tfv: get fast multiply working in C

This commit is contained in:
Vince Weaver 2017-11-25 00:56:41 -05:00
parent 783e26d369
commit c52ea7ceff
2 changed files with 575 additions and 66 deletions

View File

@ -5,7 +5,7 @@ LFLAGS = -lm
SDL_LIBS= `sdl-config --libs`
SDL_INCLUDE= `sdl-config --cflags`
all: fixed_point rainbow sparkle kaleido tfv mode7_demo text
all: fixed_point rainbow sparkle kaleido tfv mode7_demo text tfv_multiply
@ -96,9 +96,6 @@ tfv_flying.o: tfv_flying.c tfv_flying_fixed.c tfv_flying_float.c tfv_flying_6502
tfv_info.o: tfv_info.c
$(CC) $(CFLAGS) -c tfv_info.c
#tfv_multiply.o: tfv_multiply.c
# $(CC) $(CFLAGS) -c tfv_multiply.c
tfv_opener.o: tfv_opener.c tfv_utils.h
$(CC) $(CFLAGS) -c tfv_opener.c
@ -117,6 +114,14 @@ tfv_utils.o: tfv_utils.c tfv_utils.h
tfv_worldmap.o: tfv_worldmap.c
$(CC) $(CFLAGS) -c tfv_worldmap.c
tfv_multiply.o: tfv_multiply.c
$(CC) $(CFLAGS) -c tfv_multiply.c
tfv_multiply: tfv_multiply.o
$(CC) $(LFLAGS) -o tfv_multiply tfv_multiply.o
tfv.o: tfv.c gr-sim.h tfv_backgrounds.h tfv_sprites.h
$(CC) $(CFLAGS) -c tfv.c
@ -143,6 +148,6 @@ gr-sim.o: gr-sim.c gr-sim.h apple2_font.h
$(CC) $(CFLAGS) $(SDL_INCLUDE) -c gr-sim.c
clean:
rm -f *~ *.o gr-sim rainbow sparkle kaleido tfv text mode7_demo fixed_point
rm -f *~ *.o gr-sim rainbow sparkle kaleido tfv text mode7_demo fixed_point tfv_multiply

View File

@ -1,41 +1,47 @@
#include <stdio.h>
#include <stdlib.h>
//#include "tfv_zp.h"
//#define FIXED_IMPLEMENTATION 0
//#define FIXED_IMPLEMENTATION 1
#define FIXED_IMPLEMENTATION 2
#if 0
int fixed_mul(struct fixed_type *x,
struct fixed_type *y,
struct fixed_type *z, int debug) {
int a,b,c;
#if FIXED_IMPLEMENTATION==0
int fixed_mul(int x_i,int x_f,
int y_i,int y_f,
int *z_i,int *z_f,
int debug) {
a=((x->i)<<8)+(x->f);
b=((y->i)<<8)+(y->f);
short a,b;
int c;
a=((x_i)<<8)+(x_f);
b=((y_i)<<8)+(y_f);
c=a*b;
if (debug) {
printf("%x:%x (%d) * %x:%x (%d) = %x (%d)\n",
x->i,x->f,a,
y->i,y->f,b,
x_i,x_f,a,
y_i,y_f,b,
c,c);
}
c>>=8;
z->i=(c>>8);
z->f=(c&0xff);
*z_i=(c>>8);
*z_f=(c&0xff);
return a*b;
}
#else
#endif
int fixed_mul(struct fixed_type *x,
struct fixed_type *y,
struct fixed_type *z,
#if FIXED_IMPLEMENTATION==1
int fixed_mul(int x_i,int x_f,
int y_i, int y_f,
int *z_i, int *z_f,
int debug) {
int num1h,num1l;
@ -45,8 +51,8 @@ int fixed_mul(struct fixed_type *x,
int aa,xx,cc=0,cc2,yy;
int negate=0;
num1h=x->i;
num1l=x->f;
num1h=x_i;
num1l=x_f;
if (!(num1h&0x80)) goto check_num2; // bpl check_num2
@ -66,8 +72,8 @@ int fixed_mul(struct fixed_type *x,
num1h&=0xff;
check_num2:
num2h=y->i;
num2l=y->f;
num2h=y_i;
num2l=y_f;
if (!(num2h&0x80)) goto unsigned_multiply;
@ -193,8 +199,8 @@ label_l2:
}
z->i=result2&0xff;
z->f=result1&0xff;
