5.1.24 Type variants for integer intrinsics

Similar to the D/C prefixes to real functions to specify the input/output types, GNU Fortran offers B/I/J/K prefixes to integer functions for compatibility with DEC programs. The types implied by each are:

B - INTEGER(kind=1)
I - INTEGER(kind=2)
J - INTEGER(kind=4)
K - INTEGER(kind=8)

GNU Fortran supports these with the flag -fdec-intrinsic-ints. Intrinsics for which prefixed versions are available and in what form are noted in Intrinsic Procedures. The complete list of supported intrinsics is here:

IntrinsicBIJK
ABS — Absolute valueBABSIIABSJIABSKIABS
BTEST — Bit test functionBBTESTBITESTBJTESTBKTEST
IAND — Bitwise logical andBIANDIIANDJIANDKIAND
IBCLR — Clear bitBBCLRIIBCLRJIBCLRKIBCLR
IBITS — Bit extractionBBITSIIBITSJIBITSKIBITS
IBSET — Set bitBBSETIIBSETJIBSETKIBSET
IEOR — Bitwise logical exclusive orBIEORIIEORJIEORKIEOR
IOR — Bitwise logical orBIORIIORJIORKIOR
ISHFT — Shift bitsBSHFTIISHFTJISHFTKISHFT
ISHFTC — Shift bits circularlyBSHFTCIISHFTCJISHFTCKISHFTC
MOD — Remainder functionBMODIMODJMODKMOD
NOT — Logical negationBNOTINOTJNOTKNOT
REAL — Convert to real type--FLOATIFLOATJFLOATK