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Thomas Koenig wrote:
John Savard <quadibloc@servername.invalid> schrieb:On Tue, 18 Jun 2024 16:17:33 -0000 (UTC), Thomas Koenigencode >>> the FORTRAN DO loop. It does not attempt any vectorization.
<tkoenig@netcologne.de> wrote:John Savard <quadibloc@servername.invalid> schrieb:Also, this looping instruction is strictly a way to directlyWhich one, the FORTRAN 66 one or the one since FORTRAN 77?FORTRAN IV (or 66) indeed.It was actually not defined in the standard, in practice it
was usually implemented by a test at the bottom of the loop,
and programs depended on that.
FORTRAN 77 fixed that, so now
DO 100 I=1,0
...
100 CONTINUE
is executed zero times.
How does VVM handle that? It sems you must "waste" some time, notThere is a check at the top of the loop which branches around the
executing the loop body until the furst LOOP instruction tells you
whether to or not, or perhaps not actually updating the values the
first time through the loop. Neither seems optimal. :-(
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