Vintage Fortran

VIntage Fortran (VIF) is my experimental compiler for vintage Fortran, that is, Fortran II-77. VIF is experimental in the sense that it does not emulate the Fortran machine model, and therefore cannot compile a few rarely used archaic statements. Also, unlike old Fortran, VIF has reserved words, facilitating syntax directed translation. This is a trade-off between completeness and efficiency.

Even so, VIF compiles most vintage code. I like to think that programmers always have been keen on coding in a legible and portable way, and avoided Fortran's idiosyncrasies.

Here you can download the current VIF source distribution. The linux manual page can be viewed here.

A goal for VIF was to make available multiple precision data types REAL*32 and COMPLEX*64, considering that most multi-precision applications require twenty up to sixty digits. VIF is probably the only vintage Fortran implementation offering these types.

A caveat when compiling vintage code is that in the old days, different machines had different representations of types. A REAL value could occupy a 32-bit, 36-bit or 64-bit word, depending on the hardware. Portable programs from the time call routines like D1MACH for details of a type representation. Next trivial snippet x1mach.f prints machine parameters for REAL*32 analogous to the D1MACH function:

      real*32 x1mach
      do k = 1, 5
         print *, k, x1mach(k)
      end do
      end

VIF can immediately execute a program upon successful compilation, like WATFOR or WATFIV, or a JCL CLG-type procedure under MVS or z/OS. We can execute above snippet with VIF like so, specifying -g:

$ vif -g x1mach.f
** main       ** end of compilation 1
** linker     ** object size 372280 bytes
** statistics ** 1 subprogram, no errors, no warnings
** execution  **
1  3.3621031431120935062626778173217526025980793448464712401088272298088533e-4932
2  1.1897314953572317650857593266280071307634446870965102374726748212332616e+4932
3  1.1319598848533390459386399113609739725853163997673922736978268612419382e-0072
4  2.2639197697066780918772798227219479451706327995347845473956537224838764e-0072
5  3.0102999566398119521373889472449302676818988146210854131042746112710819e-0001

Below is a list with the cross-referenced source files of the current version. VIF builds a library with (selected) FOSS subprograms from BLAS, LINPACK, SLATEC etcetera. These FOSS vintage library subprograms are not indexed here.

VIF C source files

	File	Synopsis	Lines
1	assign.c	Compile assignment statements.	204
2	autosave.c	Compile storage classes, SAVE statement.	181
3	banner.c	Banner for listing files.	169
4	call.c	Compile subprogram calls.	168
5	code.c	Routines to emit C object code.	461
6	common.c	Compiler COMMON statements.	146
7	data.c	Compile DATA statements.	336
8	decls.c	Compile declarations.	310
9	diag.c	Diagnostic message routines.	93
10	dimension.c	Compile DIMENSION statements.	119
11	emit.c	Emit C object code.	211
12	equivalence.c	Compile EQUIVALENCE statements.	332
13	expr.c	Compile Fortran expressions.	613
14	factor.c	Compile Fortran expression factors.	326
15	fold.c	Constant folder.	563
16	format.c	Compile FORMAT statements.	444
17	fpp.c	Fortran preprocessor.	174
18	goto.c	Compile GOTO statements.	138
19	implicit.c	IMPLICIT declaration routines.	186
20	intrinsic.c	Compile intrinsic functions.	632
21	jcl.c	Rudimentary JCL handler	153
22	macro.c	Compile function statements.	183
23	modules.c	Compile BLOCK DATA, FUNCTION, PROGRAM and SUBROUTINE.	608
24	parameter.c	Compile PARAMETER statement.	75
25	renum.c	Vintage Fortran statement renumbering tool.	650
26	rts.c	Runtime support.	338
27	rts-char.c	Runtime support for character - integer/real conversion.	48
28	rts-io.c	Runtime support for Fortran IO.	1061
29	rts-jit.c	Just-in-time compilation of FORMAT strings.	391
30	rts-lapack.c	Runtime support for LAPACK subprograms.	805
31	rts-math.c	Runtime support for math operations.	458
32	rts-real16.c	Runtime support for REAL16 and COMPLEX32.	132
33	rts-real32.c	Runtime support for REAL32 and COMPLEX64.	2436
34	rts-slatec.c	Runtime support for SLATEC subprograms.	384
35	rts-wapr.c	Runtime support implementing the W-function.	359
36	scan.c	Fortran scanner.	734
37	slice.c	Compile array slices.	187
38	statements.c	Compile statements.	659
39	table.c	Symbol table routines.	310
40	transput.c	Compile Fortran IO.	951
41	type.c	Type routines.	361
42	vif.c	VIF driver.	676

VIF Fortran source files

	File	Synopsis	Lines
1	fortran-ii.f	FORTRAN II library functions for VIF.	47
2	fortran-iv.f	FORTRAN IV intrinsic library functions for VIF.	455
3	ml.f	Machine Learning subprograms for VIF.	211