On Thu, Jan 21, 2016 at 2:57 PM, Richard Biener <rguent...@suse.de> wrote:
>
> This makes the SSA def stmt update during inlining cheaper by adjusting
> it after remapping a SSA def instead of via an extra walk over all stmt
> defs (which incidentially is not possible with FOR_EACH_SSA_* during
> "early SSA" as we don't have SSA operands there).
>
> I've tested this independently of the
> [RFC] Delayed folding, match-and-simplify and early GIMPLE
> patch.
>
> This exposes that the walk_gimple_* stuff is somewhat awkward and
> needs some refactoring (can't re-construct wi->gsi as gsi_for_stmt
> only works for stmts in a BB and thus when we have a CFG). Need to
> think about sth (simplest is require a gsi for walk_gimple_op, like
> we do for walk_gimple_stmt).
>
> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
>
> Queued for GCC 7.
Re-bootstrapped and tested on x86_64-unknown-linux-gnu, applied
to trunk as r235190.
Richard.
> Richard.
>
> 2016-01-21 Richard Biener <rguent...@suse.de>
>
> * gimple-walk.h (struct walk_stmt_info): Add stmt member.
> * gimple-walk.c (walk_gimple_op): Initialize it.
> (walk_gimple_asm): Set wi->is_lhs before each callback invocation.
> * tree-inline.c (remap_gimple_op_r): Set SSA_NAME_DEF_STMT when
> remapping SSA names of defs.
> (copy_bb): Remove walk over all SSA defs and SSA_NAME_DEF_STMT
> adjustment.
>
> Index: gcc/gimple-walk.c
> ===================================================================
> *** gcc/gimple-walk.c (revision 232670)
> --- gcc/gimple-walk.c (working copy)
> *************** walk_gimple_asm (gasm *stmt, walk_tree_f
> *** 100,108 ****
> noutputs = gimple_asm_noutputs (stmt);
> oconstraints = (const char **) alloca ((noutputs) * sizeof (const char
> *));
>
> - if (wi)
> - wi->is_lhs = true;
> -
> for (i = 0; i < noutputs; i++)
> {
> op = gimple_asm_output_op (stmt, i);
> --- 100,105 ----
> *************** walk_gimple_asm (gasm *stmt, walk_tree_f
> *** 114,119 ****
> --- 111,118 ----
> &allows_reg, &is_inout))
> wi->val_only = (allows_reg || !allows_mem);
> }
> + if (wi)
> + wi->is_lhs = true;
> ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
> if (ret)
> return ret;
> *************** walk_gimple_op (gimple *stmt, walk_tree_
> *** 182,187 ****
> --- 181,189 ----
> unsigned i;
> tree ret = NULL_TREE;
>
> + if (wi)
> + wi->stmt = stmt;
> +
> switch (gimple_code (stmt))
> {
> case GIMPLE_ASSIGN:
> Index: gcc/gimple-walk.h
> ===================================================================
> *** gcc/gimple-walk.h (revision 232670)
> --- gcc/gimple-walk.h (working copy)
> *************** struct walk_stmt_info
> *** 28,33 ****
> --- 28,34 ----
> {
> /* Points to the current statement being walked. */
> gimple_stmt_iterator gsi;
> + gimple *stmt;
>
> /* Additional data that the callback functions may want to carry
> through the recursion. */
> Index: gcc/tree-inline.c
> ===================================================================
> *** gcc/tree-inline.c (revision 232670)
> --- gcc/tree-inline.c (working copy)
> *************** remap_gimple_op_r (tree *tp, int *walk_s
> *** 862,871 ****
> --- 862,877 ----
> copy_body_data *id = (copy_body_data *) wi_p->info;
> tree fn = id->src_fn;
>
> + /* For recursive invocations this is no longer the LHS itself. */
> + bool is_lhs = wi_p->is_lhs;
> + wi_p->is_lhs = false;
> +
> if (TREE_CODE (*tp) == SSA_NAME)
> {
> *tp = remap_ssa_name (*tp, id);
> *walk_subtrees = 0;
> + if (is_lhs)
> + SSA_NAME_DEF_STMT (*tp) = wi_p->stmt;
> return NULL;
> }
> else if (auto_var_in_fn_p (*tp, fn))
> *************** copy_bb (copy_body_data *id, basic_block
> *** 2089,2104 ****
> maybe_duplicate_eh_stmt_fn (cfun, stmt, id->src_cfun, orig_stmt,
> id->eh_map, id->eh_lp_nr);
>
> - if (gimple_in_ssa_p (cfun) && !is_gimple_debug (stmt))
> - {
> - ssa_op_iter i;
> - tree def;
> -
> - FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
> - if (TREE_CODE (def) == SSA_NAME)
> - SSA_NAME_DEF_STMT (def) = stmt;
> - }
> -
> gsi_next (©_gsi);
> }
> while (!gsi_end_p (copy_gsi));
> --- 2095,2100 ----
