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68 lines
2.7 KiB
ArmAsm
68 lines
2.7 KiB
ArmAsm
ttl ieee format equivalent arctangent (iefatan)
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***************************************
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* (c) copyright 1981 by motorola inc. *
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***************************************
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*************************************************
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* iefatan *
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* ieee format equivalent arctangent *
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* *
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* input: d7 - ieee format argument *
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* *
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* output: d7 - ieee format arctangent radian *
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* result *
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* *
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* all other registers totally transparent *
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* *
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* condition codes: *
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* z - set if result is zero *
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* n - cleared *
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* v - set if result is nan (not-a-number)*
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* (set if the input argument was nan)
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* c - undefined *
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* x - undefined *
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* *
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* all other registers transparent *
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* *
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* maximum stack used: 54 bytes *
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* *
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* *
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* notes: *
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* 1) see the mc68344 user's guide for details*
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* on ieee format range limitations. *
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* 2) spot checks show at least six digit *
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* precision on all sampled cases. *
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* *
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*************************************************
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page
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iefatan idnt 1,1 ieee format equivalent arctangent
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opt pcs
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section 9
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xdef iefatan entry point
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xref ffpatan fast floating point arctangent
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xref iefsop front-end single operand convert
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xref ieftieee back-end return ieee format
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xref ffpfieee ffp to ieee convert routine
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xref ffpcpyrt copyright stub
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********************
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* arctangent entry *
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********************
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* save registers and convert argument
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iefatan jsr iefsop convert the single argument
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bra.s iefnrm +0 branch normalized
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* argument was infinite +2 infinity
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jsr ffpfieee convert to maximum values allowed in ffp format
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* argument was normalized
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iefnrm jsr ffpatan call ffp arctangent routine
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jmp ieftieee return in ieee format
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end
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