82 lines
1.3 KiB
ArmAsm
82 lines
1.3 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 David S. Miller (davem@caip.rutgers.edu)
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* Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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#define LO_MAGIC 0x01010101
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#define HI_MAGIC 0x80808080
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0:
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ldub [%o0], %o5
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cmp %o5, 0
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be 1f
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add %o0, 1, %o0
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andcc %o0, 3, %g0
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be 4f
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or %o4, %lo(HI_MAGIC), %o3
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ldub [%o0], %o5
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cmp %o5, 0
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be 2f
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add %o0, 1, %o0
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andcc %o0, 3, %g0
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be 5f
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sethi %hi(LO_MAGIC), %o4
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ldub [%o0], %o5
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cmp %o5, 0
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be 3f
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add %o0, 1, %o0
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b 8f
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or %o4, %lo(LO_MAGIC), %o2
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1:
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retl
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mov 0, %o0
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2:
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retl
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mov 1, %o0
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3:
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retl
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mov 2, %o0
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.align 4
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.global strlen
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strlen:
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mov %o0, %o1
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andcc %o0, 3, %g0
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bne 0b
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sethi %hi(HI_MAGIC), %o4
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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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be 8b
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add %o0, 4, %o0
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/* Check every byte. */
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srl %o5, 24, %g5
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andcc %g5, 0xff, %g0
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be 1f
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add %o0, -4, %o4
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srl %o5, 16, %g5
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andcc %g5, 0xff, %g0
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be 1f
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add %o4, 1, %o4
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srl %o5, 8, %g5
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andcc %g5, 0xff, %g0
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be 1f
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add %o4, 1, %o4
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andcc %o5, 0xff, %g0
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bne,a 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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