*z_i=result2&0xff;
*z_f=result1&0xff;
result3&=0xff;
result2&=0xff;
@ -204,18 +210,18 @@ label_l2:
if (debug) {
printf("%02x:%02x * %02x:%02x = %02x:%02x:%02x:%02x\n",
num1h,num1l,y->i,y->f,
num1h,num1l,y_i,y_f,
result3&0xff,result2&0xff,result1&0xff,result0&0xff);
// printf("%02x%02x * %02x%02x = %02x%02x%02x%02x\n",
// num1h,num1l,y->i,y->f,
// num1h,num1l,y_i,y_f,
// result3,result2,result1,result0);
}
int a2;
// int s1,s2;
// s1=(num1h<<8)|(num1l);
// s2=(y->i<<8)|(y->f);
// s2=(y_i<<8)|(y_f);
a2=(result3<<24)|(result2<<16)|(result1<<8)|result0;
// printf("%d * %d = %d (0x%x)\n",s1,s2,a2,a2);
@ -223,67 +229,565 @@ label_l2:
return a2;
}
#endif
#if 0
int main(int argc, char **argv) {
#if FIXED_IMPLEMENTATION==2
struct fixed_type a,b,c;
int i,j,k;
// Description: Unsigned 16-bit multiplication with unsigned 32-bit result.
// Input: 16-bit unsigned value in T1
// 16-bit unsigned value in T2
// Carry=0: Re-use T1 from previous multiplication (faster)
// Carry=1: Set T1 (slower)
//
// Output: 32-bit unsigned value in PRODUCT
// Clobbered: PRODUCT, X, A, C
// Allocation setup: T1,T2 and PRODUCT preferably on Zero-page.
// square1_lo, square1_hi, square2_lo, square2_hi must be
// page aligned. Each table are 512 bytes. Total 2kb.
//
// Table generation: I:0..511
// square1_lo = <((I*I)/4)
// square1_hi = >((I*I)/4)
// square2_lo = <(((I-255)*(I-255))/4)
// square2_hi = >(((I-255)*(I-255))/4)
i=-32768;
j=3;
static unsigned char square1_lo[512];
static unsigned char square1_hi[512];
static unsigned char square2_lo[512];
static unsigned char square2_hi[512];
a.i=i>>8;
a.f=i&0xff;
b.i=j>>8;
b.f=j&0xff;
static int table_ready=0;
k=fixed_mul(&a,&b,&c,1);
if (k!=i*j) {
printf("Error! %d*%d=%d, %d\n",i,j,i*j,k);
static void init_table(void) {
int i;
for(i=0;i<512;i++) {
square1_lo[i]=((i*i)/4)&0xff;
square1_hi[i]=(((i*i)/4)>>8)&0xff;
square2_lo[i]=( ((i-255)*(i-255))/4)&0xff;
square2_hi[i]=(( ((i-255)*(i-255))/4)>>8)&0xff;
// printf("%d %x:%x %x:%x\n",i,square1_hi[i],square1_lo[i],
// square2_hi[i],square2_lo[i]);
}
table_ready=1;
// 3 * 2
// 3+2 = 5
// 3-2 = 1
// (25 - 1) = 24/4 = 6
// int num1l,num2l,a1,a2;
// num1l=7;
// num2l=9;
// printf("Trying %d*%d\n",num1l,num2l);
// a1=square1_lo[num1l+num2l];
// printf("((%d+%d)^2)/4: %d\n",num1l,num2l,a1);
// a2=square2_lo[((~num1l)&0xff)+num2l];
// printf("((%d-%d)^2)/4: %d\n",num1l,num2l,a2);
// printf("%d*%d=%d\n",num1l,num2l,a1-a2);
}
static unsigned int product[4];
int fixed_mul_unsigned(int x_i,int x_f,
int y_i, int y_f,
int *z_i, int *z_f,
int debug) {
// <T1 * <T2 = AAaa
// <T1 * >T2 = BBbb
// >T1 * <T2 = CCcc
// >T1 * >T2 = DDdd
//
// AAaa
// BBbb
// CCcc
// + DDdd
// ----------
// PRODUCT!
