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authorLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2020-09-28 01:19:21 +0200
committerLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2020-10-20 22:35:43 +0200
commitc28f68be15dbbdcb6e6ed08fdff2b0aa89a426e9 (patch)
tree6bcb13483d32f3fa0fa11913e529822324fbfd5b /simplify.c
parentee607141242f7ac140a58b4869bf7b7909419629 (diff)
downloadsparse-dev-c28f68be15dbbdcb6e6ed08fdff2b0aa89a426e9.tar.gz
sub: simplify C - (D - z) --> z + eval(C-D)
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'simplify.c')
-rw-r--r--simplify.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/simplify.c b/simplify.c
index b97354bc..7d1897e6 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1169,6 +1169,14 @@ static int simplify_const_leftsub(struct instruction *insn, struct instruction *
return replace_pseudo(insn, &insn->src2, def->src1);
}
break;
+ case OP_SUB:
+ if (constant(def->src1)) { // C - (D - z) --> z + eval(C-D)
+ pseudo_t val = eval_op(OP_SUB, size, src1, def->src1);
+ insn->opcode = OP_ADD;
+ use_pseudo(insn, def->src2, &insn->src1);
+ return replace_pseudo(insn, &insn->src2, val);
+ }
+ break;
}
return 0;
}