68 строки
1.2 KiB
ArmAsm
68 строки
1.2 KiB
ArmAsm
/* fls.S: SPARC default fls definition.
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*
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* SPARC default fls definition, which follows the same algorithm as
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* in generic fls(). This function will be boot time patched on T4
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* and onward.
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*/
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#include <linux/linkage.h>
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#include <asm/export.h>
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.text
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.register %g2, #scratch
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.register %g3, #scratch
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ENTRY(fls)
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brz,pn %o0, 6f
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mov 0, %o1
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sethi %hi(0xffff0000), %g3
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mov %o0, %g2
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andcc %o0, %g3, %g0
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be,pt %icc, 8f
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mov 32, %o1
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sethi %hi(0xff000000), %g3
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andcc %g2, %g3, %g0
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bne,pt %icc, 3f
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sethi %hi(0xf0000000), %g3
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sll %o0, 8, %o0
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1:
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add %o1, -8, %o1
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sra %o0, 0, %o0
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mov %o0, %g2
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2:
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sethi %hi(0xf0000000), %g3
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3:
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andcc %g2, %g3, %g0
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bne,pt %icc, 4f
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sethi %hi(0xc0000000), %g3
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sll %o0, 4, %o0
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add %o1, -4, %o1
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sra %o0, 0, %o0
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mov %o0, %g2
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4:
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andcc %g2, %g3, %g0
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be,a,pt %icc, 7f
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sll %o0, 2, %o0
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5:
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xnor %g0, %o0, %o0
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srl %o0, 31, %o0
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sub %o1, %o0, %o1
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6:
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jmp %o7 + 8
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sra %o1, 0, %o0
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7:
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add %o1, -2, %o1
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ba,pt %xcc, 5b
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sra %o0, 0, %o0
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8:
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sll %o0, 16, %o0
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sethi %hi(0xff000000), %g3
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sra %o0, 0, %o0
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mov %o0, %g2
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andcc %g2, %g3, %g0
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bne,pt %icc, 2b
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mov 16, %o1
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ba,pt %xcc, 1b
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sll %o0, 8, %o0
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ENDPROC(fls)
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EXPORT_SYMBOL(fls)
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