---
linearize.h | 6 +++++
simplify.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/linearize.h b/linearize.h
index 2c548d43526f..71a693960c9e 100644
--- a/linearize.h
+++ b/linearize.h
@@ -300,6 +300,12 @@ static inline void replace_bb_in_list(struct basic_block_list **list,
replace_ptr_list_entry((struct ptr_list **)list, old, new, count);
}
+static inline void replace_insn(struct instruction *old, struct instruction *new)
+{
+ replace_ptr_list_entry((struct ptr_list **)&old->bb->insns, old, new, 1);
+}
+
+
struct entrypoint {
struct symbol *name;
struct symbol_list *syms;
diff --git a/simplify.c b/simplify.c
index fc64e5b77adf..14a5562c84a4 100644
--- a/simplify.c
+++ b/simplify.c
@@ -61,6 +61,63 @@ static inline bool is_pow2(pseudo_t src)
return is_power_of_2(src->value);
}
+///
+// check if a pseudo is defined in a BB
+//
+// :note: this could also use the liveness information if available.
+//
+static inline bool is_defined_at(pseudo_t src, struct basic_block *bb)
+{
+ if (src->type != PSEUDO_REG)
+ return true;
+ return domtree_dominates(src->def->bb, bb);
+}
+
+///
+// move an instruction at the end of the given BB
+static void move_insn(struct instruction *insn, struct basic_block *bb)
+{
+ struct instruction *last = delete_last_instruction(&bb->insns);
+ insn->bb = bb;
+ add_instruction(&bb->insns, insn);
+ add_instruction(&bb->insns, last);
+}
+
+///
+// try to move an instruction into a BB if all its arguments are defined there
+static bool try_to_move_insn(struct instruction *insn, struct basic_block *bb)
+{
+ static struct instruction NOP; // will later be ignore because !ep
+
+ if (!bb || bb == insn->bb)
+ return 0;
+
+ switch (insn->opcode) {
+ case OP_SEL:
+ if (!is_defined_at(insn->src3, bb))
+ return 0;
+ case OP_ADD: case OP_SUB:
+ case OP_ASR: case OP_LSR: case OP_SHL:
+ case OP_AND: case OP_XOR: case OP_OR:
+ case OP_BINCMP ... OP_BINCMP_END:
+ case OP_FPCMP ... OP_FPCMP_END:
+ case OP_FADD: case OP_FSUB:
+ // basically, all the binops but multiply and divide, just because
+ if (!is_defined_at(insn->src2, bb))
+ return 0;
+ case OP_UNOP ... OP_UNOP_END:
+ if (!is_defined_at(insn->src1, bb))
+ return 0;
+ break;
+ default:
+ return 0;
+ }
+ replace_insn(insn, &NOP);
+ move_insn(insn, bb);
+ repeat_phase |= REPEAT_CSE;
+ return 1;
+}
+
///
// find the trivial parent for a phi-source
static struct basic_block *phi_parent(struct basic_block *source, pseudo_t pseudo)
@@ -68,8 +125,11 @@ static struct basic_block *phi_parent(struct basic_block *source, pseudo_t pseud
/* Can't go upwards if the pseudo is defined in the bb it came from.. */
if (pseudo->type == PSEUDO_REG) {
struct instruction *def = pseudo->def;
- if (def->bb == source)
- return source;
+ if (def->bb == source) {
+ // unless we can move the defining instruction up
+ if (!try_to_move_insn(def, source->idom))
+ return source;
+ }
}
if (bb_list_size(source->children) != 1 || bb_list_size(source->parents) != 1)
return source;
--
2.29.2
