tree-optimization/104716 - check if we can copy loop in loop distribution

The following checks whether we can copy the loop before attempting
to do so in loop distribution.  In the testcase there's a computed
goto and thus abnormal edges which we cannot redirect.

2022-03-01  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/104716
	* tree-loop-distribution.cc (find_seed_stmts_for_distribution):
	Check if we can copy the loop.

	* gfortran.dg/pr104716.f: New testcase.
This commit is contained in:
Richard Biener 2022-03-01 09:24:26 +01:00
parent 8fba8a8c26
commit 54ef95cc4d
2 changed files with 39 additions and 1 deletions

View File

@ -0,0 +1,31 @@
! { dg-do compile }
! { dg-options "-std=legacy -O2 -ftree-loop-distribution -fno-move-loop-stores -fno-tree-dominator-opts" }
SUBROUTINE FOO()
COMMON /WORK/ C2(2, 2)
DIMENSION D11(2)
EQUIVALENCE (D11(1), C2(1, 1))
DO 40 I = 1, 2
DO 30 J = 1, 2
ASSIGN 10 TO ILBL
IF (C2(J, I) .NE. 0.0) THEN
ASSIGN 20 TO ILBL
ENDIF
GO TO ILBL
10 CONTINUE
20 CONTINUE
C2(J, I) = C2(J, I) + 1
30 CONTINUE
40 CONTINUE
DO 50 I = 1, 2
PRINT 90, I
50 CONTINUE
RETURN
90 FORMAT(I5)
END

View File

@ -3277,8 +3277,15 @@ find_seed_stmts_for_distribution (class loop *loop, vec<gimple *> *work_list)
work_list->safe_push (stmt);
}
}
bool res = work_list->length () > 0;
if (res && !can_copy_bbs_p (bbs, loop->num_nodes))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "cannot copy loop %d.\n", loop->num);
res = false;
}
free (bbs);
return work_list->length () > 0;
return res;
}
/* A helper function for generate_{rawmemchr,strlen}_builtin functions in order