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Rewritten v9/64-bit sparc strcmp.
This commit is contained in:
David S. Miller
parent
39dd69dfb9
commit
ad69cc2652
@ -1,3 +1,7 @@
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2011-08-24 David S. Miller <davem@davemloft.net>
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* sysdeps/sparc/sparc64/strcmp.S: Rewrite.
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2011-08-24 Andreas Schwab <schwab@redhat.com>
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* elf/Makefile: Add rules to build and run unload8 test.
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@ -1,9 +1,8 @@
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/* Compare two strings for differences.
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For SPARC v9.
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Copyright (C) 1997, 1999, 2003 Free Software Foundation, Inc.
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Copyright (C) 2011 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Jan Vondrak <jvon4518@ss1000.ms.mff.cuni.cz> and
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Jakub Jelinek <jj@ultra.linux.cz>.
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Contributed by David S. Miller <davem@davemloft.net>
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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@ -22,259 +21,182 @@
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#include <sysdep.h>
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#include <asm/asi.h>
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#ifndef XCC
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.register %g2, #scratch
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.register %g3, #scratch
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.register %g6, #scratch
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#endif
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/* Normally, this uses
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((xword - 0x0101010101010101) & 0x8080808080808080) test
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to find out if any byte in xword could be zero. This is fast, but
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also gives false alarm for any byte in range 0x81-0xff. It does
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not matter for correctness, as if this test tells us there could
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be some zero byte, we check it byte by byte, but if bytes with
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high bits set are common in the strings, then this will give poor
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performance. You can #define EIGHTBIT_NOT_RARE and the algorithm
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will use one tick slower, but more precise test
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((xword - 0x0101010101010101) & (~xword) & 0x8080808080808080),
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which does not give any false alarms (but if some bits are set,
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one cannot assume from it which bytes are zero and which are not).
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It is yet to be measured, what is the correct default for glibc
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in these days for an average user.
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#define rSTR1 %o0
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#define rSTR2 %o1
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#define r0101 %o2 /* 0x0101010101010101 */
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#define r8080 %o3 /* 0x8080808080808080 */
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#define rSTRXOR %o4
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#define rWORD1 %o5
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#define rTMP1 %g1
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#define rTMP2 %g2
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#define rWORD2 %g3
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#define rSLL %g4
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#define rSRL %g5
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#define rBARREL %g6
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/* There are two cases, either the two pointers are aligned
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* identically or they are not. If they have the same
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* alignment we can use the normal full speed loop. Otherwise
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* we have to use the barrel-shifter version.
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*/
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.text
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.align 32
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.align 32
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ENTRY(strcmp)
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sethi %hi(0x01010101), %g1 /* IEU0 Group */
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andcc %o0, 7, %g0 /* IEU1 */
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bne,pn %icc, 7f /* CTI */
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or %g1, %lo(0x01010101), %g1 /* IEU0 Group */
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or rSTR2, rSTR1, rTMP1
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sethi %hi(0x80808080), r8080
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andcc %o1, 7, %g3 /* IEU1 */
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bne,pn %icc, 9f /* CTI */
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sllx %g1, 32, %g2 /* IEU0 Group */
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ldx [%o0], %o2 /* Load */
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andcc rTMP1, 0x7, %g0
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bne,pn %icc, .Lmaybe_barrel_shift
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or r8080, %lo(0x80808080), r8080
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ldx [rSTR1], rWORD1
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or %g1, %g2, %g1 /* IEU0 Group */
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1: ldx [%o1], %o3 /* Load */
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sub %o1, %o0, %o1 /* IEU1 */
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sllx %g1, 7, %g2 /* IEU0 Group */
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sub rSTR2, rSTR1, rSTR2
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sllx r8080, 32, rTMP1
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2: add %o0, 8, %o0 /* IEU1 */
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sub %o2, %g1, %g3 /* IEU0 Group */
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subcc %o2, %o3, %g0 /* IEU1 */
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bne,pn %xcc, 13f /* CTI */
