Assume bodies don't fit in most of the heuristics of the IPA passes.
They are usually not profitable, but since they are purely an
optimization tool and don't make it into the binary anyway , we want to
make the most of them. This patch introduces several bypasses for
checks which would prevent their optimizations, be it cloning or
parameter splitting.
gcc/ChangeLog:
* ipa-cp.cc (good_cloning_opportunity_p): Special case assume
functions.
* ipa-sra.cc (adjust_parameter_descriptions): Likewise.
* tree-sra.cc (analyze_all_variable_accesses): Likewise.
Signed-off-by: Josef Melcr <[email protected]>
---
gcc/ipa-cp.cc | 10 ++++++++++
gcc/ipa-sra.cc | 12 +++++++++---
gcc/tree-sra.cc | 4 +++-
3 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index d0428d04684..71cac065cce 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -3463,6 +3463,16 @@ good_cloning_opportunity_p (struct cgraph_node *node,
sreal time_benefit,
return false;
}
+ /* Assume bodies don't make it into the final binary, so they have no real
+ size. Special case them, as cloning them is always a good idea. */
+ if (node->assume_function)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " good_cloning_opportunity_p: Always clone "
+ "assume body functions.\n");
+ return true;
+ }
+
gcc_assert (size_cost > 0);
ipa_node_params *info = ipa_node_params_sum->get (node);
diff --git a/gcc/ipa-sra.cc b/gcc/ipa-sra.cc
index a663900fc1d..f26a7ee3ee5 100644
--- a/gcc/ipa-sra.cc
+++ b/gcc/ipa-sra.cc
@@ -2574,8 +2574,11 @@ process_scan_results (cgraph_node *node, struct function
*fun,
* param_size_limit);
}
- if (nonarg_acc_size > optimistic_limit
- || (!desc->by_ref && nonarg_acc_size == param_size_limit))
+ /* Assume functions have no real replacements, no calls to them will make
+ it into the binary, so limits don't matter. */
+ if (!node->assume_function
+ && (nonarg_acc_size > optimistic_limit
+ || (!desc->by_ref && nonarg_acc_size == param_size_limit)))
{
disqualify_split_candidate (desc, "Would result into a too big set "
"of replacements even in best "
@@ -4439,7 +4442,10 @@ adjust_parameter_descriptions (cgraph_node *node,
isra_func_summary *ifs)
param_ipa_sra_ptrwrap_growth_factor);
desc->param_size_limit = extra_factor * desc->param_size_limit;
}
- if (size_would_violate_limit_p (desc, desc->size_reached))
+ /* Don't disqualify assume bodies, as they don't make into the final
+ binary anyway. */
+ if (!node->assume_function
+ && size_would_violate_limit_p (desc, desc->size_reached))
desc->split_candidate = false;
}
diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
index f951a38442a..0adf6c7b6c7 100644
--- a/gcc/tree-sra.cc
+++ b/gcc/tree-sra.cc
@@ -3915,7 +3915,9 @@ analyze_all_variable_accesses (void)
fprintf (dump_file, "\n");
}
}
- else
+ /* Don't disqualify assume bodies. Assumes don't have any writes, but
+ scalarizing their arguments is important for later IPA. */
+ else if (!cfun->assume_function)
disqualify_candidate (var, "No scalar replacements to be created.");
}
--
2.55.0
