diff --git a/gcc/match.pd b/gcc/match.pd
index a59b6778f661cf9121dd3503f43472871e4da445..51b0a1b562409af535e53828a10c30b8a3e1ae2e 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1258,6 +1258,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (simplify
  (bit_not (plus:c (bit_not @0) @1))
  (minus @0 @1))
+/* (~X - ~Y) -> X - Y.  */
+(simplify
+ (minus (bit_not @0) (bit_not @1))
+ (minus @0 @1))
 
 /* ~(X - Y) -> ~X + Y.  */
 (simplify
diff --git a/gcc/testsuite/gcc.dg/subnot.c b/gcc/testsuite/gcc.dg/subnot.c
new file mode 100644
index 0000000000000000000000000000000000000000..d621bacd27bd3d19a010e4c9f831aa77d28bd02d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/subnot.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+float g(float a, float b)
+{
+  return ~(int)a - ~(int)b;
+}
+
+/* { dg-final { scan-tree-dump-not "~" "optimized" } } */