---
mem2reg.c | 67 ++++++++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 43 insertions(+), 24 deletions(-)
diff --git a/mem2reg.c b/mem2reg.c
index ecda6675f..d0873b051 100644
--- a/mem2reg.c
+++ b/mem2reg.c
@@ -12,38 +12,63 @@
* We should probably sort the phi list just to make it easier to compare
* later for equality.
*/
-static void rewrite_load_instruction(struct symbol *sym, struct instruction *insn, struct pseudo_list *dominators)
+static void rewrite_load_instruction(struct symbol *sym, struct instruction *insn,
+ struct basic_block *bb, struct pseudo_list *dominators)
{
- pseudo_t new, phi;
+ struct basic_block *parent;
+ struct instruction *node;
+ pseudo_t new, val;
/*
* Check for somewhat common case of duplicate
* phi nodes.
*/
- new = first_pseudo(dominators)->def->src1;
- FOR_EACH_PTR(dominators, phi) {
- if (new != phi->def->src1)
+ new = first_pseudo(dominators);
+ FOR_EACH_PTR(dominators, val) {
+ if (new != val)
goto complex_phi;
new->ident = new->ident ? : sym->ident;
- } END_FOR_EACH_PTR(phi);
+ } END_FOR_EACH_PTR(val);
/*
- * All the same pseudo - mark the phi-nodes unused
- * and convert the load into a LNOP and replace the
- * pseudo.
+ * All the same pseudo - replace the load by the unique val
*/
- FOR_EACH_PTR(dominators, phi) {
- kill_instruction(phi->def);
- } END_FOR_EACH_PTR(phi);
- convert_load_instruction(insn, new);
- return;
+ goto convert;
complex_phi:
+ /*
+ * insert a new phi-node on top and
+ * insert a phi-src at the end of each parents
+ */
+ new = insert_phi_node(bb, sym);
+ node = new->def;
+
+ PREPARE_PTR_LIST(bb->parents, parent)
+ FOR_EACH_PTR(dominators, val) {
+ struct instruction *br;
+ pseudo_t src;
+
+ br = delete_last_instruction(&parent->insns);
+ /*
+ * We could check if br is really a branch
+ * We could check if the type of val & sym matches
+ */
+ src = alloc_phi(parent, val, sym);
+ add_instruction(&parent->insns, br);
+ use_pseudo(node, src, add_pseudo(&node->phi_list, src));
+
+ NEXT_PTR_LIST(parent);
+ } END_FOR_EACH_PTR(val);
+ FINISH_PTR_LIST(parent);
+
+#if 0 // FIXME
/* We leave symbol pseudos with a bogus usage list here */
if (insn->src->type != PSEUDO_SYM)
kill_use(&insn->src);
- insn->opcode = OP_PHI;
- insn->phi_list = dominators;
+#endif
+
+convert:
+ convert_load_instruction(insn, new);
}
/*
@@ -68,8 +93,6 @@ static int find_dominating_parents(struct symbol *sym, struct instruction *insn,
FOR_EACH_PTR(bb->parents, parent) {
struct instruction *one;
- struct instruction *br;
- pseudo_t phi;
FOR_EACH_PTR_REVERSE(parent->insns, one) {
int dominance;
@@ -95,11 +118,7 @@ no_dominance:
continue;
found_dominator:
- 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));
+ add_pseudo(dominators, one->target);
} END_FOR_EACH_PTR(parent);
return 1;
}
@@ -177,7 +196,7 @@ found:
* have to turn the load into a phi-node of the
* dominators.
*/
- rewrite_load_instruction(sym, insn, dominators);
+ rewrite_load_instruction(sym, insn, bb, dominators);
return 1;
}
--
2.14.0
--
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