Currently, the only simplification of casts is CAST(AND(X))
but more simplification are possible.
Prepare for additional simplification by unsing a switch-case
for OP_AND instead of the current 'if'.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/simplify.c b/simplify.c
index a7d88069b..29ec6e6f3 100644
--- a/simplify.c
+++ b/simplify.c
@@ -946,30 +946,33 @@ static int simplify_memop(struct instruction *insn)
static int simplify_cast(struct instruction *insn)
{
+ struct instruction *def;
pseudo_t src;
int size;
if (dead_insn(insn, &insn->src, NULL, NULL))
return REPEAT_CSE;
- size = insn->size;
src = insn->src;
/* A cast of a constant? */
if (constant(src))
return simplify_constant_unop(insn);
- /* A cast of a "and" might be a no-op.. */
- if (src->type == PSEUDO_REG) {
- struct instruction *def = src->def;
- if (def->opcode == OP_AND && def->size >= size) {
+ // can merge with the previous instruction?
+ size = insn->size;
+ def = src->def;
+ switch (def_opcode(src)) {
+ case OP_AND:
+ /* A cast of a AND might be a no-op.. */
+ if (def->size >= size) {
pseudo_t val = def->src2;
if (val->type == PSEUDO_VAL) {
- unsigned long long value = val->value;
- if (!(value >> (size-1)))
+ if (!(val->value >> (size-1)))
goto simplify;
}
}
+ break;
}
return 0;
--
2.17.1
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