/****************************************************************************** * * * 64x32 BIT MULTIPLY (UNSIGNED) * * 01/12/07 (dkc) * * * ******************************************************************************/ unsigned int carry(unsigned int a, unsigned int b, unsigned int sum); void mul64_32(unsigned int a0, unsigned int a2, unsigned int m0, unsigned int *product) { unsigned int a1,a3,m1,temp; unsigned int p0,p1,p2,p3,p4,p5,p6,p7; unsigned int s1,s2,s3; unsigned int c2,c3; a1=a0&0xffff; a0=a0>>16; a3=a2&0xffff; a2=a2>>16; m1=m0&0xffff; m0=m0>>16; p0=a0*m0; p1=a0*m1; p2=a1*m0; p3=a1*m1; p4=a2*m0; p5=a2*m1; p6=a3*m0; p7=a3*m1; s3=p7+(p6<<16); c3=carry(p7,(p6<<16),s3); temp=s3+(p5<<16); c3+=carry(s3,(p5<<16),temp); s3=temp; s2=p4+(p6>>16); c2=carry(p4,(p6>>16),s2); temp=s2+(p5>>16); c2+=carry(s2,(p5>>16),temp); s2=temp; temp=s2+p3; c2+=carry(s2,p3,temp); s2=temp; temp=s2+(p2<<16); c2+=carry(s2,(p2<<16),temp); s2=temp; temp=s2+(p1<<16); c2+=carry(s2,(p1<<16),temp); s2=temp; s1=p0+(p2>>16); s1=s1+(p1>>16); temp=s2+c3; c2+=carry(s2,c3,temp); s2=temp; s1=s1+c2; *product=s1; *(product+1)=s2; *(product+2)=s3; return; }