aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/flow.c
diff options
authorLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2018-03-06 13:10:17 +0100
committerLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2018-07-01 00:18:44 +0200
commitf72c77ccd8af3fbfe76a00cdaa6d8ee01d498729 (patch)
treee288ecb1435bf4d7e43ade52ea28c79cb50a707b /flow.c
parent6dea652c4ac3aec57ffb1ce7c333184d324971f8 (diff)
downloadsparse-dev-f72c77ccd8af3fbfe76a00cdaa6d8ee01d498729.tar.gz
ssa: remove unused simplify_symbol_usage()
This patch remove simplify_symbol_usage() and the associated functions, now unneeded with the new SSA conversion. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'flow.c')
-rw-r--r--flow.c278
1 files changed, 0 insertions, 278 deletions
diff --git a/flow.c b/flow.c
index c6d68532..ca62a2c0 100644
--- a/flow.c
+++ b/flow.c
@@ -370,68 +370,6 @@ 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->bb)
- continue;
- 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.
@@ -473,79 +411,6 @@ end:
repeat_phase |= REPEAT_SYMBOL_CLEANUP;
}
-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) {
- kill_use(&insn->src);
- return 1;
- }
-
- partial = 0;
- FOR_EACH_PTR(bb->insns, one) {
- int dominance;
- if (!one->bb)
- continue;
- 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;
-}
-
/* Kill a pseudo that is dead on exit from the bb */
// The context is:
// * the variable is not global but may have its address used (local/non-local)
@@ -600,59 +465,6 @@ static void kill_dead_stores_bb(pseudo_t pseudo, unsigned long generation, struc
} 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_instruction_force(insn);
- return;
- }
- if (bb->generation == generation)
- return;
- bb->generation = generation;
- FOR_EACH_PTR_REVERSE(bb->insns, one) {
- int dominance;
- if (!one->bb)
- continue;
- 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_instruction_force(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;
@@ -673,96 +485,6 @@ 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_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_instruction_force(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_bb(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 struct pseudo_user *first_user(pseudo_t p)
{
struct pseudo_user *pu;
generated by cgit 1.2.3-korg (git 2.43.0) at 2026-03-01 18:52:03 +0000