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Diffstat (limited to 'sysdeps/alpha/strcmp.S')
| -rw-r--r-- | sysdeps/alpha/strcmp.S | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/sysdeps/alpha/strcmp.S b/sysdeps/alpha/strcmp.S deleted file mode 100644 index 9196be2ce3..0000000000 --- a/sysdeps/alpha/strcmp.S +++ /dev/null @@ -1,195 +0,0 @@ -/* Copyright (C) 1996, 1997, 2003 Free Software Foundation, Inc. - Contributed by Richard Henderson (rth@tamu.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 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. */ - -/* Bytewise compare two null-terminated strings. */ - -#include <sysdep.h> - - .set noat - .set noreorder - - .text - -ENTRY(strcmp) -#ifdef PROF - ldgp gp, 0(pv) - lda AT, _mcount - jmp AT, (AT), _mcount - .prologue 1 -#else - .prologue 0 -#endif - - ldq_u t0, 0(a0) # e0 : give cache time to catch up - xor a0, a1, t2 # .. e1 : are s1 and s2 co-aligned? - ldq_u t1, 0(a1) # e0 : - and t2, 7, t2 # .. e1 : - lda t3, -1 # e0 : - bne t2, $unaligned # .. e1 : - - /* On entry to this basic block: - t0 == the first destination word for masking back in - t1 == the first source word. - t3 == -1. */ - -$aligned: - mskqh t3, a0, t3 # e0 : - nop # .. e1 : - ornot t1, t3, t1 # e0 : - ornot t0, t3, t0 # .. e1 : - cmpbge zero, t1, t7 # e0 : bits set iff null found - bne t7, $eos # e1 (zdb) - - /* Aligned compare main loop. - On entry to this basic block: - t0 == an s1 word. - t1 == an s2 word not containing a null. */ - -$a_loop: - xor t0, t1, t2 # e0 : - bne t2, $wordcmp # .. e1 (zdb) - ldq_u t1, 8(a1) # e0 : - ldq_u t0, 8(a0) # .. e1 : - addq a1, 8, a1 # e0 : - addq a0, 8, a0 # .. e1 : - cmpbge zero, t1, t7 # e0 : - beq t7, $a_loop # .. e1 (zdb) - br $eos # e1 : - - /* The two strings are not co-aligned. Align s1 and cope. */ - -$unaligned: - and a0, 7, t4 # e0 : find s1 misalignment - and a1, 7, t5 # .. e1 : find s2 misalignment - subq a1, t4, a1 # e0 : - - /* If s2 misalignment is larger than s2 misalignment, we need - extra startup checks to avoid SEGV. */ - - cmplt t4, t5, t8 # .. e1 : - beq t8, $u_head # e1 : - - mskqh t3, t5, t3 # e0 : - ornot t1, t3, t3 # e0 : - cmpbge zero, t3, t7 # e1 : is there a zero? - beq t7, $u_head # e1 : - - /* We've found a zero in the first partial word of s2. Align - our current s1 and s2 words and compare what we've got. */ - - extql t1, t5, t1 # e0 : - extql t0, a0, t0 # e0 : - cmpbge zero, t1, t7 # .. e1 : find that zero again - br $eos # e1 : and finish up - - .align 3 -$u_head: - /* We know just enough now to be able to assemble the first - full word of s2. We can still find a zero at the end of it. - - On entry to this basic block: - t0 == first word of s1 - t1 == first partial word of s2. */ - - ldq_u t2, 8(a1) # e0 : load second partial s2 word - lda t3, -1 # .. e1 : create leading garbage mask - extql t1, a1, t1 # e0 : create first s2 word - mskqh t3, a0, t3 # e0 : - extqh t2, a1, t4 # e0 : - ornot t0, t3, t0 # .. e1 : kill s1 garbage - or t1, t4, t1 # e0 : s2 word now complete - cmpbge zero, t0, t7 # .. e1 : find zero in first s1 word - ornot t1, t3, t1 # e0 : kill s2 garbage - lda t3, -1 # .. e1 : - mskql t3, a1, t3 # e0 : mask for s2[1] bits we have seen - bne t7, $eos # .. e1 : - xor t0, t1, t4 # e0 : compare aligned words - bne t4, $wordcmp # .. e1 (zdb) - or t2, t3, t3 # e0 : - cmpbge zero, t3, t7 # e1 : - bne t7, $u_final # e1 : - - /* Unaligned copy main loop. In order to avoid reading too much, - the loop is structured to detect zeros in aligned words from s2. - This has, unfortunately, effectively pulled half of a loop - iteration out into the head and half into the tail, but it does - prevent nastiness from accumulating in the very thing we want - to run as fast as possible. - - On entry to this basic block: - t2 == the unshifted low-bits from the next s2 word. */ - - .align 3 -$u_loop: - extql t2, a1, t3 # e0 : - ldq_u t2, 16(a1) # .. e1 : load next s2 high bits - ldq_u t0, 8(a0) # e0 : load next s1 word - addq a1, 8, a1 # .. e1 : - addq a0, 8, a0 # e0 : - nop # .. e1 : - extqh t2, a1, t1 # e0 : - cmpbge zero, t0, t7 # .. e1 : find zero in current s1 word - or t1, t3, t1 # e0 : - bne t7, $eos # .. e1 : - xor t0, t1, t4 # e0 : compare the words - bne t4, $wordcmp # .. e1 (zdb) - cmpbge zero, t2, t4 # e0 : find zero in next low bits - beq t4, $u_loop # .. e1 (zdb) - - /* We've found a zero in the low bits of the last s2 word. Get - the next s1 word and align them. */ -$u_final: - ldq_u t0, 8(a0) # e1 : - extql t2, a1, t1 # .. e0 : - cmpbge zero, t1, t7 # e0 : - - /* We've found a zero somewhere in a word we just read. - On entry to this basic block: - t0 == s1 word - t1 == s2 word - t7 == cmpbge mask containing the zero. */ - - .align 3 -$eos: - negq t7, t6 # e0 : create bytemask of valid data - and t6, t7, t8 # e1 : - subq t8, 1, t6 # e0 : - or t6, t8, t7 # e1 : - zapnot t0, t7, t0 # e0 : kill the garbage - zapnot t1, t7, t1 # .. e1 : - xor t0, t1, v0 # e0 : and compare - beq v0, $done # .. e1 : - - /* Here we have two differing co-aligned words in t0 & t1. - Bytewise compare them and return (t0 > t1 ? 1 : -1). */ -$wordcmp: - cmpbge t0, t1, t2 # e0 : comparison yields bit mask of ge - cmpbge t1, t0, t3 # .. e1 : - xor t2, t3, t0 # e0 : bits set iff t0/t1 bytes differ - negq t0, t1 # e1 : clear all but least bit - and t0, t1, t0 # e0 : - lda v0, -1 # .. e1 : - and t0, t2, t1 # e0 : was bit set in t0 > t1? - cmovne t1, 1, v0 # .. e1 (zdb) - -$done: - ret # e1 : - - END(strcmp) -libc_hidden_builtin_def (strcmp) |