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ldx [rSTR1 + rSTR2], rWORD2
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or r8080, rTMP1, r8080
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#ifdef EIGHTBIT_NOT_RARE
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andn %g3, %o2, %g4 /* IEU0 Group */
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ldxa [%o0] ASI_PNF, %o2 /* Load */
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andcc %g4, %g2, %g0 /* IEU1 Group */
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#else
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ldxa [%o0] ASI_PNF, %o2 /* Load Group */
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andcc %g3, %g2, %g0 /* IEU1 */
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#endif
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be,a,pt %xcc, 2b /* CTI */
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ldxa [%o1 + %o0] ASI_PNF, %o3 /* Load Group */
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ba,pt %xcc, .Laligned_loop_entry
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srlx r8080, 7, r0101
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addcc %g3, %g1, %o4 /* IEU1 */
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srlx %g3, 32, %g3 /* IEU0 */
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andcc %g3, %g2, %g0 /* IEU1 Group */
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be,pt %xcc, 3f /* CTI */
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.align 32
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.Laligned_loop_entry:
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.Laligned_loop:
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add rSTR1, 8, rSTR1
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srlx %o4, 56, %o5 /* IEU0 */
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4f /* CTI */
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srlx %o4, 48, %o5 /* IEU0 */
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sub rWORD1, r0101, rTMP2
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xorcc rWORD1, rWORD2, rSTRXOR
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bne,pn %xcc, .Lcommon_endstring
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4f /* CTI */
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srlx %o4, 40, %o5 /* IEU0 */
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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andn r8080, rWORD1, rTMP1
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be,pn %icc, 4f /* CTI */
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srlx %o4, 32, %o5 /* IEU0 */
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4f /* CTI */
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ldxa [rSTR1] ASI_PNF, rWORD1
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andcc rTMP1, rTMP2, %g0
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be,a,pt %xcc, .Laligned_loop
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3: srlx %o4, 24, %o5 /* IEU0 */
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4f /* CTI */
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srlx %o4, 16, %o5 /* IEU0 */
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ldxa [rSTR1 + rSTR2] ASI_PNF, rWORD2
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4f /* CTI */
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srlx %o4, 8, %o5 /* IEU0 */
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andcc %o5, 0xff, %g0 /* IEU1 Group */
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.Lcommon_equal:
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retl
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mov 0, %o0
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be,pn %icc, 4f /* CTI */
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andcc %o4, 0xff, %g0 /* IEU1 Group */
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bne,a,pn %icc, 2b /* CTI */
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ldxa [%o1 + %o0] ASI_PNF, %o3 /* Load */
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/* All loops terminate here once they find an unequal word.
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* If a zero byte appears in the word before the first unequal
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* byte, we must report zero. Otherwise we report '1' or '-1'
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* depending upon whether the first mis-matching byte is larger
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* in the first string or the second, respectively.
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*
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* First we compute a 64-bit mask value that has "0x01" in
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* each byte where a zero exists in rWORD1. rSTRXOR holds the
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* value (rWORD1 ^ rWORD2). Therefore, if considered as an
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* unsigned quantity, our "0x01" mask value is "greater than"
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* rSTRXOR then a zero terminating byte comes first and
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* therefore we report '0'.
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*
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* The formula for this mask is:
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*
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* mask_tmp1 = ~rWORD1 & 0x8080808080808080;
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* mask_tmp2 = ((rWORD1 & 0x7f7f7f7f7f7f7f7f) +
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* 0x7f7f7f7f7f7f7f7f);
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*
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* mask = ((mask_tmp1 & ~mask_tmp2) >> 7);
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*/
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.Lcommon_endstring:
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andn rWORD1, r8080, rTMP2
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or r8080, 1, %o1
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4: retl /* CTI+IEU1 Group */
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clr %o0 /* IEU0 */
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mov 1, %o0
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sub rTMP2, %o1, rTMP2
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.align 32
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13: mov 0xff, %g6 /* IEU0 Group */
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#ifdef EIGHTBIT_NOT_RARE
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andcc %g4, %g2, %g0 /* IEU1 */
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#else
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andcc %g3, %g2, %g0 /* IEU1 */
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#endif