// ; Setup T1 if changed
int c=0;
int a,x;
int sm1a,sm3a,sm5a,sm7a;
int sm2a,sm4a,sm6a,sm8a;
int sm1b,sm3b,sm5b,sm7b;
int sm2b,sm4b,sm6b,sm8b;
int _AA,_BB,_CC,_DD,_aa,_bb,_cc,_dd;
if (!table_ready) init_table();
// printf("\t\t\tMultiplying %2x:%2x * %2x:%2x\n",x_i,x_f,y_i,y_f);
/* Set up self-modifying code */
if (c==0) {
a=(x_f)&0xff; // lda T1+0 ; 3
sm1a=a; // sta sm1a+1 ; 3
sm3a=a; // sta sm3a+1 ; 3
sm5a=a; // sta sm5a+1 ; 3
sm7a=a; // sta sm7a+1 ; 3
a=(~a)&0xff; // eor #$ff ; 2
sm2a=a; // sta sm2a+1 ; 3
sm4a=a; // sta sm4a+1 ; 3
sm6a=a; // sta sm6a+1 ; 3
sm8a=a; // sta sm8a+1 ; 3
a=(x_i)&0xff; // lda T1+1 ; 3
sm1b=a; // sta sm1b+1 ; 3
sm3b=a; // sta sm3b+1 ; 3
sm5b=a; // sta sm5b+1 ; 3
sm7b=a; // sta sm7b+1 ; 3
a=(~a)&0xff; // eor #$ff ; 2
sm2b=a; // sta sm2b+1 ; 3
sm4b=a; // sta sm4b+1 ; 3
sm6b=a; // sta sm6b+1 ; 3
sm8b=a; // sta sm8b+1 ; 3
}
a.i=0x0;
a.f=0x2;
/* Perform <T1 * <T2 = AAaa */
x=(y_f)&0xff; // ldx T2+0 (low le) ; 3
c=1; // sec ; 2
//sm1a:
a=square1_lo[sm1a+x]; // lda square1_lo,x ; 4
//sm2a:
a+=~(square2_lo[sm2a+x])+c; // sbc square2_lo,x ; 4
c=!(a&0x100);
a&=0xff;
b.i=0x0;
b.f=0x3;
// printf("\t\t\t\ta=(%d+%d)^2/4=%d "
// "b=(%d+%d)^2/4=%d\n",
// sm1a,x,square1_lo[sm1a+x],
// sm2a,x,square2_lo[sm2a+x]);
product[0]=a; // sta PRODUCT+0 ; 3
_aa=a;
// printf("\t\t\t\ta-b aa=%2x\n",a);
//sm3a:
a=square1_hi[sm3a+x]; // lda square1_hi,x ; 4
//sm4a:
a+=(~(square2_hi[sm4a+x]))+c; // sbc square2_hi,x ; 4
c=!(a&0x100);
a&=0xff;
fixed_mul(&a,&b,&c,0);
// printf("\t\t\t\ta=%d b=%d\n",square1_hi[sm3a+x],square2_hi[sm4a+x]);
a.i=0xff;
a.f=0xff;
_AA=a; // sta _AA+1 ; 3
// printf("\t\t\t\tAA=%2x\n",a);
b.i=0xff;
b.f=0xff;
/* Perform >T1_hi * <T2 = CCcc */
c=1; // sec ; 2
//sm1b:
a=square1_lo[sm1b+x]; // lda square1_lo,x ; 4
//sm2b:
a+=(~(square2_lo[sm2b+x]))+c; // sbc square2_lo,x ; 4
c=!(a&0x100);
a&=0xff;
fixed_mul(&a,&b,&c,0);
_cc=a; // sta _cc+1 ; 3
//sm3b:
a=square1_hi[sm3b+x]; // lda square1_hi,x ; 4
//sm4b:
a+=(~(square2_hi[sm4b+x]))+c; // sbc square2_hi,x ; 4
c=!!(a&0x100);
a&=0xff;
_CC=a; // sta _CC+1 ; 3
a.i=0xff;
a.f=0xff;
/* Perform <T1 * >T2 = BBbb */
x=(y_i)&0xff; // ldx T2+1 ; 3
c=1; // sec ; 2
//sm5a:
a=square1_lo[sm5a+x]; // lda square1_lo,x ; 4
//sm6a:
a+=(~(square2_lo[sm6a+x]))+c; // sbc square2_lo,x ; 4
c=!(a&0x100);
a&=0xff;
_bb=a; // sta _bb+1 ; 3
