------- Comment #25 from dominiq at lps dot ens dot fr 2009-08-31 15:04 -------
If I compare the results of -fdump-tree-original for the first 2 cases of
comment #21 I get:
[ibook-dhum] test/dbg_air% gfc -m64 -O2 -funsafe-math-optimizations
-fdump-tree-original air_db.f90
[ibook-dhum] test/dbg_air% mv air_db.f90.003t.original
air_db.f90.003t.original-no
[ibook-dhum] test/dbg_air% gfc -m64 -O2 -funsafe-math-optimizations
-fno-strict-overflow -fdump-tree-original air_db.f90
[ibook-dhum] test/dbg_air% diff -u air_db.f90.003t.original
air_db.f90.003t.original-no
--- air_db.f90.003t.original 2009-08-31 17:01:34.000000000 +0200
+++ air_db.f90.003t.original-no 2009-08-31 17:00:39.000000000 +0200
@@ -548,7 +548,7 @@
logical(kind=4) D.1668;
ict = (integer(kind=4)) (ict + 1);
- if (npx[(integer(kind=8)) i + -1] + 1 >
j)
+ if (NON_LVALUE_EXPR
<npx[(integer(kind=8)) i + -1]> >= j)
{
ddx[((integer(kind=8)) ict +
(integer(kind=8)) k * 150) + -151] = xp1[((integer(kind=8)) (ict + 1) +
(integer(kind=8)) k * 150) + -151] - xp1[((integer(kind=8)) ict +
(integer(kind=8)) k * 150) + -151];
}
@@ -621,7 +621,7 @@
logical(kind=4) D.1680;
ict = (integer(kind=4)) (ict + 1);
- if (npy[(integer(kind=8)) i + -1] + 1 >
j)
+ if (NON_LVALUE_EXPR
<npy[(integer(kind=8)) i + -1]> >= j)
{
ddy[((integer(kind=8)) k +
(integer(kind=8)) ict * 150) + -151] = yp1[((integer(kind=8)) k +
((integer(kind=8)) ict + 1) * 150) + -151] - yp1[((integer(kind=8)) k +
(integer(kind=8)) ict * 150) + -151];
}
where NON_LVALUE_EXPR appear when the test is compiled without
-fno-strict-overflow.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40106