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be,pt %xcc, 25f /* CTI */
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addcc %g3, %g1, %o4 /* IEU1 Group */
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cmp rWORD1, rWORD2
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andn rTMP1, rTMP2, rTMP1
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srlx %g3, 32, %g3 /* IEU0 */
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andcc %g3, %g2, %g0 /* IEU1 Group */
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be,pt %xcc, 23f /* CTI */
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sllx %g6, 56, %o5 /* IEU0 */
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movleu %xcc, -1, %o0
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srlx rTMP1, 7, rTMP1
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andcc %o4, %o5, %g0 /* IEU1 Group */
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be,pn %xcc, 24f /* CTI */
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sllx %g6, 48, %o5 /* IEU0 */
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andcc %o4, %o5, %g0 /* IEU1 Group */
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cmp rTMP1, rSTRXOR
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retl
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movgu %xcc, 0, %o0
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be,pn %xcc, 24f /* CTI */
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sllx %g6, 40, %o5 /* IEU0 */
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andcc %o4, %o5, %g0 /* IEU1 Group */
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be,pn %xcc, 24f /* CTI */
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.Lmaybe_barrel_shift:
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sub rSTR2, rSTR1, rSTR2
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sllx r8080, 32, rTMP1
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sllx %g6, 32, %o5 /* IEU0 */
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andcc %o4, %o5, %g0 /* IEU1 Group */
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be,pn %xcc, 24f /* CTI */
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23: sllx %g6, 24, %o5 /* IEU0 */
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or r8080, rTMP1, r8080
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and rSTR1, 0x7, rTMP2
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andcc %o4, %o5, %g0 /* IEU1 Group */
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be,pn %icc, 24f /* CTI */
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sllx %g6, 16, %o5 /* IEU0 */
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andcc %o4, %o5, %g0 /* IEU1 Group */
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srlx r8080, 7, r0101
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andn rSTR1, 0x7, rSTR1
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be,pn %icc, 24f /* CTI */
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sllx %g6, 8, %o5 /* IEU0 */
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andcc %o4, %o5, %g0 /* IEU1 Group */
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be,pn %icc, 24f /* CTI */
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ldxa [rSTR1] ASI_PNF, rWORD1
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andcc rSTR2, 0x7, rSLL
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sll rTMP2, 3, rSTRXOR
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mov %g6, %o5 /* IEU0 */
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25: cmp %o4, %o3 /* IEU1 Group */
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5: mov -1, %o0 /* IEU0 */
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retl /* CTI+IEU1 Group */
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bne,pn %icc, .Lneed_barrel_shift
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mov -1, rTMP1
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ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
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movgu %xcc, 1, %o0 /* Single Group */
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srlx rTMP1, rSTRXOR, rTMP2
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.align 16
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24: sub %o5, 1, %g6 /* IEU0 Group */
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clr %o0 /* IEU1 */
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or %o5, %g6, %o5 /* IEU0 Group */
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andn %o4, %o5, %o4 /* IEU0 Group */
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orn rWORD1, rTMP2, rWORD1
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ba,pt %xcc, .Laligned_loop_entry
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orn rBARREL, rTMP2, rWORD2
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andn %o3, %o5, %o3 /* IEU1 */
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cmp %o4, %o3 /* IEU1 Group */
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movgu %xcc, 1, %o0 /* Single Group */
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retl /* CTI+IEU1 Group */
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.Lneed_barrel_shift:
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sllx rSLL, 3, rSLL
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andn rSTR2, 0x7, rSTR2
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movlu %xcc, -1, %o0 /* Single Group */
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6: retl /* CTI+IEU1 Group */
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mov %o4, %o0 /* IEU0 */
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ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
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mov 64, rTMP2
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sub rTMP2, rSLL, rSRL
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.align 16
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7: ldub [%o0], %o2 /* Load */
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add %o0, 1, %o0 /* IEU1 */
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ldub [%o1], %o3 /* Load Group */
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sllx %g1, 32, %g2 /* IEU0 */
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srlx rTMP1, rSTRXOR, rTMP1
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add rSTR2, 8, rSTR2
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8: add %o1, 1, %o1 /* IEU1 */
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subcc %o2, %o3, %o4 /* IEU1 Group */
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bne,pn %xcc, 6b /* CTI */
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lduba [%o0] ASI_PNF, %o2 /* Load */
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orn rWORD1, rTMP1, rWORD1
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sllx rBARREL, rSLL, rWORD2
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ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
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brz,pn %o3, 4b /* CTI+IEU1 Group */
