On 15-04-15 15:10, Tom de Vries wrote:
Hi,
This patch series fixes PR65637.
Currently, ssa-handling code in expand_omp_for_static_chunk is dead and not
exercised by testing.
Ssa-handling code in omp-low.c is only triggered by pass_parallelize_loops, and
that pass doesn't specify a chunk size on the GIMPLE_OMP_FOR it constructs, so
that only exercises the expand_omp_for_static_nochunk path.
Using the attached trigger patch, we excercise the ssa-handling code in
expand_omp_for_static_chunk. The following patch series fixes the problems in
the ssa-handling code that we encounter.
1. Fix gcc_assert in expand_omp_for_static_chunk
2. Fix inner loop phi in expand_omp_for_static_chunk
3. Handle 2 preds for fin_bb in expand_omp_for_static_chunk
The patch series has been bootstrapped and reg-tested on x86_64 together with
attached trigger patch.
I'll post the patches from the patch series individually, in response to this
email.
This patch fixes an libgomp.c/autopar-1.c execution failure.
For autopar-1.c, the original loop has a loop phi:
...
# s.5_20 = PHI <s.5_12(4), 0.0(20)>
...
After expand_omp_for_static_chunk, there's an inner and an outer loop. The outer
loop phi is:
...
# s.5_11 = PHI <0.0(15), s.5_12(21)>
...
and the inner loop phi is:
...
# s.5_20 = PHI <s.5_12(4), 0.0(20)>
...
The inner loop phi should not have 0.0 as argument, but the result of the outer
loop phi, like this:
...
# s.5_20 = PHI <s.5_12(4), s.5_11(20)>
...
This patch fixes the inner loop phi, and allows the autopar-1.c execution test
to pass.
OK for trunk?
Thanks,
- Tom
Fix inner loop phi in expand_omp_for_static_chunk
2015-04-15 Tom de Vries <t...@codesourcery.com>
PR tree-optimization/65637
* omp-low.c (find_phi_with_arg_on_edge): New function.
(expand_omp_for_static_chunk): Fix inner loop phi.
---
gcc/omp-low.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index f7b9d11..62cbed0 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -6844,6 +6844,22 @@ expand_omp_for_static_nochunk (struct omp_region *region,
}
}
+static gphi *
+find_phi_with_arg_on_edge (tree arg, edge e)
+{
+ basic_block bb = e->dest;
+
+ for (gphi_iterator gpi = gsi_start_phis (bb);
+ !gsi_end_p (gpi);
+ gsi_next (&gpi))
+ {
+ gphi *phi = gpi.phi ();
+ if (PHI_ARG_DEF_FROM_EDGE (phi, e) == arg)
+ return phi;
+ }
+
+ return NULL;
+}
/* A subroutine of expand_omp_for. Generate code for a parallel
loop with static schedule and a specified chunk size. Given
@@ -7272,7 +7288,14 @@ expand_omp_for_static_chunk (struct omp_region *region,
t = vextra;
add_phi_arg (nphi, t, ene, locus);
locus = redirect_edge_var_map_location (vm);
- add_phi_arg (nphi, redirect_edge_var_map_def (vm), re, locus);
+ tree back_arg = redirect_edge_var_map_def (vm);
+ add_phi_arg (nphi, back_arg, re, locus);
+ gphi *inner_loop_phi
+ = find_phi_with_arg_on_edge (back_arg,
+ find_edge (cont_bb, body_bb));
+ gcc_assert (inner_loop_phi != NULL);
+ add_phi_arg (inner_loop_phi, gimple_phi_result (nphi),
+ find_edge (seq_start_bb, body_bb), locus);
}
gcc_assert (gsi_end_p (psi) && (head == NULL || i == head->length ()));
redirect_edge_var_map_clear (re);
--
1.9.1
