mirror of https://gitee.com/openkylin/linux.git
83 lines
1.5 KiB
ArmAsm
83 lines
1.5 KiB
ArmAsm
/* strlen.S: Sparc optimized strlen code
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* Hand optimized from GNU libc's strlen
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* Copyright (C) 1991,1996 Free Software Foundation
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* Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
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* Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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#include <linux/linkage.h>
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#include <asm/asm.h>
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#include <asm/export.h>
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#define LO_MAGIC 0x01010101
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#define HI_MAGIC 0x80808080
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.text
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ENTRY(strlen)
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mov %o0, %o1
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andcc %o0, 3, %g0
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BRANCH32(be, pt, 9f)
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sethi %hi(HI_MAGIC), %o4
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ldub [%o0], %o5
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BRANCH_REG_ZERO(pn, %o5, 11f)
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add %o0, 1, %o0
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andcc %o0, 3, %g0
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BRANCH32(be, pn, 4f)
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or %o4, %lo(HI_MAGIC), %o3
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ldub [%o0], %o5
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BRANCH_REG_ZERO(pn, %o5, 12f)
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add %o0, 1, %o0
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andcc %o0, 3, %g0
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BRANCH32(be, pt, 5f)
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sethi %hi(LO_MAGIC), %o4
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ldub [%o0], %o5
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BRANCH_REG_ZERO(pn, %o5, 13f)
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add %o0, 1, %o0
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BRANCH32(ba, pt, 8f)
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or %o4, %lo(LO_MAGIC), %o2
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9:
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or %o4, %lo(HI_MAGIC), %o3
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4:
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sethi %hi(LO_MAGIC), %o4
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5:
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or %o4, %lo(LO_MAGIC), %o2
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8:
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ld [%o0], %o5
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2:
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sub %o5, %o2, %o4
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andcc %o4, %o3, %g0
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BRANCH32(be, pt, 8b)
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add %o0, 4, %o0
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/* Check every byte. */
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srl %o5, 24, %g7
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andcc %g7, 0xff, %g0
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BRANCH32(be, pn, 1f)
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add %o0, -4, %o4
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srl %o5, 16, %g7
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andcc %g7, 0xff, %g0
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BRANCH32(be, pn, 1f)
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add %o4, 1, %o4
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srl %o5, 8, %g7
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andcc %g7, 0xff, %g0
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BRANCH32(be, pn, 1f)
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add %o4, 1, %o4
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andcc %o5, 0xff, %g0
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BRANCH32_ANNUL(bne, pt, 2b)
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ld [%o0], %o5
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add %o4, 1, %o4
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1:
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retl
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sub %o4, %o1, %o0
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11:
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retl
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mov 0, %o0
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12:
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retl
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mov 1, %o0
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13:
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retl
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mov 2, %o0
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ENDPROC(strlen)
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EXPORT_SYMBOL(strlen)
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