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lduba [%o1] ASI_PNF, %o3 /* Load */
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andcc %o0, 7, %g0 /* IEU1 Group */
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bne,a,pn %icc, 8b /* CTI */
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add rSTR1, 8, rSTR1
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sub rWORD1, r0101, rTMP2
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add %o0, 1, %o0 /* IEU0 */
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or %g1, %g2, %g1 /* IEU0 Group */
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andcc %o1, 7, %g3 /* IEU1 */
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be,a,pn %icc, 1b /* CTI */
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srlx rBARREL, rSRL, rSTRXOR
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ldxa [%o0] ASI_PNF, %o2 /* Load Group */
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9: sllx %g3, 3, %g5 /* IEU0 */
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mov 64, %o5 /* IEU1 */
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sub %o1, %g3, %o1 /* IEU0 Group */
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or rWORD2, rSTRXOR, rWORD2
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sub %o5, %g5, %o5 /* IEU1 */
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ldxa [%o1] ASI_PNF, %g6 /* Load Group */
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or %g1, %g2, %g1 /* IEU0 */
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sub %o1, %o0, %o1 /* IEU1 */
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orn rWORD2, rTMP1, rWORD2
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ba,pt %xcc, .Lbarrel_shift_loop_entry
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andn r8080, rWORD1, rTMP1
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sllx %g1, 7, %g2 /* IEU0 Group */
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add %o1, 8, %o1 /* IEU1 */
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/* %g1 = 0101010101010101
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* %g2 = 8080808080800880
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* %g5 = number of bits to shift left
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* %o5 = number of bits to shift right */
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10: sllx %g6, %g5, %o3 /* IEU0 Group */
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ldxa [%o1 + %o0] ASI_PNF, %g6 /* Load */
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.Lbarrel_shift_loop:
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sllx rBARREL, rSLL, rWORD2
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ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
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11: srlx %g6, %o5, %o4 /* IEU0 Group */
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ldxa [%o0] ASI_PNF, %o2 /* Load */
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or %o3, %o4, %o3 /* IEU1 */
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add %o0, 8, %o0 /* IEU0 Group */
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add rSTR1, 8, rSTR1
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sub rWORD1, r0101, rTMP2
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subcc %o2, %o3, %g0 /* IEU1 */
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#ifdef EIGHTBIT_NOT_RARE
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sub %o2, %g1, %g3 /* IEU0 Group */
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bne,pn %xcc, 13b /* CTI */
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andn %g3, %o2, %g4 /* IEU0 Group */
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srlx rBARREL, rSRL, rSTRXOR
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andn r8080, rWORD1, rTMP1
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andcc %g4, %g2, %g0 /* IEU1 Group */
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be,pt %xcc, 10b /* CTI */
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srlx %g4, 32, %g4 /* IEU0 */
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andcc %g4, %g2, %g0 /* IEU1 Group */
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#else
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bne,pn %xcc, 13b /* CTI */
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sub %o2, %g1, %g3 /* IEU0 Group */
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andcc %g3, %g2, %g0 /* IEU1 Group */
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or rWORD2, rSTRXOR, rWORD2
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be,pt %xcc, 10b /* CTI */
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srlx %g3, 32, %g3 /* IEU0 */
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andcc %g3, %g2, %g0 /* IEU1 Group */
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#endif
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be,pt %xcc, 12f /* CTI */
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.Lbarrel_shift_loop_entry:
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xorcc rWORD1, rWORD2, rSTRXOR
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bne,pn %xcc, .Lcommon_endstring
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srlx %o2, 56, %g3 /* IEU0 */
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andcc %g3, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4b /* CTI */
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srlx %o2, 48, %g3 /* IEU0 */
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andcc rTMP1, rTMP2, %g0
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be,a,pt %xcc, .Lbarrel_shift_loop
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ldxa [rSTR1] ASI_PNF, rWORD1
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andcc %g3, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4b /* CTI */
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srlx %o2, 40, %g3 /* IEU0 */
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andcc %g3, 0xff, %g0 /* IEU1 Group */
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be,pn %icc, 4b /* CTI */
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srlx %o2, 32, %g3 /* IEU0 */
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andcc %g3, 0xff, %g0 /* IEU1 Group */
|
||||
be,pn %icc, 4b /* CTI */
|
||||
|
||||
12: srlx %o2, 24, %g3 /* IEU0 */
|
||||
andcc %g3, 0xff, %g0 /* IEU1 Group */
|
||||
be,pn %icc, 4b /* CTI */
|
||||
srlx %o2, 16, %g3 /* IEU0 */
|
||||
|
||||
andcc %g3, 0xff, %g0 /* IEU1 Group */
|
||||
be,pn %icc, 4b /* CTI */
|
||||
srlx %o2, 8, %g3 /* IEU0 */
|
||||
andcc %g3, 0xff, %g0 /* IEU1 Group */
|
||||
|
||||
be,pn %icc, 4b /* CTI */
|
||||
andcc %o2, 0xff, %g0 /* IEU1 Group */
|
||||
be,pn %icc, 4b /* CTI */
|
||||
sllx %g6, %g5, %o3 /* IEU0 */
|
||||
|
||||
ba,pt %xcc, 11b /* CTI Group */
|
||||
ldxa [%o1 + %o0] ASI_PNF, %g6 /* Load */
|
||||
retl
|
||||
mov 0, %o0
|
||||
END(strcmp)
|
||||
libc_hidden_builtin_def (strcmp)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user