forked from KolibriOS/kolibrios
38 lines
606 B
ArmAsm
38 lines
606 B
ArmAsm
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/*
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* Written by J.T. Conklin <jtc@netbsd.org>.
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* Public domain.
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*/
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.file "ilogb.S"
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.text
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.align 4
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.globl _ilogb
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.def _ilogb; .scl 2; .type 32; .endef
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_ilogb:
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fldl 4(%esp)
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/* I added the following ugly construct because ilogb(+-Inf) is
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required to return INT_MAX in ISO C99.
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-- jakub@redhat.com. */
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fxam /* Is NaN or +-Inf? */
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fstsw %ax
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movb $0x45, %dh
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andb %ah, %dh
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cmpb $0x05, %dh
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je 1f /* Is +-Inf, jump. */
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fxtract
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pushl %eax
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fstp %st
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fistpl (%esp)
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fwait
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popl %eax
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ret
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1: fstp %st
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movl $0x7fffffff, %eax
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ret
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