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authorLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2020-09-30 00:36:27 +0200
committerLuc Van Oostenryck <luc.vanoostenryck@gmail.com>2020-10-24 22:58:26 +0200
commitf96c229c9ae80b40249f3ff46baa035210bbec53 (patch)
tree0b23abaca31b6721417969f263e8f547c4327d3b
parent70a22c03f856b3997d2c7dddd761daf0da3e3b1e (diff)
downloadsparse-f96c229c9ae80b40249f3ff46baa035210bbec53.tar.gz
unop: simplify ~(C - x) --> x + ~C
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
-rw-r--r--simplify.c6
-rw-r--r--validation/optim/simplify-not-sub-cte.c1
2 files changed, 6 insertions, 1 deletions
diff --git a/simplify.c b/simplify.c
index d3e8ac04..e3047431 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1471,6 +1471,12 @@ static int simplify_unop(struct instruction *insn)
return replace_pseudo(insn, &insn->src1, src);
case OP_NOT: // ~(~x) --> x
return replace_with_pseudo(insn, def->src);
+ case OP_SUB:
+ if (!constant(def->src1))
+ break;
+ insn->opcode = OP_ADD; // ~(C - x) --> x + ~C
+ insn->src2 = eval_unop(OP_NOT, insn->size, def->src1);
+ return replace_pseudo(insn, &insn->src1, def->src2);
}
break;
case OP_NEG:
diff --git a/validation/optim/simplify-not-sub-cte.c b/validation/optim/simplify-not-sub-cte.c
index ec105beb..1ea73ece 100644
--- a/validation/optim/simplify-not-sub-cte.c
+++ b/validation/optim/simplify-not-sub-cte.c
@@ -5,7 +5,6 @@ int foo(int x) { return ~(C - x) == (x + ~C); }
/*
* check-name: simplify-not-sub-cte
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-contains: ret\\..*\\$1