Kuck and Associates Preprocessor (KAP)

Kuck and Associates Preprocessor (KAP)

KAP (Kuck and Associates Preprocessor) is a Fortran optimizer that analyzes data dependence to guide traditional serial optimizations and automatic parallelization. It is built into fef77 (rather, fef77 consists largely of KAP).

This is an example of a transformation that KAP performs. The following routine:

subroutine bar(a,b,c,d,j)
real*4 a(1024),b(1024),c(1024)
real*4 d,e,f
sum = 0
do m= 1,j
do i=1,1024
b(i) = b(i) * d
enddo
enddo
call foo(a,b,c)
end

is turned into this by the KAP:

# 1 "vmuls.f"
subroutine BAR (A, B, C, D, J )
real*4 A(1024), B(1024), C(1024)
real*4 D, E, F
do 2 M=1,J-3,4
do 2 I=1,1024
B(I) = B(I) * D
B(I) = B(I) * D
B(I) = B(I) * D
B(I) = B(I) * D
2        continue
do 3 M=M,J,1
do 3 I=1,1024
B(I) = B(I) * D
3        continue
call FOO (A,B,C)
end

As you can see, some outer loop unrolling has occurred.

Passing Options to KAP
KAP's Optimization Flags (-o, -r, -so)
Opimization Levels Passed to KAP