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| author | Thomas Koenig <tkoenig@gcc.gnu.org> | 2010-08-06 22:33:37 +0000 |
|---|---|---|
| committer | Thomas Koenig <tkoenig@gcc.gnu.org> | 2010-08-06 22:33:37 +0000 |
| commit | 8a0f25c3e783c450c75a139adf91c826584afd10 (patch) | |
| tree | afb755fd34f651600e8426249fc34454e366a43a /gcc/fortran/dependency.c | |
| parent | cd6b2fa0e7cc07a7007f4928813f14cc940c50d9 (diff) | |
| download | gcc-8a0f25c3e783c450c75a139adf91c826584afd10.zip gcc-8a0f25c3e783c450c75a139adf91c826584afd10.tar.gz gcc-8a0f25c3e783c450c75a139adf91c826584afd10.tar.bz2 | |
re PR fortran/45159 (Unnecessary temporaries)
2010-08-06 Thomas Koenig <tkoenig@gcc.gnu.org>
PR fortran/45159
* dependency.c (check_section_vs_section): Handle cases where
the start expression coincides with the lower or upper
bound of the array.
2010-08-06 Thomas Koenig <tkoenig@gcc.gnu.org>
PR fortran/45159
* gfortran.dg/dependency_31.f90: New test.
From-SVN: r162966
Diffstat (limited to 'gcc/fortran/dependency.c')
| -rw-r--r-- | gcc/fortran/dependency.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c index 90b2d67..dfb0c94 100644 --- a/gcc/fortran/dependency.c +++ b/gcc/fortran/dependency.c @@ -1196,13 +1196,33 @@ check_section_vs_section (gfc_array_ref *l_ar, gfc_array_ref *r_ar, int n) return GFC_DEP_FORWARD; } - /* Check for backward dependencies: - Are the strides the same?. */ + + /* Are the strides the same? */ if ((!l_stride && !r_stride) || (l_stride && r_stride && gfc_dep_compare_expr (l_stride, r_stride) == 0)) { + + if (l_start && IS_ARRAY_EXPLICIT (l_ar->as)) + { + + /* Check for a(low:y:s) vs. a(z:a:s) where a has a lower bound + of low, which is always at least a forward dependence. */ + + if (r_dir == 1 + && gfc_dep_compare_expr (l_start, l_ar->as->lower[n]) == 0) + return GFC_DEP_FORWARD; + + /* Check for a(high:y:-s) vs. a(z:a:-s) where a has a higher bound + of high, which is always at least a forward dependence. */ + + if (r_dir == -1 + && gfc_dep_compare_expr (l_start, l_ar->as->upper[n]) == 0) + return GFC_DEP_FORWARD; + } + + /* From here, check for backwards dependencies. */ /* x:y vs. x+1:z. */ if (l_dir == 1 && r_dir == 1 && l_start && r_start |