On Wed, 14 Oct 2020, Jan Hubicka wrote:
> 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?
OK.
Richard.
> gcc/ChangeLog:
>
> 2020-10-14 Jan Hubicka <hubi...@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.
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imend
