .notfound
+ chk.s val2, .recovery
+.back:
+ mov val1 = val2
+ br.cond.dptk .l2
+.foundit:
+(p6) cmp.lt p8, p0 = pos0, poschr // we found chr and null in the word
+(p8) br.cond.spnt .notfound // null was found before chr
+ add ret0 = ret0, poschr ;;
+ adds ret0 = -15, ret0 ;; // should be -16, but we decrement
+.restore_and_exit: // ret0 in the next instruction
+ adds ret0 = -1, ret0 // ret0 was pointing 1 char too far
+ mov ar.lc = saved_lc // restore the loop counter
+ br.ret.sptk.many b0
+.notfound:
+ mov ret0 = r0 // return NULL if null was found
+ mov ar.lc = saved_lc
+ br.ret.sptk.many b0
+.recovery:
+ adds ret0 = -8, ret0;;
+ ld8 val2 = [ret0], 8 // bomb out here
+ br.cond.sptk .back
+END(strchr)
+
+weak_alias (strchr, index)
+libc_hidden_def (strchr)