aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/simplify.c
diff options
authorLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2020-09-30 00:36:27 +0200
committerLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2020-10-24 22:58:24 +0200
commit70a22c03f856b3997d2c7dddd761daf0da3e3b1e (patch)
treeb9cc158a5caa1397dac3aa74d34521e883ac7f00 /simplify.c
parentf28372ddc5f19bbed4fbd6cff33bb111a4261ce7 (diff)
downloadsparse-dev-70a22c03f856b3997d2c7dddd761daf0da3e3b1e.tar.gz
unop: simplify ~(x + C) --> ~C - x
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'simplify.c')
-rw-r--r--simplify.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/simplify.c b/simplify.c
index 31f3bb6d..d3e8ac04 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1462,6 +1462,13 @@ static int simplify_unop(struct instruction *insn)
switch (insn->opcode) {
case OP_NOT:
switch (DEF_OPCODE(def, src)) {
+ case OP_ADD:
+ if (!constant(def->src2))
+ break;
+ insn->opcode = OP_SUB; // ~(x + C) --> ~C - x
+ src = eval_unop(OP_NOT, insn->size, def->src2);
+ use_pseudo(insn, def->src1, &insn->src2);
+ return replace_pseudo(insn, &insn->src1, src);
case OP_NOT: // ~(~x) --> x
return replace_with_pseudo(insn, def->src);
}