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tfv: forgot to update the signed multiply part of things

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This commit is contained in:
Vince Weaver 2017-11-29 00:49:01 -05:00
parent f6d358e025
commit fa45d4bd72
3 changed files with 30 additions and 30 deletions
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34
gr-sim/tfv_flying_6502.c
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@ -398,7 +398,7 @@ static int fixed_mul_unsigned(
a&=0xff;
// product[0]=a; // sta PRODUCT+0 ;
_aa=a;
// _aa=a;
//sm3a:
a=square1_hi[sm3a+x]; // lda square1_hi,x ; 4
@ -569,27 +569,27 @@ static void fixed_mul(unsigned char x_i, unsigned char x_f,
a=(x_i&0xff); // lda T1+1 ; 3
cycles.multiply+=12;
if ((a&0x80)==0) goto x_positive; // bpl :+ ; 3/2nt
cycles.multiply--;
if ((a&0x80)==0) goto x_positive; // bpl :+ ;^3/2nt
c=1; // sec ; 2
a=product[2]; // lda PRODUCT+2 ; 3
a+=(~y_f)+c; // sbc T2+0 ; 3
c=!(a&0x100);
a&=0xff;
product[2]=a; // sta PRODUCT+2 ; 3
a=product[3]; // lda PRODUCT+3 ; 3
a+=(~y_i)+c; // sbc T2+1 ; 3
c=!(a&0x100);
a&=0xff;
product[3]=a; // sta PRODUCT+3 ; 3
cycles.multiply+=20;
// a=product[3]; // lda PRODUCT+3 ;
// a+=(~y_i)+c; // sbc T2+1 ;
// c=!(a&0x100);
// a&=0xff;
// product[3]=a; // sta PRODUCT+3 ;
cycles.multiply+=10;
x_positive:
a=(y_i&0xff); // lda T2+1 ; 3
cycles.multiply+=6;
if ((a&0x80)==0) goto y_positive; // bpl :+ ; 3/2nt
cycles.multiply--;
if ((a&0x80)==0) goto y_positive; // bpl :+ ;^3/2nt
c=1; // sec ; 2
a=product[2]; // lda PRODUCT+2 ; 3
@ -597,12 +597,12 @@ x_positive:
c=!(a&0x100);
a&=0xff;
product[2]=a; // sta PRODUCT+2 ; 3
a=product[3]; // lda PRODUCT+3 ; 3
a+=(~x_i)+c; // sbc T1+1 ; 3
c=!(a&0x100);
a&=0xff;
product[3]=a; // sta PRODUCT+3 ; 3
cycles.multiply+=20;
// a=product[3]; // lda PRODUCT+3 ;
// a+=(~x_i)+c; // sbc T1+1 ;
// c=!(a&0x100);
// a&=0xff;
// product[3]=a; // sta PRODUCT+3 ;
cycles.multiply+=10;
y_positive:
*z_i=product[2];
*z_f=product[1];

7
tfv/OPTIMIZATION
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@ -162,14 +162,13 @@ Remove unneeded precision in the 8.8 x 8.8 fixed point multiply
Cycles: flying= 187
Cycles: getkey= 46
Cycles: page_flip= 26
Cycles: multiply= 44,785
Cycles: multiply= 43,588
Cycles: mode7= 118,034
Cycles: lookup_map= 22,747
Cycles: put_sprite= 2,561
================================
Total = 188,386
Frame Rate = 5.31 fps
Total = 187,189
Frame Rate = 5.34 fps
Each cycle removed from inner X loop saves
32*40=1280 cycles

19
tfv/tfv_multiply.s
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@ -312,29 +312,30 @@ multiply:
lda RESULT+2 ; 3
sbc NUM2L ; 3
sta RESULT+2 ; 3
lda RESULT+3 ; 3
sbc NUM2H ; 3
sta RESULT+3 ; 3
; lda RESULT+3 ;
; sbc NUM2H ;
; sta RESULT+3 ;
;============
; 19
; 10
x_positive:
lda NUM2H ; y_i ; 3
;============
; ; 6
bpl y_positive ; 3/2nt
bpl y_positive ;^3/2nt
sec ; 2
lda RESULT+2 ; 3
sbc NUM1L ; 3
sta RESULT+2 ; 3
lda RESULT+3 ; 3
sbc NUM1H ; 3
sta RESULT+3 ; 3
; lda RESULT+3 ;
; sbc NUM1H ;
; sta RESULT+3 ;
;===========
; 19
; 10
y_positive:
lda RESULT+2 ; *z_i=product[2]; ; 3