Renesas SuperH SH-4A - Page 333

Rev. 1.50, 10/04, page 313 of 448
Operation:
SHLD(int m,n)/*SHLD Rm,Rn */
{
int sgn = R[m] & 0x80000000;
if (sgn == 0)
R[n] <<= (R[m] & 0x1F);
else if ((R[m] & 0x1F) == 0)
R[n] = 0;
else
R[n] = (unsigned)R[n] >> ((~R[m] & 0x1F)+1);
PC += 2;
}
Example:
SHLD R1, R2 ;Before execution R1 = H'FFFFFFEC, R2 = H'80180000
;After execution R1 = H'FFFFFFEC, R2 = H'00000801
SHLD R3, R4 ;Before execution R3 = H'00000014, R4 = H'FFFFF801
;After execution R3 = H'00000014, R4 = H'80100000