// printf("\t\t\t\tbb=%x c=%d\n",_bb,c);
//sm7a:
a=square1_hi[sm7a+x]; // lda square1_hi,x ; 4
//sm8a:
a+=(~(square2_hi[sm8a+x]))+c; // sbc square2_hi,x ; 4
c=!(a&0x100);
a&=0xff;
_BB=a; // sta _BB+1
b.i=0x00;
b.f=0x01;
/* Perform >T1 * >T2 = DDdd */
c=1; // sec ; 2
//sm5b:
a=square1_lo[sm5b+x]; // lda square1_lo,x ; 4
//sm6b:
a+=(~(square2_lo[sm6b+x]))+c; // sbc square2_lo,x ; 4
c=!(a&0x100);
a&=0xff;
_dd=a; // sta _dd+1 ; 3
//sm7b:
a=square1_hi[sm7b+x]; // lda square1_hi,x ; 4
//sm8b:
a+=(~(square2_hi[sm8b+x]))+c; // sbc square2_hi,x ; 4
c=!(a&0x100);
a&=0xff;
fixed_mul(&a,&b,&c,0);
product[3]=a; // sta PRODUCT+3 ; 3
_DD=a;
/*********************************************/
/* Add the separate multiplications together */
/*********************************************/
// product[0]=_aa;
if (debug) printf("product[0]=0.%02x\n",_aa);
// product[1]=_AA+_bb+(_cc)
if (debug) printf("product[1]=%02x+%02x+0=",_AA,_bb);
c=0; // clc ; 2
//_AA:
a=_AA; // lda #0 ; 2
//_bb:
a+=(c+_bb); // adc #0 ; 2
c=!!(a&0x100);
a&=0xff;
product[1]=a; // sta PRODUCT+1 ; 3
if (debug) printf("%x.%02x\n",c,a);
// product[2]=_BB+_CC+c
if (debug) printf("product[2]=%02x+%02x+%d=",_BB,_CC,c);
//_BB:
a=_BB; // lda #0 ; 2
//_CC:
a+=(c+_CC); // adc #0 ; 2
c=!!(a&0x100);
a&=0xff;
product[2]=a; // sta PRODUCT+2 ; 3
if (debug) printf("%x.%02x\n",c,a);
// product[3]=_DD+c
if (debug) printf("product[3]=%02x+%d=",_DD,c);
if (c==0) goto urgh2; // bcc :+ ; 2nt/3
product[3]++; // inc PRODUCT+3 ; 5
product[3]&=0xff;
c=0; // clc ; 2
urgh2:
if (debug) printf("%x.%02x\n",c,product[3]);
// product[1]=_AA+_bb+_cc
if (debug) printf("product[1]=%02x+%02x+%d=",product[1],_cc,c);
//_cc:
a=_cc; // lda #0 ; 2
a+=c+product[1]; // adc PRODUCT+1 ; 3
c=!!(a&0x100);
a&=0xff;
product[1]=a; // sta PRODUCT+1 ; 3
if (debug) printf("%x.%02x\n",c,product[1]);
// product[2]=_BB+_CC+_dd+c
if (debug) printf("product[2]=%02x+%02x+%d=",product[2],_dd,c);
//_dd:
a=_dd; // lda #0 ; 2
a+=c+product[2]; // adc PRODUCT+2 ; 3
c=!!(a&0x100);
a&=0xff;
product[2]=a; // sta PRODUCT+2 ; 3
if (debug) printf("%x.%02x\n",c,product[2]);
// product[3]=_DD+c
if (debug) printf("product[3]=%02x+%d=",product[3],c);
if (c==0) goto urgh; // bcc :+ ; 2nt/3
product[3]++; // inc PRODUCT+3 ; 5
product[3]&=0xff;
urgh:
if (debug) printf("%x.%02x\n",c,product[3]);
*z_i=product[1];
