50 lines
822 B
ArmAsm
50 lines
822 B
ArmAsm
// #LAYOUT# STD * #TAKE
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// #LAYOUT# * BASIC_0 #TAKE
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// #LAYOUT# * * #IGNORE
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//
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// Math package - copy FAC2 to FAC1
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//
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// Output (found by experimentation):
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// - .A - FAC1 exponent
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// - .X - always 0
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//
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// Preserves:
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// - .Y
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//
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// See also:
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// - [CM64] Computes Mapping the Commodore 64 - page 115
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// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
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// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
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//
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mov_FAC2_FAC1:
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// Copy the mantissa
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lda FAC2_mantissa+3
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sta FAC1_mantissa+3
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lda FAC2_mantissa+2
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sta FAC1_mantissa+2
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lda FAC2_mantissa+1
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sta FAC1_mantissa+1
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lda FAC2_mantissa+0
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sta FAC1_mantissa+0
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// Copy the sign
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lda FAC2_sign
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sta FAC1_sign
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// Copy the exponent
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lda FAC2_exponent
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sta FAC1_exponent
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// Clear FACOV
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ldx #$00
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stx FACOV
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rts
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