CALL FMSIMG (IMD, LOC, LEN)
CALL FMSRMG (RMD, LOC, LEN)
CALL FMSCMG (CMD, LOC, LEN)
|MAXMD||Amount of memory to use|
|MDUSED||Amount of memory already used|
The first step is to declare an array in your program that you will use to reference the allocated memory. There are currently two mechanisms used to do this.
POINTER (CMD_PTR, CMD) POINTER (RMD_PTR, RMD) POINTER (IMD_PTR, IMD) COMPLEX*16 CMD(0:1) REAL*8 RMD(0:1) INTEGER IMD(0:1) ... CALL FMSIGT ('MEMPTR',CMD_PTR) CALL FMSIGT ('MEMPTR',RMD_PTR) CALL FMSIGT ('MEMPTR',IMD_PTR)
COMMON CMD EQUIVALENCE (IMD, RMD, CMD) COMPLEX*16 CMD(0:1) REAL*8 RMD(0:1) INTEGER IMD(0:1)
On most machines, FMS automatically aligns BLANK COMMON on a 16-byte boundary.
You should not be concerned if you use BLANK COMMON for other purposes. FMS does not store any data in CMD(0:1). It simply uses the arrays IMD, RMD and CMD as reference points for the allocated memory.
Once the reference arrays are established in your subroutine, you call FMSIMG to allocate LEN integer words starting at IMD(LOC), FMSRMG to allocate LEN REAL*8 words starting at RMD(LOC), or FMSCMG to allocate LEN COMPLEX*16 words starting at CMD(LOC).
The value of LOC returned is relative to the array value you provide on the call. For example, if you make the call:
CALL FMSIMG (IMD(10), LOC, LEN)the allocated memory will start at IMD(10+LOC).
You may make the value of LOC be an actual subscript of the array by dimensioning the array to start at 0,
INTEGER IMD (0:1)Then when you call the memory allocation subroutine
CALL FMSIMG (IMD, LOC, LEN)the allocated memory will start at IMD(LOC).
CALL FMSIMG (IMD, LLOWEQ, NUMEQ)You may address LOWEQ(I) as
IMD(LLOWEQ-1+I)You may also pass the LOWEQ array to a subroutine as
CALL RSDI (IMD(LLOWEQ), NUMEQ, 'LUA', LUA)When storage for LOWEQ(NUMEQ) is no longer required, you may return it to FMS.
CALL FMSIMR (IMD, LLOWEQ, NUMEQ)You may allocate storage for several arrays with a single call by requesting the total length. For example, to allocate storage for A(N), B(N) and C(N) use
CALL FMSRMG (RMD, LA, 3*N) LB = LA + N LC = LB + N