------- Comment #2 from toon at moene dot org 2009-11-21 17:33 -------
Sorry, Steve - my mistake.
The original message should have been:
To illustrate this with a simple example:
DO I = M1, M2, M3
B(I) = A(I)
ENDDO
would be most easily, and straightforwardly, implemented as follows:
IF (M3 > 0 .AND. M1 > M2) GOTO 200 ! Loop executed zero times
IF (M3 < 0 .AND. M1 < M2) GOTO 200 ! Ditto
ITEMP = (M2 - M1 + M3) / M3 ! Temporary loop counter
I = M1
100 CONTINUE
B(I) = A(I)
ITEMP = ITEMP - 1 ! Adjust internal loop counter
I = I + M3 ! Adjust DO loop variable
IF (ITEMP >= 0) GOTO 100
200 CONTINUE
I hope this makes clear what's weird about the way the Fortran Frontend does it
now. The example code follows the Standard as close as possible (it only
doesn't check that m3 isn't zero, which isn't allowed), except that I follow
Note 8.7 instead of the reasoning in the "sequence of steps".
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42131