*z_f=product[0];
// printf("Result=%02x:%02x\n",*z_i,*z_f);
if (debug) {
printf(" AAaa %02x:%02x\n",_AA,_aa);
printf(" BBbb %02x:%02x\n",_BB,_bb);
printf(" CCcc %02x:%02x\n",_CC,_cc);
printf("DDdd %02x:%02x\n",_DD,_dd);
}
return (product[3]<<24)|(product[2]<<16)|(product[1]<<8)|product[0];
// rts ; 6
}
/* signed */
int fixed_mul(int x_i,int x_f,
int y_i, int y_f,
int *z_i, int *z_f,
int debug) {
int a,c;
fixed_mul_unsigned(x_i,x_f,y_i,y_f,z_i,z_f,debug);
// jsr multiply_16bit_unsigned ; 6
a=(x_i&0xff); // lda T1+1 ; 3
if ((a&0x80)==0) goto x_positive; // bpl :+ ; 3/2nt
if (debug) printf("Before: %02x:%02x:%02x:%02x\n",product[3],product[2],product[1],product[0]);
// a=0xff; // lda #$ff ; 2
// c=1; // sec ; 2
// a=product[0]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[0]=a; // sta product[0]; 3
// a=0xff; // lda #$ff ; 2
// a=product[1]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[1]=a; // sta product[0]; 3
// a=0xff;
// a=product[2]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[2]=a; // sta product[0]; 3
// a=0xff;
// a=product[3]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[3]=a; // sta product[0]; 3
// product[1]^=a;
// product[2]^=a;
// product[3]^=a;
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
if (debug) printf("After: %02x:%02x:%02x:%02x\n",product[3],product[2],product[1],product[0]);
x_positive:
a=(y_i&0xff); // lda T2+1 ; 3
if ((a&0x80)==0) goto y_positive; // bpl :+ ; 3/2nt
if (debug) printf("Before: %02x:%02x:%02x:%02x\n",product[3],product[2],product[1],product[0]);
// a=0xff; // lda #$ff ; 2
// c=1; // sec ; 2
// a=product[0]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[0]=a; // sta product[0]; 3
// a=0xff; // lda #$ff ; 2
// a=product[1]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[1]=a; // sta product[0]; 3
// a=0xff;
// a=product[2]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[2]=a; // sta product[0]; 3
// a=0xff;
// a=product[3]^a; // eor product[0]; 3
// a&=0xff;
// a+=0+c; // adc #0 ; 2
// c=!!(a&0x100);
// a&=0xff;
// product[3]=a; // sta product[0]; 3
c=1; // sec ; 2
a=product[2]; // lda PRODUCT+2 ; 3
a+=(~x_f)+c; // sbc T1+0 ; 3
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
if (debug) printf("After: %02x:%02x:%02x:%02x\n",product[3],product[2],product[1],product[0]);
y_positive:
*z_i=product[1];
