Now that this function is not called anymore, we can remove the associated code. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> --- flow.c | 324 ----------------------------------------------------------------- flow.h | 1 - 2 files changed, 325 deletions(-) diff --git a/flow.c b/flow.c index 78dd6b3a5..58ff24d23 100644 --- a/flow.c +++ b/flow.c @@ -362,66 +362,6 @@ int dominates(pseudo_t pseudo, struct instruction *insn, struct instruction *dom return 1; } -static int phisrc_in_bb(struct pseudo_list *list, struct basic_block *bb) -{ - pseudo_t p; - FOR_EACH_PTR(list, p) { - if (p->def->bb == bb) - return 1; - } END_FOR_EACH_PTR(p); - - return 0; -} - -static int find_dominating_parents(pseudo_t pseudo, struct instruction *insn, - struct basic_block *bb, unsigned long generation, struct pseudo_list **dominators, - int local) -{ - struct basic_block *parent; - - if (!bb->parents) - return !!local; - - FOR_EACH_PTR(bb->parents, parent) { - struct instruction *one; - struct instruction *br; - pseudo_t phi; - - FOR_EACH_PTR_REVERSE(parent->insns, one) { - int dominance; - if (one == insn) - goto no_dominance; - dominance = dominates(pseudo, insn, one, local); - if (dominance < 0) { - if (one->opcode == OP_LOAD) - continue; - return 0; - } - if (!dominance) - continue; - goto found_dominator; - } END_FOR_EACH_PTR_REVERSE(one); -no_dominance: - if (parent->generation == generation) - continue; - parent->generation = generation; - - if (!find_dominating_parents(pseudo, insn, parent, generation, dominators, local)) - return 0; - continue; - -found_dominator: - if (dominators && phisrc_in_bb(*dominators, parent)) - continue; - br = delete_last_instruction(&parent->insns); - phi = alloc_phi(parent, one->target, one->type); - phi->ident = phi->ident ? : pseudo->ident; - add_instruction(&parent->insns, br); - use_pseudo(insn, phi, add_pseudo(dominators, phi)); - } END_FOR_EACH_PTR(parent); - return 1; -} - /* * We should probably sort the phi list just to make it easier to compare * later for equality. @@ -460,178 +400,6 @@ complex_phi: insn->phi_list = dominators; } -static int find_dominating_stores(pseudo_t pseudo, struct instruction *insn, - unsigned long generation, int local) -{ - struct basic_block *bb = insn->bb; - struct instruction *one, *dom = NULL; - struct pseudo_list *dominators; - int partial; - - /* Unreachable load? Undo it */ - if (!bb) { - insn->opcode = OP_LNOP; - return 1; - } - - partial = 0; - FOR_EACH_PTR(bb->insns, one) { - int dominance; - if (one == insn) - goto found; - dominance = dominates(pseudo, insn, one, local); - if (dominance < 0) { - /* Ignore partial load dominators */ - if (one->opcode == OP_LOAD) - continue; - dom = NULL; - partial = 1; - continue; - } - if (!dominance) - continue; - dom = one; - partial = 0; - } END_FOR_EACH_PTR(one); - /* Whaa? */ - warning(pseudo->sym->pos, "unable to find symbol read"); - return 0; -found: - if (partial) - return 0; - - if (dom) { - convert_load_instruction(insn, dom->target); - return 1; - } - - /* OK, go find the parents */ - bb->generation = generation; - - dominators = NULL; - if (!find_dominating_parents(pseudo, insn, bb, generation, &dominators, local)) - return 0; - - /* This happens with initial assignments to structures etc.. */ - if (!dominators) { - if (!local) - return 0; - check_access(insn); - convert_load_instruction(insn, value_pseudo(0)); - return 1; - } - - /* - * If we find just one dominating instruction, we - * can turn it into a direct thing. Otherwise we'll - * have to turn the load into a phi-node of the - * dominators. - */ - rewrite_load_instruction(insn, dominators); - return 1; -} - -static void kill_store(struct instruction *insn) -{ - if (insn) { - insn->bb = NULL; - insn->opcode = OP_SNOP; - kill_use(&insn->target); - } -} - -/* Kill a pseudo that is dead on exit from the bb */ -static void kill_dead_stores(pseudo_t pseudo, unsigned long generation, struct basic_block *bb, int local) -{ - struct instruction *insn; - struct basic_block *parent; - - if (bb->generation == generation) - return; - bb->generation = generation; - FOR_EACH_PTR_REVERSE(bb->insns, insn) { - int opcode = insn->opcode; - - if (opcode != OP_LOAD && opcode != OP_STORE) { - if (local) - continue; - if (opcode == OP_CALL) - return; - continue; - } - if (insn->src == pseudo) { - if (opcode == OP_LOAD) - return; - kill_store(insn); - continue; - } - if (local) - continue; - if (insn->src->type != PSEUDO_SYM) - return; - } END_FOR_EACH_PTR_REVERSE(insn); - - FOR_EACH_PTR(bb->parents, parent) { - struct basic_block *child; - FOR_EACH_PTR(parent->children, child) { - if (child && child != bb) - return; - } END_FOR_EACH_PTR(child); - kill_dead_stores(pseudo, generation, parent, local); - } END_FOR_EACH_PTR(parent); -} - -/* - * This should see if the "insn" trivially dominates some previous store, and kill the - * store if unnecessary. - */ -static void kill_dominated_stores(pseudo_t pseudo, struct instruction *insn, - unsigned long generation, struct basic_block *bb, int local, int found) -{ - struct instruction *one; - struct basic_block *parent; - - /* Unreachable store? Undo it */ - if (!bb) { - kill_store(insn); - return; - } - if (bb->generation == generation) - return; - bb->generation = generation; - FOR_EACH_PTR_REVERSE(bb->insns, one) { - int dominance; - if (!found) { - if (one != insn) - continue; - found = 1; - continue; - } - dominance = dominates(pseudo, insn, one, local); - if (!dominance) - continue; - if (dominance < 0) - return; - if (one->opcode == OP_LOAD) - return; - kill_store(one); - } END_FOR_EACH_PTR_REVERSE(one); - - if (!found) { - warning(bb->pos, "Unable to find instruction"); - return; - } - - FOR_EACH_PTR(bb->parents, parent) { - struct basic_block *child; - FOR_EACH_PTR(parent->children, child) { - if (child && child != bb) - return; - } END_FOR_EACH_PTR(child); - kill_dominated_stores(pseudo, insn, generation, parent, local, found); - } END_FOR_EACH_PTR(parent); -} - void check_access(struct instruction *insn) { pseudo_t pseudo = insn->src; @@ -648,98 +416,6 @@ void check_access(struct instruction *insn) } } -static void simplify_one_symbol(struct entrypoint *ep, struct symbol *sym) -{ - pseudo_t pseudo; - struct pseudo_user *pu; - unsigned long mod; - int all; - - /* Never used as a symbol? */ - pseudo = sym->pseudo; - if (!pseudo) - return; - - /* We don't do coverage analysis of volatiles.. */ - if (sym->ctype.modifiers & MOD_VOLATILE) - return; - - /* ..and symbols with external visibility need more care */ - mod = sym->ctype.modifiers & (MOD_NONLOCAL | MOD_STATIC | MOD_ADDRESSABLE); - if (mod) - goto external_visibility; - - FOR_EACH_PTR(pseudo->users, pu) { - /* We know that the symbol-pseudo use is the "src" in the instruction */ - struct instruction *insn = pu->insn; - - switch (insn->opcode) { - case OP_STORE: - break; - case OP_LOAD: - break; - case OP_SYMADDR: - if (!insn->bb) - continue; - mod |= MOD_ADDRESSABLE; - goto external_visibility; - case OP_NOP: - case OP_SNOP: - case OP_LNOP: - case OP_PHI: - continue; - default: - warning(sym->pos, "symbol '%s' pseudo used in unexpected way", show_ident(sym->ident)); - } - } END_FOR_EACH_PTR(pu); - -external_visibility: - all = 1; - FOR_EACH_PTR_REVERSE(pseudo->users, pu) { - struct instruction *insn = pu->insn; - if (insn->opcode == OP_LOAD) - all &= find_dominating_stores(pseudo, insn, ++bb_generation, !mod); - } END_FOR_EACH_PTR_REVERSE(pu); - - /* If we converted all the loads, remove the stores. They are dead */ - if (all && !mod) { - FOR_EACH_PTR(pseudo->users, pu) { - struct instruction *insn = pu->insn; - if (insn->opcode == OP_STORE) - kill_store(insn); - } END_FOR_EACH_PTR(pu); - } else { - /* - * If we couldn't take the shortcut, see if we can at least kill some - * of them.. - */ - FOR_EACH_PTR(pseudo->users, pu) { - struct instruction *insn = pu->insn; - if (insn->opcode == OP_STORE) - kill_dominated_stores(pseudo, insn, ++bb_generation, insn->bb, !mod, 0); - } END_FOR_EACH_PTR(pu); - - if (!(mod & (MOD_NONLOCAL | MOD_STATIC))) { - struct basic_block *bb; - FOR_EACH_PTR(ep->bbs, bb) { - if (!bb->children) - kill_dead_stores(pseudo, ++bb_generation, bb, !mod); - } END_FOR_EACH_PTR(bb); - } - } - - return; -} - -void simplify_symbol_usage(struct entrypoint *ep) -{ - pseudo_t pseudo; - - FOR_EACH_PTR(ep->accesses, pseudo) { - simplify_one_symbol(ep, pseudo->sym); - } END_FOR_EACH_PTR(pseudo); -} - static void mark_bb_reachable(struct basic_block *bb, unsigned long generation) { struct basic_block *child; diff --git a/flow.h b/flow.h index 3133245e5..ecacd42e1 100644 --- a/flow.h +++ b/flow.h @@ -14,7 +14,6 @@ struct instruction; extern int simplify_flow(struct entrypoint *ep); -extern void simplify_symbol_usage(struct entrypoint *ep); extern void simplify_memops(struct entrypoint *ep); extern void pack_basic_blocks(struct entrypoint *ep); -- 2.14.0 -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html