On 05/11/15 11:16, Tom de Vries wrote:
Hi,
now that we have committed -foffload-alias in gomp-4_0-branch (
https://gcc.gnu.org/ml/gcc-patches/2015-11/msg00214.html ), we no longer
need the kernels region to be a part of the original function when doing
alias analysis.
So, we no longer have the need to postpone splitting off the kernels
region into a seperate function until after alias analysis, but we can
do this at the same time as when we expand the parallel region.
The following patch series implements that:
1 Move expansion of kernels region back to first omp-expand
2 Update gate_oacc_kernels to handle oacc function
3 Revert "Add skip_stmt parm to pass_dominator::get_sese ()"
4 Revert "Add pass_dominator::sese_mode_p ()"
5 Handle oacc function in parloops
6 Update goacc kernels C testcases
7 Update goacc kernels Fortran testcases
8 Release_defs in expand_omp_atomic_fetch_op
9 Remove BUILT_IN_GOACC_KERNELS_INTERNAL
[ The patch series is broken up into logical bits, but intended as
single commit. Various things in kernels support will be broken in
intermediate stages. ]
Committed to gomp-4_0-branch.
I'll post the patches in reply to this message.
The parloops pass constructs an atomic update:
...
#pragma omp atomic_load
D.1839_59 = *&.paral_data_load.33_51->reduction.23;
D.1840_60 = sum.27_56 + D.1839_59;
#pragma omp atomic_store (D.1840_60);
...
The expand_omp_atomic_fetch_op function removes the update statement but
doesn't release the ssa-name D.1840_60 defined by the update statement.
This causes an error when running ccp in lto1. We run into trouble here
for this unreleased ssa-name, because SSA_NAME_VAR (var) == NULL_TREE
and TREE_CODE (NULL_TREE) causes a sigsegv:
...
get_default_value (tree var)
{
ccp_prop_value_t val = { UNINITIALIZED, NULL_TREE, 0 };
gimple *stmt;
stmt = SSA_NAME_DEF_STMT (var);
if (gimple_nop_p (stmt))
{
/* Variables defined by an empty statement are those used
before being initialized. If VAR is a local variable, we
can assume initially that it is UNDEFINED, otherwise we must
consider it VARYING. */
if (!virtual_operand_p (var)
&& TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL)
val.lattice_val = UNDEFINED;
...
This patch fixes the problem by releasing the ssa-name in
expand_omp_atomic_fetch_op function.
Thanks,
- Tom
Release_defs in expand_omp_atomic_fetch_op
2015-11-04 Tom de Vries <t...@codesourcery.com>
* omp-low.c (expand_omp_atomic_fetch_op): Release defs of update stmt.
---
gcc/omp-low.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 58cb959..84accd9 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -11914,10 +11914,14 @@ expand_omp_atomic_fetch_op (basic_block load_bb,
gcc_assert (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_ATOMIC_STORE);
gsi_remove (&gsi, true);
gsi = gsi_last_bb (store_bb);
+ stmt = gsi_stmt (gsi);
gsi_remove (&gsi, true);
if (gimple_in_ssa_p (cfun))
- update_ssa (TODO_update_ssa_no_phi);
+ {
+ release_defs (stmt);
+ update_ssa (TODO_update_ssa_no_phi);
+ }
return true;
}
--
1.9.1
