| Author(s): C. Letertre, J. Zoll | Library: KERNLIB |
| Submitter: | Submitted: 28.01.1971 |
| Language: Fortran or Assembler | Revised: 12.06.1987 |
This package manipulates individual bits and bytes in a word.
A bit in a word is specified by giving its position J (=1,2,...,32[,...,64]) in the word, bit 1 being the least significant bit.
A byte in a word is a group of NBITS consecutive bits. The byte is specified by giving NBITS and the bit position J of the least significant bit of the byte.
Structure:
SUBROUTINE and FUNCTION subprograms
User Entry Names:
| JBIT, | SBIT0, | SBIT1, | SBIT, | MSBIT0, | MSBIT1, | MSBIT, |
| JBYT, | SBYT, | MSBYT, | CBYT, | MCBYT, | JBYTET, | JBYTOR, |
| SBYTOR, | MBYTOR, | MBYTET, | JRSBYT |
Usage:
| IX = JBIT(IW,J) | returns IX=0 or 1, the value of bit J in IW. |
| CALL SBIT0(IX,J) | sets 0 into bit J of IX. |
| CALL SBIT1(IX,J) | sets 1 into bit J of IX. |
| CALL SBIT(IA,IX,J) | copies bit 1 of IA into bit J of IX. |
| IX = MSBIT0(IW,J) | returns IW in IX with bit J set to 0. |
| IX = MSBIT1(IW,J) | returns IW in IX with bit J set to 1. |
| IX = MSBIT(IA,IW,J) | returns IW in IX with bit J set to the value of bit 1 in IA. |
| IX = JBYT(IW,J,NBITS) | returns in IX right-justified the byte at J in IW. |
| CALL SBYT(IA,IX,J,NBITS) | copies the byte at 1 of IA into the byte at J of IX. |
| IX = MSBYT(IA,IW,J,NBITS) | returns IW in IX with the byte at J replaced by the byte at |
| 1 of IA. | |
| CALL CBYT(IA,JA,IX,J,NBITS) | copies the byte at JA of IA into the byte at J of IX. |
| IX = MCBYT(IA,JA,IW,J,NBITS) | returns IW in IX with the byte at J replaced by the byte at |
| JA of IA. | |
| IX = JBYTET(IA,IW,J,NBITS) | returns in IX the logical AND of IA and the byte at J of IW |
| right-justified. | |
| IX = JBYTOR(IA,IW,J,NBITS) | returns in IX the logical OR of IA and the byte at J of IW |
| right-justified. | |
| CALL SBYTOR(IA,IX,J,NBITS) | replaces the byte at J in IX by the logical OR of this byte |
| and the byte at 1 of IA. | |
| IX = MBYTOR(IA,IW,J,NBITS | returns IW in IX with the byte at J replaced by the logical |
| OR of this byte and the byte at 1 of IA. | |
| IX = MBYTET(IA,IW,J,NBITS) | returns IW in IX with the byte at J replaced by the logical |
| AND of this byte and the byte at 1 of IA. | |
| IY = JRSBYT(IA,IX,J,NBITS) | read and reset byte; equivalent to |
| IY = JBYT(IX,J,NBITS) | |
| CALL SBYT(IA,IX,J,NBITS). |
Notes:
The subroutines
SBIT0 SBIT1 SBIT SBYT CBYT SBYTORare duplicated by the functions
MSBIT0 MSBIT1 MSBIT MSBYT MCBYT MBYTORto allow implementation by statement functions. Such implementations can be picked up from the ZEBRA CDE Pam-file for different machines as sequence definitions
Q$JBIT : JBIT, JBYT Q$SBIT : MSBIT0, MSBIT1, MSBIT Q$SBYT : MSBYT Q$CBYT : MCBYT Q$JBYTET : JBYTET, JBYTOR, MBYTET, MBYTOR
