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Optimize sign extension.
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@ -24,13 +24,17 @@ imul8x8r16:
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sta ptr3
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sta ptr3
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imul8x8r16m:
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imul8x8r16m:
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; Extend sign of Left-Hand Side
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lda #$7f
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cmp ptr3
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adc #$80
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sta ptr3+1
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; Clear .XY accumulator
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ldy #<$0000
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ldx #>$0000
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ldx #>$0000
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bit ptr3
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bpl @L7
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; Check the multiplier sign.
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dex
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@L7: stx ptr3+1 ; Extend sign of Left-Hand Side
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ldy #<$0000 ; Clear .XY accumulator
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ldx #>$0000
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lda ptr1
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lda ptr1
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bpl PosStart
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bpl PosStart
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