Hello, I’m stil trying to fix this <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106731> ICE bug for an automatic array of a derived type with DTIO:
63 | type(t) :: automatic(n)
| 1
internal compiler error: in gfc_trans_auto_array_allocation, at
fortran/trans-array.cc:6617
Still digging for the first time in the gfortran code, I need help to move
further.
So far I’ve found:
1. ICE is triggered in trans-array line 6617 by gcc_assert
(!TREE_STATIC (decl)); Makes sense, an automatic array is not SAVEd.
2. Elsewhere, in trans-decl.cc, I found this chunk and commented it out.
This fixed the ICE issue, but crashes some test cases i.e. dtio_4.f90 and
dtio_14.f90, when built with full optimization (-O3)
/* If derived-type variables with DTIO procedures are not made static
some bits of code referencing them get optimized away.
TODO Understand why this is so and fix it. */
// if (!sym->attr.use_assoc
// && ((sym->ts.type == BT_DERIVED
// && sym->ts.u.derived->attr.has_dtio_procs)
// || (sym->ts.type == BT_CLASS
// && CLASS_DATA (sym)->ts.u.derived->attr.has_dtio_procs)))
// TREE_STATIC (decl) = 1;3.
3. Of the optimization flags "-fpeel-loops" is the one that triggers the
failing tests
3. in dtio_4.f90, the first test fails for 1) non-extended class; 2)
derived-type READ. Write works; extended type (BT_CLASS) works. It appears
that the optimizer thinks the derived type is not modified by the read
statement.
4. If i replace the READ statement with a direct call to the udt routine
(`call user_defined_read`) the test succeeds, so I've looked how the tree
dumps compare:
federico@Federicos-MacBook-Pro dtio % diff callsub withdtio
498c498,500
< CALL user_defined_read ((test1:udt1) (10) ('dt') ((/ 1 /)) (iostat =
test1:ios) (iomsg = test1:iomsg))
---
> READ UNIT=10 FMT='(dt)' IOMSG=test1:iomsg IOSTAT=test1:ios ADVANCE='no'
> TRANSFER test1:udt1
> DT_END
federico@Federicos-MacBook-Pro dtio %
while -fdump-tree-original returns exactly identical dumps:
federico@Federicos-MacBook-Pro dtio % diff callsub withdtio
federico@Federicos-MacBook-Pro dtio %
Now I'm a bit stuck because I have no experience in gfortran coding, more
so with the gcc optimizer.
I hope some of you can help! But at least, I'm starting to understand how
the code structure works.
Best,
Federico
dtio_4.f90
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