Support ofsetted parameters in local modref
Jan Hubicka
hubicka@ucw.cz
Wed Oct 14 09:13:46 GMT 2020
Hi,
here is updated patch with cap on number of iterations.
I set the limit to 8 and bootstrapped it with additional assert that the
limit is not met, it did not fire.
Bootstrapped/regtested x86_64-linux, OK?
gcc/ChangeLog:
2020-10-14 Jan Hubicka <hubicka@ucw.cz>
* doc/invoke.texi: (ipa-jump-function-lookups): Document param.
* ipa-modref.c (merge_call_side_effects): Use
unadjusted_ptr_and_unit_offset.
* ipa-prop.c (unadjusted_ptr_and_unit_offset): New function.
* ipa-prop.h (unadjusted_ptr_and_unit_offset): Declare.
* params.opt: (-param-ipa-jump-function-lookups): New.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index c8281ecf502..47aa69530ab 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -13456,6 +13456,9 @@ loop in the loop nest by a given number of iterations. The strip
length can be changed using the @option{loop-block-tile-size}
parameter.
+@item ipa-jump-function-lookups
+Specifies number of statements visited during jump function offset discovery.
+
@item ipa-cp-value-list-size
IPA-CP attempts to track all possible values and types passed to a function's
parameter in order to propagate them and perform devirtualization.
diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index 771a0a88f9a..a6dfe1fc401 100644
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -531,6 +531,10 @@ merge_call_side_effects (modref_summary *cur_summary,
for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
{
tree op = gimple_call_arg (stmt, i);
+ bool offset_known;
+ poly_int64 offset;
+
+ offset_known = unadjusted_ptr_and_unit_offset (op, &op, &offset);
if (TREE_CODE (op) == SSA_NAME
&& SSA_NAME_IS_DEFAULT_DEF (op)
&& TREE_CODE (SSA_NAME_VAR (op)) == PARM_DECL)
@@ -547,15 +551,23 @@ merge_call_side_effects (modref_summary *cur_summary,
index++;
}
parm_map[i].parm_index = index;
- parm_map[i].parm_offset_known = true;
- parm_map[i].parm_offset = 0;
+ parm_map[i].parm_offset_known = offset_known;
+ parm_map[i].parm_offset = offset;
}
else if (points_to_local_or_readonly_memory_p (op))
parm_map[i].parm_index = -2;
else
parm_map[i].parm_index = -1;
if (dump_file)
- fprintf (dump_file, " %i", parm_map[i].parm_index);
+ {
+ fprintf (dump_file, " %i", parm_map[i].parm_index);
+ if (parm_map[i].parm_offset_known)
+ {
+ fprintf (dump_file, " offset:");
+ print_dec ((poly_int64_pod)parm_map[i].parm_offset,
+ dump_file, SIGNED);
+ }
+ }
}
if (dump_file)
fprintf (dump_file, "\n");
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 2d09d913051..cf3da6a6568 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -52,6 +52,7 @@ along with GCC; see the file COPYING3. If not see
#include "domwalk.h"
#include "builtins.h"
#include "tree-cfgcleanup.h"
+#include "options.h"
/* Function summary where the parameter infos are actually stored. */
ipa_node_params_t *ipa_node_params_sum = NULL;
@@ -1222,6 +1223,73 @@ load_from_unmodified_param_or_agg (struct ipa_func_body_info *fbi,
return index;
}
+/* Walk pointer adjustemnts from OP (such as POINTER_PLUS and ADDR_EXPR)
+ to find original pointer. Initialize RET to the pointer which results from
+ the walk.
+ If offset is known return true and initialize OFFSET_RET. */
+
+bool
+unadjusted_ptr_and_unit_offset (tree op, tree *ret, poly_int64 *offset_ret)
+{
+ poly_int64 offset = 0;
+ bool offset_known = true;
+ int i;
+
+ for (i = 0; i < param_ipa_jump_function_lookups; i++)
+ {
+ if (TREE_CODE (op) == ADDR_EXPR)
+ {
+ poly_int64 extra_offset = 0;
+ tree base = get_addr_base_and_unit_offset (TREE_OPERAND (op, 0),
+ &offset);
+ if (!base)
+ {
+ base = get_base_address (TREE_OPERAND (op, 0));
+ if (TREE_CODE (base) != MEM_REF)
+ break;
+ offset_known = false;
+ }
+ else
+ {
+ if (TREE_CODE (base) != MEM_REF)
+ break;
+ offset += extra_offset;
+ }
+ op = TREE_OPERAND (base, 0);
+ if (mem_ref_offset (base).to_shwi (&extra_offset))
+ offset += extra_offset;
+ else
+ offset_known = false;
+ }
+ else if (TREE_CODE (op) == SSA_NAME
+ && !SSA_NAME_IS_DEFAULT_DEF (op))
+ {
+ gimple *pstmt = SSA_NAME_DEF_STMT (op);
+
+ if (gimple_assign_single_p (pstmt))
+ op = gimple_assign_rhs1 (pstmt);
+ else if (is_gimple_assign (pstmt)
+ && gimple_assign_rhs_code (pstmt) == POINTER_PLUS_EXPR)
+ {
+ poly_int64 extra_offset = 0;
+ if (ptrdiff_tree_p (gimple_assign_rhs2 (pstmt),
+ &extra_offset))
+ offset += extra_offset;
+ else
+ offset_known = false;
+ op = gimple_assign_rhs1 (pstmt);
+ }
+ else
+ break;
+ }
+ else
+ break;
+ }
+ *ret = op;
+ *offset_ret = offset;
+ return offset_known;
+}
+
/* Given that an actual argument is an SSA_NAME (given in NAME) and is a result
of an assignment statement STMT, try to determine whether we are actually
handling any of the following cases and construct an appropriate jump
diff --git a/gcc/ipa-prop.h b/gcc/ipa-prop.h
index 8b2edf6300c..0bbbbf9bd9f 100644
--- a/gcc/ipa-prop.h
+++ b/gcc/ipa-prop.h
@@ -1144,6 +1144,8 @@ void ipa_dump_param (FILE *, class ipa_node_params *info, int i);
void ipa_release_body_info (struct ipa_func_body_info *);
tree ipa_get_callee_param_type (struct cgraph_edge *e, int i);
bool ipcp_get_parm_bits (tree, tree *, widest_int *);
+bool unadjusted_ptr_and_unit_offset (tree op, tree *ret,
+ poly_int64 *offset_ret);
/* From tree-sra.c: */
tree build_ref_for_offset (location_t, tree, poly_int64, bool, tree,
diff --git a/gcc/params.opt b/gcc/params.opt
index d770c55143b..ec69ba04eaf 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -253,6 +253,10 @@ The size of translation unit that IPA-CP pass considers large.
Common Joined UInteger Var(param_ipa_cp_value_list_size) Init(8) Param Optimization
Maximum size of a list of values associated with each parameter for interprocedural constant propagation.
+-param-ipa-jump-function-lookups=
+Common Joined UInteger Var(param_ipa_jump_function_lookups) Init(8) Param Optimization
+Maximum number of statements visited during jump function offset discovery
+
-param=ipa-max-aa-steps=
Common Joined UInteger Var(param_ipa_max_aa_steps) Init(25000) Param Optimization
Maximum number of statements that will be visited by IPA formal parameter analysis based on alias analysis in any given function.
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