*z_f=product[0];
return (product[3]<<24)|(product[2]<<16)|(product[1]<<8)|product[0];
// rts ; 6
}
#endif
int main(int argc, char **argv) {
int a_i,b_i,c_i;
int a_f,b_f,c_f;
short x,y;
int k,i,j;
printf("Some tests\n");
x=-32768;
y=3;
a_i=x>>8;
a_f=x&0xff;
b_i=y>>8;
b_f=y&0xff;
printf("\tTrying %d*%d=%d (0x%x)\n",x,y,x*y,x*y);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=x*y) {
printf("\t\tError! got %d (0x%x)\n",k,k);
exit(1);
}
else {
printf("\t\tProperly calculated %d\n",k);
}
a_i=0x0;
a_f=0x7;
b_i=0x0;
b_f=0x9;
x=7;
y=9;
printf("\tTrying %d*%d=%d (0x%x)\n",x,y,x*y,x*y);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=x*y) {
printf("\t\tError! got %d (0x%x)\n",k,k);
exit(1);
}
else {
printf("\t\tProperly calculated %d (0x%x)\n",k,k);
}
a_i=0x0;
a_f=0x2;
b_i=0x0;
b_f=0x3;
x=2;
y=3;
printf("\tTrying %d*%d=%d (0x%x)\n",x,y,x*y,x*y);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=x*y) {
printf("\t\tError! got %d (0x%x)\n",k,k);
exit(1);
}
else {
printf("\t\tProperly calculated %d (0x%x)\n",k,k);
}
a_i=0xff;
a_f=0xff;
b_i=0xff;
b_f=0xff;
x=0xffff;
y=0xffff;
printf("\tTrying %d*%d=%d (0x%x)\n",x,y,x*y,x*y);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=x*y) {
printf("\t\tError! got %d (0x%x)\n",k,k);
exit(1);
}
else {
printf("\t\tProperly calculated %d (0x%x)\n",k,k);
}
a_i=0xff;
a_f=0xff;
b_i=0x00;
b_f=0x01;
x=0xffff;
y=0x1;
printf("\tTrying %d*%d=%d (0x%x)\n",x,y,x*y,x*y);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=x*y) {
printf("\t\tError! got %d (0x%x)\n",k,k);
exit(1);
}
else {
printf("\t\tProperly calculated %d (0x%x)\n",k,k);
}
a_i=0x00;
a_f=0xff;
b_i=0x00;
b_f=0x01;
x=0xff;
y=0x1;
printf("\tTrying %d*%d=%d (0x%x)\n",x,y,x*y,x*y);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=x*y) {
printf("\t\tError! got %d (0x%x)\n",k,k);
exit(1);
}
else {
printf("\t\tProperly calculated %d (0x%x)\n",k,k);
}
for(i=-32768;i<32768;i++) {
for(j=-32768;j<32768;j++) {
a.i=i>>8;
a.f=i&0xff;
b.i=j>>8;
b.f=j&0xff;
a_i=i>>8;
a_f=i&0xff;
b_i=j>>8;
b_f=j&0xff;
k=fixed_mul(&a,&b,&c,0);
k=fixed_mul(a_i,a_f,b_i,b_f,&c_i,&c_f,0);
if (k!=i*j) {
printf("WRONG! %x*%x = %x not %x\n",
i,j,i*j,k);
printf("%d * %d = %d not %d\n",i,j,i*j,k);
printf(" %d * %d = %d not %d\n",i,j,i*j,k);
exit(1);
}
}
@ -293,4 +797,4 @@ int main(int argc, char **argv) {
return 0;
}
#endif