Since an LSR with an in-range shift count will insert a zero in
the MSB, a subsequent ASR will be equivalent to an LSR of the same
count or equivalently, the combinaison the these two shifts is
equivalent to a single LSR with a shift count equal to the sum
of the two initial counts.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index 7475d9e6c..322450b86 100644
--- a/simplify.c
+++ b/simplify.c
@@ -594,6 +594,7 @@ static int simplify_shift(struct instruction *insn, pseudo_t pseudo, long long v
if (value >= size)
return 0;
switch(DEF_OPCODE(def, pseudo)) {
+ case OP_LSR:
case OP_ASR:
src2 = def->src2;
if (src2->type != PSEUDO_VAL)
@@ -602,7 +603,9 @@ static int simplify_shift(struct instruction *insn, pseudo_t pseudo, long long v
if (nval > insn->size)
break;
value += nval;
- if (value >= size)
+ if (def->opcode == OP_LSR)
+ insn->opcode = OP_LSR;
+ else if (value >= size)
value = size - 1;
goto new_value;
}
--
2.18.0
--
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