BASIC-MTHPAK

* NAME BASIC-MTHPAK DOC. 70181832000 REV. A PAGE 32

1089 * 1090 * 1091 * GREATEST INTEGER FUNCTION 1092 * 1093 * CALLING SEQUENCE: 1094 * 1095 * JST INTF 1096 * DAC ARG POINTER TO THE ARGUMENT 1097 * ......RETURN RESULT IN A AND B REGISTERS 1098 * 1099 * 1100 * THE ARGUMENT IS LOADED AND UNPACKED. THE BIAS PLUS THE NUM- 1101 * BER OF SIGNIFICANT BITS IS SUBTRACTED FROM THE EXPONENT TO CUMPUTE 1102 * THE NUMBER OF FRACTIONAL BITS IN THE MANTISSA. IF THERE ARE NO 1103 * FRACTIONAL BITS THE NUMBER IS REPACKED AND THE ROUTINE EXITS. 1104 * OTHERWISE, THE FRACTIONAL BITS ARE SHIFTED OUT OF THE MANTISSA. 1105 * ZEROS ARE THEN SHIFTED IN TO REPLACE THE FRACTIONAL BITS. THERE IS 1106 * A SPECIAL TEST SO THAT MINUS ONE IS GENERATED FOR ARGUMENT IN THE 1107 * RANGE OF MINUS ONE AND ZERO. 1108 * 1109 * 1110 00651 0 000000 INTF DAC ** 1111 00652 0 02 00651 LDA INTF 1112 00653 0 10 00070 JST LARG LOAD ARGUMENT ROUTINE 1113 00654 0 10 00134 JST UNPK UNPACK THE FLOATING POINT 1114 00655 0 04 00677 STA IN03 SAVE HIGH 1115 * 1116 * TEST FOR FRACTIONAL BITS 1117 * 1118 00656 0 02 00152 LDA EXPT LOAD THE EXPONENT 1119 00657 0 06 00707 ADD M227 SUBTRACT BIAS PLUS NUMBER OF SIGNIFICANT 1120 * BITS IN THE MANTISSA 1121 00660 100400 SPL SKIP IF POSITIVE 1122 00661 0 01 00665 JMP IN01 JUMP TO SHIFT OUT FRACTIONAL BITS 1123 00662 0 02 00677 LDA IN03 RECOVER HIGH 1124 * 1125 * REPACK AND RETURN 1126 * 1127 00663 0 10 00202 IN04 JST NORM REPACK 1128 00664 -0 01 00120 JMP* LHTS+1 GREATEST INTEGER FUNCTION EXIT 1129 * 1130 * FORM THE SHIFT INSTRUCIIONS AND SHIFT OUT THE MANTISSA'S 1131 * FRACTIONAL BITS 1132 * 1133 00665 0 06 01165 IN01 ADD M7 ADD -7 TO THE SHIFT COUNT TO RIGHT 1134 * JUSTIFY MANTISSA 1135 00666 0 11 00710 CAS M36 TEST IF ALL MANTISSA BITS ARE FRACTIONAL 1136 00667 0 03 00357 ANA C77 NO- MASK SHIFT COUNT AND 1137 00670 0 05 00360 ERA LRS FORM SHIFT INSTRUCTION 1138 00671 100400 SPL